1 /*
2 * Cryptographic API.
3 *
4 * MD5 Message Digest Algorithm (RFC1321).
5 *
6 * Derived from cryptoapi implementation, originally based on the
7 * public domain implementation written by Colin Plumb in 1993.
8 *
9 * Copyright (c) Cryptoapi developers.
10 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 2 of the License, or (at your option)
15 * any later version.
16 *
17 */
18 #include <crypto/internal/hash.h>
19 #include <crypto/md5.h>
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/string.h>
23 #include <linux/types.h>
24 #include <linux/cryptohash.h>
25 #include <asm/byteorder.h>
26
27 /* XXX: this stuff can be optimized */
le32_to_cpu_array(u32 * buf,unsigned int words)28 static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
29 {
30 while (words--) {
31 __le32_to_cpus(buf);
32 buf++;
33 }
34 }
35
cpu_to_le32_array(u32 * buf,unsigned int words)36 static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
37 {
38 while (words--) {
39 __cpu_to_le32s(buf);
40 buf++;
41 }
42 }
43
md5_transform_helper(struct md5_state * ctx)44 static inline void md5_transform_helper(struct md5_state *ctx)
45 {
46 le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
47 md5_transform(ctx->hash, ctx->block);
48 }
49
md5_init(struct shash_desc * desc)50 static int md5_init(struct shash_desc *desc)
51 {
52 struct md5_state *mctx = shash_desc_ctx(desc);
53
54 mctx->hash[0] = 0x67452301;
55 mctx->hash[1] = 0xefcdab89;
56 mctx->hash[2] = 0x98badcfe;
57 mctx->hash[3] = 0x10325476;
58 mctx->byte_count = 0;
59
60 return 0;
61 }
62
md5_update(struct shash_desc * desc,const u8 * data,unsigned int len)63 static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
64 {
65 struct md5_state *mctx = shash_desc_ctx(desc);
66 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
67
68 mctx->byte_count += len;
69
70 if (avail > len) {
71 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
72 data, len);
73 return 0;
74 }
75
76 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
77 data, avail);
78
79 md5_transform_helper(mctx);
80 data += avail;
81 len -= avail;
82
83 while (len >= sizeof(mctx->block)) {
84 memcpy(mctx->block, data, sizeof(mctx->block));
85 md5_transform_helper(mctx);
86 data += sizeof(mctx->block);
87 len -= sizeof(mctx->block);
88 }
89
90 memcpy(mctx->block, data, len);
91
92 return 0;
93 }
94
md5_final(struct shash_desc * desc,u8 * out)95 static int md5_final(struct shash_desc *desc, u8 *out)
96 {
97 struct md5_state *mctx = shash_desc_ctx(desc);
98 const unsigned int offset = mctx->byte_count & 0x3f;
99 char *p = (char *)mctx->block + offset;
100 int padding = 56 - (offset + 1);
101
102 *p++ = 0x80;
103 if (padding < 0) {
104 memset(p, 0x00, padding + sizeof (u64));
105 md5_transform_helper(mctx);
106 p = (char *)mctx->block;
107 padding = 56;
108 }
109
110 memset(p, 0, padding);
111 mctx->block[14] = mctx->byte_count << 3;
112 mctx->block[15] = mctx->byte_count >> 29;
113 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
114 sizeof(u64)) / sizeof(u32));
115 md5_transform(mctx->hash, mctx->block);
116 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
117 memcpy(out, mctx->hash, sizeof(mctx->hash));
118 memset(mctx, 0, sizeof(*mctx));
119
120 return 0;
121 }
122
md5_export(struct shash_desc * desc,void * out)123 static int md5_export(struct shash_desc *desc, void *out)
124 {
125 struct md5_state *ctx = shash_desc_ctx(desc);
126
127 memcpy(out, ctx, sizeof(*ctx));
128 return 0;
129 }
130
md5_import(struct shash_desc * desc,const void * in)131 static int md5_import(struct shash_desc *desc, const void *in)
132 {
133 struct md5_state *ctx = shash_desc_ctx(desc);
134
135 memcpy(ctx, in, sizeof(*ctx));
136 return 0;
137 }
138
139 static struct shash_alg alg = {
140 .digestsize = MD5_DIGEST_SIZE,
141 .init = md5_init,
142 .update = md5_update,
143 .final = md5_final,
144 .export = md5_export,
145 .import = md5_import,
146 .descsize = sizeof(struct md5_state),
147 .statesize = sizeof(struct md5_state),
148 .base = {
149 .cra_name = "md5",
150 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
151 .cra_blocksize = MD5_HMAC_BLOCK_SIZE,
152 .cra_module = THIS_MODULE,
153 }
154 };
155
md5_mod_init(void)156 static int __init md5_mod_init(void)
157 {
158 return crypto_register_shash(&alg);
159 }
160
md5_mod_fini(void)161 static void __exit md5_mod_fini(void)
162 {
163 crypto_unregister_shash(&alg);
164 }
165
166 module_init(md5_mod_init);
167 module_exit(md5_mod_fini);
168
169 MODULE_LICENSE("GPL");
170 MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
171 MODULE_ALIAS_CRYPTO("md5");
172