cifs_md4.c

  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_DESCRIPTION("MD4 Message Digest Algorithm (RFC1320)");
 28MODULE_LICENSE("GPL");
 29
 30static inline u32 lshift(u32 x, unsigned int s)
 31{
 32	x &= 0xFFFFFFFF;
 33	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
 34}
 35
 36static inline u32 F(u32 x, u32 y, u32 z)
 37{
 38	return (x & y) | ((~x) & z);
 39}
 40
 41static inline u32 G(u32 x, u32 y, u32 z)
 42{
 43	return (x & y) | (x & z) | (y & z);
 44}
 45
 46static 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
 55static 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
121static 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
127int 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}
138EXPORT_SYMBOL_GPL(cifs_md4_init);
139
140int 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}
170EXPORT_SYMBOL_GPL(cifs_md4_update);
171
172int 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}
198EXPORT_SYMBOL_GPL(cifs_md4_final);