[2] | 1 | /* |
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| 2 | * This code implements the MD5 message-digest algorithm. The algorithm was |
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| 3 | * written by Ron Rivest. This code was written by Colin Plumb in 1993, our |
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| 4 | * understanding is that no copyright is claimed and that this code is in the |
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| 5 | * public domain. |
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| 6 | * |
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| 7 | * Equivalent code is available from RSA Data Security, Inc. |
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| 8 | * This code has been tested against that, and is functionally equivalent, |
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| 9 | * |
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| 10 | * To compute the message digest of a chunk of bytes, declare an MD5Context |
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| 11 | * structure, pass it to MD5Init, call MD5Update as needed on buffers full of |
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| 12 | * bytes, and then call MD5Final, which will fill a supplied 16-byte array with |
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| 13 | * the digest. |
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| 14 | */ |
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| 15 | |
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| 16 | #include <stdint.h> |
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| 17 | #include <string.h> |
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| 18 | #include "libmd5.h" |
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| 19 | |
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| 20 | //! \ingroup libMD5 |
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| 21 | //! \{ |
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| 22 | |
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| 23 | static void MD5Transform(uint32_t buf[4], uint32_t const in[16]); |
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| 24 | |
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| 25 | #ifndef __BIG_ENDIAN__ |
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| 26 | # define byteReverse(buf, len) /* Nothing */ |
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| 27 | #else |
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| 28 | void byteReverse(uint32_t *buf, unsigned len); |
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| 29 | /* |
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| 30 | * Note: this code is harmless on little-endian machines. |
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| 31 | */ |
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| 32 | void byteReverse(uint32_t *buf, unsigned len) |
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| 33 | { |
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| 34 | uint32_t t; |
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| 35 | do { |
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| 36 | char* bytes = (char *) buf; |
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| 37 | t = ((unsigned) bytes[3] << 8 | bytes[2]) << 16 | |
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| 38 | ((unsigned) bytes[1] << 8 | bytes[0]); |
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| 39 | *buf = t; |
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| 40 | buf++; |
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| 41 | } while (--len); |
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| 42 | } |
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| 43 | #endif |
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| 44 | |
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| 45 | /* |
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| 46 | * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious |
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| 47 | * initialization constants. |
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| 48 | */ |
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| 49 | void MD5Init(context_md5_t *ctx) |
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| 50 | { |
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| 51 | ctx->buf[0] = 0x67452301; |
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| 52 | ctx->buf[1] = 0xefcdab89; |
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| 53 | ctx->buf[2] = 0x98badcfe; |
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| 54 | ctx->buf[3] = 0x10325476; |
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| 55 | |
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| 56 | ctx->bits[0] = 0; |
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| 57 | ctx->bits[1] = 0; |
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| 58 | } |
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| 59 | |
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| 60 | /* |
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| 61 | * Update context to reflect the concatenation of another buffer full |
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| 62 | * of bytes. |
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| 63 | */ |
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| 64 | void MD5Update(context_md5_t *ctx, unsigned char *buf, unsigned len) |
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| 65 | { |
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| 66 | uint32_t t; |
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| 67 | |
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| 68 | /* Update bitcount */ |
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| 69 | |
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| 70 | t = ctx->bits[0]; |
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| 71 | if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t) |
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| 72 | ctx->bits[1]++; /* Carry from low to high */ |
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| 73 | ctx->bits[1] += len >> 29; |
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| 74 | |
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| 75 | t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */ |
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| 76 | |
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| 77 | /* Handle any leading odd-sized chunks */ |
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| 78 | |
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| 79 | if (t) { |
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| 80 | unsigned char *p = ctx->in.b8 + t; |
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| 81 | |
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| 82 | t = 64 - t; |
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| 83 | if (len < t) { |
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| 84 | memcpy(p, buf, len); |
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| 85 | return; |
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| 86 | } |
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| 87 | memcpy(p, buf, t); |
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| 88 | byteReverse(ctx->in.b32, 16); |
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| 89 | MD5Transform(ctx->buf, ctx->in.b32); |
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| 90 | buf += t; |
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| 91 | len -= t; |
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| 92 | } |
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| 93 | /* Process data in 64-byte chunks */ |
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| 94 | |
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| 95 | while (len >= 64) { |
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| 96 | memcpy(ctx->in.b8, buf, 64); |
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| 97 | byteReverse(ctx->in.b32, 16); |
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| 98 | MD5Transform(ctx->buf, ctx->in.b32); |
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| 99 | buf += 64; |
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| 100 | len -= 64; |
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| 101 | } |
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| 102 | |
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| 103 | /* Handle any remaining bytes of data. */ |
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| 104 | |
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| 105 | memcpy(ctx->in.b8, buf, len); |
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| 106 | } |
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| 107 | |
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| 108 | /* |
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| 109 | * Final wrapup - pad to 64-byte boundary with the bit pattern |
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| 110 | * 1 0* (64-bit count of bits processed, MSB-first) |
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| 111 | */ |
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| 112 | void MD5Final(unsigned char digest[16], context_md5_t *ctx) |
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| 113 | { |
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| 114 | unsigned count; |
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| 115 | unsigned char *p; |
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| 116 | |
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| 117 | /* Compute number of bytes mod 64 */ |
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| 118 | count = (ctx->bits[0] >> 3) & 0x3F; |
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| 119 | |
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| 120 | /* Set the first char of padding to 0x80. This is safe since there is |
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| 121 | always at least one byte free */ |
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| 122 | p = ctx->in.b8 + count; |
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| 123 | *p++ = 0x80; |
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| 124 | |
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| 125 | /* Bytes of padding needed to make 64 bytes */ |
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| 126 | count = 64 - 1 - count; |
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| 127 | |
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| 128 | /* Pad out to 56 mod 64 */ |
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| 129 | if (count < 8) { |
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| 130 | /* Two lots of padding: Pad the first block to 64 bytes */ |
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| 131 | memset(p, 0, count); |
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| 132 | byteReverse(ctx->in.b32, 16); |
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| 133 | MD5Transform(ctx->buf, ctx->in.b32); |
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| 134 | |
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| 135 | /* Now fill the next block with 56 bytes */ |
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| 136 | memset(ctx->in.b8, 0, 56); |
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| 137 | } else { |
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| 138 | /* Pad block to 56 bytes */ |
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| 139 | memset(p, 0, count - 8); |
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| 140 | } |
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| 141 | byteReverse(ctx->in.b32, 14); |
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| 142 | |
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| 143 | /* Append length in bits and transform */ |
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| 144 | ctx->in.b32[14] = ctx->bits[0]; |
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| 145 | ctx->in.b32[15] = ctx->bits[1]; |
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| 146 | |
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| 147 | MD5Transform(ctx->buf, ctx->in.b32); |
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| 148 | byteReverse((uint32_t *) ctx->buf, 4); |
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| 149 | memcpy(digest, ctx->buf, 16); |
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| 150 | |
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| 151 | memset(ctx, 0, sizeof(* ctx)); /* In case it's sensitive */ |
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| 152 | /* The original version of this code omitted the asterisk. In |
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| 153 | effect, only the first part of ctx was wiped with zeros, not |
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| 154 | the whole thing. Bug found by Derek Jones. Original line: */ |
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| 155 | // memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */ |
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| 156 | } |
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| 157 | |
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| 158 | /* The four core functions - F1 is optimized somewhat */ |
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| 159 | |
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| 160 | /* #define F1(x, y, z) (x & y | ~x & z) */ |
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| 161 | #define F1(x, y, z) (z ^ (x & (y ^ z))) |
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| 162 | #define F2(x, y, z) F1(z, x, y) |
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| 163 | #define F3(x, y, z) (x ^ y ^ z) |
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| 164 | #define F4(x, y, z) (y ^ (x | ~z)) |
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| 165 | |
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| 166 | /* This is the central step in the MD5 algorithm. */ |
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| 167 | #define MD5STEP(f, w, x, y, z, data, s) \ |
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| 168 | ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) |
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| 169 | |
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| 170 | /* |
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| 171 | * The core of the MD5 algorithm, this alters an existing MD5 hash to |
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| 172 | * reflect the addition of 16 longwords of new data. MD5Update blocks |
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| 173 | * the data and converts bytes into longwords for this routine. |
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| 174 | */ |
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| 175 | static void MD5Transform(uint32_t buf[4], uint32_t const in[16]) |
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| 176 | { |
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| 177 | register uint32_t a, b, c, d; |
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| 178 | |
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| 179 | a = buf[0]; |
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| 180 | b = buf[1]; |
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| 181 | c = buf[2]; |
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| 182 | d = buf[3]; |
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| 183 | |
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| 184 | MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); |
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| 185 | MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); |
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| 186 | MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); |
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| 187 | MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); |
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| 188 | MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); |
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| 189 | MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); |
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| 190 | MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); |
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| 191 | MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); |
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| 192 | MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); |
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| 193 | MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); |
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| 194 | MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); |
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| 195 | MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); |
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| 196 | MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); |
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| 197 | MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); |
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| 198 | MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); |
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| 199 | MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); |
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| 200 | |
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| 201 | MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); |
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| 202 | MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); |
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| 203 | MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); |
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| 204 | MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); |
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| 205 | MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); |
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| 206 | MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); |
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| 207 | MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); |
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| 208 | MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); |
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| 209 | MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); |
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| 210 | MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); |
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| 211 | MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); |
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| 212 | MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); |
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| 213 | MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); |
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| 214 | MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); |
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| 215 | MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); |
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| 216 | MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); |
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| 217 | |
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| 218 | MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); |
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| 219 | MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); |
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| 220 | MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); |
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| 221 | MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); |
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| 222 | MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); |
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| 223 | MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); |
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| 224 | MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); |
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| 225 | MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); |
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| 226 | MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); |
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| 227 | MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); |
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| 228 | MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); |
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| 229 | MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); |
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| 230 | MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); |
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| 231 | MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); |
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| 232 | MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); |
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| 233 | MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); |
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| 234 | |
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| 235 | MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); |
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| 236 | MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); |
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| 237 | MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); |
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| 238 | MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); |
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| 239 | MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); |
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| 240 | MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); |
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| 241 | MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); |
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| 242 | MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); |
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| 243 | MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); |
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| 244 | MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); |
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| 245 | MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); |
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| 246 | MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); |
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| 247 | MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); |
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| 248 | MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); |
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| 249 | MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); |
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| 250 | MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); |
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| 251 | |
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| 252 | buf[0] += a; |
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| 253 | buf[1] += b; |
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| 254 | buf[2] += c; |
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| 255 | buf[3] += d; |
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| 256 | } |
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