Line data Source code
1 : /* vim:set ts=2 sw=2 et cindent: */
2 : /* This Source Code Form is subject to the terms of the Mozilla Public
3 : * License, v. 2.0. If a copy of the MPL was not distributed with this
4 : * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 :
6 : /*
7 : * "clean room" MD4 implementation (see RFC 1320)
8 : */
9 :
10 : #include <string.h>
11 : #include "md4.h"
12 :
13 : /* the "conditional" function */
14 : #define F(x,y,z) (((x) & (y)) | (~(x) & (z)))
15 :
16 : /* the "majority" function */
17 : #define G(x,y,z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
18 :
19 : /* the "parity" function */
20 : #define H(x,y,z) ((x) ^ (y) ^ (z))
21 :
22 : /* rotate n-bits to the left */
23 : #define ROTL(x,n) (((x) << (n)) | ((x) >> (0x20 - n)))
24 :
25 : /* round 1: [abcd k s]: a = (a + F(b,c,d) + X[k]) <<< s */
26 : #define RD1(a,b,c,d,k,s) a += F(b,c,d) + X[k]; a = ROTL(a,s)
27 :
28 : /* round 2: [abcd k s]: a = (a + G(b,c,d) + X[k] + MAGIC) <<< s */
29 : #define RD2(a,b,c,d,k,s) a += G(b,c,d) + X[k] + 0x5A827999; a = ROTL(a,s)
30 :
31 : /* round 3: [abcd k s]: a = (a + H(b,c,d) + X[k] + MAGIC) <<< s */
32 : #define RD3(a,b,c,d,k,s) a += H(b,c,d) + X[k] + 0x6ED9EBA1; a = ROTL(a,s)
33 :
34 : /* converts from word array to byte array, len is number of bytes */
35 0 : static void w2b(uint8_t *out, const uint32_t *in, uint32_t len)
36 : {
37 : uint8_t *bp; const uint32_t *wp, *wpend;
38 :
39 0 : bp = out;
40 0 : wp = in;
41 0 : wpend = wp + (len >> 2);
42 :
43 0 : for (; wp != wpend; ++wp, bp += 4)
44 : {
45 0 : bp[0] = (uint8_t) ((*wp ) & 0xFF);
46 0 : bp[1] = (uint8_t) ((*wp >> 8) & 0xFF);
47 0 : bp[2] = (uint8_t) ((*wp >> 16) & 0xFF);
48 0 : bp[3] = (uint8_t) ((*wp >> 24) & 0xFF);
49 : }
50 0 : }
51 :
52 : /* converts from byte array to word array, len is number of bytes */
53 0 : static void b2w(uint32_t *out, const uint8_t *in, uint32_t len)
54 : {
55 : uint32_t *wp; const uint8_t *bp, *bpend;
56 :
57 0 : wp = out;
58 0 : bp = in;
59 0 : bpend = in + len;
60 :
61 0 : for (; bp != bpend; bp += 4, ++wp)
62 : {
63 0 : *wp = (uint32_t) (bp[0] ) |
64 0 : (uint32_t) (bp[1] << 8) |
65 0 : (uint32_t) (bp[2] << 16) |
66 0 : (uint32_t) (bp[3] << 24);
67 : }
68 0 : }
69 :
70 : /* update state: data is 64 bytes in length */
71 0 : static void md4step(uint32_t state[4], const uint8_t *data)
72 : {
73 : uint32_t A, B, C, D, X[16];
74 :
75 0 : b2w(X, data, 64);
76 :
77 0 : A = state[0];
78 0 : B = state[1];
79 0 : C = state[2];
80 0 : D = state[3];
81 :
82 0 : RD1(A,B,C,D, 0,3); RD1(D,A,B,C, 1,7); RD1(C,D,A,B, 2,11); RD1(B,C,D,A, 3,19);
83 0 : RD1(A,B,C,D, 4,3); RD1(D,A,B,C, 5,7); RD1(C,D,A,B, 6,11); RD1(B,C,D,A, 7,19);
84 0 : RD1(A,B,C,D, 8,3); RD1(D,A,B,C, 9,7); RD1(C,D,A,B,10,11); RD1(B,C,D,A,11,19);
85 0 : RD1(A,B,C,D,12,3); RD1(D,A,B,C,13,7); RD1(C,D,A,B,14,11); RD1(B,C,D,A,15,19);
86 :
87 0 : RD2(A,B,C,D, 0,3); RD2(D,A,B,C, 4,5); RD2(C,D,A,B, 8, 9); RD2(B,C,D,A,12,13);
88 0 : RD2(A,B,C,D, 1,3); RD2(D,A,B,C, 5,5); RD2(C,D,A,B, 9, 9); RD2(B,C,D,A,13,13);
89 0 : RD2(A,B,C,D, 2,3); RD2(D,A,B,C, 6,5); RD2(C,D,A,B,10, 9); RD2(B,C,D,A,14,13);
90 0 : RD2(A,B,C,D, 3,3); RD2(D,A,B,C, 7,5); RD2(C,D,A,B,11, 9); RD2(B,C,D,A,15,13);
91 :
92 0 : RD3(A,B,C,D, 0,3); RD3(D,A,B,C, 8,9); RD3(C,D,A,B, 4,11); RD3(B,C,D,A,12,15);
93 0 : RD3(A,B,C,D, 2,3); RD3(D,A,B,C,10,9); RD3(C,D,A,B, 6,11); RD3(B,C,D,A,14,15);
94 0 : RD3(A,B,C,D, 1,3); RD3(D,A,B,C, 9,9); RD3(C,D,A,B, 5,11); RD3(B,C,D,A,13,15);
95 0 : RD3(A,B,C,D, 3,3); RD3(D,A,B,C,11,9); RD3(C,D,A,B, 7,11); RD3(B,C,D,A,15,15);
96 :
97 0 : state[0] += A;
98 0 : state[1] += B;
99 0 : state[2] += C;
100 0 : state[3] += D;
101 0 : }
102 :
103 0 : void md4sum(const uint8_t *input, uint32_t inputLen, uint8_t *result)
104 : {
105 : uint8_t final[128];
106 : uint32_t i, n, m, state[4];
107 : uint64_t inputLenBits;
108 : uint32_t inputLenBitsLow;
109 : uint32_t inputLenBitsHigh;
110 :
111 : /* magic initial states */
112 0 : state[0] = 0x67452301;
113 0 : state[1] = 0xEFCDAB89;
114 0 : state[2] = 0x98BADCFE;
115 0 : state[3] = 0x10325476;
116 :
117 : /* compute number of complete 64-byte segments contained in input */
118 0 : m = inputLen >> 6;
119 :
120 : /* digest first m segments */
121 0 : for (i=0; i<m; ++i)
122 0 : md4step(state, (input + (i << 6)));
123 :
124 : /* build final buffer */
125 0 : n = inputLen % 64;
126 0 : memcpy(final, input + (m << 6), n);
127 0 : final[n] = 0x80;
128 0 : memset(final + n + 1, 0, 120 - (n + 1));
129 :
130 : /* Append the original input length in bits as a 64-bit number. This is done
131 : * in two 32-bit chunks, with the least-significant 32 bits first.
132 : * w2b will handle endianness. */
133 0 : inputLenBits = inputLen << 3;
134 0 : inputLenBitsLow = (uint32_t)(inputLenBits & 0xFFFFFFFF);
135 0 : w2b(final + (n >= 56 ? 120 : 56), &inputLenBitsLow, 4);
136 0 : inputLenBitsHigh = (uint32_t)((inputLenBits >> 32) & 0xFFFFFFFF);
137 0 : w2b(final + (n >= 56 ? 124 : 60), &inputLenBitsHigh, 4);
138 :
139 0 : md4step(state, final);
140 0 : if (n >= 56)
141 0 : md4step(state, final + 64);
142 :
143 : /* copy state to result */
144 0 : w2b(result, state, 16);
145 0 : }
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