diff options
Diffstat (limited to 'crypto/md5.c')
| -rw-r--r-- | crypto/md5.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/crypto/md5.c b/crypto/md5.c new file mode 100644 index 00000000..7febeaab --- /dev/null +++ b/crypto/md5.c @@ -0,0 +1,170 @@ +/* + * 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. + * + */ +#include <crypto/internal/hash.h> +#include <crypto/md5.h> +#include <linux/init.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) +{ + while (words--) { + __le32_to_cpus(buf); + buf++; + } +} + +static inline void cpu_to_le32_array(u32 *buf, unsigned int words) +{ + while (words--) { + __cpu_to_le32s(buf); + buf++; + } +} + +static inline void md5_transform_helper(struct md5_state *ctx) +{ + le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32)); + md5_transform(ctx->hash, ctx->block); +} + +static int md5_init(struct shash_desc *desc) +{ + struct md5_state *mctx = shash_desc_ctx(desc); + + mctx->hash[0] = 0x67452301; + mctx->hash[1] = 0xefcdab89; + mctx->hash[2] = 0x98badcfe; + mctx->hash[3] = 0x10325476; + mctx->byte_count = 0; + + return 0; +} + +static int 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); + + mctx->byte_count += len; + + if (avail > len) { + memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), + data, len); + return 0; + } + + memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), + data, avail); + + md5_transform_helper(mctx); + data += avail; + len -= avail; + + while (len >= sizeof(mctx->block)) { + memcpy(mctx->block, data, sizeof(mctx->block)); + md5_transform_helper(mctx); + data += sizeof(mctx->block); + len -= sizeof(mctx->block); + } + + memcpy(mctx->block, data, len); + + return 0; +} + +static int md5_final(struct shash_desc *desc, u8 *out) +{ + 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); + + *p++ = 0x80; + if (padding < 0) { + memset(p, 0x00, padding + sizeof (u64)); + md5_transform_helper(mctx); + p = (char *)mctx->block; + padding = 56; + } + + 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)); + + return 0; +} + +static int md5_export(struct shash_desc *desc, void *out) +{ + struct md5_state *ctx = shash_desc_ctx(desc); + + memcpy(out, ctx, sizeof(*ctx)); + return 0; +} + +static int md5_import(struct shash_desc *desc, const void *in) +{ + struct md5_state *ctx = shash_desc_ctx(desc); + + memcpy(ctx, in, sizeof(*ctx)); + return 0; +} + +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 int __init md5_mod_init(void) +{ + return crypto_register_shash(&alg); +} + +static void __exit md5_mod_fini(void) +{ + crypto_unregister_shash(&alg); +} + +module_init(md5_mod_init); +module_exit(md5_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("MD5 Message Digest Algorithm"); |