--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/vtls/openssl.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,4069 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+/*
+ * Source file for all OpenSSL-specific code for the TLS/SSL layer. No code
+ * but vtls.c should ever call or use these functions.
+ */
+
+#include "curl_setup.h"
+
+#ifdef USE_OPENSSL
+
+#include <limits.h>
+
+#include "urldata.h"
+#include "sendf.h"
+#include "formdata.h" /* for the boundary function */
+#include "url.h" /* for the ssl config check function */
+#include "inet_pton.h"
+#include "openssl.h"
+#include "connect.h"
+#include "slist.h"
+#include "select.h"
+#include "vtls.h"
+#include "strcase.h"
+#include "hostcheck.h"
+#include "multiif.h"
+#include "curl_printf.h"
+#include <openssl/ssl.h>
+#include <openssl/rand.h>
+#include <openssl/x509v3.h>
+#ifndef OPENSSL_NO_DSA
+#include <openssl/dsa.h>
+#endif
+#include <openssl/dh.h>
+#include <openssl/err.h>
+#include <openssl/md5.h>
+#include <openssl/conf.h>
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/bio.h>
+#include <openssl/buffer.h>
+#include <openssl/pkcs12.h>
+
+#ifdef USE_AMISSL
+#include "amigaos.h"
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x0090808fL) && !defined(OPENSSL_NO_OCSP)
+#include <openssl/ocsp.h>
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x0090700fL) && /* 0.9.7 or later */     \
+  !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_UI_CONSOLE)
+#define USE_OPENSSL_ENGINE
+#include <openssl/engine.h>
+#endif
+
+#include "warnless.h"
+#include "non-ascii.h" /* for Curl_convert_from_utf8 prototype */
+
+/* The last #include files should be: */
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/* Uncomment the ALLOW_RENEG line to a real #define if you want to allow TLS
+   renegotiations when built with BoringSSL. Renegotiating is non-compliant
+   with HTTP/2 and "an extremely dangerous protocol feature". Beware.
+
+#define ALLOW_RENEG 1
+ */
+
+#ifndef OPENSSL_VERSION_NUMBER
+#error "OPENSSL_VERSION_NUMBER not defined"
+#endif
+
+#ifdef USE_OPENSSL_ENGINE
+#include <openssl/ui.h>
+#endif
+
+#if OPENSSL_VERSION_NUMBER >= 0x00909000L
+#define SSL_METHOD_QUAL const
+#else
+#define SSL_METHOD_QUAL
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10000000L)
+#define HAVE_ERR_REMOVE_THREAD_STATE 1
+#endif
+
+#if !defined(HAVE_SSLV2_CLIENT_METHOD) || \
+  OPENSSL_VERSION_NUMBER >= 0x10100000L /* 1.1.0+ has no SSLv2 */
+#undef OPENSSL_NO_SSL2 /* undef first to avoid compiler warnings */
+#define OPENSSL_NO_SSL2
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) && /* OpenSSL 1.1.0+ */ \
+    !(defined(LIBRESSL_VERSION_NUMBER) && \
+      LIBRESSL_VERSION_NUMBER < 0x20700000L)
+#define SSLEAY_VERSION_NUMBER OPENSSL_VERSION_NUMBER
+#define HAVE_X509_GET0_EXTENSIONS 1 /* added in 1.1.0 -pre1 */
+#define HAVE_OPAQUE_EVP_PKEY 1 /* since 1.1.0 -pre3 */
+#define HAVE_OPAQUE_RSA_DSA_DH 1 /* since 1.1.0 -pre5 */
+#define CONST_EXTS const
+#define HAVE_ERR_REMOVE_THREAD_STATE_DEPRECATED 1
+
+/* funny typecast define due to difference in API */
+#ifdef LIBRESSL_VERSION_NUMBER
+#define ARG2_X509_signature_print (X509_ALGOR *)
+#else
+#define ARG2_X509_signature_print
+#endif
+
+#else
+/* For OpenSSL before 1.1.0 */
+#define ASN1_STRING_get0_data(x) ASN1_STRING_data(x)
+#define X509_get0_notBefore(x) X509_get_notBefore(x)
+#define X509_get0_notAfter(x) X509_get_notAfter(x)
+#define CONST_EXTS /* nope */
+#ifndef LIBRESSL_VERSION_NUMBER
+#define OpenSSL_version_num() SSLeay()
+#endif
+#endif
+
+#ifdef LIBRESSL_VERSION_NUMBER
+#define OpenSSL_version_num() LIBRESSL_VERSION_NUMBER
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x1000200fL) && /* 1.0.2 or later */ \
+    !(defined(LIBRESSL_VERSION_NUMBER) && \
+      LIBRESSL_VERSION_NUMBER < 0x20700000L)
+#define HAVE_X509_GET0_SIGNATURE 1
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x1000200fL) /* 1.0.2 or later */
+#define HAVE_SSL_GET_SHUTDOWN 1
+#endif
+
+#if OPENSSL_VERSION_NUMBER >= 0x10002003L && \
+  OPENSSL_VERSION_NUMBER <= 0x10002FFFL && \
+  !defined(OPENSSL_NO_COMP)
+#define HAVE_SSL_COMP_FREE_COMPRESSION_METHODS 1
+#endif
+
+#if (OPENSSL_VERSION_NUMBER < 0x0090808fL)
+/* not present in older OpenSSL */
+#define OPENSSL_load_builtin_modules(x)
+#endif
+
+/*
+ * Whether SSL_CTX_set_keylog_callback is available.
+ * OpenSSL: supported since 1.1.1 https://github.com/openssl/openssl/pull/2287
+ * BoringSSL: supported since d28f59c27bac (committed 2015-11-19)
+ * LibreSSL: unsupported in at least 2.7.2 (explicitly check for it since it
+ *           lies and pretends to be OpenSSL 2.0.0).
+ */
+#if (OPENSSL_VERSION_NUMBER >= 0x10101000L && \
+     !defined(LIBRESSL_VERSION_NUMBER)) || \
+    defined(OPENSSL_IS_BORINGSSL)
+#define HAVE_KEYLOG_CALLBACK
+#endif
+
+/* Whether SSL_CTX_set_ciphersuites is available.
+ * OpenSSL: supported since 1.1.1 (commit a53b5be6a05)
+ * BoringSSL: no
+ * LibreSSL: no
+ */
+#if ((OPENSSL_VERSION_NUMBER >= 0x10101000L) && \
+     !defined(LIBRESSL_VERSION_NUMBER) &&       \
+     !defined(OPENSSL_IS_BORINGSSL))
+#define HAVE_SSL_CTX_SET_CIPHERSUITES
+#define HAVE_SSL_CTX_SET_POST_HANDSHAKE_AUTH
+#endif
+
+#if defined(LIBRESSL_VERSION_NUMBER)
+#define OSSL_PACKAGE "LibreSSL"
+#elif defined(OPENSSL_IS_BORINGSSL)
+#define OSSL_PACKAGE "BoringSSL"
+#else
+#define OSSL_PACKAGE "OpenSSL"
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
+/* up2date versions of OpenSSL maintain the default reasonably secure without
+ * breaking compatibility, so it is better not to override the default by curl
+ */
+#define DEFAULT_CIPHER_SELECTION NULL
+#else
+/* ... but it is not the case with old versions of OpenSSL */
+#define DEFAULT_CIPHER_SELECTION \
+  "ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH"
+#endif
+
+#define ENABLE_SSLKEYLOGFILE
+
+#ifdef ENABLE_SSLKEYLOGFILE
+typedef struct ssl_tap_state {
+  int master_key_length;
+  unsigned char master_key[SSL_MAX_MASTER_KEY_LENGTH];
+  unsigned char client_random[SSL3_RANDOM_SIZE];
+} ssl_tap_state_t;
+#endif /* ENABLE_SSLKEYLOGFILE */
+
+struct ssl_backend_data {
+  /* these ones requires specific SSL-types */
+  SSL_CTX* ctx;
+  SSL*     handle;
+  X509*    server_cert;
+#ifdef ENABLE_SSLKEYLOGFILE
+  /* tap_state holds the last seen master key if we're logging them */
+  ssl_tap_state_t tap_state;
+#endif
+};
+
+#define BACKEND connssl->backend
+
+/*
+ * Number of bytes to read from the random number seed file. This must be
+ * a finite value (because some entropy "files" like /dev/urandom have
+ * an infinite length), but must be large enough to provide enough
+ * entropy to properly seed OpenSSL's PRNG.
+ */
+#define RAND_LOAD_LENGTH 1024
+
+#ifdef ENABLE_SSLKEYLOGFILE
+/* The fp for the open SSLKEYLOGFILE, or NULL if not open */
+static FILE *keylog_file_fp;
+
+#ifdef HAVE_KEYLOG_CALLBACK
+static void ossl_keylog_callback(const SSL *ssl, const char *line)
+{
+  (void)ssl;
+
+  /* Using fputs here instead of fprintf since libcurl's fprintf replacement
+     may not be thread-safe. */
+  if(keylog_file_fp && line && *line) {
+    char stackbuf[256];
+    char *buf;
+    size_t linelen = strlen(line);
+
+    if(linelen <= sizeof(stackbuf) - 2)
+      buf = stackbuf;
+    else {
+      buf = malloc(linelen + 2);
+      if(!buf)
+        return;
+    }
+    memcpy(buf, line, linelen);
+    buf[linelen] = '\n';
+    buf[linelen + 1] = '\0';
+
+    fputs(buf, keylog_file_fp);
+    if(buf != stackbuf)
+      free(buf);
+  }
+}
+#else
+#define KEYLOG_PREFIX      "CLIENT_RANDOM "
+#define KEYLOG_PREFIX_LEN  (sizeof(KEYLOG_PREFIX) - 1)
+/*
+ * tap_ssl_key is called by libcurl to make the CLIENT_RANDOMs if the OpenSSL
+ * being used doesn't have native support for doing that.
+ */
+static void tap_ssl_key(const SSL *ssl, ssl_tap_state_t *state)
+{
+  const char *hex = "0123456789ABCDEF";
+  int pos, i;
+  char line[KEYLOG_PREFIX_LEN + 2 * SSL3_RANDOM_SIZE + 1 +
+            2 * SSL_MAX_MASTER_KEY_LENGTH + 1 + 1];
+  const SSL_SESSION *session = SSL_get_session(ssl);
+  unsigned char client_random[SSL3_RANDOM_SIZE];
+  unsigned char master_key[SSL_MAX_MASTER_KEY_LENGTH];
+  int master_key_length = 0;
+
+  if(!session || !keylog_file_fp)
+    return;
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && \
+    !(defined(LIBRESSL_VERSION_NUMBER) && \
+      LIBRESSL_VERSION_NUMBER < 0x20700000L)
+  /* ssl->s3 is not checked in openssl 1.1.0-pre6, but let's assume that
+   * we have a valid SSL context if we have a non-NULL session. */
+  SSL_get_client_random(ssl, client_random, SSL3_RANDOM_SIZE);
+  master_key_length = (int)
+    SSL_SESSION_get_master_key(session, master_key, SSL_MAX_MASTER_KEY_LENGTH);
+#else
+  if(ssl->s3 && session->master_key_length > 0) {
+    master_key_length = session->master_key_length;
+    memcpy(master_key, session->master_key, session->master_key_length);
+    memcpy(client_random, ssl->s3->client_random, SSL3_RANDOM_SIZE);
+  }
+#endif
+
+  if(master_key_length <= 0)
+    return;
+
+  /* Skip writing keys if there is no key or it did not change. */
+  if(state->master_key_length == master_key_length &&
+     !memcmp(state->master_key, master_key, master_key_length) &&
+     !memcmp(state->client_random, client_random, SSL3_RANDOM_SIZE)) {
+    return;
+  }
+
+  state->master_key_length = master_key_length;
+  memcpy(state->master_key, master_key, master_key_length);
+  memcpy(state->client_random, client_random, SSL3_RANDOM_SIZE);
+
+  memcpy(line, KEYLOG_PREFIX, KEYLOG_PREFIX_LEN);
+  pos = KEYLOG_PREFIX_LEN;
+
+  /* Client Random for SSLv3/TLS */
+  for(i = 0; i < SSL3_RANDOM_SIZE; i++) {
+    line[pos++] = hex[client_random[i] >> 4];
+    line[pos++] = hex[client_random[i] & 0xF];
+  }
+  line[pos++] = ' ';
+
+  /* Master Secret (size is at most SSL_MAX_MASTER_KEY_LENGTH) */
+  for(i = 0; i < master_key_length; i++) {
+    line[pos++] = hex[master_key[i] >> 4];
+    line[pos++] = hex[master_key[i] & 0xF];
+  }
+  line[pos++] = '\n';
+  line[pos] = '\0';
+
+  /* Using fputs here instead of fprintf since libcurl's fprintf replacement
+     may not be thread-safe. */
+  fputs(line, keylog_file_fp);
+}
+#endif /* !HAVE_KEYLOG_CALLBACK */
+#endif /* ENABLE_SSLKEYLOGFILE */
+
+static const char *SSL_ERROR_to_str(int err)
+{
+  switch(err) {
+  case SSL_ERROR_NONE:
+    return "SSL_ERROR_NONE";
+  case SSL_ERROR_SSL:
+    return "SSL_ERROR_SSL";
+  case SSL_ERROR_WANT_READ:
+    return "SSL_ERROR_WANT_READ";
+  case SSL_ERROR_WANT_WRITE:
+    return "SSL_ERROR_WANT_WRITE";
+  case SSL_ERROR_WANT_X509_LOOKUP:
+    return "SSL_ERROR_WANT_X509_LOOKUP";
+  case SSL_ERROR_SYSCALL:
+    return "SSL_ERROR_SYSCALL";
+  case SSL_ERROR_ZERO_RETURN:
+    return "SSL_ERROR_ZERO_RETURN";
+  case SSL_ERROR_WANT_CONNECT:
+    return "SSL_ERROR_WANT_CONNECT";
+  case SSL_ERROR_WANT_ACCEPT:
+    return "SSL_ERROR_WANT_ACCEPT";
+#if defined(SSL_ERROR_WANT_ASYNC)
+  case SSL_ERROR_WANT_ASYNC:
+    return "SSL_ERROR_WANT_ASYNC";
+#endif
+#if defined(SSL_ERROR_WANT_ASYNC_JOB)
+  case SSL_ERROR_WANT_ASYNC_JOB:
+    return "SSL_ERROR_WANT_ASYNC_JOB";
+#endif
+#if defined(SSL_ERROR_WANT_EARLY)
+  case SSL_ERROR_WANT_EARLY:
+    return "SSL_ERROR_WANT_EARLY";
+#endif
+  default:
+    return "SSL_ERROR unknown";
+  }
+}
+
+/* Return error string for last OpenSSL error
+ */
+static char *ossl_strerror(unsigned long error, char *buf, size_t size)
+{
+#ifdef OPENSSL_IS_BORINGSSL
+  ERR_error_string_n((uint32_t)error, buf, size);
+#else
+  ERR_error_string_n(error, buf, size);
+#endif
+  return buf;
+}
+
+/* Return an extra data index for the connection data.
+ * This index can be used with SSL_get_ex_data() and SSL_set_ex_data().
+ */
+static int ossl_get_ssl_conn_index(void)
+{
+  static int ssl_ex_data_conn_index = -1;
+  if(ssl_ex_data_conn_index < 0) {
+    ssl_ex_data_conn_index = SSL_get_ex_new_index(0, NULL, NULL, NULL, NULL);
+  }
+  return ssl_ex_data_conn_index;
+}
+
+/* Return an extra data index for the sockindex.
+ * This index can be used with SSL_get_ex_data() and SSL_set_ex_data().
+ */
+static int ossl_get_ssl_sockindex_index(void)
+{
+  static int ssl_ex_data_sockindex_index = -1;
+  if(ssl_ex_data_sockindex_index < 0) {
+    ssl_ex_data_sockindex_index = SSL_get_ex_new_index(0, NULL, NULL, NULL,
+        NULL);
+  }
+  return ssl_ex_data_sockindex_index;
+}
+
+static int passwd_callback(char *buf, int num, int encrypting,
+                           void *global_passwd)
+{
+  DEBUGASSERT(0 == encrypting);
+
+  if(!encrypting) {
+    int klen = curlx_uztosi(strlen((char *)global_passwd));
+    if(num > klen) {
+      memcpy(buf, global_passwd, klen + 1);
+      return klen;
+    }
+  }
+  return 0;
+}
+
+/*
+ * rand_enough() returns TRUE if we have seeded the random engine properly.
+ */
+static bool rand_enough(void)
+{
+  return (0 != RAND_status()) ? TRUE : FALSE;
+}
+
+static CURLcode Curl_ossl_seed(struct Curl_easy *data)
+{
+  /* we have the "SSL is seeded" boolean static to prevent multiple
+     time-consuming seedings in vain */
+  static bool ssl_seeded = FALSE;
+  char fname[256];
+
+  if(ssl_seeded)
+    return CURLE_OK;
+
+  if(rand_enough()) {
+    /* OpenSSL 1.1.0+ will return here */
+    ssl_seeded = TRUE;
+    return CURLE_OK;
+  }
+
+#ifndef RANDOM_FILE
+  /* if RANDOM_FILE isn't defined, we only perform this if an option tells
+     us to! */
+  if(data->set.str[STRING_SSL_RANDOM_FILE])
+#define RANDOM_FILE "" /* doesn't matter won't be used */
+#endif
+  {
+    /* let the option override the define */
+    RAND_load_file((data->set.str[STRING_SSL_RANDOM_FILE]?
+                    data->set.str[STRING_SSL_RANDOM_FILE]:
+                    RANDOM_FILE),
+                   RAND_LOAD_LENGTH);
+    if(rand_enough())
+      return CURLE_OK;
+  }
+
+#if defined(HAVE_RAND_EGD)
+  /* only available in OpenSSL 0.9.5 and later */
+  /* EGD_SOCKET is set at configure time or not at all */
+#ifndef EGD_SOCKET
+  /* If we don't have the define set, we only do this if the egd-option
+     is set */
+  if(data->set.str[STRING_SSL_EGDSOCKET])
+#define EGD_SOCKET "" /* doesn't matter won't be used */
+#endif
+  {
+    /* If there's an option and a define, the option overrides the
+       define */
+    int ret = RAND_egd(data->set.str[STRING_SSL_EGDSOCKET]?
+                       data->set.str[STRING_SSL_EGDSOCKET]:EGD_SOCKET);
+    if(-1 != ret) {
+      if(rand_enough())
+        return CURLE_OK;
+    }
+  }
+#endif
+
+  /* fallback to a custom seeding of the PRNG using a hash based on a current
+     time */
+  do {
+    unsigned char randb[64];
+    size_t len = sizeof(randb);
+    size_t i, i_max;
+    for(i = 0, i_max = len / sizeof(struct curltime); i < i_max; ++i) {
+      struct curltime tv = Curl_now();
+      Curl_wait_ms(1);
+      tv.tv_sec *= i + 1;
+      tv.tv_usec *= (unsigned int)i + 2;
+      tv.tv_sec ^= ((Curl_now().tv_sec + Curl_now().tv_usec) *
+                    (i + 3)) << 8;
+      tv.tv_usec ^= (unsigned int) ((Curl_now().tv_sec +
+                                     Curl_now().tv_usec) *
+                                    (i + 4)) << 16;
+      memcpy(&randb[i * sizeof(struct curltime)], &tv,
+             sizeof(struct curltime));
+    }
+    RAND_add(randb, (int)len, (double)len/2);
+  } while(!rand_enough());
+
+  /* generates a default path for the random seed file */
+  fname[0] = 0; /* blank it first */
+  RAND_file_name(fname, sizeof(fname));
+  if(fname[0]) {
+    /* we got a file name to try */
+    RAND_load_file(fname, RAND_LOAD_LENGTH);
+    if(rand_enough())
+      return CURLE_OK;
+  }
+
+  infof(data, "libcurl is now using a weak random seed!\n");
+  return (rand_enough() ? CURLE_OK :
+    CURLE_SSL_CONNECT_ERROR /* confusing error code */);
+}
+
+#ifndef SSL_FILETYPE_ENGINE
+#define SSL_FILETYPE_ENGINE 42
+#endif
+#ifndef SSL_FILETYPE_PKCS12
+#define SSL_FILETYPE_PKCS12 43
+#endif
+static int do_file_type(const char *type)
+{
+  if(!type || !type[0])
+    return SSL_FILETYPE_PEM;
+  if(strcasecompare(type, "PEM"))
+    return SSL_FILETYPE_PEM;
+  if(strcasecompare(type, "DER"))
+    return SSL_FILETYPE_ASN1;
+  if(strcasecompare(type, "ENG"))
+    return SSL_FILETYPE_ENGINE;
+  if(strcasecompare(type, "P12"))
+    return SSL_FILETYPE_PKCS12;
+  return -1;
+}
+
+#ifdef USE_OPENSSL_ENGINE
+/*
+ * Supply default password to the engine user interface conversation.
+ * The password is passed by OpenSSL engine from ENGINE_load_private_key()
+ * last argument to the ui and can be obtained by UI_get0_user_data(ui) here.
+ */
+static int ssl_ui_reader(UI *ui, UI_STRING *uis)
+{
+  const char *password;
+  switch(UI_get_string_type(uis)) {
+  case UIT_PROMPT:
+  case UIT_VERIFY:
+    password = (const char *)UI_get0_user_data(ui);
+    if(password && (UI_get_input_flags(uis) & UI_INPUT_FLAG_DEFAULT_PWD)) {
+      UI_set_result(ui, uis, password);
+      return 1;
+    }
+  default:
+    break;
+  }
+  return (UI_method_get_reader(UI_OpenSSL()))(ui, uis);
+}
+
+/*
+ * Suppress interactive request for a default password if available.
+ */
+static int ssl_ui_writer(UI *ui, UI_STRING *uis)
+{
+  switch(UI_get_string_type(uis)) {
+  case UIT_PROMPT:
+  case UIT_VERIFY:
+    if(UI_get0_user_data(ui) &&
+       (UI_get_input_flags(uis) & UI_INPUT_FLAG_DEFAULT_PWD)) {
+      return 1;
+    }
+  default:
+    break;
+  }
+  return (UI_method_get_writer(UI_OpenSSL()))(ui, uis);
+}
+
+/*
+ * Check if a given string is a PKCS#11 URI
+ */
+static bool is_pkcs11_uri(const char *string)
+{
+  return (string && strncasecompare(string, "pkcs11:", 7));
+}
+
+#endif
+
+static CURLcode Curl_ossl_set_engine(struct Curl_easy *data,
+                                     const char *engine);
+
+static
+int cert_stuff(struct connectdata *conn,
+               SSL_CTX* ctx,
+               char *cert_file,
+               const char *cert_type,
+               char *key_file,
+               const char *key_type,
+               char *key_passwd)
+{
+  struct Curl_easy *data = conn->data;
+  char error_buffer[256];
+  bool check_privkey = TRUE;
+
+  int file_type = do_file_type(cert_type);
+
+  if(cert_file || (file_type == SSL_FILETYPE_ENGINE)) {
+    SSL *ssl;
+    X509 *x509;
+    int cert_done = 0;
+
+    if(key_passwd) {
+      /* set the password in the callback userdata */
+      SSL_CTX_set_default_passwd_cb_userdata(ctx, key_passwd);
+      /* Set passwd callback: */
+      SSL_CTX_set_default_passwd_cb(ctx, passwd_callback);
+    }
+
+
+    switch(file_type) {
+    case SSL_FILETYPE_PEM:
+      /* SSL_CTX_use_certificate_chain_file() only works on PEM files */
+      if(SSL_CTX_use_certificate_chain_file(ctx,
+                                            cert_file) != 1) {
+        failf(data,
+              "could not load PEM client certificate, " OSSL_PACKAGE
+              " error %s, "
+              "(no key found, wrong pass phrase, or wrong file format?)",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        return 0;
+      }
+      break;
+
+    case SSL_FILETYPE_ASN1:
+      /* SSL_CTX_use_certificate_file() works with either PEM or ASN1, but
+         we use the case above for PEM so this can only be performed with
+         ASN1 files. */
+      if(SSL_CTX_use_certificate_file(ctx,
+                                      cert_file,
+                                      file_type) != 1) {
+        failf(data,
+              "could not load ASN1 client certificate, " OSSL_PACKAGE
+              " error %s, "
+              "(no key found, wrong pass phrase, or wrong file format?)",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        return 0;
+      }
+      break;
+    case SSL_FILETYPE_ENGINE:
+#if defined(USE_OPENSSL_ENGINE) && defined(ENGINE_CTRL_GET_CMD_FROM_NAME)
+      {
+        /* Implicitly use pkcs11 engine if none was provided and the
+         * cert_file is a PKCS#11 URI */
+        if(!data->state.engine) {
+          if(is_pkcs11_uri(cert_file)) {
+            if(Curl_ossl_set_engine(data, "pkcs11") != CURLE_OK) {
+              return 0;
+            }
+          }
+        }
+
+        if(data->state.engine) {
+          const char *cmd_name = "LOAD_CERT_CTRL";
+          struct {
+            const char *cert_id;
+            X509 *cert;
+          } params;
+
+          params.cert_id = cert_file;
+          params.cert = NULL;
+
+          /* Does the engine supports LOAD_CERT_CTRL ? */
+          if(!ENGINE_ctrl(data->state.engine, ENGINE_CTRL_GET_CMD_FROM_NAME,
+                          0, (void *)cmd_name, NULL)) {
+            failf(data, "ssl engine does not support loading certificates");
+            return 0;
+          }
+
+          /* Load the certificate from the engine */
+          if(!ENGINE_ctrl_cmd(data->state.engine, cmd_name,
+                              0, &params, NULL, 1)) {
+            failf(data, "ssl engine cannot load client cert with id"
+                  " '%s' [%s]", cert_file,
+                  ossl_strerror(ERR_get_error(), error_buffer,
+                                sizeof(error_buffer)));
+            return 0;
+          }
+
+          if(!params.cert) {
+            failf(data, "ssl engine didn't initialized the certificate "
+                  "properly.");
+            return 0;
+          }
+
+          if(SSL_CTX_use_certificate(ctx, params.cert) != 1) {
+            failf(data, "unable to set client certificate");
+            X509_free(params.cert);
+            return 0;
+          }
+          X509_free(params.cert); /* we don't need the handle any more... */
+        }
+        else {
+          failf(data, "crypto engine not set, can't load certificate");
+          return 0;
+        }
+      }
+      break;
+#else
+      failf(data, "file type ENG for certificate not implemented");
+      return 0;
+#endif
+
+    case SSL_FILETYPE_PKCS12:
+    {
+      BIO *fp = NULL;
+      PKCS12 *p12 = NULL;
+      EVP_PKEY *pri;
+      STACK_OF(X509) *ca = NULL;
+
+      fp = BIO_new(BIO_s_file());
+      if(fp == NULL) {
+        failf(data,
+              "BIO_new return NULL, " OSSL_PACKAGE
+              " error %s",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        return 0;
+      }
+
+      if(BIO_read_filename(fp, cert_file) <= 0) {
+        failf(data, "could not open PKCS12 file '%s'", cert_file);
+        BIO_free(fp);
+        return 0;
+      }
+      p12 = d2i_PKCS12_bio(fp, NULL);
+      BIO_free(fp);
+
+      if(!p12) {
+        failf(data, "error reading PKCS12 file '%s'", cert_file);
+        return 0;
+      }
+
+      PKCS12_PBE_add();
+
+      if(!PKCS12_parse(p12, key_passwd, &pri, &x509,
+                       &ca)) {
+        failf(data,
+              "could not parse PKCS12 file, check password, " OSSL_PACKAGE
+              " error %s",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        PKCS12_free(p12);
+        return 0;
+      }
+
+      PKCS12_free(p12);
+
+      if(SSL_CTX_use_certificate(ctx, x509) != 1) {
+        failf(data,
+              "could not load PKCS12 client certificate, " OSSL_PACKAGE
+              " error %s",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        goto fail;
+      }
+
+      if(SSL_CTX_use_PrivateKey(ctx, pri) != 1) {
+        failf(data, "unable to use private key from PKCS12 file '%s'",
+              cert_file);
+        goto fail;
+      }
+
+      if(!SSL_CTX_check_private_key (ctx)) {
+        failf(data, "private key from PKCS12 file '%s' "
+              "does not match certificate in same file", cert_file);
+        goto fail;
+      }
+      /* Set Certificate Verification chain */
+      if(ca) {
+        while(sk_X509_num(ca)) {
+          /*
+           * Note that sk_X509_pop() is used below to make sure the cert is
+           * removed from the stack properly before getting passed to
+           * SSL_CTX_add_extra_chain_cert(), which takes ownership. Previously
+           * we used sk_X509_value() instead, but then we'd clean it in the
+           * subsequent sk_X509_pop_free() call.
+           */
+          X509 *x = sk_X509_pop(ca);
+          if(!SSL_CTX_add_client_CA(ctx, x)) {
+            X509_free(x);
+            failf(data, "cannot add certificate to client CA list");
+            goto fail;
+          }
+          if(!SSL_CTX_add_extra_chain_cert(ctx, x)) {
+            X509_free(x);
+            failf(data, "cannot add certificate to certificate chain");
+            goto fail;
+          }
+        }
+      }
+
+      cert_done = 1;
+  fail:
+      EVP_PKEY_free(pri);
+      X509_free(x509);
+#ifdef USE_AMISSL
+      sk_X509_pop_free(ca, Curl_amiga_X509_free);
+#else
+      sk_X509_pop_free(ca, X509_free);
+#endif
+      if(!cert_done)
+        return 0; /* failure! */
+      break;
+    }
+    default:
+      failf(data, "not supported file type '%s' for certificate", cert_type);
+      return 0;
+    }
+
+    if(!key_file)
+      key_file = cert_file;
+    else
+      file_type = do_file_type(key_type);
+
+    switch(file_type) {
+    case SSL_FILETYPE_PEM:
+      if(cert_done)
+        break;
+      /* FALLTHROUGH */
+    case SSL_FILETYPE_ASN1:
+      if(SSL_CTX_use_PrivateKey_file(ctx, key_file, file_type) != 1) {
+        failf(data, "unable to set private key file: '%s' type %s",
+              key_file, key_type?key_type:"PEM");
+        return 0;
+      }
+      break;
+    case SSL_FILETYPE_ENGINE:
+#ifdef USE_OPENSSL_ENGINE
+      {                         /* XXXX still needs some work */
+        EVP_PKEY *priv_key = NULL;
+
+        /* Implicitly use pkcs11 engine if none was provided and the
+         * key_file is a PKCS#11 URI */
+        if(!data->state.engine) {
+          if(is_pkcs11_uri(key_file)) {
+            if(Curl_ossl_set_engine(data, "pkcs11") != CURLE_OK) {
+              return 0;
+            }
+          }
+        }
+
+        if(data->state.engine) {
+          UI_METHOD *ui_method =
+            UI_create_method((char *)"curl user interface");
+          if(!ui_method) {
+            failf(data, "unable do create " OSSL_PACKAGE
+                  " user-interface method");
+            return 0;
+          }
+          UI_method_set_opener(ui_method, UI_method_get_opener(UI_OpenSSL()));
+          UI_method_set_closer(ui_method, UI_method_get_closer(UI_OpenSSL()));
+          UI_method_set_reader(ui_method, ssl_ui_reader);
+          UI_method_set_writer(ui_method, ssl_ui_writer);
+          /* the typecast below was added to please mingw32 */
+          priv_key = (EVP_PKEY *)
+            ENGINE_load_private_key(data->state.engine, key_file,
+                                    ui_method,
+                                    key_passwd);
+          UI_destroy_method(ui_method);
+          if(!priv_key) {
+            failf(data, "failed to load private key from crypto engine");
+            return 0;
+          }
+          if(SSL_CTX_use_PrivateKey(ctx, priv_key) != 1) {
+            failf(data, "unable to set private key");
+            EVP_PKEY_free(priv_key);
+            return 0;
+          }
+          EVP_PKEY_free(priv_key);  /* we don't need the handle any more... */
+        }
+        else {
+          failf(data, "crypto engine not set, can't load private key");
+          return 0;
+        }
+      }
+      break;
+#else
+      failf(data, "file type ENG for private key not supported");
+      return 0;
+#endif
+    case SSL_FILETYPE_PKCS12:
+      if(!cert_done) {
+        failf(data, "file type P12 for private key not supported");
+        return 0;
+      }
+      break;
+    default:
+      failf(data, "not supported file type for private key");
+      return 0;
+    }
+
+    ssl = SSL_new(ctx);
+    if(!ssl) {
+      failf(data, "unable to create an SSL structure");
+      return 0;
+    }
+
+    x509 = SSL_get_certificate(ssl);
+
+    /* This version was provided by Evan Jordan and is supposed to not
+       leak memory as the previous version: */
+    if(x509) {
+      EVP_PKEY *pktmp = X509_get_pubkey(x509);
+      EVP_PKEY_copy_parameters(pktmp, SSL_get_privatekey(ssl));
+      EVP_PKEY_free(pktmp);
+    }
+
+#if !defined(OPENSSL_NO_RSA) && !defined(OPENSSL_IS_BORINGSSL)
+    {
+      /* If RSA is used, don't check the private key if its flags indicate
+       * it doesn't support it. */
+      EVP_PKEY *priv_key = SSL_get_privatekey(ssl);
+      int pktype;
+#ifdef HAVE_OPAQUE_EVP_PKEY
+      pktype = EVP_PKEY_id(priv_key);
+#else
+      pktype = priv_key->type;
+#endif
+      if(pktype == EVP_PKEY_RSA) {
+        RSA *rsa = EVP_PKEY_get1_RSA(priv_key);
+        if(RSA_flags(rsa) & RSA_METHOD_FLAG_NO_CHECK)
+          check_privkey = FALSE;
+        RSA_free(rsa); /* Decrement reference count */
+      }
+    }
+#endif
+
+    SSL_free(ssl);
+
+    /* If we are using DSA, we can copy the parameters from
+     * the private key */
+
+    if(check_privkey == TRUE) {
+      /* Now we know that a key and cert have been set against
+       * the SSL context */
+      if(!SSL_CTX_check_private_key(ctx)) {
+        failf(data, "Private key does not match the certificate public key");
+        return 0;
+      }
+    }
+  }
+  return 1;
+}
+
+/* returns non-zero on failure */
+static int x509_name_oneline(X509_NAME *a, char *buf, size_t size)
+{
+#if 0
+  return X509_NAME_oneline(a, buf, size);
+#else
+  BIO *bio_out = BIO_new(BIO_s_mem());
+  BUF_MEM *biomem;
+  int rc;
+
+  if(!bio_out)
+    return 1; /* alloc failed! */
+
+  rc = X509_NAME_print_ex(bio_out, a, 0, XN_FLAG_SEP_SPLUS_SPC);
+  BIO_get_mem_ptr(bio_out, &biomem);
+
+  if((size_t)biomem->length < size)
+    size = biomem->length;
+  else
+    size--; /* don't overwrite the buffer end */
+
+  memcpy(buf, biomem->data, size);
+  buf[size] = 0;
+
+  BIO_free(bio_out);
+
+  return !rc;
+#endif
+}
+
+/**
+ * Global SSL init
+ *
+ * @retval 0 error initializing SSL
+ * @retval 1 SSL initialized successfully
+ */
+static int Curl_ossl_init(void)
+{
+#ifdef ENABLE_SSLKEYLOGFILE
+  char *keylog_file_name;
+#endif
+
+  OPENSSL_load_builtin_modules();
+
+#ifdef USE_OPENSSL_ENGINE
+  ENGINE_load_builtin_engines();
+#endif
+
+/* CONF_MFLAGS_DEFAULT_SECTION was introduced some time between 0.9.8b and
+   0.9.8e */
+#ifndef CONF_MFLAGS_DEFAULT_SECTION
+#define CONF_MFLAGS_DEFAULT_SECTION 0x0
+#endif
+
+#ifndef CURL_DISABLE_OPENSSL_AUTO_LOAD_CONFIG
+  CONF_modules_load_file(NULL, NULL,
+                         CONF_MFLAGS_DEFAULT_SECTION|
+                         CONF_MFLAGS_IGNORE_MISSING_FILE);
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) && \
+    !defined(LIBRESSL_VERSION_NUMBER)
+  /* OpenSSL 1.1.0+ takes care of initialization itself */
+#else
+  /* Lets get nice error messages */
+  SSL_load_error_strings();
+
+  /* Init the global ciphers and digests */
+  if(!SSLeay_add_ssl_algorithms())
+    return 0;
+
+  OpenSSL_add_all_algorithms();
+#endif
+
+#ifdef ENABLE_SSLKEYLOGFILE
+  if(!keylog_file_fp) {
+    keylog_file_name = curl_getenv("SSLKEYLOGFILE");
+    if(keylog_file_name) {
+      keylog_file_fp = fopen(keylog_file_name, FOPEN_APPENDTEXT);
+      if(keylog_file_fp) {
+#ifdef WIN32
+        if(setvbuf(keylog_file_fp, NULL, _IONBF, 0))
+#else
+        if(setvbuf(keylog_file_fp, NULL, _IOLBF, 4096))
+#endif
+        {
+          fclose(keylog_file_fp);
+          keylog_file_fp = NULL;
+        }
+      }
+      Curl_safefree(keylog_file_name);
+    }
+  }
+#endif
+
+  /* Initialize the extra data indexes */
+  if(ossl_get_ssl_conn_index() < 0 || ossl_get_ssl_sockindex_index() < 0)
+    return 0;
+
+  return 1;
+}
+
+/* Global cleanup */
+static void Curl_ossl_cleanup(void)
+{
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) && \
+    !defined(LIBRESSL_VERSION_NUMBER)
+  /* OpenSSL 1.1 deprecates all these cleanup functions and
+     turns them into no-ops in OpenSSL 1.0 compatibility mode */
+#else
+  /* Free ciphers and digests lists */
+  EVP_cleanup();
+
+#ifdef USE_OPENSSL_ENGINE
+  /* Free engine list */
+  ENGINE_cleanup();
+#endif
+
+  /* Free OpenSSL error strings */
+  ERR_free_strings();
+
+  /* Free thread local error state, destroying hash upon zero refcount */
+#ifdef HAVE_ERR_REMOVE_THREAD_STATE
+  ERR_remove_thread_state(NULL);
+#else
+  ERR_remove_state(0);
+#endif
+
+  /* Free all memory allocated by all configuration modules */
+  CONF_modules_free();
+
+#ifdef HAVE_SSL_COMP_FREE_COMPRESSION_METHODS
+  SSL_COMP_free_compression_methods();
+#endif
+#endif
+
+#ifdef ENABLE_SSLKEYLOGFILE
+  if(keylog_file_fp) {
+    fclose(keylog_file_fp);
+    keylog_file_fp = NULL;
+  }
+#endif
+}
+
+/*
+ * This function is used to determine connection status.
+ *
+ * Return codes:
+ *     1 means the connection is still in place
+ *     0 means the connection has been closed
+ *    -1 means the connection status is unknown
+ */
+static int Curl_ossl_check_cxn(struct connectdata *conn)
+{
+  /* SSL_peek takes data out of the raw recv buffer without peeking so we use
+     recv MSG_PEEK instead. Bug #795 */
+#ifdef MSG_PEEK
+  char buf;
+  ssize_t nread;
+  nread = recv((RECV_TYPE_ARG1)conn->sock[FIRSTSOCKET], (RECV_TYPE_ARG2)&buf,
+               (RECV_TYPE_ARG3)1, (RECV_TYPE_ARG4)MSG_PEEK);
+  if(nread == 0)
+    return 0; /* connection has been closed */
+  if(nread == 1)
+    return 1; /* connection still in place */
+  else if(nread == -1) {
+      int err = SOCKERRNO;
+      if(err == EINPROGRESS ||
+#if defined(EAGAIN) && (EAGAIN != EWOULDBLOCK)
+         err == EAGAIN ||
+#endif
+         err == EWOULDBLOCK)
+        return 1; /* connection still in place */
+      if(err == ECONNRESET ||
+#ifdef ECONNABORTED
+         err == ECONNABORTED ||
+#endif
+#ifdef ENETDOWN
+         err == ENETDOWN ||
+#endif
+#ifdef ENETRESET
+         err == ENETRESET ||
+#endif
+#ifdef ESHUTDOWN
+         err == ESHUTDOWN ||
+#endif
+#ifdef ETIMEDOUT
+         err == ETIMEDOUT ||
+#endif
+         err == ENOTCONN)
+        return 0; /* connection has been closed */
+  }
+#endif
+  return -1; /* connection status unknown */
+}
+
+/* Selects an OpenSSL crypto engine
+ */
+static CURLcode Curl_ossl_set_engine(struct Curl_easy *data,
+                                     const char *engine)
+{
+#ifdef USE_OPENSSL_ENGINE
+  ENGINE *e;
+
+#if OPENSSL_VERSION_NUMBER >= 0x00909000L
+  e = ENGINE_by_id(engine);
+#else
+  /* avoid memory leak */
+  for(e = ENGINE_get_first(); e; e = ENGINE_get_next(e)) {
+    const char *e_id = ENGINE_get_id(e);
+    if(!strcmp(engine, e_id))
+      break;
+  }
+#endif
+
+  if(!e) {
+    failf(data, "SSL Engine '%s' not found", engine);
+    return CURLE_SSL_ENGINE_NOTFOUND;
+  }
+
+  if(data->state.engine) {
+    ENGINE_finish(data->state.engine);
+    ENGINE_free(data->state.engine);
+    data->state.engine = NULL;
+  }
+  if(!ENGINE_init(e)) {
+    char buf[256];
+
+    ENGINE_free(e);
+    failf(data, "Failed to initialise SSL Engine '%s':\n%s",
+          engine, ossl_strerror(ERR_get_error(), buf, sizeof(buf)));
+    return CURLE_SSL_ENGINE_INITFAILED;
+  }
+  data->state.engine = e;
+  return CURLE_OK;
+#else
+  (void)engine;
+  failf(data, "SSL Engine not supported");
+  return CURLE_SSL_ENGINE_NOTFOUND;
+#endif
+}
+
+/* Sets engine as default for all SSL operations
+ */
+static CURLcode Curl_ossl_set_engine_default(struct Curl_easy *data)
+{
+#ifdef USE_OPENSSL_ENGINE
+  if(data->state.engine) {
+    if(ENGINE_set_default(data->state.engine, ENGINE_METHOD_ALL) > 0) {
+      infof(data, "set default crypto engine '%s'\n",
+            ENGINE_get_id(data->state.engine));
+    }
+    else {
+      failf(data, "set default crypto engine '%s' failed",
+            ENGINE_get_id(data->state.engine));
+      return CURLE_SSL_ENGINE_SETFAILED;
+    }
+  }
+#else
+  (void) data;
+#endif
+  return CURLE_OK;
+}
+
+/* Return list of OpenSSL crypto engine names.
+ */
+static struct curl_slist *Curl_ossl_engines_list(struct Curl_easy *data)
+{
+  struct curl_slist *list = NULL;
+#ifdef USE_OPENSSL_ENGINE
+  struct curl_slist *beg;
+  ENGINE *e;
+
+  for(e = ENGINE_get_first(); e; e = ENGINE_get_next(e)) {
+    beg = curl_slist_append(list, ENGINE_get_id(e));
+    if(!beg) {
+      curl_slist_free_all(list);
+      return NULL;
+    }
+    list = beg;
+  }
+#endif
+  (void) data;
+  return list;
+}
+
+
+static void ossl_close(struct ssl_connect_data *connssl)
+{
+  if(BACKEND->handle) {
+    (void)SSL_shutdown(BACKEND->handle);
+    SSL_set_connect_state(BACKEND->handle);
+
+    SSL_free(BACKEND->handle);
+    BACKEND->handle = NULL;
+  }
+  if(BACKEND->ctx) {
+    SSL_CTX_free(BACKEND->ctx);
+    BACKEND->ctx = NULL;
+  }
+}
+
+/*
+ * This function is called when an SSL connection is closed.
+ */
+static void Curl_ossl_close(struct connectdata *conn, int sockindex)
+{
+  ossl_close(&conn->ssl[sockindex]);
+  ossl_close(&conn->proxy_ssl[sockindex]);
+}
+
+/*
+ * This function is called to shut down the SSL layer but keep the
+ * socket open (CCC - Clear Command Channel)
+ */
+static int Curl_ossl_shutdown(struct connectdata *conn, int sockindex)
+{
+  int retval = 0;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  struct Curl_easy *data = conn->data;
+  char buf[256]; /* We will use this for the OpenSSL error buffer, so it has
+                    to be at least 256 bytes long. */
+  unsigned long sslerror;
+  ssize_t nread;
+  int buffsize;
+  int err;
+  bool done = FALSE;
+
+#ifndef CURL_DISABLE_FTP
+  /* This has only been tested on the proftpd server, and the mod_tls code
+     sends a close notify alert without waiting for a close notify alert in
+     response. Thus we wait for a close notify alert from the server, but
+     we do not send one. Let's hope other servers do the same... */
+
+  if(data->set.ftp_ccc == CURLFTPSSL_CCC_ACTIVE)
+      (void)SSL_shutdown(BACKEND->handle);
+#endif
+
+  if(BACKEND->handle) {
+    buffsize = (int)sizeof(buf);
+    while(!done) {
+      int what = SOCKET_READABLE(conn->sock[sockindex],
+                                 SSL_SHUTDOWN_TIMEOUT);
+      if(what > 0) {
+        ERR_clear_error();
+
+        /* Something to read, let's do it and hope that it is the close
+           notify alert from the server */
+        nread = (ssize_t)SSL_read(BACKEND->handle, buf, buffsize);
+        err = SSL_get_error(BACKEND->handle, (int)nread);
+
+        switch(err) {
+        case SSL_ERROR_NONE: /* this is not an error */
+        case SSL_ERROR_ZERO_RETURN: /* no more data */
+          /* This is the expected response. There was no data but only
+             the close notify alert */
+          done = TRUE;
+          break;
+        case SSL_ERROR_WANT_READ:
+          /* there's data pending, re-invoke SSL_read() */
+          infof(data, "SSL_ERROR_WANT_READ\n");
+          break;
+        case SSL_ERROR_WANT_WRITE:
+          /* SSL wants a write. Really odd. Let's bail out. */
+          infof(data, "SSL_ERROR_WANT_WRITE\n");
+          done = TRUE;
+          break;
+        default:
+          /* openssl/ssl.h says "look at error stack/return value/errno" */
+          sslerror = ERR_get_error();
+          failf(conn->data, OSSL_PACKAGE " SSL_read on shutdown: %s, errno %d",
+                (sslerror ?
+                 ossl_strerror(sslerror, buf, sizeof(buf)) :
+                 SSL_ERROR_to_str(err)),
+                SOCKERRNO);
+          done = TRUE;
+          break;
+        }
+      }
+      else if(0 == what) {
+        /* timeout */
+        failf(data, "SSL shutdown timeout");
+        done = TRUE;
+      }
+      else {
+        /* anything that gets here is fatally bad */
+        failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
+        retval = -1;
+        done = TRUE;
+      }
+    } /* while()-loop for the select() */
+
+    if(data->set.verbose) {
+#ifdef HAVE_SSL_GET_SHUTDOWN
+      switch(SSL_get_shutdown(BACKEND->handle)) {
+      case SSL_SENT_SHUTDOWN:
+        infof(data, "SSL_get_shutdown() returned SSL_SENT_SHUTDOWN\n");
+        break;
+      case SSL_RECEIVED_SHUTDOWN:
+        infof(data, "SSL_get_shutdown() returned SSL_RECEIVED_SHUTDOWN\n");
+        break;
+      case SSL_SENT_SHUTDOWN|SSL_RECEIVED_SHUTDOWN:
+        infof(data, "SSL_get_shutdown() returned SSL_SENT_SHUTDOWN|"
+              "SSL_RECEIVED__SHUTDOWN\n");
+        break;
+      }
+#endif
+    }
+
+    SSL_free(BACKEND->handle);
+    BACKEND->handle = NULL;
+  }
+  return retval;
+}
+
+static void Curl_ossl_session_free(void *ptr)
+{
+  /* free the ID */
+  SSL_SESSION_free(ptr);
+}
+
+/*
+ * This function is called when the 'data' struct is going away. Close
+ * down everything and free all resources!
+ */
+static void Curl_ossl_close_all(struct Curl_easy *data)
+{
+#ifdef USE_OPENSSL_ENGINE
+  if(data->state.engine) {
+    ENGINE_finish(data->state.engine);
+    ENGINE_free(data->state.engine);
+    data->state.engine = NULL;
+  }
+#else
+  (void)data;
+#endif
+#if !defined(HAVE_ERR_REMOVE_THREAD_STATE_DEPRECATED) && \
+  defined(HAVE_ERR_REMOVE_THREAD_STATE)
+  /* OpenSSL 1.0.1 and 1.0.2 build an error queue that is stored per-thread
+     so we need to clean it here in case the thread will be killed. All OpenSSL
+     code should extract the error in association with the error so clearing
+     this queue here should be harmless at worst. */
+  ERR_remove_thread_state(NULL);
+#endif
+}
+
+/* ====================================================== */
+
+/*
+ * Match subjectAltName against the host name. This requires a conversion
+ * in CURL_DOES_CONVERSIONS builds.
+ */
+static bool subj_alt_hostcheck(struct Curl_easy *data,
+                               const char *match_pattern, const char *hostname,
+                               const char *dispname)
+#ifdef CURL_DOES_CONVERSIONS
+{
+  bool res = FALSE;
+
+  /* Curl_cert_hostcheck uses host encoding, but we get ASCII from
+     OpenSSl.
+   */
+  char *match_pattern2 = strdup(match_pattern);
+
+  if(match_pattern2) {
+    if(Curl_convert_from_network(data, match_pattern2,
+                                strlen(match_pattern2)) == CURLE_OK) {
+      if(Curl_cert_hostcheck(match_pattern2, hostname)) {
+        res = TRUE;
+        infof(data,
+                " subjectAltName: host \"%s\" matched cert's \"%s\"\n",
+                dispname, match_pattern2);
+      }
+    }
+    free(match_pattern2);
+  }
+  else {
+    failf(data,
+        "SSL: out of memory when allocating temporary for subjectAltName");
+  }
+  return res;
+}
+#else
+{
+#ifdef CURL_DISABLE_VERBOSE_STRINGS
+  (void)dispname;
+  (void)data;
+#endif
+  if(Curl_cert_hostcheck(match_pattern, hostname)) {
+    infof(data, " subjectAltName: host \"%s\" matched cert's \"%s\"\n",
+                  dispname, match_pattern);
+    return TRUE;
+  }
+  return FALSE;
+}
+#endif
+
+
+/* Quote from RFC2818 section 3.1 "Server Identity"
+
+   If a subjectAltName extension of type dNSName is present, that MUST
+   be used as the identity. Otherwise, the (most specific) Common Name
+   field in the Subject field of the certificate MUST be used. Although
+   the use of the Common Name is existing practice, it is deprecated and
+   Certification Authorities are encouraged to use the dNSName instead.
+
+   Matching is performed using the matching rules specified by
+   [RFC2459].  If more than one identity of a given type is present in
+   the certificate (e.g., more than one dNSName name, a match in any one
+   of the set is considered acceptable.) Names may contain the wildcard
+   character * which is considered to match any single domain name
+   component or component fragment. E.g., *.a.com matches foo.a.com but
+   not bar.foo.a.com. f*.com matches foo.com but not bar.com.
+
+   In some cases, the URI is specified as an IP address rather than a
+   hostname. In this case, the iPAddress subjectAltName must be present
+   in the certificate and must exactly match the IP in the URI.
+
+*/
+static CURLcode verifyhost(struct connectdata *conn, X509 *server_cert)
+{
+  bool matched = FALSE;
+  int target = GEN_DNS; /* target type, GEN_DNS or GEN_IPADD */
+  size_t addrlen = 0;
+  struct Curl_easy *data = conn->data;
+  STACK_OF(GENERAL_NAME) *altnames;
+#ifdef ENABLE_IPV6
+  struct in6_addr addr;
+#else
+  struct in_addr addr;
+#endif
+  CURLcode result = CURLE_OK;
+  bool dNSName = FALSE; /* if a dNSName field exists in the cert */
+  bool iPAddress = FALSE; /* if a iPAddress field exists in the cert */
+  const char * const hostname = SSL_IS_PROXY() ? conn->http_proxy.host.name :
+    conn->host.name;
+  const char * const dispname = SSL_IS_PROXY() ?
+    conn->http_proxy.host.dispname : conn->host.dispname;
+
+#ifdef ENABLE_IPV6
+  if(conn->bits.ipv6_ip &&
+     Curl_inet_pton(AF_INET6, hostname, &addr)) {
+    target = GEN_IPADD;
+    addrlen = sizeof(struct in6_addr);
+  }
+  else
+#endif
+    if(Curl_inet_pton(AF_INET, hostname, &addr)) {
+      target = GEN_IPADD;
+      addrlen = sizeof(struct in_addr);
+    }
+
+  /* get a "list" of alternative names */
+  altnames = X509_get_ext_d2i(server_cert, NID_subject_alt_name, NULL, NULL);
+
+  if(altnames) {
+#ifdef OPENSSL_IS_BORINGSSL
+    size_t numalts;
+    size_t i;
+#else
+    int numalts;
+    int i;
+#endif
+    bool dnsmatched = FALSE;
+    bool ipmatched = FALSE;
+
+    /* get amount of alternatives, RFC2459 claims there MUST be at least
+       one, but we don't depend on it... */
+    numalts = sk_GENERAL_NAME_num(altnames);
+
+    /* loop through all alternatives - until a dnsmatch */
+    for(i = 0; (i < numalts) && !dnsmatched; i++) {
+      /* get a handle to alternative name number i */
+      const GENERAL_NAME *check = sk_GENERAL_NAME_value(altnames, i);
+
+      if(check->type == GEN_DNS)
+        dNSName = TRUE;
+      else if(check->type == GEN_IPADD)
+        iPAddress = TRUE;
+
+      /* only check alternatives of the same type the target is */
+      if(check->type == target) {
+        /* get data and length */
+        const char *altptr = (char *)ASN1_STRING_get0_data(check->d.ia5);
+        size_t altlen = (size_t) ASN1_STRING_length(check->d.ia5);
+
+        switch(target) {
+        case GEN_DNS: /* name/pattern comparison */
+          /* The OpenSSL man page explicitly says: "In general it cannot be
+             assumed that the data returned by ASN1_STRING_data() is null
+             terminated or does not contain embedded nulls." But also that
+             "The actual format of the data will depend on the actual string
+             type itself: for example for an IA5String the data will be ASCII"
+
+             It has been however verified that in 0.9.6 and 0.9.7, IA5String
+             is always zero-terminated.
+          */
+          if((altlen == strlen(altptr)) &&
+             /* if this isn't true, there was an embedded zero in the name
+                string and we cannot match it. */
+             subj_alt_hostcheck(data, altptr, hostname, dispname)) {
+            dnsmatched = TRUE;
+          }
+          break;
+
+        case GEN_IPADD: /* IP address comparison */
+          /* compare alternative IP address if the data chunk is the same size
+             our server IP address is */
+          if((altlen == addrlen) && !memcmp(altptr, &addr, altlen)) {
+            ipmatched = TRUE;
+            infof(data,
+                  " subjectAltName: host \"%s\" matched cert's IP address!\n",
+                  dispname);
+          }
+          break;
+        }
+      }
+    }
+    GENERAL_NAMES_free(altnames);
+
+    if(dnsmatched || ipmatched)
+      matched = TRUE;
+  }
+
+  if(matched)
+    /* an alternative name matched */
+    ;
+  else if(dNSName || iPAddress) {
+    infof(data, " subjectAltName does not match %s\n", dispname);
+    failf(data, "SSL: no alternative certificate subject name matches "
+          "target host name '%s'", dispname);
+    result = CURLE_PEER_FAILED_VERIFICATION;
+  }
+  else {
+    /* we have to look to the last occurrence of a commonName in the
+       distinguished one to get the most significant one. */
+    int j, i = -1;
+
+    /* The following is done because of a bug in 0.9.6b */
+
+    unsigned char *nulstr = (unsigned char *)"";
+    unsigned char *peer_CN = nulstr;
+
+    X509_NAME *name = X509_get_subject_name(server_cert);
+    if(name)
+      while((j = X509_NAME_get_index_by_NID(name, NID_commonName, i)) >= 0)
+        i = j;
+
+    /* we have the name entry and we will now convert this to a string
+       that we can use for comparison. Doing this we support BMPstring,
+       UTF8 etc. */
+
+    if(i >= 0) {
+      ASN1_STRING *tmp =
+        X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, i));
+
+      /* In OpenSSL 0.9.7d and earlier, ASN1_STRING_to_UTF8 fails if the input
+         is already UTF-8 encoded. We check for this case and copy the raw
+         string manually to avoid the problem. This code can be made
+         conditional in the future when OpenSSL has been fixed. */
+      if(tmp) {
+        if(ASN1_STRING_type(tmp) == V_ASN1_UTF8STRING) {
+          j = ASN1_STRING_length(tmp);
+          if(j >= 0) {
+            peer_CN = OPENSSL_malloc(j + 1);
+            if(peer_CN) {
+              memcpy(peer_CN, ASN1_STRING_get0_data(tmp), j);
+              peer_CN[j] = '\0';
+            }
+          }
+        }
+        else /* not a UTF8 name */
+          j = ASN1_STRING_to_UTF8(&peer_CN, tmp);
+
+        if(peer_CN && (curlx_uztosi(strlen((char *)peer_CN)) != j)) {
+          /* there was a terminating zero before the end of string, this
+             cannot match and we return failure! */
+          failf(data, "SSL: illegal cert name field");
+          result = CURLE_PEER_FAILED_VERIFICATION;
+        }
+      }
+    }
+
+    if(peer_CN == nulstr)
+       peer_CN = NULL;
+    else {
+      /* convert peer_CN from UTF8 */
+      CURLcode rc = Curl_convert_from_utf8(data, (char *)peer_CN,
+                                           strlen((char *)peer_CN));
+      /* Curl_convert_from_utf8 calls failf if unsuccessful */
+      if(rc) {
+        OPENSSL_free(peer_CN);
+        return rc;
+      }
+    }
+
+    if(result)
+      /* error already detected, pass through */
+      ;
+    else if(!peer_CN) {
+      failf(data,
+            "SSL: unable to obtain common name from peer certificate");
+      result = CURLE_PEER_FAILED_VERIFICATION;
+    }
+    else if(!Curl_cert_hostcheck((const char *)peer_CN, hostname)) {
+      failf(data, "SSL: certificate subject name '%s' does not match "
+            "target host name '%s'", peer_CN, dispname);
+      result = CURLE_PEER_FAILED_VERIFICATION;
+    }
+    else {
+      infof(data, " common name: %s (matched)\n", peer_CN);
+    }
+    if(peer_CN)
+      OPENSSL_free(peer_CN);
+  }
+
+  return result;
+}
+
+#if (OPENSSL_VERSION_NUMBER >= 0x0090808fL) && !defined(OPENSSL_NO_TLSEXT) && \
+    !defined(OPENSSL_NO_OCSP)
+static CURLcode verifystatus(struct connectdata *conn,
+                             struct ssl_connect_data *connssl)
+{
+  int i, ocsp_status;
+  unsigned char *status;
+  const unsigned char *p;
+  CURLcode result = CURLE_OK;
+  struct Curl_easy *data = conn->data;
+
+  OCSP_RESPONSE *rsp = NULL;
+  OCSP_BASICRESP *br = NULL;
+  X509_STORE     *st = NULL;
+  STACK_OF(X509) *ch = NULL;
+
+  long len = SSL_get_tlsext_status_ocsp_resp(BACKEND->handle, &status);
+
+  if(!status) {
+    failf(data, "No OCSP response received");
+    result = CURLE_SSL_INVALIDCERTSTATUS;
+    goto end;
+  }
+  p = status;
+  rsp = d2i_OCSP_RESPONSE(NULL, &p, len);
+  if(!rsp) {
+    failf(data, "Invalid OCSP response");
+    result = CURLE_SSL_INVALIDCERTSTATUS;
+    goto end;
+  }
+
+  ocsp_status = OCSP_response_status(rsp);
+  if(ocsp_status != OCSP_RESPONSE_STATUS_SUCCESSFUL) {
+    failf(data, "Invalid OCSP response status: %s (%d)",
+          OCSP_response_status_str(ocsp_status), ocsp_status);
+    result = CURLE_SSL_INVALIDCERTSTATUS;
+    goto end;
+  }
+
+  br = OCSP_response_get1_basic(rsp);
+  if(!br) {
+    failf(data, "Invalid OCSP response");
+    result = CURLE_SSL_INVALIDCERTSTATUS;
+    goto end;
+  }
+
+  ch = SSL_get_peer_cert_chain(BACKEND->handle);
+  st = SSL_CTX_get_cert_store(BACKEND->ctx);
+
+#if ((OPENSSL_VERSION_NUMBER <= 0x1000201fL) /* Fixed after 1.0.2a */ || \
+     (defined(LIBRESSL_VERSION_NUMBER) &&                               \
+      LIBRESSL_VERSION_NUMBER <= 0x2040200fL))
+  /* The authorized responder cert in the OCSP response MUST be signed by the
+     peer cert's issuer (see RFC6960 section 4.2.2.2). If that's a root cert,
+     no problem, but if it's an intermediate cert OpenSSL has a bug where it
+     expects this issuer to be present in the chain embedded in the OCSP
+     response. So we add it if necessary. */
+
+  /* First make sure the peer cert chain includes both a peer and an issuer,
+     and the OCSP response contains a responder cert. */
+  if(sk_X509_num(ch) >= 2 && sk_X509_num(br->certs) >= 1) {
+    X509 *responder = sk_X509_value(br->certs, sk_X509_num(br->certs) - 1);
+
+    /* Find issuer of responder cert and add it to the OCSP response chain */
+    for(i = 0; i < sk_X509_num(ch); i++) {
+      X509 *issuer = sk_X509_value(ch, i);
+      if(X509_check_issued(issuer, responder) == X509_V_OK) {
+        if(!OCSP_basic_add1_cert(br, issuer)) {
+          failf(data, "Could not add issuer cert to OCSP response");
+          result = CURLE_SSL_INVALIDCERTSTATUS;
+          goto end;
+        }
+      }
+    }
+  }
+#endif
+
+  if(OCSP_basic_verify(br, ch, st, 0) <= 0) {
+    failf(data, "OCSP response verification failed");
+    result = CURLE_SSL_INVALIDCERTSTATUS;
+    goto end;
+  }
+
+  for(i = 0; i < OCSP_resp_count(br); i++) {
+    int cert_status, crl_reason;
+    OCSP_SINGLERESP *single = NULL;
+
+    ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
+
+    single = OCSP_resp_get0(br, i);
+    if(!single)
+      continue;
+
+    cert_status = OCSP_single_get0_status(single, &crl_reason, &rev,
+                                          &thisupd, &nextupd);
+
+    if(!OCSP_check_validity(thisupd, nextupd, 300L, -1L)) {
+      failf(data, "OCSP response has expired");
+      result = CURLE_SSL_INVALIDCERTSTATUS;
+      goto end;
+    }
+
+    infof(data, "SSL certificate status: %s (%d)\n",
+          OCSP_cert_status_str(cert_status), cert_status);
+
+    switch(cert_status) {
+      case V_OCSP_CERTSTATUS_GOOD:
+        break;
+
+      case V_OCSP_CERTSTATUS_REVOKED:
+        result = CURLE_SSL_INVALIDCERTSTATUS;
+
+        failf(data, "SSL certificate revocation reason: %s (%d)",
+              OCSP_crl_reason_str(crl_reason), crl_reason);
+        goto end;
+
+      case V_OCSP_CERTSTATUS_UNKNOWN:
+        result = CURLE_SSL_INVALIDCERTSTATUS;
+        goto end;
+    }
+  }
+
+end:
+  if(br) OCSP_BASICRESP_free(br);
+  OCSP_RESPONSE_free(rsp);
+
+  return result;
+}
+#endif
+
+#endif /* USE_OPENSSL */
+
+/* The SSL_CTRL_SET_MSG_CALLBACK doesn't exist in ancient OpenSSL versions
+   and thus this cannot be done there. */
+#ifdef SSL_CTRL_SET_MSG_CALLBACK
+
+static const char *ssl_msg_type(int ssl_ver, int msg)
+{
+#ifdef SSL2_VERSION_MAJOR
+  if(ssl_ver == SSL2_VERSION_MAJOR) {
+    switch(msg) {
+      case SSL2_MT_ERROR:
+        return "Error";
+      case SSL2_MT_CLIENT_HELLO:
+        return "Client hello";
+      case SSL2_MT_CLIENT_MASTER_KEY:
+        return "Client key";
+      case SSL2_MT_CLIENT_FINISHED:
+        return "Client finished";
+      case SSL2_MT_SERVER_HELLO:
+        return "Server hello";
+      case SSL2_MT_SERVER_VERIFY:
+        return "Server verify";
+      case SSL2_MT_SERVER_FINISHED:
+        return "Server finished";
+      case SSL2_MT_REQUEST_CERTIFICATE:
+        return "Request CERT";
+      case SSL2_MT_CLIENT_CERTIFICATE:
+        return "Client CERT";
+    }
+  }
+  else
+#endif
+  if(ssl_ver == SSL3_VERSION_MAJOR) {
+    switch(msg) {
+      case SSL3_MT_HELLO_REQUEST:
+        return "Hello request";
+      case SSL3_MT_CLIENT_HELLO:
+        return "Client hello";
+      case SSL3_MT_SERVER_HELLO:
+        return "Server hello";
+#ifdef SSL3_MT_NEWSESSION_TICKET
+      case SSL3_MT_NEWSESSION_TICKET:
+        return "Newsession Ticket";
+#endif
+      case SSL3_MT_CERTIFICATE:
+        return "Certificate";
+      case SSL3_MT_SERVER_KEY_EXCHANGE:
+        return "Server key exchange";
+      case SSL3_MT_CLIENT_KEY_EXCHANGE:
+        return "Client key exchange";
+      case SSL3_MT_CERTIFICATE_REQUEST:
+        return "Request CERT";
+      case SSL3_MT_SERVER_DONE:
+        return "Server finished";
+      case SSL3_MT_CERTIFICATE_VERIFY:
+        return "CERT verify";
+      case SSL3_MT_FINISHED:
+        return "Finished";
+#ifdef SSL3_MT_CERTIFICATE_STATUS
+      case SSL3_MT_CERTIFICATE_STATUS:
+        return "Certificate Status";
+#endif
+#ifdef SSL3_MT_ENCRYPTED_EXTENSIONS
+      case SSL3_MT_ENCRYPTED_EXTENSIONS:
+        return "Encrypted Extensions";
+#endif
+#ifdef SSL3_MT_END_OF_EARLY_DATA
+      case SSL3_MT_END_OF_EARLY_DATA:
+        return "End of early data";
+#endif
+#ifdef SSL3_MT_KEY_UPDATE
+      case SSL3_MT_KEY_UPDATE:
+        return "Key update";
+#endif
+#ifdef SSL3_MT_NEXT_PROTO
+      case SSL3_MT_NEXT_PROTO:
+        return "Next protocol";
+#endif
+#ifdef SSL3_MT_MESSAGE_HASH
+      case SSL3_MT_MESSAGE_HASH:
+        return "Message hash";
+#endif
+    }
+  }
+  return "Unknown";
+}
+
+static const char *tls_rt_type(int type)
+{
+  switch(type) {
+#ifdef SSL3_RT_HEADER
+  case SSL3_RT_HEADER:
+    return "TLS header";
+#endif
+  case SSL3_RT_CHANGE_CIPHER_SPEC:
+    return "TLS change cipher";
+  case SSL3_RT_ALERT:
+    return "TLS alert";
+  case SSL3_RT_HANDSHAKE:
+    return "TLS handshake";
+  case SSL3_RT_APPLICATION_DATA:
+    return "TLS app data";
+  default:
+    return "TLS Unknown";
+  }
+}
+
+
+/*
+ * Our callback from the SSL/TLS layers.
+ */
+static void ssl_tls_trace(int direction, int ssl_ver, int content_type,
+                          const void *buf, size_t len, SSL *ssl,
+                          void *userp)
+{
+  struct Curl_easy *data;
+  char unknown[32];
+  const char *verstr = NULL;
+  struct connectdata *conn = userp;
+
+  if(!conn || !conn->data || !conn->data->set.fdebug ||
+     (direction != 0 && direction != 1))
+    return;
+
+  data = conn->data;
+
+  switch(ssl_ver) {
+#ifdef SSL2_VERSION /* removed in recent versions */
+  case SSL2_VERSION:
+    verstr = "SSLv2";
+    break;
+#endif
+#ifdef SSL3_VERSION
+  case SSL3_VERSION:
+    verstr = "SSLv3";
+    break;
+#endif
+  case TLS1_VERSION:
+    verstr = "TLSv1.0";
+    break;
+#ifdef TLS1_1_VERSION
+  case TLS1_1_VERSION:
+    verstr = "TLSv1.1";
+    break;
+#endif
+#ifdef TLS1_2_VERSION
+  case TLS1_2_VERSION:
+    verstr = "TLSv1.2";
+    break;
+#endif
+#ifdef TLS1_3_VERSION
+  case TLS1_3_VERSION:
+    verstr = "TLSv1.3";
+    break;
+#endif
+  case 0:
+    break;
+  default:
+    msnprintf(unknown, sizeof(unknown), "(%x)", ssl_ver);
+    verstr = unknown;
+    break;
+  }
+
+  /* Log progress for interesting records only (like Handshake or Alert), skip
+   * all raw record headers (content_type == SSL3_RT_HEADER or ssl_ver == 0).
+   * For TLS 1.3, skip notification of the decrypted inner Content Type.
+   */
+  if(ssl_ver
+#ifdef SSL3_RT_INNER_CONTENT_TYPE
+     && content_type != SSL3_RT_INNER_CONTENT_TYPE
+#endif
+    ) {
+    const char *msg_name, *tls_rt_name;
+    char ssl_buf[1024];
+    int msg_type, txt_len;
+
+    /* the info given when the version is zero is not that useful for us */
+
+    ssl_ver >>= 8; /* check the upper 8 bits only below */
+
+    /* SSLv2 doesn't seem to have TLS record-type headers, so OpenSSL
+     * always pass-up content-type as 0. But the interesting message-type
+     * is at 'buf[0]'.
+     */
+    if(ssl_ver == SSL3_VERSION_MAJOR && content_type)
+      tls_rt_name = tls_rt_type(content_type);
+    else
+      tls_rt_name = "";
+
+    if(content_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
+      msg_type = *(char *)buf;
+      msg_name = "Change cipher spec";
+    }
+    else if(content_type == SSL3_RT_ALERT) {
+      msg_type = (((char *)buf)[0] << 8) + ((char *)buf)[1];
+      msg_name = SSL_alert_desc_string_long(msg_type);
+    }
+    else {
+      msg_type = *(char *)buf;
+      msg_name = ssl_msg_type(ssl_ver, msg_type);
+    }
+
+    txt_len = msnprintf(ssl_buf, sizeof(ssl_buf), "%s (%s), %s, %s (%d):\n",
+                        verstr, direction?"OUT":"IN",
+                        tls_rt_name, msg_name, msg_type);
+    if(0 <= txt_len && (unsigned)txt_len < sizeof(ssl_buf)) {
+      Curl_debug(data, CURLINFO_TEXT, ssl_buf, (size_t)txt_len);
+    }
+  }
+
+  Curl_debug(data, (direction == 1) ? CURLINFO_SSL_DATA_OUT :
+             CURLINFO_SSL_DATA_IN, (char *)buf, len);
+  (void) ssl;
+}
+#endif
+
+#ifdef USE_OPENSSL
+/* ====================================================== */
+
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+#  define use_sni(x)  sni = (x)
+#else
+#  define use_sni(x)  Curl_nop_stmt
+#endif
+
+/* Check for OpenSSL 1.0.2 which has ALPN support. */
+#undef HAS_ALPN
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L \
+    && !defined(OPENSSL_NO_TLSEXT)
+#  define HAS_ALPN 1
+#endif
+
+/* Check for OpenSSL 1.0.1 which has NPN support. */
+#undef HAS_NPN
+#if OPENSSL_VERSION_NUMBER >= 0x10001000L \
+    && !defined(OPENSSL_NO_TLSEXT) \
+    && !defined(OPENSSL_NO_NEXTPROTONEG)
+#  define HAS_NPN 1
+#endif
+
+#ifdef HAS_NPN
+
+/*
+ * in is a list of length prefixed strings. this function has to select
+ * the protocol we want to use from the list and write its string into out.
+ */
+
+static int
+select_next_protocol(unsigned char **out, unsigned char *outlen,
+                     const unsigned char *in, unsigned int inlen,
+                     const char *key, unsigned int keylen)
+{
+  unsigned int i;
+  for(i = 0; i + keylen <= inlen; i += in[i] + 1) {
+    if(memcmp(&in[i + 1], key, keylen) == 0) {
+      *out = (unsigned char *) &in[i + 1];
+      *outlen = in[i];
+      return 0;
+    }
+  }
+  return -1;
+}
+
+static int
+select_next_proto_cb(SSL *ssl,
+                     unsigned char **out, unsigned char *outlen,
+                     const unsigned char *in, unsigned int inlen,
+                     void *arg)
+{
+  struct connectdata *conn = (struct connectdata*) arg;
+
+  (void)ssl;
+
+#ifdef USE_NGHTTP2
+  if(conn->data->set.httpversion >= CURL_HTTP_VERSION_2 &&
+     !select_next_protocol(out, outlen, in, inlen, NGHTTP2_PROTO_VERSION_ID,
+                           NGHTTP2_PROTO_VERSION_ID_LEN)) {
+    infof(conn->data, "NPN, negotiated HTTP2 (%s)\n",
+          NGHTTP2_PROTO_VERSION_ID);
+    conn->negnpn = CURL_HTTP_VERSION_2;
+    return SSL_TLSEXT_ERR_OK;
+  }
+#endif
+
+  if(!select_next_protocol(out, outlen, in, inlen, ALPN_HTTP_1_1,
+                           ALPN_HTTP_1_1_LENGTH)) {
+    infof(conn->data, "NPN, negotiated HTTP1.1\n");
+    conn->negnpn = CURL_HTTP_VERSION_1_1;
+    return SSL_TLSEXT_ERR_OK;
+  }
+
+  infof(conn->data, "NPN, no overlap, use HTTP1.1\n");
+  *out = (unsigned char *)ALPN_HTTP_1_1;
+  *outlen = ALPN_HTTP_1_1_LENGTH;
+  conn->negnpn = CURL_HTTP_VERSION_1_1;
+
+  return SSL_TLSEXT_ERR_OK;
+}
+#endif /* HAS_NPN */
+
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+static const char *
+get_ssl_version_txt(SSL *ssl)
+{
+  if(!ssl)
+    return "";
+
+  switch(SSL_version(ssl)) {
+#ifdef TLS1_3_VERSION
+  case TLS1_3_VERSION:
+    return "TLSv1.3";
+#endif
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+  case TLS1_2_VERSION:
+    return "TLSv1.2";
+  case TLS1_1_VERSION:
+    return "TLSv1.1";
+#endif
+  case TLS1_VERSION:
+    return "TLSv1.0";
+  case SSL3_VERSION:
+    return "SSLv3";
+  case SSL2_VERSION:
+    return "SSLv2";
+  }
+  return "unknown";
+}
+#endif
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) /* 1.1.0 */
+static CURLcode
+set_ssl_version_min_max(SSL_CTX *ctx, struct connectdata *conn)
+{
+  /* first, TLS min version... */
+  long curl_ssl_version_min = SSL_CONN_CONFIG(version);
+  long curl_ssl_version_max;
+
+  /* convert cURL min SSL version option to OpenSSL constant */
+  long ossl_ssl_version_min = 0;
+  long ossl_ssl_version_max = 0;
+  switch(curl_ssl_version_min) {
+    case CURL_SSLVERSION_TLSv1: /* TLS 1.x */
+    case CURL_SSLVERSION_TLSv1_0:
+      ossl_ssl_version_min = TLS1_VERSION;
+      break;
+    case CURL_SSLVERSION_TLSv1_1:
+      ossl_ssl_version_min = TLS1_1_VERSION;
+      break;
+    case CURL_SSLVERSION_TLSv1_2:
+      ossl_ssl_version_min = TLS1_2_VERSION;
+      break;
+#ifdef TLS1_3_VERSION
+    case CURL_SSLVERSION_TLSv1_3:
+      ossl_ssl_version_min = TLS1_3_VERSION;
+      break;
+#endif
+  }
+
+  /* CURL_SSLVERSION_DEFAULT means that no option was selected.
+    We don't want to pass 0 to SSL_CTX_set_min_proto_version as
+    it would enable all versions down to the lowest supported by
+    the library.
+    So we skip this, and stay with the OS default
+  */
+  if(curl_ssl_version_min != CURL_SSLVERSION_DEFAULT) {
+    if(!SSL_CTX_set_min_proto_version(ctx, ossl_ssl_version_min)) {
+      return CURLE_SSL_CONNECT_ERROR;
+    }
+  }
+
+  /* ... then, TLS max version */
+  curl_ssl_version_max = SSL_CONN_CONFIG(version_max);
+
+  /* convert cURL max SSL version option to OpenSSL constant */
+  ossl_ssl_version_max = 0;
+  switch(curl_ssl_version_max) {
+    case CURL_SSLVERSION_MAX_TLSv1_0:
+      ossl_ssl_version_max = TLS1_VERSION;
+      break;
+    case CURL_SSLVERSION_MAX_TLSv1_1:
+      ossl_ssl_version_max = TLS1_1_VERSION;
+      break;
+    case CURL_SSLVERSION_MAX_TLSv1_2:
+      ossl_ssl_version_max = TLS1_2_VERSION;
+      break;
+#ifdef TLS1_3_VERSION
+    case CURL_SSLVERSION_MAX_TLSv1_3:
+      ossl_ssl_version_max = TLS1_3_VERSION;
+      break;
+#endif
+    case CURL_SSLVERSION_MAX_NONE:  /* none selected */
+    case CURL_SSLVERSION_MAX_DEFAULT:  /* max selected */
+    default:
+      /* SSL_CTX_set_max_proto_version states that:
+        setting the maximum to 0 will enable
+        protocol versions up to the highest version
+        supported by the library */
+      ossl_ssl_version_max = 0;
+      break;
+  }
+
+  if(!SSL_CTX_set_max_proto_version(ctx, ossl_ssl_version_max)) {
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  return CURLE_OK;
+}
+#endif
+
+#ifdef OPENSSL_IS_BORINGSSL
+typedef uint32_t ctx_option_t;
+#else
+typedef long ctx_option_t;
+#endif
+
+#if (OPENSSL_VERSION_NUMBER < 0x10100000L) /* 1.1.0 */
+static CURLcode
+set_ssl_version_min_max_legacy(ctx_option_t *ctx_options,
+                              struct connectdata *conn, int sockindex)
+{
+#if (OPENSSL_VERSION_NUMBER < 0x1000100FL) || !defined(TLS1_3_VERSION)
+  /* convoluted #if condition just to avoid compiler warnings on unused
+     variable */
+  struct Curl_easy *data = conn->data;
+#endif
+  long ssl_version = SSL_CONN_CONFIG(version);
+  long ssl_version_max = SSL_CONN_CONFIG(version_max);
+
+  switch(ssl_version) {
+    case CURL_SSLVERSION_TLSv1_3:
+#ifdef TLS1_3_VERSION
+    {
+      struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+      SSL_CTX_set_max_proto_version(BACKEND->ctx, TLS1_3_VERSION);
+      *ctx_options |= SSL_OP_NO_TLSv1_2;
+    }
+#else
+      (void)sockindex;
+      (void)ctx_options;
+      failf(data, OSSL_PACKAGE " was built without TLS 1.3 support");
+      return CURLE_NOT_BUILT_IN;
+#endif
+      /* FALLTHROUGH */
+    case CURL_SSLVERSION_TLSv1_2:
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+      *ctx_options |= SSL_OP_NO_TLSv1_1;
+#else
+      failf(data, OSSL_PACKAGE " was built without TLS 1.2 support");
+      return CURLE_NOT_BUILT_IN;
+#endif
+      /* FALLTHROUGH */
+    case CURL_SSLVERSION_TLSv1_1:
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+      *ctx_options |= SSL_OP_NO_TLSv1;
+#else
+      failf(data, OSSL_PACKAGE " was built without TLS 1.1 support");
+      return CURLE_NOT_BUILT_IN;
+#endif
+      /* FALLTHROUGH */
+    case CURL_SSLVERSION_TLSv1_0:
+    case CURL_SSLVERSION_TLSv1:
+      break;
+  }
+
+  switch(ssl_version_max) {
+    case CURL_SSLVERSION_MAX_TLSv1_0:
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+      *ctx_options |= SSL_OP_NO_TLSv1_1;
+#endif
+      /* FALLTHROUGH */
+    case CURL_SSLVERSION_MAX_TLSv1_1:
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+      *ctx_options |= SSL_OP_NO_TLSv1_2;
+#endif
+      /* FALLTHROUGH */
+    case CURL_SSLVERSION_MAX_TLSv1_2:
+#ifdef TLS1_3_VERSION
+      *ctx_options |= SSL_OP_NO_TLSv1_3;
+#endif
+      break;
+    case CURL_SSLVERSION_MAX_TLSv1_3:
+#ifdef TLS1_3_VERSION
+      break;
+#else
+      failf(data, OSSL_PACKAGE " was built without TLS 1.3 support");
+      return CURLE_NOT_BUILT_IN;
+#endif
+  }
+  return CURLE_OK;
+}
+#endif
+
+/* The "new session" callback must return zero if the session can be removed
+ * or non-zero if the session has been put into the session cache.
+ */
+static int ossl_new_session_cb(SSL *ssl, SSL_SESSION *ssl_sessionid)
+{
+  int res = 0;
+  struct connectdata *conn;
+  struct Curl_easy *data;
+  int sockindex;
+  curl_socket_t *sockindex_ptr;
+  int connectdata_idx = ossl_get_ssl_conn_index();
+  int sockindex_idx = ossl_get_ssl_sockindex_index();
+
+  if(connectdata_idx < 0 || sockindex_idx < 0)
+    return 0;
+
+  conn = (struct connectdata*) SSL_get_ex_data(ssl, connectdata_idx);
+  if(!conn)
+    return 0;
+
+  data = conn->data;
+
+  /* The sockindex has been stored as a pointer to an array element */
+  sockindex_ptr = (curl_socket_t*) SSL_get_ex_data(ssl, sockindex_idx);
+  sockindex = (int)(sockindex_ptr - conn->sock);
+
+  if(SSL_SET_OPTION(primary.sessionid)) {
+    bool incache;
+    void *old_ssl_sessionid = NULL;
+
+    Curl_ssl_sessionid_lock(conn);
+    incache = !(Curl_ssl_getsessionid(conn, &old_ssl_sessionid, NULL,
+                                      sockindex));
+    if(incache) {
+      if(old_ssl_sessionid != ssl_sessionid) {
+        infof(data, "old SSL session ID is stale, removing\n");
+        Curl_ssl_delsessionid(conn, old_ssl_sessionid);
+        incache = FALSE;
+      }
+    }
+
+    if(!incache) {
+      if(!Curl_ssl_addsessionid(conn, ssl_sessionid,
+                                      0 /* unknown size */, sockindex)) {
+        /* the session has been put into the session cache */
+        res = 1;
+      }
+      else
+        failf(data, "failed to store ssl session");
+    }
+    Curl_ssl_sessionid_unlock(conn);
+  }
+
+  return res;
+}
+
+static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
+{
+  CURLcode result = CURLE_OK;
+  char *ciphers;
+  struct Curl_easy *data = conn->data;
+  SSL_METHOD_QUAL SSL_METHOD *req_method = NULL;
+  X509_LOOKUP *lookup = NULL;
+  curl_socket_t sockfd = conn->sock[sockindex];
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  ctx_option_t ctx_options = 0;
+
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+  bool sni;
+  const char * const hostname = SSL_IS_PROXY() ? conn->http_proxy.host.name :
+    conn->host.name;
+#ifdef ENABLE_IPV6
+  struct in6_addr addr;
+#else
+  struct in_addr addr;
+#endif
+#endif
+  long * const certverifyresult = SSL_IS_PROXY() ?
+    &data->set.proxy_ssl.certverifyresult : &data->set.ssl.certverifyresult;
+  const long int ssl_version = SSL_CONN_CONFIG(version);
+#ifdef USE_TLS_SRP
+  const enum CURL_TLSAUTH ssl_authtype = SSL_SET_OPTION(authtype);
+#endif
+  char * const ssl_cert = SSL_SET_OPTION(cert);
+  const char * const ssl_cert_type = SSL_SET_OPTION(cert_type);
+  const char * const ssl_cafile = SSL_CONN_CONFIG(CAfile);
+  const char * const ssl_capath = SSL_CONN_CONFIG(CApath);
+  const bool verifypeer = SSL_CONN_CONFIG(verifypeer);
+  const char * const ssl_crlfile = SSL_SET_OPTION(CRLfile);
+  char error_buffer[256];
+
+  DEBUGASSERT(ssl_connect_1 == connssl->connecting_state);
+
+  /* Make funny stuff to get random input */
+  result = Curl_ossl_seed(data);
+  if(result)
+    return result;
+
+  *certverifyresult = !X509_V_OK;
+
+  /* check to see if we've been told to use an explicit SSL/TLS version */
+
+  switch(ssl_version) {
+  case CURL_SSLVERSION_DEFAULT:
+  case CURL_SSLVERSION_TLSv1:
+  case CURL_SSLVERSION_TLSv1_0:
+  case CURL_SSLVERSION_TLSv1_1:
+  case CURL_SSLVERSION_TLSv1_2:
+  case CURL_SSLVERSION_TLSv1_3:
+    /* it will be handled later with the context options */
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
+    req_method = TLS_client_method();
+#else
+    req_method = SSLv23_client_method();
+#endif
+    use_sni(TRUE);
+    break;
+  case CURL_SSLVERSION_SSLv2:
+#ifdef OPENSSL_NO_SSL2
+    failf(data, OSSL_PACKAGE " was built without SSLv2 support");
+    return CURLE_NOT_BUILT_IN;
+#else
+#ifdef USE_TLS_SRP
+    if(ssl_authtype == CURL_TLSAUTH_SRP)
+      return CURLE_SSL_CONNECT_ERROR;
+#endif
+    req_method = SSLv2_client_method();
+    use_sni(FALSE);
+    break;
+#endif
+  case CURL_SSLVERSION_SSLv3:
+#ifdef OPENSSL_NO_SSL3_METHOD
+    failf(data, OSSL_PACKAGE " was built without SSLv3 support");
+    return CURLE_NOT_BUILT_IN;
+#else
+#ifdef USE_TLS_SRP
+    if(ssl_authtype == CURL_TLSAUTH_SRP)
+      return CURLE_SSL_CONNECT_ERROR;
+#endif
+    req_method = SSLv3_client_method();
+    use_sni(FALSE);
+    break;
+#endif
+  default:
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  if(BACKEND->ctx)
+    SSL_CTX_free(BACKEND->ctx);
+  BACKEND->ctx = SSL_CTX_new(req_method);
+
+  if(!BACKEND->ctx) {
+    failf(data, "SSL: couldn't create a context: %s",
+          ossl_strerror(ERR_peek_error(), error_buffer, sizeof(error_buffer)));
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+#ifdef SSL_MODE_RELEASE_BUFFERS
+  SSL_CTX_set_mode(BACKEND->ctx, SSL_MODE_RELEASE_BUFFERS);
+#endif
+
+#ifdef SSL_CTRL_SET_MSG_CALLBACK
+  if(data->set.fdebug && data->set.verbose) {
+    /* the SSL trace callback is only used for verbose logging */
+    SSL_CTX_set_msg_callback(BACKEND->ctx, ssl_tls_trace);
+    SSL_CTX_set_msg_callback_arg(BACKEND->ctx, conn);
+  }
+#endif
+
+  /* OpenSSL contains code to work-around lots of bugs and flaws in various
+     SSL-implementations. SSL_CTX_set_options() is used to enabled those
+     work-arounds. The man page for this option states that SSL_OP_ALL enables
+     all the work-arounds and that "It is usually safe to use SSL_OP_ALL to
+     enable the bug workaround options if compatibility with somewhat broken
+     implementations is desired."
+
+     The "-no_ticket" option was introduced in Openssl0.9.8j. It's a flag to
+     disable "rfc4507bis session ticket support".  rfc4507bis was later turned
+     into the proper RFC5077 it seems: https://tools.ietf.org/html/rfc5077
+
+     The enabled extension concerns the session management. I wonder how often
+     libcurl stops a connection and then resumes a TLS session. also, sending
+     the session data is some overhead. .I suggest that you just use your
+     proposed patch (which explicitly disables TICKET).
+
+     If someone writes an application with libcurl and openssl who wants to
+     enable the feature, one can do this in the SSL callback.
+
+     SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG option enabling allowed proper
+     interoperability with web server Netscape Enterprise Server 2.0.1 which
+     was released back in 1996.
+
+     Due to CVE-2010-4180, option SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG has
+     become ineffective as of OpenSSL 0.9.8q and 1.0.0c. In order to mitigate
+     CVE-2010-4180 when using previous OpenSSL versions we no longer enable
+     this option regardless of OpenSSL version and SSL_OP_ALL definition.
+
+     OpenSSL added a work-around for a SSL 3.0/TLS 1.0 CBC vulnerability
+     (https://www.openssl.org/~bodo/tls-cbc.txt). In 0.9.6e they added a bit to
+     SSL_OP_ALL that _disables_ that work-around despite the fact that
+     SSL_OP_ALL is documented to do "rather harmless" workarounds. In order to
+     keep the secure work-around, the SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS bit
+     must not be set.
+  */
+
+  ctx_options = SSL_OP_ALL;
+
+#ifdef SSL_OP_NO_TICKET
+  ctx_options |= SSL_OP_NO_TICKET;
+#endif
+
+#ifdef SSL_OP_NO_COMPRESSION
+  ctx_options |= SSL_OP_NO_COMPRESSION;
+#endif
+
+#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
+  /* mitigate CVE-2010-4180 */
+  ctx_options &= ~SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG;
+#endif
+
+#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
+  /* unless the user explicitly ask to allow the protocol vulnerability we
+     use the work-around */
+  if(!SSL_SET_OPTION(enable_beast))
+    ctx_options &= ~SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
+#endif
+
+  switch(ssl_version) {
+    /* "--sslv2" option means SSLv2 only, disable all others */
+    case CURL_SSLVERSION_SSLv2:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L /* 1.1.0 */
+      SSL_CTX_set_min_proto_version(BACKEND->ctx, SSL2_VERSION);
+      SSL_CTX_set_max_proto_version(BACKEND->ctx, SSL2_VERSION);
+#else
+      ctx_options |= SSL_OP_NO_SSLv3;
+      ctx_options |= SSL_OP_NO_TLSv1;
+#  if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+      ctx_options |= SSL_OP_NO_TLSv1_1;
+      ctx_options |= SSL_OP_NO_TLSv1_2;
+#    ifdef TLS1_3_VERSION
+      ctx_options |= SSL_OP_NO_TLSv1_3;
+#    endif
+#  endif
+#endif
+      break;
+
+    /* "--sslv3" option means SSLv3 only, disable all others */
+    case CURL_SSLVERSION_SSLv3:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L /* 1.1.0 */
+      SSL_CTX_set_min_proto_version(BACKEND->ctx, SSL3_VERSION);
+      SSL_CTX_set_max_proto_version(BACKEND->ctx, SSL3_VERSION);
+#else
+      ctx_options |= SSL_OP_NO_SSLv2;
+      ctx_options |= SSL_OP_NO_TLSv1;
+#  if OPENSSL_VERSION_NUMBER >= 0x1000100FL
+      ctx_options |= SSL_OP_NO_TLSv1_1;
+      ctx_options |= SSL_OP_NO_TLSv1_2;
+#    ifdef TLS1_3_VERSION
+      ctx_options |= SSL_OP_NO_TLSv1_3;
+#    endif
+#  endif
+#endif
+      break;
+
+    /* "--tlsv<x.y>" options mean TLS >= version <x.y> */
+    case CURL_SSLVERSION_DEFAULT:
+    case CURL_SSLVERSION_TLSv1: /* TLS >= version 1.0 */
+    case CURL_SSLVERSION_TLSv1_0: /* TLS >= version 1.0 */
+    case CURL_SSLVERSION_TLSv1_1: /* TLS >= version 1.1 */
+    case CURL_SSLVERSION_TLSv1_2: /* TLS >= version 1.2 */
+    case CURL_SSLVERSION_TLSv1_3: /* TLS >= version 1.3 */
+      /* asking for any TLS version as the minimum, means no SSL versions
+        allowed */
+      ctx_options |= SSL_OP_NO_SSLv2;
+      ctx_options |= SSL_OP_NO_SSLv3;
+
+#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) /* 1.1.0 */
+      result = set_ssl_version_min_max(BACKEND->ctx, conn);
+#else
+      result = set_ssl_version_min_max_legacy(&ctx_options, conn, sockindex);
+#endif
+      if(result != CURLE_OK)
+        return result;
+      break;
+
+    default:
+      failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+      return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  SSL_CTX_set_options(BACKEND->ctx, ctx_options);
+
+#ifdef HAS_NPN
+  if(conn->bits.tls_enable_npn)
+    SSL_CTX_set_next_proto_select_cb(BACKEND->ctx, select_next_proto_cb, conn);
+#endif
+
+#ifdef HAS_ALPN
+  if(conn->bits.tls_enable_alpn) {
+    int cur = 0;
+    unsigned char protocols[128];
+
+#ifdef USE_NGHTTP2
+    if(data->set.httpversion >= CURL_HTTP_VERSION_2 &&
+       (!SSL_IS_PROXY() || !conn->bits.tunnel_proxy)) {
+      protocols[cur++] = NGHTTP2_PROTO_VERSION_ID_LEN;
+
+      memcpy(&protocols[cur], NGHTTP2_PROTO_VERSION_ID,
+          NGHTTP2_PROTO_VERSION_ID_LEN);
+      cur += NGHTTP2_PROTO_VERSION_ID_LEN;
+      infof(data, "ALPN, offering %s\n", NGHTTP2_PROTO_VERSION_ID);
+    }
+#endif
+
+    protocols[cur++] = ALPN_HTTP_1_1_LENGTH;
+    memcpy(&protocols[cur], ALPN_HTTP_1_1, ALPN_HTTP_1_1_LENGTH);
+    cur += ALPN_HTTP_1_1_LENGTH;
+    infof(data, "ALPN, offering %s\n", ALPN_HTTP_1_1);
+
+    /* expects length prefixed preference ordered list of protocols in wire
+     * format
+     */
+    SSL_CTX_set_alpn_protos(BACKEND->ctx, protocols, cur);
+  }
+#endif
+
+  if(ssl_cert || ssl_cert_type) {
+    if(!cert_stuff(conn, BACKEND->ctx, ssl_cert, ssl_cert_type,
+                   SSL_SET_OPTION(key), SSL_SET_OPTION(key_type),
+                   SSL_SET_OPTION(key_passwd))) {
+      /* failf() is already done in cert_stuff() */
+      return CURLE_SSL_CERTPROBLEM;
+    }
+  }
+
+  ciphers = SSL_CONN_CONFIG(cipher_list);
+  if(!ciphers)
+    ciphers = (char *)DEFAULT_CIPHER_SELECTION;
+  if(ciphers) {
+    if(!SSL_CTX_set_cipher_list(BACKEND->ctx, ciphers)) {
+      failf(data, "failed setting cipher list: %s", ciphers);
+      return CURLE_SSL_CIPHER;
+    }
+    infof(data, "Cipher selection: %s\n", ciphers);
+  }
+
+#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
+  {
+    char *ciphers13 = SSL_CONN_CONFIG(cipher_list13);
+    if(ciphers13) {
+      if(!SSL_CTX_set_ciphersuites(BACKEND->ctx, ciphers13)) {
+        failf(data, "failed setting TLS 1.3 cipher suite: %s", ciphers13);
+        return CURLE_SSL_CIPHER;
+      }
+      infof(data, "TLS 1.3 cipher selection: %s\n", ciphers13);
+    }
+  }
+#endif
+
+#ifdef HAVE_SSL_CTX_SET_POST_HANDSHAKE_AUTH
+  /* OpenSSL 1.1.1 requires clients to opt-in for PHA */
+  SSL_CTX_set_post_handshake_auth(BACKEND->ctx, 1);
+#endif
+
+#ifdef USE_TLS_SRP
+  if(ssl_authtype == CURL_TLSAUTH_SRP) {
+    char * const ssl_username = SSL_SET_OPTION(username);
+
+    infof(data, "Using TLS-SRP username: %s\n", ssl_username);
+
+    if(!SSL_CTX_set_srp_username(BACKEND->ctx, ssl_username)) {
+      failf(data, "Unable to set SRP user name");
+      return CURLE_BAD_FUNCTION_ARGUMENT;
+    }
+    if(!SSL_CTX_set_srp_password(BACKEND->ctx, SSL_SET_OPTION(password))) {
+      failf(data, "failed setting SRP password");
+      return CURLE_BAD_FUNCTION_ARGUMENT;
+    }
+    if(!SSL_CONN_CONFIG(cipher_list)) {
+      infof(data, "Setting cipher list SRP\n");
+
+      if(!SSL_CTX_set_cipher_list(BACKEND->ctx, "SRP")) {
+        failf(data, "failed setting SRP cipher list");
+        return CURLE_SSL_CIPHER;
+      }
+    }
+  }
+#endif
+
+  if(ssl_cafile || ssl_capath) {
+    /* tell SSL where to find CA certificates that are used to verify
+       the servers certificate. */
+    if(!SSL_CTX_load_verify_locations(BACKEND->ctx, ssl_cafile, ssl_capath)) {
+      if(verifypeer) {
+        /* Fail if we insist on successfully verifying the server. */
+        failf(data, "error setting certificate verify locations:\n"
+              "  CAfile: %s\n  CApath: %s",
+              ssl_cafile ? ssl_cafile : "none",
+              ssl_capath ? ssl_capath : "none");
+        return CURLE_SSL_CACERT_BADFILE;
+      }
+      /* Just continue with a warning if no strict  certificate verification
+         is required. */
+      infof(data, "error setting certificate verify locations,"
+            " continuing anyway:\n");
+    }
+    else {
+      /* Everything is fine. */
+      infof(data, "successfully set certificate verify locations:\n");
+    }
+    infof(data,
+          "  CAfile: %s\n"
+          "  CApath: %s\n",
+          ssl_cafile ? ssl_cafile : "none",
+          ssl_capath ? ssl_capath : "none");
+  }
+#ifdef CURL_CA_FALLBACK
+  else if(verifypeer) {
+    /* verifying the peer without any CA certificates won't
+       work so use openssl's built in default as fallback */
+    SSL_CTX_set_default_verify_paths(BACKEND->ctx);
+  }
+#endif
+
+  if(ssl_crlfile) {
+    /* tell SSL where to find CRL file that is used to check certificate
+     * revocation */
+    lookup = X509_STORE_add_lookup(SSL_CTX_get_cert_store(BACKEND->ctx),
+                                 X509_LOOKUP_file());
+    if(!lookup ||
+       (!X509_load_crl_file(lookup, ssl_crlfile, X509_FILETYPE_PEM)) ) {
+      failf(data, "error loading CRL file: %s", ssl_crlfile);
+      return CURLE_SSL_CRL_BADFILE;
+    }
+    /* Everything is fine. */
+    infof(data, "successfully load CRL file:\n");
+    X509_STORE_set_flags(SSL_CTX_get_cert_store(BACKEND->ctx),
+                         X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL);
+
+    infof(data, "  CRLfile: %s\n", ssl_crlfile);
+  }
+
+  /* Try building a chain using issuers in the trusted store first to avoid
+     problems with server-sent legacy intermediates.  Newer versions of
+     OpenSSL do alternate chain checking by default which gives us the same
+     fix without as much of a performance hit (slight), so we prefer that if
+     available.
+     https://rt.openssl.org/Ticket/Display.html?id=3621&user=guest&pass=guest
+  */
+#if defined(X509_V_FLAG_TRUSTED_FIRST) && !defined(X509_V_FLAG_NO_ALT_CHAINS)
+  if(verifypeer) {
+    X509_STORE_set_flags(SSL_CTX_get_cert_store(BACKEND->ctx),
+                         X509_V_FLAG_TRUSTED_FIRST);
+  }
+#endif
+
+  /* SSL always tries to verify the peer, this only says whether it should
+   * fail to connect if the verification fails, or if it should continue
+   * anyway. In the latter case the result of the verification is checked with
+   * SSL_get_verify_result() below. */
+  SSL_CTX_set_verify(BACKEND->ctx,
+                     verifypeer ? SSL_VERIFY_PEER : SSL_VERIFY_NONE, NULL);
+
+  /* Enable logging of secrets to the file specified in env SSLKEYLOGFILE. */
+#if defined(ENABLE_SSLKEYLOGFILE) && defined(HAVE_KEYLOG_CALLBACK)
+  if(keylog_file_fp) {
+    SSL_CTX_set_keylog_callback(BACKEND->ctx, ossl_keylog_callback);
+  }
+#endif
+
+  /* Enable the session cache because it's a prerequisite for the "new session"
+   * callback. Use the "external storage" mode to avoid that OpenSSL creates
+   * an internal session cache.
+   */
+  SSL_CTX_set_session_cache_mode(BACKEND->ctx,
+      SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_NO_INTERNAL);
+  SSL_CTX_sess_set_new_cb(BACKEND->ctx, ossl_new_session_cb);
+
+  /* give application a chance to interfere with SSL set up. */
+  if(data->set.ssl.fsslctx) {
+    result = (*data->set.ssl.fsslctx)(data, BACKEND->ctx,
+                                      data->set.ssl.fsslctxp);
+    if(result) {
+      failf(data, "error signaled by ssl ctx callback");
+      return result;
+    }
+  }
+
+  /* Lets make an SSL structure */
+  if(BACKEND->handle)
+    SSL_free(BACKEND->handle);
+  BACKEND->handle = SSL_new(BACKEND->ctx);
+  if(!BACKEND->handle) {
+    failf(data, "SSL: couldn't create a context (handle)!");
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+#if (OPENSSL_VERSION_NUMBER >= 0x0090808fL) && !defined(OPENSSL_NO_TLSEXT) && \
+    !defined(OPENSSL_NO_OCSP)
+  if(SSL_CONN_CONFIG(verifystatus))
+    SSL_set_tlsext_status_type(BACKEND->handle, TLSEXT_STATUSTYPE_ocsp);
+#endif
+
+#if defined(OPENSSL_IS_BORINGSSL) && defined(ALLOW_RENEG)
+  SSL_set_renegotiate_mode(BACKEND->handle, ssl_renegotiate_freely);
+#endif
+
+  SSL_set_connect_state(BACKEND->handle);
+
+  BACKEND->server_cert = 0x0;
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+  if((0 == Curl_inet_pton(AF_INET, hostname, &addr)) &&
+#ifdef ENABLE_IPV6
+     (0 == Curl_inet_pton(AF_INET6, hostname, &addr)) &&
+#endif
+     sni &&
+     !SSL_set_tlsext_host_name(BACKEND->handle, hostname))
+    infof(data, "WARNING: failed to configure server name indication (SNI) "
+          "TLS extension\n");
+#endif
+
+  /* Check if there's a cached ID we can/should use here! */
+  if(SSL_SET_OPTION(primary.sessionid)) {
+    void *ssl_sessionid = NULL;
+    int connectdata_idx = ossl_get_ssl_conn_index();
+    int sockindex_idx = ossl_get_ssl_sockindex_index();
+
+    if(connectdata_idx >= 0 && sockindex_idx >= 0) {
+      /* Store the data needed for the "new session" callback.
+       * The sockindex is stored as a pointer to an array element. */
+      SSL_set_ex_data(BACKEND->handle, connectdata_idx, conn);
+      SSL_set_ex_data(BACKEND->handle, sockindex_idx, conn->sock + sockindex);
+    }
+
+    Curl_ssl_sessionid_lock(conn);
+    if(!Curl_ssl_getsessionid(conn, &ssl_sessionid, NULL, sockindex)) {
+      /* we got a session id, use it! */
+      if(!SSL_set_session(BACKEND->handle, ssl_sessionid)) {
+        Curl_ssl_sessionid_unlock(conn);
+        failf(data, "SSL: SSL_set_session failed: %s",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)));
+        return CURLE_SSL_CONNECT_ERROR;
+      }
+      /* Informational message */
+      infof(data, "SSL re-using session ID\n");
+    }
+    Curl_ssl_sessionid_unlock(conn);
+  }
+
+  if(conn->proxy_ssl[sockindex].use) {
+    BIO *const bio = BIO_new(BIO_f_ssl());
+    SSL *handle = conn->proxy_ssl[sockindex].backend->handle;
+    DEBUGASSERT(ssl_connection_complete == conn->proxy_ssl[sockindex].state);
+    DEBUGASSERT(handle != NULL);
+    DEBUGASSERT(bio != NULL);
+    BIO_set_ssl(bio, handle, FALSE);
+    SSL_set_bio(BACKEND->handle, bio, bio);
+  }
+  else if(!SSL_set_fd(BACKEND->handle, (int)sockfd)) {
+    /* pass the raw socket into the SSL layers */
+    failf(data, "SSL: SSL_set_fd failed: %s",
+          ossl_strerror(ERR_get_error(), error_buffer, sizeof(error_buffer)));
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  connssl->connecting_state = ssl_connect_2;
+
+  return CURLE_OK;
+}
+
+static CURLcode ossl_connect_step2(struct connectdata *conn, int sockindex)
+{
+  struct Curl_easy *data = conn->data;
+  int err;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  long * const certverifyresult = SSL_IS_PROXY() ?
+    &data->set.proxy_ssl.certverifyresult : &data->set.ssl.certverifyresult;
+  DEBUGASSERT(ssl_connect_2 == connssl->connecting_state
+              || ssl_connect_2_reading == connssl->connecting_state
+              || ssl_connect_2_writing == connssl->connecting_state);
+
+  ERR_clear_error();
+
+  err = SSL_connect(BACKEND->handle);
+  /* If keylogging is enabled but the keylog callback is not supported then log
+     secrets here, immediately after SSL_connect by using tap_ssl_key. */
+#if defined(ENABLE_SSLKEYLOGFILE) && !defined(HAVE_KEYLOG_CALLBACK)
+  tap_ssl_key(BACKEND->handle, &BACKEND->tap_state);
+#endif
+
+  /* 1  is fine
+     0  is "not successful but was shut down controlled"
+     <0 is "handshake was not successful, because a fatal error occurred" */
+  if(1 != err) {
+    int detail = SSL_get_error(BACKEND->handle, err);
+
+    if(SSL_ERROR_WANT_READ == detail) {
+      connssl->connecting_state = ssl_connect_2_reading;
+      return CURLE_OK;
+    }
+    if(SSL_ERROR_WANT_WRITE == detail) {
+      connssl->connecting_state = ssl_connect_2_writing;
+      return CURLE_OK;
+    }
+#ifdef SSL_ERROR_WANT_ASYNC
+    if(SSL_ERROR_WANT_ASYNC == detail) {
+      connssl->connecting_state = ssl_connect_2;
+      return CURLE_OK;
+    }
+#endif
+    else {
+      /* untreated error */
+      unsigned long errdetail;
+      char error_buffer[256]="";
+      CURLcode result;
+      long lerr;
+      int lib;
+      int reason;
+
+      /* the connection failed, we're not waiting for anything else. */
+      connssl->connecting_state = ssl_connect_2;
+
+      /* Get the earliest error code from the thread's error queue and removes
+         the entry. */
+      errdetail = ERR_get_error();
+
+      /* Extract which lib and reason */
+      lib = ERR_GET_LIB(errdetail);
+      reason = ERR_GET_REASON(errdetail);
+
+      if((lib == ERR_LIB_SSL) &&
+         (reason == SSL_R_CERTIFICATE_VERIFY_FAILED)) {
+        result = CURLE_PEER_FAILED_VERIFICATION;
+
+        lerr = SSL_get_verify_result(BACKEND->handle);
+        if(lerr != X509_V_OK) {
+          *certverifyresult = lerr;
+          msnprintf(error_buffer, sizeof(error_buffer),
+                    "SSL certificate problem: %s",
+                    X509_verify_cert_error_string(lerr));
+        }
+        else
+          /* strcpy() is fine here as long as the string fits within
+             error_buffer */
+          strcpy(error_buffer, "SSL certificate verification failed");
+      }
+      else {
+        result = CURLE_SSL_CONNECT_ERROR;
+        ossl_strerror(errdetail, error_buffer, sizeof(error_buffer));
+      }
+
+      /* detail is already set to the SSL error above */
+
+      /* If we e.g. use SSLv2 request-method and the server doesn't like us
+       * (RST connection etc.), OpenSSL gives no explanation whatsoever and
+       * the SO_ERROR is also lost.
+       */
+      if(CURLE_SSL_CONNECT_ERROR == result && errdetail == 0) {
+        const char * const hostname = SSL_IS_PROXY() ?
+          conn->http_proxy.host.name : conn->host.name;
+        const long int port = SSL_IS_PROXY() ? conn->port : conn->remote_port;
+        failf(data, OSSL_PACKAGE " SSL_connect: %s in connection to %s:%ld ",
+              SSL_ERROR_to_str(detail), hostname, port);
+        return result;
+      }
+
+      /* Could be a CERT problem */
+      failf(data, "%s", error_buffer);
+
+      return result;
+    }
+  }
+  else {
+    /* we have been connected fine, we're not waiting for anything else. */
+    connssl->connecting_state = ssl_connect_3;
+
+    /* Informational message */
+    infof(data, "SSL connection using %s / %s\n",
+          get_ssl_version_txt(BACKEND->handle),
+          SSL_get_cipher(BACKEND->handle));
+
+#ifdef HAS_ALPN
+    /* Sets data and len to negotiated protocol, len is 0 if no protocol was
+     * negotiated
+     */
+    if(conn->bits.tls_enable_alpn) {
+      const unsigned char *neg_protocol;
+      unsigned int len;
+      SSL_get0_alpn_selected(BACKEND->handle, &neg_protocol, &len);
+      if(len != 0) {
+        infof(data, "ALPN, server accepted to use %.*s\n", len, neg_protocol);
+
+#ifdef USE_NGHTTP2
+        if(len == NGHTTP2_PROTO_VERSION_ID_LEN &&
+           !memcmp(NGHTTP2_PROTO_VERSION_ID, neg_protocol, len)) {
+          conn->negnpn = CURL_HTTP_VERSION_2;
+        }
+        else
+#endif
+        if(len == ALPN_HTTP_1_1_LENGTH &&
+           !memcmp(ALPN_HTTP_1_1, neg_protocol, ALPN_HTTP_1_1_LENGTH)) {
+          conn->negnpn = CURL_HTTP_VERSION_1_1;
+        }
+      }
+      else
+        infof(data, "ALPN, server did not agree to a protocol\n");
+
+      Curl_multiuse_state(conn, conn->negnpn == CURL_HTTP_VERSION_2 ?
+                          BUNDLE_MULTIPLEX : BUNDLE_NO_MULTIUSE);
+    }
+#endif
+
+    return CURLE_OK;
+  }
+}
+
+static int asn1_object_dump(ASN1_OBJECT *a, char *buf, size_t len)
+{
+  int i, ilen;
+
+  ilen = (int)len;
+  if(ilen < 0)
+    return 1; /* buffer too big */
+
+  i = i2t_ASN1_OBJECT(buf, ilen, a);
+
+  if(i >= ilen)
+    return 1; /* buffer too small */
+
+  return 0;
+}
+
+#define push_certinfo(_label, _num) \
+do {                              \
+  long info_len = BIO_get_mem_data(mem, &ptr); \
+  Curl_ssl_push_certinfo_len(data, _num, _label, ptr, info_len); \
+  if(1 != BIO_reset(mem))                                        \
+    break;                                                       \
+} WHILE_FALSE
+
+static void pubkey_show(struct Curl_easy *data,
+                        BIO *mem,
+                        int num,
+                        const char *type,
+                        const char *name,
+#ifdef HAVE_OPAQUE_RSA_DSA_DH
+                        const
+#endif
+                        BIGNUM *bn)
+{
+  char *ptr;
+  char namebuf[32];
+
+  msnprintf(namebuf, sizeof(namebuf), "%s(%s)", type, name);
+
+  if(bn)
+    BN_print(mem, bn);
+  push_certinfo(namebuf, num);
+}
+
+#ifdef HAVE_OPAQUE_RSA_DSA_DH
+#define print_pubkey_BN(_type, _name, _num)              \
+  pubkey_show(data, mem, _num, #_type, #_name, _name)
+
+#else
+#define print_pubkey_BN(_type, _name, _num)    \
+do {                              \
+  if(_type->_name) { \
+    pubkey_show(data, mem, _num, #_type, #_name, _type->_name); \
+  } \
+} WHILE_FALSE
+#endif
+
+static int X509V3_ext(struct Curl_easy *data,
+                      int certnum,
+                      CONST_EXTS STACK_OF(X509_EXTENSION) *exts)
+{
+  int i;
+  size_t j;
+
+  if((int)sk_X509_EXTENSION_num(exts) <= 0)
+    /* no extensions, bail out */
+    return 1;
+
+  for(i = 0; i < (int)sk_X509_EXTENSION_num(exts); i++) {
+    ASN1_OBJECT *obj;
+    X509_EXTENSION *ext = sk_X509_EXTENSION_value(exts, i);
+    BUF_MEM *biomem;
+    char buf[512];
+    char *ptr = buf;
+    char namebuf[128];
+    BIO *bio_out = BIO_new(BIO_s_mem());
+
+    if(!bio_out)
+      return 1;
+
+    obj = X509_EXTENSION_get_object(ext);
+
+    asn1_object_dump(obj, namebuf, sizeof(namebuf));
+
+    if(!X509V3_EXT_print(bio_out, ext, 0, 0))
+      ASN1_STRING_print(bio_out, (ASN1_STRING *)X509_EXTENSION_get_data(ext));
+
+    BIO_get_mem_ptr(bio_out, &biomem);
+
+    for(j = 0; j < (size_t)biomem->length; j++) {
+      const char *sep = "";
+      if(biomem->data[j] == '\n') {
+        sep = ", ";
+        j++; /* skip the newline */
+      };
+      while((j<(size_t)biomem->length) && (biomem->data[j] == ' '))
+        j++;
+      if(j<(size_t)biomem->length)
+        ptr += msnprintf(ptr, sizeof(buf)-(ptr-buf), "%s%c", sep,
+                         biomem->data[j]);
+    }
+
+    Curl_ssl_push_certinfo(data, certnum, namebuf, buf);
+
+    BIO_free(bio_out);
+
+  }
+  return 0; /* all is fine */
+}
+
+#ifdef OPENSSL_IS_BORINGSSL
+typedef size_t numcert_t;
+#else
+typedef int numcert_t;
+#endif
+
+static CURLcode get_cert_chain(struct connectdata *conn,
+                               struct ssl_connect_data *connssl)
+
+{
+  CURLcode result;
+  STACK_OF(X509) *sk;
+  int i;
+  struct Curl_easy *data = conn->data;
+  numcert_t numcerts;
+  BIO *mem;
+
+  sk = SSL_get_peer_cert_chain(BACKEND->handle);
+  if(!sk) {
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  numcerts = sk_X509_num(sk);
+
+  result = Curl_ssl_init_certinfo(data, (int)numcerts);
+  if(result) {
+    return result;
+  }
+
+  mem = BIO_new(BIO_s_mem());
+
+  for(i = 0; i < (int)numcerts; i++) {
+    ASN1_INTEGER *num;
+    X509 *x = sk_X509_value(sk, i);
+    EVP_PKEY *pubkey = NULL;
+    int j;
+    char *ptr;
+    const ASN1_BIT_STRING *psig = NULL;
+
+    X509_NAME_print_ex(mem, X509_get_subject_name(x), 0, XN_FLAG_ONELINE);
+    push_certinfo("Subject", i);
+
+    X509_NAME_print_ex(mem, X509_get_issuer_name(x), 0, XN_FLAG_ONELINE);
+    push_certinfo("Issuer", i);
+
+    BIO_printf(mem, "%lx", X509_get_version(x));
+    push_certinfo("Version", i);
+
+    num = X509_get_serialNumber(x);
+    if(num->type == V_ASN1_NEG_INTEGER)
+      BIO_puts(mem, "-");
+    for(j = 0; j < num->length; j++)
+      BIO_printf(mem, "%02x", num->data[j]);
+    push_certinfo("Serial Number", i);
+
+#if defined(HAVE_X509_GET0_SIGNATURE) && defined(HAVE_X509_GET0_EXTENSIONS)
+    {
+      const X509_ALGOR *sigalg = NULL;
+      X509_PUBKEY *xpubkey = NULL;
+      ASN1_OBJECT *pubkeyoid = NULL;
+
+      X509_get0_signature(&psig, &sigalg, x);
+      if(sigalg) {
+        i2a_ASN1_OBJECT(mem, sigalg->algorithm);
+        push_certinfo("Signature Algorithm", i);
+      }
+
+      xpubkey = X509_get_X509_PUBKEY(x);
+      if(xpubkey) {
+        X509_PUBKEY_get0_param(&pubkeyoid, NULL, NULL, NULL, xpubkey);
+        if(pubkeyoid) {
+          i2a_ASN1_OBJECT(mem, pubkeyoid);
+          push_certinfo("Public Key Algorithm", i);
+        }
+      }
+
+      X509V3_ext(data, i, X509_get0_extensions(x));
+    }
+#else
+    {
+      /* before OpenSSL 1.0.2 */
+      X509_CINF *cinf = x->cert_info;
+
+      i2a_ASN1_OBJECT(mem, cinf->signature->algorithm);
+      push_certinfo("Signature Algorithm", i);
+
+      i2a_ASN1_OBJECT(mem, cinf->key->algor->algorithm);
+      push_certinfo("Public Key Algorithm", i);
+
+      X509V3_ext(data, i, cinf->extensions);
+
+      psig = x->signature;
+    }
+#endif
+
+    ASN1_TIME_print(mem, X509_get0_notBefore(x));
+    push_certinfo("Start date", i);
+
+    ASN1_TIME_print(mem, X509_get0_notAfter(x));
+    push_certinfo("Expire date", i);
+
+    pubkey = X509_get_pubkey(x);
+    if(!pubkey)
+      infof(data, "   Unable to load public key\n");
+    else {
+      int pktype;
+#ifdef HAVE_OPAQUE_EVP_PKEY
+      pktype = EVP_PKEY_id(pubkey);
+#else
+      pktype = pubkey->type;
+#endif
+      switch(pktype) {
+      case EVP_PKEY_RSA:
+      {
+        RSA *rsa;
+#ifdef HAVE_OPAQUE_EVP_PKEY
+        rsa = EVP_PKEY_get0_RSA(pubkey);
+#else
+        rsa = pubkey->pkey.rsa;
+#endif
+
+#ifdef HAVE_OPAQUE_RSA_DSA_DH
+        {
+          const BIGNUM *n;
+          const BIGNUM *e;
+
+          RSA_get0_key(rsa, &n, &e, NULL);
+          BIO_printf(mem, "%d", BN_num_bits(n));
+          push_certinfo("RSA Public Key", i);
+          print_pubkey_BN(rsa, n, i);
+          print_pubkey_BN(rsa, e, i);
+        }
+#else
+        BIO_printf(mem, "%d", BN_num_bits(rsa->n));
+        push_certinfo("RSA Public Key", i);
+        print_pubkey_BN(rsa, n, i);
+        print_pubkey_BN(rsa, e, i);
+#endif
+
+        break;
+      }
+      case EVP_PKEY_DSA:
+      {
+#ifndef OPENSSL_NO_DSA
+        DSA *dsa;
+#ifdef HAVE_OPAQUE_EVP_PKEY
+        dsa = EVP_PKEY_get0_DSA(pubkey);
+#else
+        dsa = pubkey->pkey.dsa;
+#endif
+#ifdef HAVE_OPAQUE_RSA_DSA_DH
+        {
+          const BIGNUM *p;
+          const BIGNUM *q;
+          const BIGNUM *g;
+          const BIGNUM *pub_key;
+
+          DSA_get0_pqg(dsa, &p, &q, &g);
+          DSA_get0_key(dsa, &pub_key, NULL);
+
+          print_pubkey_BN(dsa, p, i);
+          print_pubkey_BN(dsa, q, i);
+          print_pubkey_BN(dsa, g, i);
+          print_pubkey_BN(dsa, pub_key, i);
+        }
+#else
+        print_pubkey_BN(dsa, p, i);
+        print_pubkey_BN(dsa, q, i);
+        print_pubkey_BN(dsa, g, i);
+        print_pubkey_BN(dsa, pub_key, i);
+#endif
+#endif /* !OPENSSL_NO_DSA */
+        break;
+      }
+      case EVP_PKEY_DH:
+      {
+        DH *dh;
+#ifdef HAVE_OPAQUE_EVP_PKEY
+        dh = EVP_PKEY_get0_DH(pubkey);
+#else
+        dh = pubkey->pkey.dh;
+#endif
+#ifdef HAVE_OPAQUE_RSA_DSA_DH
+        {
+          const BIGNUM *p;
+          const BIGNUM *q;
+          const BIGNUM *g;
+          const BIGNUM *pub_key;
+          DH_get0_pqg(dh, &p, &q, &g);
+          DH_get0_key(dh, &pub_key, NULL);
+          print_pubkey_BN(dh, p, i);
+          print_pubkey_BN(dh, q, i);
+          print_pubkey_BN(dh, g, i);
+          print_pubkey_BN(dh, pub_key, i);
+       }
+#else
+        print_pubkey_BN(dh, p, i);
+        print_pubkey_BN(dh, g, i);
+        print_pubkey_BN(dh, pub_key, i);
+#endif
+        break;
+      }
+      }
+      EVP_PKEY_free(pubkey);
+    }
+
+    if(psig) {
+      for(j = 0; j < psig->length; j++)
+        BIO_printf(mem, "%02x:", psig->data[j]);
+      push_certinfo("Signature", i);
+    }
+
+    PEM_write_bio_X509(mem, x);
+    push_certinfo("Cert", i);
+  }
+
+  BIO_free(mem);
+
+  return CURLE_OK;
+}
+
+/*
+ * Heavily modified from:
+ * https://www.owasp.org/index.php/Certificate_and_Public_Key_Pinning#OpenSSL
+ */
+static CURLcode pkp_pin_peer_pubkey(struct Curl_easy *data, X509* cert,
+                                    const char *pinnedpubkey)
+{
+  /* Scratch */
+  int len1 = 0, len2 = 0;
+  unsigned char *buff1 = NULL, *temp = NULL;
+
+  /* Result is returned to caller */
+  CURLcode result = CURLE_SSL_PINNEDPUBKEYNOTMATCH;
+
+  /* if a path wasn't specified, don't pin */
+  if(!pinnedpubkey)
+    return CURLE_OK;
+
+  if(!cert)
+    return result;
+
+  do {
+    /* Begin Gyrations to get the subjectPublicKeyInfo     */
+    /* Thanks to Viktor Dukhovni on the OpenSSL mailing list */
+
+    /* https://groups.google.com/group/mailing.openssl.users/browse_thread
+     /thread/d61858dae102c6c7 */
+    len1 = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), NULL);
+    if(len1 < 1)
+      break; /* failed */
+
+    buff1 = temp = malloc(len1);
+    if(!buff1)
+      break; /* failed */
+
+    /* https://www.openssl.org/docs/crypto/d2i_X509.html */
+    len2 = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &temp);
+
+    /*
+     * These checks are verifying we got back the same values as when we
+     * sized the buffer. It's pretty weak since they should always be the
+     * same. But it gives us something to test.
+     */
+    if((len1 != len2) || !temp || ((temp - buff1) != len1))
+      break; /* failed */
+
+    /* End Gyrations */
+
+    /* The one good exit point */
+    result = Curl_pin_peer_pubkey(data, pinnedpubkey, buff1, len1);
+  } while(0);
+
+  if(buff1)
+    free(buff1);
+
+  return result;
+}
+
+/*
+ * Get the server cert, verify it and show it etc, only call failf() if the
+ * 'strict' argument is TRUE as otherwise all this is for informational
+ * purposes only!
+ *
+ * We check certificates to authenticate the server; otherwise we risk
+ * man-in-the-middle attack.
+ */
+static CURLcode servercert(struct connectdata *conn,
+                           struct ssl_connect_data *connssl,
+                           bool strict)
+{
+  CURLcode result = CURLE_OK;
+  int rc;
+  long lerr;
+  struct Curl_easy *data = conn->data;
+  X509 *issuer;
+  BIO *fp = NULL;
+  char error_buffer[256]="";
+  char buffer[2048];
+  const char *ptr;
+  long * const certverifyresult = SSL_IS_PROXY() ?
+    &data->set.proxy_ssl.certverifyresult : &data->set.ssl.certverifyresult;
+  BIO *mem = BIO_new(BIO_s_mem());
+
+  if(data->set.ssl.certinfo)
+    /* we've been asked to gather certificate info! */
+    (void)get_cert_chain(conn, connssl);
+
+  BACKEND->server_cert = SSL_get_peer_certificate(BACKEND->handle);
+  if(!BACKEND->server_cert) {
+    BIO_free(mem);
+    if(!strict)
+      return CURLE_OK;
+
+    failf(data, "SSL: couldn't get peer certificate!");
+    return CURLE_PEER_FAILED_VERIFICATION;
+  }
+
+  infof(data, "%s certificate:\n", SSL_IS_PROXY() ? "Proxy" : "Server");
+
+  rc = x509_name_oneline(X509_get_subject_name(BACKEND->server_cert),
+                         buffer, sizeof(buffer));
+  infof(data, " subject: %s\n", rc?"[NONE]":buffer);
+
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+  {
+    long len;
+    ASN1_TIME_print(mem, X509_get0_notBefore(BACKEND->server_cert));
+    len = BIO_get_mem_data(mem, (char **) &ptr);
+    infof(data, " start date: %.*s\n", len, ptr);
+    (void)BIO_reset(mem);
+
+    ASN1_TIME_print(mem, X509_get0_notAfter(BACKEND->server_cert));
+    len = BIO_get_mem_data(mem, (char **) &ptr);
+    infof(data, " expire date: %.*s\n", len, ptr);
+    (void)BIO_reset(mem);
+  }
+#endif
+
+  BIO_free(mem);
+
+  if(SSL_CONN_CONFIG(verifyhost)) {
+    result = verifyhost(conn, BACKEND->server_cert);
+    if(result) {
+      X509_free(BACKEND->server_cert);
+      BACKEND->server_cert = NULL;
+      return result;
+    }
+  }
+
+  rc = x509_name_oneline(X509_get_issuer_name(BACKEND->server_cert),
+                         buffer, sizeof(buffer));
+  if(rc) {
+    if(strict)
+      failf(data, "SSL: couldn't get X509-issuer name!");
+    result = CURLE_PEER_FAILED_VERIFICATION;
+  }
+  else {
+    infof(data, " issuer: %s\n", buffer);
+
+    /* We could do all sorts of certificate verification stuff here before
+       deallocating the certificate. */
+
+    /* e.g. match issuer name with provided issuer certificate */
+    if(SSL_SET_OPTION(issuercert)) {
+      fp = BIO_new(BIO_s_file());
+      if(fp == NULL) {
+        failf(data,
+              "BIO_new return NULL, " OSSL_PACKAGE
+              " error %s",
+              ossl_strerror(ERR_get_error(), error_buffer,
+                            sizeof(error_buffer)) );
+        X509_free(BACKEND->server_cert);
+        BACKEND->server_cert = NULL;
+        return CURLE_OUT_OF_MEMORY;
+      }
+
+      if(BIO_read_filename(fp, SSL_SET_OPTION(issuercert)) <= 0) {
+        if(strict)
+          failf(data, "SSL: Unable to open issuer cert (%s)",
+                SSL_SET_OPTION(issuercert));
+        BIO_free(fp);
+        X509_free(BACKEND->server_cert);
+        BACKEND->server_cert = NULL;
+        return CURLE_SSL_ISSUER_ERROR;
+      }
+
+      issuer = PEM_read_bio_X509(fp, NULL, ZERO_NULL, NULL);
+      if(!issuer) {
+        if(strict)
+          failf(data, "SSL: Unable to read issuer cert (%s)",
+                SSL_SET_OPTION(issuercert));
+        BIO_free(fp);
+        X509_free(issuer);
+        X509_free(BACKEND->server_cert);
+        BACKEND->server_cert = NULL;
+        return CURLE_SSL_ISSUER_ERROR;
+      }
+
+      if(X509_check_issued(issuer, BACKEND->server_cert) != X509_V_OK) {
+        if(strict)
+          failf(data, "SSL: Certificate issuer check failed (%s)",
+                SSL_SET_OPTION(issuercert));
+        BIO_free(fp);
+        X509_free(issuer);
+        X509_free(BACKEND->server_cert);
+        BACKEND->server_cert = NULL;
+        return CURLE_SSL_ISSUER_ERROR;
+      }
+
+      infof(data, " SSL certificate issuer check ok (%s)\n",
+            SSL_SET_OPTION(issuercert));
+      BIO_free(fp);
+      X509_free(issuer);
+    }
+
+    lerr = *certverifyresult = SSL_get_verify_result(BACKEND->handle);
+
+    if(*certverifyresult != X509_V_OK) {
+      if(SSL_CONN_CONFIG(verifypeer)) {
+        /* We probably never reach this, because SSL_connect() will fail
+           and we return earlier if verifypeer is set? */
+        if(strict)
+          failf(data, "SSL certificate verify result: %s (%ld)",
+                X509_verify_cert_error_string(lerr), lerr);
+        result = CURLE_PEER_FAILED_VERIFICATION;
+      }
+      else
+        infof(data, " SSL certificate verify result: %s (%ld),"
+              " continuing anyway.\n",
+              X509_verify_cert_error_string(lerr), lerr);
+    }
+    else
+      infof(data, " SSL certificate verify ok.\n");
+  }
+
+#if (OPENSSL_VERSION_NUMBER >= 0x0090808fL) && !defined(OPENSSL_NO_TLSEXT) && \
+    !defined(OPENSSL_NO_OCSP)
+  if(SSL_CONN_CONFIG(verifystatus)) {
+    result = verifystatus(conn, connssl);
+    if(result) {
+      X509_free(BACKEND->server_cert);
+      BACKEND->server_cert = NULL;
+      return result;
+    }
+  }
+#endif
+
+  if(!strict)
+    /* when not strict, we don't bother about the verify cert problems */
+    result = CURLE_OK;
+
+  ptr = SSL_IS_PROXY() ? data->set.str[STRING_SSL_PINNEDPUBLICKEY_PROXY] :
+                         data->set.str[STRING_SSL_PINNEDPUBLICKEY_ORIG];
+  if(!result && ptr) {
+    result = pkp_pin_peer_pubkey(data, BACKEND->server_cert, ptr);
+    if(result)
+      failf(data, "SSL: public key does not match pinned public key!");
+  }
+
+  X509_free(BACKEND->server_cert);
+  BACKEND->server_cert = NULL;
+  connssl->connecting_state = ssl_connect_done;
+
+  return result;
+}
+
+static CURLcode ossl_connect_step3(struct connectdata *conn, int sockindex)
+{
+  CURLcode result = CURLE_OK;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+
+  DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
+
+  /*
+   * We check certificates to authenticate the server; otherwise we risk
+   * man-in-the-middle attack; NEVERTHELESS, if we're told explicitly not to
+   * verify the peer ignore faults and failures from the server cert
+   * operations.
+   */
+
+  result = servercert(conn, connssl, (SSL_CONN_CONFIG(verifypeer) ||
+                                      SSL_CONN_CONFIG(verifyhost)));
+
+  if(!result)
+    connssl->connecting_state = ssl_connect_done;
+
+  return result;
+}
+
+static Curl_recv ossl_recv;
+static Curl_send ossl_send;
+
+static CURLcode ossl_connect_common(struct connectdata *conn,
+                                    int sockindex,
+                                    bool nonblocking,
+                                    bool *done)
+{
+  CURLcode result;
+  struct Curl_easy *data = conn->data;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  curl_socket_t sockfd = conn->sock[sockindex];
+  time_t timeout_ms;
+  int what;
+
+  /* check if the connection has already been established */
+  if(ssl_connection_complete == connssl->state) {
+    *done = TRUE;
+    return CURLE_OK;
+  }
+
+  if(ssl_connect_1 == connssl->connecting_state) {
+    /* Find out how much more time we're allowed */
+    timeout_ms = Curl_timeleft(data, NULL, TRUE);
+
+    if(timeout_ms < 0) {
+      /* no need to continue if time already is up */
+      failf(data, "SSL connection timeout");
+      return CURLE_OPERATION_TIMEDOUT;
+    }
+
+    result = ossl_connect_step1(conn, sockindex);
+    if(result)
+      return result;
+  }
+
+  while(ssl_connect_2 == connssl->connecting_state ||
+        ssl_connect_2_reading == connssl->connecting_state ||
+        ssl_connect_2_writing == connssl->connecting_state) {
+
+    /* check allowed time left */
+    timeout_ms = Curl_timeleft(data, NULL, TRUE);
+
+    if(timeout_ms < 0) {
+      /* no need to continue if time already is up */
+      failf(data, "SSL connection timeout");
+      return CURLE_OPERATION_TIMEDOUT;
+    }
+
+    /* if ssl is expecting something, check if it's available. */
+    if(connssl->connecting_state == ssl_connect_2_reading ||
+       connssl->connecting_state == ssl_connect_2_writing) {
+
+      curl_socket_t writefd = ssl_connect_2_writing ==
+        connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
+      curl_socket_t readfd = ssl_connect_2_reading ==
+        connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
+
+      what = Curl_socket_check(readfd, CURL_SOCKET_BAD, writefd,
+                               nonblocking?0:timeout_ms);
+      if(what < 0) {
+        /* fatal error */
+        failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
+        return CURLE_SSL_CONNECT_ERROR;
+      }
+      if(0 == what) {
+        if(nonblocking) {
+          *done = FALSE;
+          return CURLE_OK;
+        }
+        /* timeout */
+        failf(data, "SSL connection timeout");
+        return CURLE_OPERATION_TIMEDOUT;
+      }
+      /* socket is readable or writable */
+    }
+
+    /* Run transaction, and return to the caller if it failed or if this
+     * connection is done nonblocking and this loop would execute again. This
+     * permits the owner of a multi handle to abort a connection attempt
+     * before step2 has completed while ensuring that a client using select()
+     * or epoll() will always have a valid fdset to wait on.
+     */
+    result = ossl_connect_step2(conn, sockindex);
+    if(result || (nonblocking &&
+                  (ssl_connect_2 == connssl->connecting_state ||
+                   ssl_connect_2_reading == connssl->connecting_state ||
+                   ssl_connect_2_writing == connssl->connecting_state)))
+      return result;
+
+  } /* repeat step2 until all transactions are done. */
+
+  if(ssl_connect_3 == connssl->connecting_state) {
+    result = ossl_connect_step3(conn, sockindex);
+    if(result)
+      return result;
+  }
+
+  if(ssl_connect_done == connssl->connecting_state) {
+    connssl->state = ssl_connection_complete;
+    conn->recv[sockindex] = ossl_recv;
+    conn->send[sockindex] = ossl_send;
+    *done = TRUE;
+  }
+  else
+    *done = FALSE;
+
+  /* Reset our connect state machine */
+  connssl->connecting_state = ssl_connect_1;
+
+  return CURLE_OK;
+}
+
+static CURLcode Curl_ossl_connect_nonblocking(struct connectdata *conn,
+                                              int sockindex,
+                                              bool *done)
+{
+  return ossl_connect_common(conn, sockindex, TRUE, done);
+}
+
+static CURLcode Curl_ossl_connect(struct connectdata *conn, int sockindex)
+{
+  CURLcode result;
+  bool done = FALSE;
+
+  result = ossl_connect_common(conn, sockindex, FALSE, &done);
+  if(result)
+    return result;
+
+  DEBUGASSERT(done);
+
+  return CURLE_OK;
+}
+
+static bool Curl_ossl_data_pending(const struct connectdata *conn,
+                                   int connindex)
+{
+  const struct ssl_connect_data *connssl = &conn->ssl[connindex];
+  const struct ssl_connect_data *proxyssl = &conn->proxy_ssl[connindex];
+
+  if(connssl->backend->handle && SSL_pending(connssl->backend->handle))
+    return TRUE;
+
+  if(proxyssl->backend->handle && SSL_pending(proxyssl->backend->handle))
+    return TRUE;
+
+  return FALSE;
+}
+
+static size_t Curl_ossl_version(char *buffer, size_t size);
+
+static ssize_t ossl_send(struct connectdata *conn,
+                         int sockindex,
+                         const void *mem,
+                         size_t len,
+                         CURLcode *curlcode)
+{
+  /* SSL_write() is said to return 'int' while write() and send() returns
+     'size_t' */
+  int err;
+  char error_buffer[256];
+  unsigned long sslerror;
+  int memlen;
+  int rc;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+
+  ERR_clear_error();
+
+  memlen = (len > (size_t)INT_MAX) ? INT_MAX : (int)len;
+  rc = SSL_write(BACKEND->handle, mem, memlen);
+
+  if(rc <= 0) {
+    err = SSL_get_error(BACKEND->handle, rc);
+
+    switch(err) {
+    case SSL_ERROR_WANT_READ:
+    case SSL_ERROR_WANT_WRITE:
+      /* The operation did not complete; the same TLS/SSL I/O function
+         should be called again later. This is basically an EWOULDBLOCK
+         equivalent. */
+      *curlcode = CURLE_AGAIN;
+      return -1;
+    case SSL_ERROR_SYSCALL:
+      failf(conn->data, "SSL_write() returned SYSCALL, errno = %d",
+            SOCKERRNO);
+      *curlcode = CURLE_SEND_ERROR;
+      return -1;
+    case SSL_ERROR_SSL:
+      /*  A failure in the SSL library occurred, usually a protocol error.
+          The OpenSSL error queue contains more information on the error. */
+      sslerror = ERR_get_error();
+      if(ERR_GET_LIB(sslerror) == ERR_LIB_SSL &&
+         ERR_GET_REASON(sslerror) == SSL_R_BIO_NOT_SET &&
+         conn->ssl[sockindex].state == ssl_connection_complete &&
+         conn->proxy_ssl[sockindex].state == ssl_connection_complete) {
+        char ver[120];
+        Curl_ossl_version(ver, 120);
+        failf(conn->data, "Error: %s does not support double SSL tunneling.",
+              ver);
+      }
+      else
+        failf(conn->data, "SSL_write() error: %s",
+              ossl_strerror(sslerror, error_buffer, sizeof(error_buffer)));
+      *curlcode = CURLE_SEND_ERROR;
+      return -1;
+    }
+    /* a true error */
+    failf(conn->data, OSSL_PACKAGE " SSL_write: %s, errno %d",
+          SSL_ERROR_to_str(err), SOCKERRNO);
+    *curlcode = CURLE_SEND_ERROR;
+    return -1;
+  }
+  *curlcode = CURLE_OK;
+  return (ssize_t)rc; /* number of bytes */
+}
+
+static ssize_t ossl_recv(struct connectdata *conn, /* connection data */
+                         int num,                  /* socketindex */
+                         char *buf,                /* store read data here */
+                         size_t buffersize,        /* max amount to read */
+                         CURLcode *curlcode)
+{
+  char error_buffer[256];
+  unsigned long sslerror;
+  ssize_t nread;
+  int buffsize;
+  struct ssl_connect_data *connssl = &conn->ssl[num];
+
+  ERR_clear_error();
+
+  buffsize = (buffersize > (size_t)INT_MAX) ? INT_MAX : (int)buffersize;
+  nread = (ssize_t)SSL_read(BACKEND->handle, buf, buffsize);
+  if(nread <= 0) {
+    /* failed SSL_read */
+    int err = SSL_get_error(BACKEND->handle, (int)nread);
+
+    switch(err) {
+    case SSL_ERROR_NONE: /* this is not an error */
+      break;
+    case SSL_ERROR_ZERO_RETURN: /* no more data */
+      /* close_notify alert */
+      connclose(conn, "TLS close_notify");
+      break;
+    case SSL_ERROR_WANT_READ:
+    case SSL_ERROR_WANT_WRITE:
+      /* there's data pending, re-invoke SSL_read() */
+      *curlcode = CURLE_AGAIN;
+      return -1;
+    default:
+      /* openssl/ssl.h for SSL_ERROR_SYSCALL says "look at error stack/return
+         value/errno" */
+      /* https://www.openssl.org/docs/crypto/ERR_get_error.html */
+      sslerror = ERR_get_error();
+      if((nread < 0) || sslerror) {
+        /* If the return code was negative or there actually is an error in the
+           queue */
+        failf(conn->data, OSSL_PACKAGE " SSL_read: %s, errno %d",
+              (sslerror ?
+               ossl_strerror(sslerror, error_buffer, sizeof(error_buffer)) :
+               SSL_ERROR_to_str(err)),
+              SOCKERRNO);
+        *curlcode = CURLE_RECV_ERROR;
+        return -1;
+      }
+    }
+  }
+  return nread;
+}
+
+static size_t Curl_ossl_version(char *buffer, size_t size)
+{
+#ifdef OPENSSL_IS_BORINGSSL
+  return msnprintf(buffer, size, OSSL_PACKAGE);
+#elif defined(HAVE_OPENSSL_VERSION) && defined(OPENSSL_VERSION_STRING)
+  return msnprintf(buffer, size, "%s/%s",
+                   OSSL_PACKAGE, OpenSSL_version(OPENSSL_VERSION_STRING));
+#else
+  /* not BoringSSL and not using OpenSSL_version */
+
+  char sub[3];
+  unsigned long ssleay_value;
+  sub[2]='\0';
+  sub[1]='\0';
+  ssleay_value = OpenSSL_version_num();
+  if(ssleay_value < 0x906000) {
+    ssleay_value = SSLEAY_VERSION_NUMBER;
+    sub[0]='\0';
+  }
+  else {
+    if(ssleay_value&0xff0) {
+      int minor_ver = (ssleay_value >> 4) & 0xff;
+      if(minor_ver > 26) {
+        /* handle extended version introduced for 0.9.8za */
+        sub[1] = (char) ((minor_ver - 1) % 26 + 'a' + 1);
+        sub[0] = 'z';
+      }
+      else {
+        sub[0] = (char) (minor_ver + 'a' - 1);
+      }
+    }
+    else
+      sub[0]='\0';
+  }
+
+  return msnprintf(buffer, size, "%s/%lx.%lx.%lx%s"
+#ifdef OPENSSL_FIPS
+                   "-fips"
+#endif
+                   ,
+                   OSSL_PACKAGE,
+                   (ssleay_value>>28)&0xf,
+                   (ssleay_value>>20)&0xff,
+                   (ssleay_value>>12)&0xff,
+                   sub);
+#endif /* OPENSSL_IS_BORINGSSL */
+}
+
+/* can be called with data == NULL */
+static CURLcode Curl_ossl_random(struct Curl_easy *data,
+                                 unsigned char *entropy, size_t length)
+{
+  int rc;
+  if(data) {
+    if(Curl_ossl_seed(data)) /* Initiate the seed if not already done */
+      return CURLE_FAILED_INIT; /* couldn't seed for some reason */
+  }
+  else {
+    if(!rand_enough())
+      return CURLE_FAILED_INIT;
+  }
+  /* RAND_bytes() returns 1 on success, 0 otherwise.  */
+  rc = RAND_bytes(entropy, curlx_uztosi(length));
+  return (rc == 1 ? CURLE_OK : CURLE_FAILED_INIT);
+}
+
+static CURLcode Curl_ossl_md5sum(unsigned char *tmp, /* input */
+                                 size_t tmplen,
+                                 unsigned char *md5sum /* output */,
+                                 size_t unused)
+{
+  EVP_MD_CTX *mdctx;
+  unsigned int len = 0;
+  (void) unused;
+
+  mdctx = EVP_MD_CTX_create();
+  EVP_DigestInit_ex(mdctx, EVP_md5(), NULL);
+  EVP_DigestUpdate(mdctx, tmp, tmplen);
+  EVP_DigestFinal_ex(mdctx, md5sum, &len);
+  EVP_MD_CTX_destroy(mdctx);
+  return CURLE_OK;
+}
+
+#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
+static CURLcode Curl_ossl_sha256sum(const unsigned char *tmp, /* input */
+                                size_t tmplen,
+                                unsigned char *sha256sum /* output */,
+                                size_t unused)
+{
+  EVP_MD_CTX *mdctx;
+  unsigned int len = 0;
+  (void) unused;
+
+  mdctx =  EVP_MD_CTX_create();
+  EVP_DigestInit_ex(mdctx, EVP_sha256(), NULL);
+  EVP_DigestUpdate(mdctx, tmp, tmplen);
+  EVP_DigestFinal_ex(mdctx, sha256sum, &len);
+  EVP_MD_CTX_destroy(mdctx);
+  return CURLE_OK;
+}
+#endif
+
+static bool Curl_ossl_cert_status_request(void)
+{
+#if (OPENSSL_VERSION_NUMBER >= 0x0090808fL) && !defined(OPENSSL_NO_TLSEXT) && \
+    !defined(OPENSSL_NO_OCSP)
+  return TRUE;
+#else
+  return FALSE;
+#endif
+}
+
+static void *Curl_ossl_get_internals(struct ssl_connect_data *connssl,
+                                     CURLINFO info)
+{
+  /* Legacy: CURLINFO_TLS_SESSION must return an SSL_CTX pointer. */
+  return info == CURLINFO_TLS_SESSION ?
+         (void *)BACKEND->ctx : (void *)BACKEND->handle;
+}
+
+const struct Curl_ssl Curl_ssl_openssl = {
+  { CURLSSLBACKEND_OPENSSL, "openssl" }, /* info */
+
+  SSLSUPP_CA_PATH |
+  SSLSUPP_CERTINFO |
+  SSLSUPP_PINNEDPUBKEY |
+  SSLSUPP_SSL_CTX |
+#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
+  SSLSUPP_TLS13_CIPHERSUITES |
+#endif
+  SSLSUPP_HTTPS_PROXY,
+
+  sizeof(struct ssl_backend_data),
+
+  Curl_ossl_init,                /* init */
+  Curl_ossl_cleanup,             /* cleanup */
+  Curl_ossl_version,             /* version */
+  Curl_ossl_check_cxn,           /* check_cxn */
+  Curl_ossl_shutdown,            /* shutdown */
+  Curl_ossl_data_pending,        /* data_pending */
+  Curl_ossl_random,              /* random */
+  Curl_ossl_cert_status_request, /* cert_status_request */
+  Curl_ossl_connect,             /* connect */
+  Curl_ossl_connect_nonblocking, /* connect_nonblocking */
+  Curl_ossl_get_internals,       /* get_internals */
+  Curl_ossl_close,               /* close_one */
+  Curl_ossl_close_all,           /* close_all */
+  Curl_ossl_session_free,        /* session_free */
+  Curl_ossl_set_engine,          /* set_engine */
+  Curl_ossl_set_engine_default,  /* set_engine_default */
+  Curl_ossl_engines_list,        /* engines_list */
+  Curl_none_false_start,         /* false_start */
+  Curl_ossl_md5sum,              /* md5sum */
+#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
+  Curl_ossl_sha256sum            /* sha256sum */
+#else
+  NULL                           /* sha256sum */
+#endif
+};
+
+#endif /* USE_OPENSSL */