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/*
* 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] = MD5_H0;
mctx->hash[1] = MD5_H1;
mctx->hash[2] = MD5_H2;
mctx->hash[3] = MD5_H3;
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");
MODULE_ALIAS_CRYPTO("md5");
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