[388] | 1 | /*
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| 2 | * md5 crypt implementation
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| 3 | *
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| 4 | * original md5 crypt design is from Poul-Henning Kamp
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| 5 | * this implementation was created based on the code in freebsd
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| 6 | * at least 32bit int is assumed, key is limited and $1$ prefix is mandatory,
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| 7 | * on error "*" is returned
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| 8 | */
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| 9 | #include <string.h>
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| 10 | #include <stdint.h>
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| 11 |
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| 12 | /* public domain md5 implementation based on rfc1321 and libtomcrypt */
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| 13 |
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| 14 | struct md5 {
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| 15 | uint64_t len; /* processed message length */
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| 16 | uint32_t h[4]; /* hash state */
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| 17 | uint8_t buf[64]; /* message block buffer */
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| 18 | };
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| 19 |
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| 20 | static uint32_t rol(uint32_t n, int k) { return (n << k) | (n >> (32-k)); }
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| 21 | #define F(x,y,z) (z ^ (x & (y ^ z)))
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| 22 | #define G(x,y,z) (y ^ (z & (y ^ x)))
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| 23 | #define H(x,y,z) (x ^ y ^ z)
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| 24 | #define I(x,y,z) (y ^ (x | ~z))
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| 25 | #define FF(a,b,c,d,w,s,t) a += F(b,c,d) + w + t; a = rol(a,s) + b
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| 26 | #define GG(a,b,c,d,w,s,t) a += G(b,c,d) + w + t; a = rol(a,s) + b
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| 27 | #define HH(a,b,c,d,w,s,t) a += H(b,c,d) + w + t; a = rol(a,s) + b
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| 28 | #define II(a,b,c,d,w,s,t) a += I(b,c,d) + w + t; a = rol(a,s) + b
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| 29 |
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| 30 | static const uint32_t tab[64] = {
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| 31 | 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
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| 32 | 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be, 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
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| 33 | 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
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| 34 | 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
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| 35 | 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
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| 36 | 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
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| 37 | 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
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| 38 | 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1, 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
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| 39 | };
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| 40 |
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| 41 | static void processblock(struct md5 *s, const uint8_t *buf)
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| 42 | {
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| 43 | uint32_t i, W[16], a, b, c, d;
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| 44 |
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| 45 | for (i = 0; i < 16; i++) {
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| 46 | W[i] = buf[4*i];
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| 47 | W[i] |= (uint32_t)buf[4*i+1]<<8;
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| 48 | W[i] |= (uint32_t)buf[4*i+2]<<16;
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| 49 | W[i] |= (uint32_t)buf[4*i+3]<<24;
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| 50 | }
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| 51 |
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| 52 | a = s->h[0];
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| 53 | b = s->h[1];
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| 54 | c = s->h[2];
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| 55 | d = s->h[3];
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| 56 |
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| 57 | i = 0;
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| 58 | while (i < 16) {
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| 59 | FF(a,b,c,d, W[i], 7, tab[i]); i++;
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| 60 | FF(d,a,b,c, W[i], 12, tab[i]); i++;
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| 61 | FF(c,d,a,b, W[i], 17, tab[i]); i++;
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| 62 | FF(b,c,d,a, W[i], 22, tab[i]); i++;
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| 63 | }
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| 64 | while (i < 32) {
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| 65 | GG(a,b,c,d, W[(5*i+1)%16], 5, tab[i]); i++;
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| 66 | GG(d,a,b,c, W[(5*i+1)%16], 9, tab[i]); i++;
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| 67 | GG(c,d,a,b, W[(5*i+1)%16], 14, tab[i]); i++;
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| 68 | GG(b,c,d,a, W[(5*i+1)%16], 20, tab[i]); i++;
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| 69 | }
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| 70 | while (i < 48) {
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| 71 | HH(a,b,c,d, W[(3*i+5)%16], 4, tab[i]); i++;
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| 72 | HH(d,a,b,c, W[(3*i+5)%16], 11, tab[i]); i++;
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| 73 | HH(c,d,a,b, W[(3*i+5)%16], 16, tab[i]); i++;
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| 74 | HH(b,c,d,a, W[(3*i+5)%16], 23, tab[i]); i++;
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| 75 | }
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| 76 | while (i < 64) {
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| 77 | II(a,b,c,d, W[7*i%16], 6, tab[i]); i++;
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| 78 | II(d,a,b,c, W[7*i%16], 10, tab[i]); i++;
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| 79 | II(c,d,a,b, W[7*i%16], 15, tab[i]); i++;
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| 80 | II(b,c,d,a, W[7*i%16], 21, tab[i]); i++;
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| 81 | }
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| 82 |
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| 83 | s->h[0] += a;
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| 84 | s->h[1] += b;
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| 85 | s->h[2] += c;
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| 86 | s->h[3] += d;
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| 87 | }
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| 88 |
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| 89 | static void pad(struct md5 *s)
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| 90 | {
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| 91 | unsigned r = s->len % 64;
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| 92 |
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| 93 | s->buf[r++] = 0x80;
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| 94 | if (r > 56) {
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| 95 | memset(s->buf + r, 0, 64 - r);
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| 96 | r = 0;
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| 97 | processblock(s, s->buf);
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| 98 | }
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| 99 | memset(s->buf + r, 0, 56 - r);
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| 100 | s->len *= 8;
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| 101 | s->buf[56] = s->len;
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| 102 | s->buf[57] = s->len >> 8;
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| 103 | s->buf[58] = s->len >> 16;
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| 104 | s->buf[59] = s->len >> 24;
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| 105 | s->buf[60] = s->len >> 32;
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| 106 | s->buf[61] = s->len >> 40;
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| 107 | s->buf[62] = s->len >> 48;
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| 108 | s->buf[63] = s->len >> 56;
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| 109 | processblock(s, s->buf);
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| 110 | }
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| 111 |
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| 112 | static void md5_init(struct md5 *s)
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| 113 | {
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| 114 | s->len = 0;
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| 115 | s->h[0] = 0x67452301;
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| 116 | s->h[1] = 0xefcdab89;
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| 117 | s->h[2] = 0x98badcfe;
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| 118 | s->h[3] = 0x10325476;
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| 119 | }
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| 120 |
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| 121 | static void md5_sum(struct md5 *s, uint8_t *md)
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| 122 | {
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| 123 | int i;
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| 124 |
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| 125 | pad(s);
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| 126 | for (i = 0; i < 4; i++) {
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| 127 | md[4*i] = s->h[i];
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| 128 | md[4*i+1] = s->h[i] >> 8;
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| 129 | md[4*i+2] = s->h[i] >> 16;
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| 130 | md[4*i+3] = s->h[i] >> 24;
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| 131 | }
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| 132 | }
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| 133 |
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| 134 | static void md5_update(struct md5 *s, const void *m, unsigned long len)
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| 135 | {
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| 136 | const uint8_t *p = m;
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| 137 | unsigned r = s->len % 64;
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| 138 |
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| 139 | s->len += len;
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| 140 | if (r) {
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| 141 | if (len < 64 - r) {
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| 142 | memcpy(s->buf + r, p, len);
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| 143 | return;
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| 144 | }
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| 145 | memcpy(s->buf + r, p, 64 - r);
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| 146 | len -= 64 - r;
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| 147 | p += 64 - r;
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| 148 | processblock(s, s->buf);
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| 149 | }
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| 150 | for (; len >= 64; len -= 64, p += 64)
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| 151 | processblock(s, p);
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| 152 | memcpy(s->buf, p, len);
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| 153 | }
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| 154 |
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| 155 | /*-
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| 156 | * Copyright (c) 2003 Poul-Henning Kamp
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| 157 | * All rights reserved.
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| 158 | *
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| 159 | * Redistribution and use in source and binary forms, with or without
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| 160 | * modification, are permitted provided that the following conditions
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| 161 | * are met:
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| 162 | * 1. Redistributions of source code must retain the above copyright
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| 163 | * notice, this list of conditions and the following disclaimer.
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| 164 | * 2. Redistributions in binary form must reproduce the above copyright
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| 165 | * notice, this list of conditions and the following disclaimer in the
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| 166 | * documentation and/or other materials provided with the distribution.
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| 167 | *
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| 168 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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| 169 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 170 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| 171 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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| 172 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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| 173 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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| 174 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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| 175 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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| 176 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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| 177 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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| 178 | * SUCH DAMAGE.
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| 179 | */
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| 180 |
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| 181 | /* key limit is not part of the original design, added for DoS protection */
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| 182 | #define KEY_MAX 30000
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| 183 | #define SALT_MAX 8
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| 184 |
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| 185 | static const unsigned char b64[] =
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| 186 | "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
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| 187 |
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| 188 | static char *to64(char *s, unsigned int u, int n)
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| 189 | {
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| 190 | while (--n >= 0) {
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| 191 | *s++ = b64[u % 64];
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| 192 | u /= 64;
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| 193 | }
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| 194 | return s;
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| 195 | }
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| 196 |
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| 197 | static char *md5crypt(const char *key, const char *setting, char *output)
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| 198 | {
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| 199 | struct md5 ctx;
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| 200 | unsigned char md[16];
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| 201 | unsigned int i, klen, slen;
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| 202 | const char *salt;
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| 203 | char *p;
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| 204 |
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| 205 | /* reject large keys */
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| 206 | klen = strnlen(key, KEY_MAX+1);
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| 207 | if (klen > KEY_MAX)
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| 208 | return 0;
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| 209 |
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| 210 | /* setting: $1$salt$ (closing $ is optional) */
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| 211 | if (strncmp(setting, "$1$", 3) != 0)
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| 212 | return 0;
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| 213 | salt = setting + 3;
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| 214 | for (i = 0; i < SALT_MAX && salt[i] && salt[i] != '$'; i++);
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| 215 | slen = i;
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| 216 |
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| 217 | /* md5(key salt key) */
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| 218 | md5_init(&ctx);
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| 219 | md5_update(&ctx, key, klen);
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| 220 | md5_update(&ctx, salt, slen);
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| 221 | md5_update(&ctx, key, klen);
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| 222 | md5_sum(&ctx, md);
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| 223 |
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| 224 | /* md5(key $1$ salt repeated-md weird-key[0]-0) */
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| 225 | md5_init(&ctx);
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| 226 | md5_update(&ctx, key, klen);
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| 227 | md5_update(&ctx, setting, 3 + slen);
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| 228 | for (i = klen; i > sizeof md; i -= sizeof md)
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| 229 | md5_update(&ctx, md, sizeof md);
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| 230 | md5_update(&ctx, md, i);
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| 231 | md[0] = 0;
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| 232 | for (i = klen; i; i >>= 1)
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| 233 | if (i & 1)
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| 234 | md5_update(&ctx, md, 1);
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| 235 | else
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| 236 | md5_update(&ctx, key, 1);
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| 237 | md5_sum(&ctx, md);
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| 238 |
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| 239 | /* md = f(md, key, salt) iteration */
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| 240 | for (i = 0; i < 1000; i++) {
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| 241 | md5_init(&ctx);
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| 242 | if (i % 2)
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| 243 | md5_update(&ctx, key, klen);
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| 244 | else
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| 245 | md5_update(&ctx, md, sizeof md);
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| 246 | if (i % 3)
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| 247 | md5_update(&ctx, salt, slen);
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| 248 | if (i % 7)
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| 249 | md5_update(&ctx, key, klen);
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| 250 | if (i % 2)
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| 251 | md5_update(&ctx, md, sizeof md);
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| 252 | else
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| 253 | md5_update(&ctx, key, klen);
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| 254 | md5_sum(&ctx, md);
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| 255 | }
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| 256 |
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| 257 | /* output is $1$salt$hash */
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| 258 | memcpy(output, setting, 3 + slen);
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| 259 | p = output + 3 + slen;
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| 260 | *p++ = '$';
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| 261 | static const unsigned char perm[][3] = {
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| 262 | 0,6,12,1,7,13,2,8,14,3,9,15,4,10,5 };
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| 263 | for (i=0; i<5; i++) p = to64(p,
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| 264 | (md[perm[i][0]]<<16)|(md[perm[i][1]]<<8)|md[perm[i][2]], 4);
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| 265 | p = to64(p, md[11], 2);
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| 266 | *p = 0;
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| 267 |
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| 268 | return output;
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| 269 | }
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| 270 |
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| 271 | char *__crypt_md5(const char *key, const char *setting, char *output)
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| 272 | {
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| 273 | static const char testkey[] = "Xy01@#\x01\x02\x80\x7f\xff\r\n\x81\t !";
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| 274 | static const char testsetting[] = "$1$abcd0123$";
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| 275 | static const char testhash[] = "$1$abcd0123$9Qcg8DyviekV3tDGMZynJ1";
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| 276 | char testbuf[64];
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| 277 | char *p, *q;
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| 278 |
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| 279 | p = md5crypt(key, setting, output);
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| 280 | /* self test and stack cleanup */
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| 281 | q = md5crypt(testkey, testsetting, testbuf);
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| 282 | if (!p || q != testbuf || memcmp(testbuf, testhash, sizeof testhash))
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| 283 | return "*";
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| 284 | return p;
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| 285 | }
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