1 files changed, 180 insertions, 114 deletions

diff --git a/crypto/md5.c b/crypto/md5.c
index 7febeaab923b..c167d203c710 100644
--- a/crypto/md5.c
+++ b/crypto/md5.c
@@ -1,170 +1,236 @@
-/* 
- * Cryptographic API.
- *
- * MD5 Message Digest Algorithm (RFC1321).
- *
- * Derived from cryptoapi implementation, originally based on the
- * public domain implementation written by Colin Plumb in 1993.
- *
- * Copyright (c) Cryptoapi developers.
- * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
- * 
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option) 
- * any later version.
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Crypto API support for MD5 and HMAC-MD5
  *
+ * Copyright 2025 Google LLC
  */
 #include <crypto/internal/hash.h>
 #include <crypto/md5.h>
-#include <linux/init.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/cryptohash.h>
-#include <asm/byteorder.h>
 
-/* XXX: this stuff can be optimized */
-static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
+/*
+ * Export and import functions.  crypto_shash wants a particular format that
+ * matches that used by some legacy drivers.  It currently is the same as the
+ * library MD5 context, except the value in bytecount must be block-aligned and
+ * the remainder must be stored in an extra u8 appended to the struct.
+ */
+
+#define MD5_SHASH_STATE_SIZE (sizeof(struct md5_ctx) + 1)
+static_assert(sizeof(struct md5_ctx) == sizeof(struct md5_state));
+static_assert(offsetof(struct md5_ctx, state) == offsetof(struct md5_state, hash));
+static_assert(offsetof(struct md5_ctx, bytecount) == offsetof(struct md5_state, byte_count));
+static_assert(offsetof(struct md5_ctx, buf) == offsetof(struct md5_state, block));
+
+static int __crypto_md5_export(const struct md5_ctx *ctx0, void *out)
 {
-	while (words--) {
-		__le32_to_cpus(buf);
-		buf++;
-	}
+	struct md5_ctx ctx = *ctx0;
+	unsigned int partial;
+	u8 *p = out;
+
+	partial = ctx.bytecount % MD5_BLOCK_SIZE;
+	ctx.bytecount -= partial;
+	memcpy(p, &ctx, sizeof(ctx));
+	p += sizeof(ctx);
+	*p = partial;
+	return 0;
 }
 
-static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
+static int __crypto_md5_import(struct md5_ctx *ctx, const void *in)
 {
-	while (words--) {
-		__cpu_to_le32s(buf);
-		buf++;
-	}
+	const u8 *p = in;
+
+	memcpy(ctx, p, sizeof(*ctx));
+	p += sizeof(*ctx);
+	ctx->bytecount += *p;
+	return 0;
 }
 
-static inline void md5_transform_helper(struct md5_state *ctx)
+static int __crypto_md5_export_core(const struct md5_ctx *ctx, void *out)
 {
-	le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
-	md5_transform(ctx->hash, ctx->block);
+	memcpy(out, ctx, offsetof(struct md5_ctx, buf));
+	return 0;
 }
 
-static int md5_init(struct shash_desc *desc)
+static int __crypto_md5_import_core(struct md5_ctx *ctx, const void *in)
 {
-	struct md5_state *mctx = shash_desc_ctx(desc);
+	memcpy(ctx, in, offsetof(struct md5_ctx, buf));
+	return 0;
+}
+
+const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = {
+	0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04,
+	0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e,
+};
+EXPORT_SYMBOL_GPL(md5_zero_message_hash);
 
-	mctx->hash[0] = 0x67452301;
-	mctx->hash[1] = 0xefcdab89;
-	mctx->hash[2] = 0x98badcfe;
-	mctx->hash[3] = 0x10325476;
-	mctx->byte_count = 0;
+#define MD5_CTX(desc) ((struct md5_ctx *)shash_desc_ctx(desc))
 
+static int crypto_md5_init(struct shash_desc *desc)
+{
+	md5_init(MD5_CTX(desc));
 	return 0;
 }
 
-static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
+static int crypto_md5_update(struct shash_desc *desc,
+			     const u8 *data, unsigned int len)
 {
-	struct md5_state *mctx = shash_desc_ctx(desc);
-	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
+	md5_update(MD5_CTX(desc), data, len);
+	return 0;
+}
 
-	mctx->byte_count += len;
+static int crypto_md5_final(struct shash_desc *desc, u8 *out)
+{
+	md5_final(MD5_CTX(desc), out);
+	return 0;
+}
 
-	if (avail > len) {
-		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
-		       data, len);
-		return 0;
-	}
+static int crypto_md5_digest(struct shash_desc *desc,
+			     const u8 *data, unsigned int len, u8 *out)
+{
+	md5(data, len, out);
+	return 0;
+}
+
+static int crypto_md5_export(struct shash_desc *desc, void *out)
+{
+	return __crypto_md5_export(MD5_CTX(desc), out);
+}
 
-	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
-	       data, avail);
+static int crypto_md5_import(struct shash_desc *desc, const void *in)
+{
+	return __crypto_md5_import(MD5_CTX(desc), in);
+}
 
-	md5_transform_helper(mctx);
-	data += avail;
-	len -= avail;
+static int crypto_md5_export_core(struct shash_desc *desc, void *out)
+{
+	return __crypto_md5_export_core(MD5_CTX(desc), out);
+}
 
-	while (len >= sizeof(mctx->block)) {
-		memcpy(mctx->block, data, sizeof(mctx->block));
-		md5_transform_helper(mctx);
-		data += sizeof(mctx->block);
-		len -= sizeof(mctx->block);
-	}
+static int crypto_md5_import_core(struct shash_desc *desc, const void *in)
+{
+	return __crypto_md5_import_core(MD5_CTX(desc), in);
+}
 
-	memcpy(mctx->block, data, len);
+#define HMAC_MD5_KEY(tfm) ((struct hmac_md5_key *)crypto_shash_ctx(tfm))
+#define HMAC_MD5_CTX(desc) ((struct hmac_md5_ctx *)shash_desc_ctx(desc))
 
+static int crypto_hmac_md5_setkey(struct crypto_shash *tfm,
+				  const u8 *raw_key, unsigned int keylen)
+{
+	hmac_md5_preparekey(HMAC_MD5_KEY(tfm), raw_key, keylen);
 	return 0;
 }
 
-static int md5_final(struct shash_desc *desc, u8 *out)
+static int crypto_hmac_md5_init(struct shash_desc *desc)
 {
-	struct md5_state *mctx = shash_desc_ctx(desc);
-	const unsigned int offset = mctx->byte_count & 0x3f;
-	char *p = (char *)mctx->block + offset;
-	int padding = 56 - (offset + 1);
+	hmac_md5_init(HMAC_MD5_CTX(desc), HMAC_MD5_KEY(desc->tfm));
+	return 0;
+}
 
-	*p++ = 0x80;
-	if (padding < 0) {
-		memset(p, 0x00, padding + sizeof (u64));
-		md5_transform_helper(mctx);
-		p = (char *)mctx->block;
-		padding = 56;
-	}
+static int crypto_hmac_md5_update(struct shash_desc *desc,
+				  const u8 *data, unsigned int len)
+{
+	hmac_md5_update(HMAC_MD5_CTX(desc), data, len);
+	return 0;
+}
 
-	memset(p, 0, padding);
-	mctx->block[14] = mctx->byte_count << 3;
-	mctx->block[15] = mctx->byte_count >> 29;
-	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
-	                  sizeof(u64)) / sizeof(u32));
-	md5_transform(mctx->hash, mctx->block);
-	cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
-	memcpy(out, mctx->hash, sizeof(mctx->hash));
-	memset(mctx, 0, sizeof(*mctx));
+static int crypto_hmac_md5_final(struct shash_desc *desc, u8 *out)
+{
+	hmac_md5_final(HMAC_MD5_CTX(desc), out);
+	return 0;
+}
 
+static int crypto_hmac_md5_digest(struct shash_desc *desc,
+				  const u8 *data, unsigned int len, u8 *out)
+{
+	hmac_md5(HMAC_MD5_KEY(desc->tfm), data, len, out);
 	return 0;
 }
 
-static int md5_export(struct shash_desc *desc, void *out)
+static int crypto_hmac_md5_export(struct shash_desc *desc, void *out)
 {
-	struct md5_state *ctx = shash_desc_ctx(desc);
+	return __crypto_md5_export(&HMAC_MD5_CTX(desc)->hash_ctx, out);
+}
 
-	memcpy(out, ctx, sizeof(*ctx));
-	return 0;
+static int crypto_hmac_md5_import(struct shash_desc *desc, const void *in)
+{
+	struct hmac_md5_ctx *ctx = HMAC_MD5_CTX(desc);
+
+	ctx->ostate = HMAC_MD5_KEY(desc->tfm)->ostate;
+	return __crypto_md5_import(&ctx->hash_ctx, in);
 }
 
-static int md5_import(struct shash_desc *desc, const void *in)
+static int crypto_hmac_md5_export_core(struct shash_desc *desc, void *out)
 {
-	struct md5_state *ctx = shash_desc_ctx(desc);
+	return __crypto_md5_export_core(&HMAC_MD5_CTX(desc)->hash_ctx, out);
+}
 
-	memcpy(ctx, in, sizeof(*ctx));
-	return 0;
+static int crypto_hmac_md5_import_core(struct shash_desc *desc, const void *in)
+{
+	struct hmac_md5_ctx *ctx = HMAC_MD5_CTX(desc);
+
+	ctx->ostate = HMAC_MD5_KEY(desc->tfm)->ostate;
+	return __crypto_md5_import_core(&ctx->hash_ctx, in);
 }
 
-static struct shash_alg alg = {
-	.digestsize	=	MD5_DIGEST_SIZE,
-	.init		=	md5_init,
-	.update		=	md5_update,
-	.final		=	md5_final,
-	.export		=	md5_export,
-	.import		=	md5_import,
-	.descsize	=	sizeof(struct md5_state),
-	.statesize	=	sizeof(struct md5_state),
-	.base		=	{
-		.cra_name	=	"md5",
-		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
-		.cra_blocksize	=	MD5_HMAC_BLOCK_SIZE,
-		.cra_module	=	THIS_MODULE,
-	}
+static struct shash_alg algs[] = {
+	{
+		.base.cra_name		= "md5",
+		.base.cra_driver_name	= "md5-lib",
+		.base.cra_priority	= 300,
+		.base.cra_blocksize	= MD5_BLOCK_SIZE,
+		.base.cra_module	= THIS_MODULE,
+		.digestsize		= MD5_DIGEST_SIZE,
+		.init			= crypto_md5_init,
+		.update			= crypto_md5_update,
+		.final			= crypto_md5_final,
+		.digest			= crypto_md5_digest,
+		.export			= crypto_md5_export,
+		.import			= crypto_md5_import,
+		.export_core		= crypto_md5_export_core,
+		.import_core		= crypto_md5_import_core,
+		.descsize		= sizeof(struct md5_ctx),
+		.statesize		= MD5_SHASH_STATE_SIZE,
+	},
+	{
+		.base.cra_name		= "hmac(md5)",
+		.base.cra_driver_name	= "hmac-md5-lib",
+		.base.cra_priority	= 300,
+		.base.cra_blocksize	= MD5_BLOCK_SIZE,
+		.base.cra_ctxsize	= sizeof(struct hmac_md5_key),
+		.base.cra_module	= THIS_MODULE,
+		.digestsize		= MD5_DIGEST_SIZE,
+		.setkey			= crypto_hmac_md5_setkey,
+		.init			= crypto_hmac_md5_init,
+		.update			= crypto_hmac_md5_update,
+		.final			= crypto_hmac_md5_final,
+		.digest			= crypto_hmac_md5_digest,
+		.export			= crypto_hmac_md5_export,
+		.import			= crypto_hmac_md5_import,
+		.export_core		= crypto_hmac_md5_export_core,
+		.import_core		= crypto_hmac_md5_import_core,
+		.descsize		= sizeof(struct hmac_md5_ctx),
+		.statesize		= MD5_SHASH_STATE_SIZE,
+	},
 };
 
-static int __init md5_mod_init(void)
+static int __init crypto_md5_mod_init(void)
 {
-	return crypto_register_shash(&alg);
+	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
 }
+module_init(crypto_md5_mod_init);
 
-static void __exit md5_mod_fini(void)
+static void __exit crypto_md5_mod_exit(void)
 {
-	crypto_unregister_shash(&alg);
+	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
 }
-
-module_init(md5_mod_init);
-module_exit(md5_mod_fini);
+module_exit(crypto_md5_mod_exit);
 
 MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
+MODULE_DESCRIPTION("Crypto API support for MD5 and HMAC-MD5");
+
+MODULE_ALIAS_CRYPTO("md5");
+MODULE_ALIAS_CRYPTO("md5-lib");
+MODULE_ALIAS_CRYPTO("hmac(md5)");
+MODULE_ALIAS_CRYPTO("hmac-md5-lib");