--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/include/mupdf/fitz/crypt.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,270 @@
+// Copyright (C) 2004-2025 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.
+
+#ifndef MUPDF_FITZ_CRYPT_H
+#define MUPDF_FITZ_CRYPT_H
+
+#include "mupdf/fitz/system.h"
+
+/* md5 digests */
+
+/**
+	Structure definition is public to enable stack
+	based allocation. Do not access the members directly.
+*/
+typedef struct
+{
+	uint32_t lo, hi;
+	uint32_t a, b, c, d;
+	unsigned char buffer[64];
+} fz_md5;
+
+/**
+	MD5 initialization. Begins an MD5 operation, writing a new
+	context.
+
+	Never throws an exception.
+*/
+void fz_md5_init(fz_md5 *state);
+
+/**
+	MD5 block update operation. Continues an MD5 message-digest
+	operation, processing another message block, and updating the
+	context.
+
+	Never throws an exception.
+*/
+void fz_md5_update(fz_md5 *state, const unsigned char *input, size_t inlen);
+
+/**
+	MD5 block update operation. Continues an MD5 message-digest
+	operation, processing an int64, and updating the context.
+
+	Never throws an exception.
+*/
+void fz_md5_update_int64(fz_md5 *state, int64_t i);
+
+/**
+	MD5 finalization. Ends an MD5 message-digest operation, writing
+	the message digest and zeroizing the context.
+
+	Never throws an exception.
+*/
+void fz_md5_final(fz_md5 *state, unsigned char digest[16]);
+
+/* sha-256 digests */
+
+/**
+	Structure definition is public to enable stack
+	based allocation. Do not access the members directly.
+*/
+typedef struct
+{
+	unsigned int state[8];
+	unsigned int count[2];
+	union {
+		unsigned char u8[64];
+		unsigned int u32[16];
+	} buffer;
+} fz_sha256;
+
+/**
+	SHA256 initialization. Begins an SHA256 operation, initialising
+	the supplied context.
+
+	Never throws an exception.
+*/
+void fz_sha256_init(fz_sha256 *state);
+
+/**
+	SHA256 block update operation. Continues an SHA256 message-
+	digest operation, processing another message block, and updating
+	the context.
+
+	Never throws an exception.
+*/
+void fz_sha256_update(fz_sha256 *state, const unsigned char *input, size_t inlen);
+
+/**
+	MD5 finalization. Ends an MD5 message-digest operation, writing
+	the message digest and zeroizing the context.
+
+	Never throws an exception.
+*/
+void fz_sha256_final(fz_sha256 *state, unsigned char digest[32]);
+
+/* sha-512 digests */
+
+/**
+	Structure definition is public to enable stack
+	based allocation. Do not access the members directly.
+*/
+typedef struct
+{
+	uint64_t state[8];
+	unsigned int count[2];
+	union {
+		unsigned char u8[128];
+		uint64_t u64[16];
+	} buffer;
+} fz_sha512;
+
+/**
+	SHA512 initialization. Begins an SHA512 operation, initialising
+	the supplied context.
+
+	Never throws an exception.
+*/
+void fz_sha512_init(fz_sha512 *state);
+
+/**
+	SHA512 block update operation. Continues an SHA512 message-
+	digest operation, processing another message block, and updating
+	the context.
+
+	Never throws an exception.
+*/
+void fz_sha512_update(fz_sha512 *state, const unsigned char *input, size_t inlen);
+
+/**
+	SHA512 finalization. Ends an SHA512 message-digest operation,
+	writing the message digest and zeroizing the context.
+
+	Never throws an exception.
+*/
+void fz_sha512_final(fz_sha512 *state, unsigned char digest[64]);
+
+/* sha-384 digests */
+
+typedef fz_sha512 fz_sha384;
+
+/**
+	SHA384 initialization. Begins an SHA384 operation, initialising
+	the supplied context.
+
+	Never throws an exception.
+*/
+void fz_sha384_init(fz_sha384 *state);
+
+/**
+	SHA384 block update operation. Continues an SHA384 message-
+	digest operation, processing another message block, and updating
+	the context.
+
+	Never throws an exception.
+*/
+void fz_sha384_update(fz_sha384 *state, const unsigned char *input, size_t inlen);
+
+/**
+	SHA384 finalization. Ends an SHA384 message-digest operation,
+	writing the message digest and zeroizing the context.
+
+	Never throws an exception.
+*/
+void fz_sha384_final(fz_sha384 *state, unsigned char digest[64]);
+
+/* arc4 crypto */
+
+/**
+	Structure definition is public to enable stack
+	based allocation. Do not access the members directly.
+*/
+typedef struct
+{
+	unsigned x;
+	unsigned y;
+	unsigned char state[256];
+} fz_arc4;
+
+/**
+	RC4 initialization. Begins an RC4 operation, writing a new
+	context.
+
+	Never throws an exception.
+*/
+void fz_arc4_init(fz_arc4 *state, const unsigned char *key, size_t len);
+
+/**
+	RC4 block encrypt operation; encrypt src into dst (both of
+	length len) updating the RC4 state as we go.
+
+	Never throws an exception.
+*/
+void fz_arc4_encrypt(fz_arc4 *state, unsigned char *dest, const unsigned char *src, size_t len);
+
+/**
+	RC4 finalization. Zero the context.
+
+	Never throws an exception.
+*/
+void fz_arc4_final(fz_arc4 *state);
+
+/* AES block cipher implementation from XYSSL */
+
+/**
+	Structure definitions are public to enable stack
+	based allocation. Do not access the members directly.
+*/
+typedef struct
+{
+	int nr; /* number of rounds */
+	uint32_t *rk; /* AES round keys */
+	uint32_t buf[68]; /* unaligned data */
+} fz_aes;
+
+#define FZ_AES_DECRYPT 0
+#define FZ_AES_ENCRYPT 1
+
+/**
+	AES encryption initialization. Fills in the supplied context
+	and prepares for encryption using the given key.
+
+	Returns non-zero for error (key size other than 128/192/256).
+
+	Never throws an exception.
+*/
+int fz_aes_setkey_enc(fz_aes *ctx, const unsigned char *key, int keysize);
+
+/**
+	AES decryption initialization. Fills in the supplied context
+	and prepares for decryption using the given key.
+
+	Returns non-zero for error (key size other than 128/192/256).
+
+	Never throws an exception.
+*/
+int fz_aes_setkey_dec(fz_aes *ctx, const unsigned char *key, int keysize);
+
+/**
+	AES block processing. Encrypts or Decrypts (according to mode,
+	which must match what was initially set up) length bytes (which
+	must be a multiple of 16), using (and modifying) the insertion
+	vector iv, reading from input, and writing to output.
+
+	Never throws an exception.
+*/
+void fz_aes_crypt_cbc(fz_aes *ctx, int mode, size_t length,
+	unsigned char iv[16],
+	const unsigned char *input,
+	unsigned char *output );
+
+#endif