cifs_md4.c revision 23e91d8b
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Cryptographic API.
4 *
5 * MD4 Message Digest Algorithm (RFC1320).
6 *
7 * Implementation derived from Andrew Tridgell and Steve French's
8 * CIFS MD4 implementation, and the cryptoapi implementation
9 * originally based on the public domain implementation written
10 * by Colin Plumb in 1993.
11 *
12 * Copyright (c) Andrew Tridgell 1997-1998.
13 * Modified by Steve French (sfrench@us.ibm.com) 2002
14 * Copyright (c) Cryptoapi developers.
15 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
16 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
17 *
18 */
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/string.h>
23#include <linux/types.h>
24#include <asm/byteorder.h>
25#include "md4.h"
26
27MODULE_LICENSE("GPL");
28
29static inline u32 lshift(u32 x, unsigned int s)
30{
31	x &= 0xFFFFFFFF;
32	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
33}
34
35static inline u32 F(u32 x, u32 y, u32 z)
36{
37	return (x & y) | ((~x) & z);
38}
39
40static inline u32 G(u32 x, u32 y, u32 z)
41{
42	return (x & y) | (x & z) | (y & z);
43}
44
45static inline u32 H(u32 x, u32 y, u32 z)
46{
47	return x ^ y ^ z;
48}
49
50#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
51#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
52#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
53
54static void md4_transform(u32 *hash, u32 const *in)
55{
56	u32 a, b, c, d;
57
58	a = hash[0];
59	b = hash[1];
60	c = hash[2];
61	d = hash[3];
62
63	ROUND1(a, b, c, d, in[0], 3);
64	ROUND1(d, a, b, c, in[1], 7);
65	ROUND1(c, d, a, b, in[2], 11);
66	ROUND1(b, c, d, a, in[3], 19);
67	ROUND1(a, b, c, d, in[4], 3);
68	ROUND1(d, a, b, c, in[5], 7);
69	ROUND1(c, d, a, b, in[6], 11);
70	ROUND1(b, c, d, a, in[7], 19);
71	ROUND1(a, b, c, d, in[8], 3);
72	ROUND1(d, a, b, c, in[9], 7);
73	ROUND1(c, d, a, b, in[10], 11);
74	ROUND1(b, c, d, a, in[11], 19);
75	ROUND1(a, b, c, d, in[12], 3);
76	ROUND1(d, a, b, c, in[13], 7);
77	ROUND1(c, d, a, b, in[14], 11);
78	ROUND1(b, c, d, a, in[15], 19);
79
80	ROUND2(a, b, c, d, in[0], 3);
81	ROUND2(d, a, b, c, in[4], 5);
82	ROUND2(c, d, a, b, in[8], 9);
83	ROUND2(b, c, d, a, in[12], 13);
84	ROUND2(a, b, c, d, in[1], 3);
85	ROUND2(d, a, b, c, in[5], 5);
86	ROUND2(c, d, a, b, in[9], 9);
87	ROUND2(b, c, d, a, in[13], 13);
88	ROUND2(a, b, c, d, in[2], 3);
89	ROUND2(d, a, b, c, in[6], 5);
90	ROUND2(c, d, a, b, in[10], 9);
91	ROUND2(b, c, d, a, in[14], 13);
92	ROUND2(a, b, c, d, in[3], 3);
93	ROUND2(d, a, b, c, in[7], 5);
94	ROUND2(c, d, a, b, in[11], 9);
95	ROUND2(b, c, d, a, in[15], 13);
96
97	ROUND3(a, b, c, d, in[0], 3);
98	ROUND3(d, a, b, c, in[8], 9);
99	ROUND3(c, d, a, b, in[4], 11);
100	ROUND3(b, c, d, a, in[12], 15);
101	ROUND3(a, b, c, d, in[2], 3);
102	ROUND3(d, a, b, c, in[10], 9);
103	ROUND3(c, d, a, b, in[6], 11);
104	ROUND3(b, c, d, a, in[14], 15);
105	ROUND3(a, b, c, d, in[1], 3);
106	ROUND3(d, a, b, c, in[9], 9);
107	ROUND3(c, d, a, b, in[5], 11);
108	ROUND3(b, c, d, a, in[13], 15);
109	ROUND3(a, b, c, d, in[3], 3);
110	ROUND3(d, a, b, c, in[11], 9);
111	ROUND3(c, d, a, b, in[7], 11);
112	ROUND3(b, c, d, a, in[15], 15);
113
114	hash[0] += a;
115	hash[1] += b;
116	hash[2] += c;
117	hash[3] += d;
118}
119
120static inline void md4_transform_helper(struct md4_ctx *ctx)
121{
122	le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
123	md4_transform(ctx->hash, ctx->block);
124}
125
126int cifs_md4_init(struct md4_ctx *mctx)
127{
128	memset(mctx, 0, sizeof(struct md4_ctx));
129	mctx->hash[0] = 0x67452301;
130	mctx->hash[1] = 0xefcdab89;
131	mctx->hash[2] = 0x98badcfe;
132	mctx->hash[3] = 0x10325476;
133	mctx->byte_count = 0;
134
135	return 0;
136}
137EXPORT_SYMBOL_GPL(cifs_md4_init);
138
139int cifs_md4_update(struct md4_ctx *mctx, const u8 *data, unsigned int len)
140{
141	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
142
143	mctx->byte_count += len;
144
145	if (avail > len) {
146		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
147		       data, len);
148		return 0;
149	}
150
151	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
152	       data, avail);
153
154	md4_transform_helper(mctx);
155	data += avail;
156	len -= avail;
157
158	while (len >= sizeof(mctx->block)) {
159		memcpy(mctx->block, data, sizeof(mctx->block));
160		md4_transform_helper(mctx);
161		data += sizeof(mctx->block);
162		len -= sizeof(mctx->block);
163	}
164
165	memcpy(mctx->block, data, len);
166
167	return 0;
168}
169EXPORT_SYMBOL_GPL(cifs_md4_update);
170
171int cifs_md4_final(struct md4_ctx *mctx, u8 *out)
172{
173	const unsigned int offset = mctx->byte_count & 0x3f;
174	char *p = (char *)mctx->block + offset;
175	int padding = 56 - (offset + 1);
176
177	*p++ = 0x80;
178	if (padding < 0) {
179		memset(p, 0x00, padding + sizeof(u64));
180		md4_transform_helper(mctx);
181		p = (char *)mctx->block;
182		padding = 56;
183	}
184
185	memset(p, 0, padding);
186	mctx->block[14] = mctx->byte_count << 3;
187	mctx->block[15] = mctx->byte_count >> 29;
188	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
189			  sizeof(u64)) / sizeof(u32));
190	md4_transform(mctx->hash, mctx->block);
191	cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
192	memcpy(out, mctx->hash, sizeof(mctx->hash));
193	memset(mctx, 0, sizeof(*mctx));
194
195	return 0;
196}
197EXPORT_SYMBOL_GPL(cifs_md4_final);
198