// 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/kernel.h>#include <linux/module.h> /* * 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){	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 int __crypto_md5_import(struct md5_ctx *ctx, const void *in){	const u8 *p = in; 	memcpy(ctx, p, sizeof(*ctx));	p += sizeof(*ctx);	ctx->bytecount += *p;	return 0;} static int __crypto_md5_export_core(const struct md5_ctx *ctx, void *out){	memcpy(out, ctx, offsetof(struct md5_ctx, buf));	return 0;} static int __crypto_md5_import_core(struct md5_ctx *ctx, const void *in){	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); #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 crypto_md5_update(struct shash_desc *desc,			     const u8 *data, unsigned int len){	md5_update(MD5_CTX(desc), data, len);	return 0;} static int crypto_md5_final(struct shash_desc *desc, u8 *out){	md5_final(MD5_CTX(desc), out);	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);} static int crypto_md5_import(struct shash_desc *desc, const void *in){	return __crypto_md5_import(MD5_CTX(desc), in);} static int crypto_md5_export_core(struct shash_desc *desc, void *out){	return __crypto_md5_export_core(MD5_CTX(desc), out);} static int crypto_md5_import_core(struct shash_desc *desc, const void *in){	return __crypto_md5_import_core(MD5_CTX(desc), in);} #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 crypto_hmac_md5_init(struct shash_desc *desc){	hmac_md5_init(HMAC_MD5_CTX(desc), HMAC_MD5_KEY(desc->tfm));	return 0;} 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;} 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 crypto_hmac_md5_export(struct shash_desc *desc, void *out){	return __crypto_md5_export(&HMAC_MD5_CTX(desc)->hash_ctx, out);} 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 crypto_hmac_md5_export_core(struct shash_desc *desc, void *out){	return __crypto_md5_export_core(&HMAC_MD5_CTX(desc)->hash_ctx, out);} 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 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 crypto_md5_mod_init(void){	return crypto_register_shashes(algs, ARRAY_SIZE(algs));}module_init(crypto_md5_mod_init); static void __exit crypto_md5_mod_exit(void){	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));}module_exit(crypto_md5_mod_exit); MODULE_LICENSE("GPL");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");