xref: /linux/fs/smb/common/cifs_md4.c (revision 6af91e3d2cfc8bb579b1aa2d22cd91f8c34acdf6)
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 
27 MODULE_DESCRIPTION("MD4 Message Digest Algorithm (RFC1320)");
28 MODULE_LICENSE("GPL");
29 
30 static inline u32 lshift(u32 x, unsigned int s)
31 {
32 	x &= 0xFFFFFFFF;
33 	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
34 }
35 
36 static inline u32 F(u32 x, u32 y, u32 z)
37 {
38 	return (x & y) | ((~x) & z);
39 }
40 
41 static inline u32 G(u32 x, u32 y, u32 z)
42 {
43 	return (x & y) | (x & z) | (y & z);
44 }
45 
46 static inline u32 H(u32 x, u32 y, u32 z)
47 {
48 	return x ^ y ^ z;
49 }
50 
51 #define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
52 #define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
53 #define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
54 
55 static void md4_transform(u32 *hash, u32 const *in)
56 {
57 	u32 a, b, c, d;
58 
59 	a = hash[0];
60 	b = hash[1];
61 	c = hash[2];
62 	d = hash[3];
63 
64 	ROUND1(a, b, c, d, in[0], 3);
65 	ROUND1(d, a, b, c, in[1], 7);
66 	ROUND1(c, d, a, b, in[2], 11);
67 	ROUND1(b, c, d, a, in[3], 19);
68 	ROUND1(a, b, c, d, in[4], 3);
69 	ROUND1(d, a, b, c, in[5], 7);
70 	ROUND1(c, d, a, b, in[6], 11);
71 	ROUND1(b, c, d, a, in[7], 19);
72 	ROUND1(a, b, c, d, in[8], 3);
73 	ROUND1(d, a, b, c, in[9], 7);
74 	ROUND1(c, d, a, b, in[10], 11);
75 	ROUND1(b, c, d, a, in[11], 19);
76 	ROUND1(a, b, c, d, in[12], 3);
77 	ROUND1(d, a, b, c, in[13], 7);
78 	ROUND1(c, d, a, b, in[14], 11);
79 	ROUND1(b, c, d, a, in[15], 19);
80 
81 	ROUND2(a, b, c, d, in[0], 3);
82 	ROUND2(d, a, b, c, in[4], 5);
83 	ROUND2(c, d, a, b, in[8], 9);
84 	ROUND2(b, c, d, a, in[12], 13);
85 	ROUND2(a, b, c, d, in[1], 3);
86 	ROUND2(d, a, b, c, in[5], 5);
87 	ROUND2(c, d, a, b, in[9], 9);
88 	ROUND2(b, c, d, a, in[13], 13);
89 	ROUND2(a, b, c, d, in[2], 3);
90 	ROUND2(d, a, b, c, in[6], 5);
91 	ROUND2(c, d, a, b, in[10], 9);
92 	ROUND2(b, c, d, a, in[14], 13);
93 	ROUND2(a, b, c, d, in[3], 3);
94 	ROUND2(d, a, b, c, in[7], 5);
95 	ROUND2(c, d, a, b, in[11], 9);
96 	ROUND2(b, c, d, a, in[15], 13);
97 
98 	ROUND3(a, b, c, d, in[0], 3);
99 	ROUND3(d, a, b, c, in[8], 9);
100 	ROUND3(c, d, a, b, in[4], 11);
101 	ROUND3(b, c, d, a, in[12], 15);
102 	ROUND3(a, b, c, d, in[2], 3);
103 	ROUND3(d, a, b, c, in[10], 9);
104 	ROUND3(c, d, a, b, in[6], 11);
105 	ROUND3(b, c, d, a, in[14], 15);
106 	ROUND3(a, b, c, d, in[1], 3);
107 	ROUND3(d, a, b, c, in[9], 9);
108 	ROUND3(c, d, a, b, in[5], 11);
109 	ROUND3(b, c, d, a, in[13], 15);
110 	ROUND3(a, b, c, d, in[3], 3);
111 	ROUND3(d, a, b, c, in[11], 9);
112 	ROUND3(c, d, a, b, in[7], 11);
113 	ROUND3(b, c, d, a, in[15], 15);
114 
115 	hash[0] += a;
116 	hash[1] += b;
117 	hash[2] += c;
118 	hash[3] += d;
119 }
120 
121 static inline void md4_transform_helper(struct md4_ctx *ctx)
122 {
123 	le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
124 	md4_transform(ctx->hash, ctx->block);
125 }
126 
127 int cifs_md4_init(struct md4_ctx *mctx)
128 {
129 	memset(mctx, 0, sizeof(struct md4_ctx));
130 	mctx->hash[0] = 0x67452301;
131 	mctx->hash[1] = 0xefcdab89;
132 	mctx->hash[2] = 0x98badcfe;
133 	mctx->hash[3] = 0x10325476;
134 	mctx->byte_count = 0;
135 
136 	return 0;
137 }
138 EXPORT_SYMBOL_GPL(cifs_md4_init);
139 
140 int cifs_md4_update(struct md4_ctx *mctx, const u8 *data, unsigned int len)
141 {
142 	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
143 
144 	mctx->byte_count += len;
145 
146 	if (avail > len) {
147 		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
148 		       data, len);
149 		return 0;
150 	}
151 
152 	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
153 	       data, avail);
154 
155 	md4_transform_helper(mctx);
156 	data += avail;
157 	len -= avail;
158 
159 	while (len >= sizeof(mctx->block)) {
160 		memcpy(mctx->block, data, sizeof(mctx->block));
161 		md4_transform_helper(mctx);
162 		data += sizeof(mctx->block);
163 		len -= sizeof(mctx->block);
164 	}
165 
166 	memcpy(mctx->block, data, len);
167 
168 	return 0;
169 }
170 EXPORT_SYMBOL_GPL(cifs_md4_update);
171 
172 int cifs_md4_final(struct md4_ctx *mctx, u8 *out)
173 {
174 	const unsigned int offset = mctx->byte_count & 0x3f;
175 	char *p = (char *)mctx->block + offset;
176 	int padding = 56 - (offset + 1);
177 
178 	*p++ = 0x80;
179 	if (padding < 0) {
180 		memset(p, 0x00, padding + sizeof(u64));
181 		md4_transform_helper(mctx);
182 		p = (char *)mctx->block;
183 		padding = 56;
184 	}
185 
186 	memset(p, 0, padding);
187 	mctx->block[14] = mctx->byte_count << 3;
188 	mctx->block[15] = mctx->byte_count >> 29;
189 	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
190 			  sizeof(u64)) / sizeof(u32));
191 	md4_transform(mctx->hash, mctx->block);
192 	cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
193 	memcpy(out, mctx->hash, sizeof(mctx->hash));
194 	memset(mctx, 0, sizeof(*mctx));
195 
196 	return 0;
197 }
198 EXPORT_SYMBOL_GPL(cifs_md4_final);
199