--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/platform/java/jni/pkcs7signer.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,265 @@
+// Copyright (C) 2004-2021 Artifex Software, Inc.
+//
+// This file is part of MuPDF.
+//
+// MuPDF is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
+//
+// Alternative licensing terms are available from the licensor.
+// For commercial licensing, see <https://www.artifex.com/> or contact
+// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
+// CA 94129, USA, for further information.
+
+/* PKCS7Signer interface */
+
+typedef struct
+{
+	pdf_pkcs7_signer base; // Mupdf callbacks
+	int refs;
+	jobject java_signer;
+} java_pkcs7_signer;
+
+static pdf_pkcs7_signer *signer_keep(fz_context *ctx, pdf_pkcs7_signer *signer_)
+{
+	java_pkcs7_signer *signer = (java_pkcs7_signer *)signer_;
+
+	if (!signer) return NULL;
+
+	return fz_keep_imp(ctx, signer, &signer->refs);
+}
+
+static void signer_drop(fz_context *ctx, pdf_pkcs7_signer *signer_)
+{
+	java_pkcs7_signer *signer = (java_pkcs7_signer *)signer_;
+
+	if (!signer) return;
+
+	if (fz_drop_imp(ctx, signer, &signer->refs))
+	{
+		jboolean detach = JNI_FALSE;
+		JNIEnv *env = NULL;
+
+		env = jni_attach_thread(&detach);
+		if (env == NULL)
+		{
+			fz_warn(ctx, "cannot attach to JVM in signer_drop");
+			fz_free(ctx, signer);
+			jni_detach_thread(detach);
+			return;
+		}
+
+		(*env)->DeleteGlobalRef(env, signer->java_signer);
+		fz_free(ctx, signer);
+
+		jni_detach_thread(detach);
+	}
+}
+
+static char *string_field_to_utfchars(fz_context *ctx, JNIEnv *env, jobject obj, jfieldID fid)
+{
+	const char *str = NULL;
+	char *val = NULL;
+	jobject jstr;
+
+	jstr = (*env)->GetObjectField(env, obj, fid);
+	if (!jstr) return NULL;
+
+	str = (*env)->GetStringUTFChars(env, jstr, NULL);
+	if (!str)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot not get UTF string");
+
+	fz_try(ctx)
+		val = Memento_label(fz_strdup(ctx, str), "string field");
+	fz_always(ctx)
+		(*env)->ReleaseStringUTFChars(env, jstr, str);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
+
+	return val;
+}
+
+static pdf_pkcs7_distinguished_name *signer_distinguished_name(fz_context *ctx, pdf_pkcs7_signer *signer_)
+{
+	java_pkcs7_signer *signer = (java_pkcs7_signer *)signer_;
+	pdf_pkcs7_distinguished_name *name = NULL;
+	jboolean detach = JNI_FALSE;
+	jobject desname = NULL;
+	JNIEnv *env = NULL;
+
+	if (signer == NULL) return NULL;
+
+	env = jni_attach_thread(&detach);
+	if (env == NULL)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot attach to JVM in pdf_pkcs7_distinguished_name");
+
+	desname = (*env)->CallObjectMethod(env, signer->java_signer, mid_PKCS7Signer_name);
+	if ((*env)->ExceptionCheck(env))
+		fz_throw_java_and_detach_thread(ctx, env, detach);
+	if (desname == NULL)
+		fz_throw_and_detach_thread(ctx, detach, FZ_ERROR_GENERIC, "cannot retrieve distinguished name");
+
+	fz_var(name);
+	fz_try(ctx)
+	{
+		name = Memento_label(fz_calloc(ctx, 1, sizeof(*name)), "distinguished name");
+		name->cn = string_field_to_utfchars(ctx, env, desname, fid_PKCS7DistinguishedName_cn);
+		name->o = string_field_to_utfchars(ctx, env, desname, fid_PKCS7DistinguishedName_o);
+		name->ou = string_field_to_utfchars(ctx, env, desname, fid_PKCS7DistinguishedName_ou);
+		name->email = string_field_to_utfchars(ctx, env, desname, fid_PKCS7DistinguishedName_email);
+		name->c = string_field_to_utfchars(ctx, env, desname, fid_PKCS7DistinguishedName_c);
+	}
+	fz_catch(ctx)
+	{
+		if (name) fz_free(ctx, name->c);
+		if (name) fz_free(ctx, name->email);
+		if (name) fz_free(ctx, name->ou);
+		if (name) fz_free(ctx, name->o);
+		if (name) fz_free(ctx, name->cn);
+		fz_free(ctx, name);
+		fz_rethrow_and_detach_thread(ctx, detach);
+	}
+
+	jni_detach_thread(detach);
+
+	return name;
+}
+
+static size_t signer_max_digest_size(fz_context *ctx, pdf_pkcs7_signer *signer_)
+{
+	java_pkcs7_signer *signer = (java_pkcs7_signer *)signer_;
+	jboolean detach = JNI_FALSE;
+	size_t max_digest = 0;
+	int len;
+
+	JNIEnv *env = jni_attach_thread(&detach);
+	if (env == NULL)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot attach to JVM in signer_max_digest_size");
+
+	/* get the size in bytes we should allow for the digest buffer */
+	len = (*env)->CallIntMethod(env, signer->java_signer, mid_PKCS7Signer_maxDigest);
+	if (len < 0)
+		len = 0;
+	max_digest = (size_t)len;
+	if ((*env)->ExceptionCheck(env))
+		fz_throw_java_and_detach_thread(ctx, env, detach);
+
+	jni_detach_thread(detach);
+
+	return max_digest;
+}
+
+static int signer_create_digest(fz_context *ctx, pdf_pkcs7_signer *signer_, fz_stream *stm, unsigned char *digest, size_t digest_len)
+{
+	java_pkcs7_signer *signer = (java_pkcs7_signer *)signer_;
+	jobject jsigner = signer->java_signer;
+	jboolean detach = JNI_FALSE;
+	jobject jdigest;
+	jobject jstm;
+	int result = 1;
+
+	JNIEnv *env = jni_attach_thread(&detach);
+	if (env == NULL)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot attach to JVM in signer_create_digest");
+
+	jstm = to_FitzInputStream(ctx, env, stm);
+
+	jdigest = (*env)->CallObjectMethod(env, jsigner, mid_PKCS7Signer_sign, jstm);
+	if ((*env)->ExceptionCheck(env))
+		fz_throw_java_and_detach_thread(ctx, env, detach);
+	if (!jdigest)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "did not receive digest from signer");
+
+	if (digest != NULL)
+	{
+		jbyte *src = NULL;
+		int srclen = 0;
+
+		src = (*env)->GetByteArrayElements(env, jdigest, 0);
+		if (src == NULL)
+			fz_throw_and_detach_thread(ctx, detach, FZ_ERROR_GENERIC, "cannot get digest");
+
+		srclen = (*env)->GetArrayLength(env, jdigest);
+
+		if ((size_t)srclen > digest_len)
+		{
+			(*env)->ReleaseByteArrayElements(env, jdigest, src, JNI_ABORT);
+			fz_throw_and_detach_thread(ctx, detach, FZ_ERROR_GENERIC, "digest destination shorter than digest");
+		}
+
+		memcpy(digest, src, srclen);
+		result = srclen;
+
+		(*env)->ReleaseByteArrayElements(env, jdigest, src, JNI_ABORT);
+	}
+
+	jni_detach_thread(detach);
+
+	return result;
+}
+
+static pdf_pkcs7_signer *pdf_pkcs7_java_signer_create(JNIEnv *env, fz_context *ctx, jobject java_signer)
+{
+	java_pkcs7_signer *signer = Memento_label(fz_calloc(ctx, 1, sizeof(*signer)), "java_pkcs7_signer");
+
+	if (signer == NULL) return NULL;
+
+	signer->base.keep = signer_keep;
+	signer->base.drop = signer_drop;
+	signer->base.get_signing_name = signer_distinguished_name;
+	signer->base.max_digest_size = signer_max_digest_size;
+	signer->base.create_digest = signer_create_digest;
+	signer->refs = 1;
+
+	signer->java_signer = (*env)->NewGlobalRef(env, java_signer);
+	if (signer->java_signer == NULL)
+	{
+		fz_free(ctx, signer);
+		return NULL;
+	}
+
+	return &signer->base;
+}
+
+JNIEXPORT jlong JNICALL
+FUN(PKCS7Signer_newNative)(JNIEnv *env, jclass cls, jobject jsigner)
+{
+	fz_context *ctx = get_context(env);
+	pdf_pkcs7_signer *signer = NULL;
+
+	if (!ctx) return 0;
+	if (!jsigner) jni_throw_arg(env, "signer must not be null");
+
+	jsigner = (*env)->NewGlobalRef(env, jsigner);
+	if (!jsigner) jni_throw_arg(env, "unable to get reference to signer");
+
+	fz_try(ctx)
+		signer = pdf_pkcs7_java_signer_create(env, ctx, jsigner);
+	fz_catch(ctx)
+	{
+		(*env)->DeleteGlobalRef(env, jsigner);
+		jni_rethrow(env, ctx);
+	}
+
+	return jlong_cast(signer);
+}
+
+
+JNIEXPORT void JNICALL
+FUN(PKCS7Signer_finalize)(JNIEnv *env, jobject self)
+{
+	fz_context *ctx = get_context(env);
+	pdf_pkcs7_signer *signer = from_PKCS7Signer_safe(env, self);
+	if (!ctx || !signer) return;
+	(*env)->SetLongField(env, self, fid_PKCS7Signer_pointer, 0);
+	pdf_drop_signer(ctx, signer);
+}