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Diffstat (limited to 'libbb/hash_md5.c')
| -rw-r--r-- | libbb/hash_md5.c | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/libbb/hash_md5.c b/libbb/hash_md5.c new file mode 100644 index 000000000..051c8ede4 --- /dev/null +++ b/libbb/hash_md5.c @@ -0,0 +1,442 @@ +/* vi: set sw=4 ts=4: */ +/* + * Compute MD5 checksum of strings according to the + * definition of MD5 in RFC 1321 from April 1992. + * + * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. + * + * Copyright (C) 1995-1999 Free Software Foundation, Inc. + * Copyright (C) 2001 Manuel Novoa III + * Copyright (C) 2003 Glenn L. McGrath + * Copyright (C) 2003 Erik Andersen + * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. + */ + +#include "libbb.h" + +/* 0: fastest, 3: smallest */ +#if CONFIG_MD5_SIZE_VS_SPEED < 0 +# define MD5_SIZE_VS_SPEED 0 +#elif CONFIG_MD5_SIZE_VS_SPEED > 3 +# define MD5_SIZE_VS_SPEED 3 +#else +# define MD5_SIZE_VS_SPEED CONFIG_MD5_SIZE_VS_SPEED +#endif + +/* Initialize structure containing state of computation. + * (RFC 1321, 3.3: Step 3) + */ +void FAST_FUNC md5_begin(md5_ctx_t *ctx) +{ + ctx->A = 0x67452301; + ctx->B = 0xefcdab89; + ctx->C = 0x98badcfe; + ctx->D = 0x10325476; + ctx->total64 = 0; +} + +/* These are the four functions used in the four steps of the MD5 algorithm + * and defined in the RFC 1321. The first function is a little bit optimized + * (as found in Colin Plumbs public domain implementation). + * #define FF(b, c, d) ((b & c) | (~b & d)) + */ +#define FF(b, c, d) (d ^ (b & (c ^ d))) +#define FG(b, c, d) FF(d, b, c) +#define FH(b, c, d) (b ^ c ^ d) +#define FI(b, c, d) (c ^ (b | ~d)) + +#define rotl32(w, s) (((w) << (s)) | ((w) >> (32 - (s)))) + +/* Hash a single block, 64 bytes long and 4-byte aligned */ +static void md5_process_block64(md5_ctx_t *ctx) +{ +#if MD5_SIZE_VS_SPEED > 0 + /* Before we start, one word to the strange constants. + They are defined in RFC 1321 as + T[i] = (int)(4294967296.0 * fabs(sin(i))), i=1..64 + */ + static const uint32_t C_array[] = { + /* round 1 */ + 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, + 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501, + 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be, + 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, + /* round 2 */ + 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, + 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8, + 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, + 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a, + /* round 3 */ + 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, + 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, + 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05, + 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, + /* round 4 */ + 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, + 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1, + 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1, + 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 + }; + static const char P_array[] ALIGN1 = { +# if MD5_SIZE_VS_SPEED > 1 + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 1 */ +# endif + 1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12, /* 2 */ + 5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2, /* 3 */ + 0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9 /* 4 */ + }; +#endif + uint32_t *words = (void*) ctx->wbuffer; + uint32_t A = ctx->A; + uint32_t B = ctx->B; + uint32_t C = ctx->C; + uint32_t D = ctx->D; + +#if MD5_SIZE_VS_SPEED >= 2 /* 2 or 3 */ + + static const char S_array[] ALIGN1 = { + 7, 12, 17, 22, + 5, 9, 14, 20, + 4, 11, 16, 23, + 6, 10, 15, 21 + }; + const uint32_t *pc; + const char *pp; + const char *ps; + int i; + uint32_t temp; + +# if BB_BIG_ENDIAN + for (i = 0; i < 16; i++) + words[i] = SWAP_LE32(words[i]); +# endif + +# if MD5_SIZE_VS_SPEED == 3 + pc = C_array; + pp = P_array; + ps = S_array - 4; + + for (i = 0; i < 64; i++) { + if ((i & 0x0f) == 0) + ps += 4; + temp = A; + switch (i >> 4) { + case 0: + temp += FF(B, C, D); + break; + case 1: + temp += FG(B, C, D); + break; + case 2: + temp += FH(B, C, D); + break; + case 3: + temp += FI(B, C, D); + } + temp += words[(int) (*pp++)] + *pc++; + temp = rotl32(temp, ps[i & 3]); + temp += B; + A = D; + D = C; + C = B; + B = temp; + } +# else /* MD5_SIZE_VS_SPEED == 2 */ + pc = C_array; + pp = P_array; + ps = S_array; + + for (i = 0; i < 16; i++) { + temp = A + FF(B, C, D) + words[(int) (*pp++)] + *pc++; + temp = rotl32(temp, ps[i & 3]); + temp += B; + A = D; + D = C; + C = B; + B = temp; + } + ps += 4; + for (i = 0; i < 16; i++) { + temp = A + FG(B, C, D) + words[(int) (*pp++)] + *pc++; + temp = rotl32(temp, ps[i & 3]); + temp += B; + A = D; + D = C; + C = B; + B = temp; + } + ps += 4; + for (i = 0; i < 16; i++) { + temp = A + FH(B, C, D) + words[(int) (*pp++)] + *pc++; + temp = rotl32(temp, ps[i & 3]); + temp += B; + A = D; + D = C; + C = B; + B = temp; + } + ps += 4; + for (i = 0; i < 16; i++) { + temp = A + FI(B, C, D) + words[(int) (*pp++)] + *pc++; + temp = rotl32(temp, ps[i & 3]); + temp += B; + A = D; + D = C; + C = B; + B = temp; + } +# endif + /* Add checksum to the starting values */ + ctx->A += A; + ctx->B += B; + ctx->C += C; + ctx->D += D; + +#else /* MD5_SIZE_VS_SPEED == 0 or 1 */ + + uint32_t A_save = A; + uint32_t B_save = B; + uint32_t C_save = C; + uint32_t D_save = D; +# if MD5_SIZE_VS_SPEED == 1 + const uint32_t *pc; + const char *pp; + int i; +# endif + + /* First round: using the given function, the context and a constant + the next context is computed. Because the algorithm's processing + unit is a 32-bit word and it is determined to work on words in + little endian byte order we perhaps have to change the byte order + before the computation. To reduce the work for the next steps + we save swapped words in WORDS array. */ +# undef OP +# define OP(a, b, c, d, s, T) \ + do { \ + a += FF(b, c, d) + (*words IF_BIG_ENDIAN(= SWAP_LE32(*words))) + T; \ + words++; \ + a = rotl32(a, s); \ + a += b; \ + } while (0) + + /* Round 1 */ +# if MD5_SIZE_VS_SPEED == 1 + pc = C_array; + for (i = 0; i < 4; i++) { + OP(A, B, C, D, 7, *pc++); + OP(D, A, B, C, 12, *pc++); + OP(C, D, A, B, 17, *pc++); + OP(B, C, D, A, 22, *pc++); + } +# else + OP(A, B, C, D, 7, 0xd76aa478); + OP(D, A, B, C, 12, 0xe8c7b756); + OP(C, D, A, B, 17, 0x242070db); + OP(B, C, D, A, 22, 0xc1bdceee); + OP(A, B, C, D, 7, 0xf57c0faf); + OP(D, A, B, C, 12, 0x4787c62a); + OP(C, D, A, B, 17, 0xa8304613); + OP(B, C, D, A, 22, 0xfd469501); + OP(A, B, C, D, 7, 0x698098d8); + OP(D, A, B, C, 12, 0x8b44f7af); + OP(C, D, A, B, 17, 0xffff5bb1); + OP(B, C, D, A, 22, 0x895cd7be); + OP(A, B, C, D, 7, 0x6b901122); + OP(D, A, B, C, 12, 0xfd987193); + OP(C, D, A, B, 17, 0xa679438e); + OP(B, C, D, A, 22, 0x49b40821); +# endif + words -= 16; + + /* For the second to fourth round we have the possibly swapped words + in WORDS. Redefine the macro to take an additional first + argument specifying the function to use. */ +# undef OP +# define OP(f, a, b, c, d, k, s, T) \ + do { \ + a += f(b, c, d) + words[k] + T; \ + a = rotl32(a, s); \ + a += b; \ + } while (0) + + /* Round 2 */ +# if MD5_SIZE_VS_SPEED == 1 + pp = P_array; + for (i = 0; i < 4; i++) { + OP(FG, A, B, C, D, (int) (*pp++), 5, *pc++); + OP(FG, D, A, B, C, (int) (*pp++), 9, *pc++); + OP(FG, C, D, A, B, (int) (*pp++), 14, *pc++); + OP(FG, B, C, D, A, (int) (*pp++), 20, *pc++); + } +# else + OP(FG, A, B, C, D, 1, 5, 0xf61e2562); + OP(FG, D, A, B, C, 6, 9, 0xc040b340); + OP(FG, C, D, A, B, 11, 14, 0x265e5a51); + OP(FG, B, C, D, A, 0, 20, 0xe9b6c7aa); + OP(FG, A, B, C, D, 5, 5, 0xd62f105d); + OP(FG, D, A, B, C, 10, 9, 0x02441453); + OP(FG, C, D, A, B, 15, 14, 0xd8a1e681); + OP(FG, B, C, D, A, 4, 20, 0xe7d3fbc8); + OP(FG, A, B, C, D, 9, 5, 0x21e1cde6); + OP(FG, D, A, B, C, 14, 9, 0xc33707d6); + OP(FG, C, D, A, B, 3, 14, 0xf4d50d87); + OP(FG, B, C, D, A, 8, 20, 0x455a14ed); + OP(FG, A, B, C, D, 13, 5, 0xa9e3e905); + OP(FG, D, A, B, C, 2, 9, 0xfcefa3f8); + OP(FG, C, D, A, B, 7, 14, 0x676f02d9); + OP(FG, B, C, D, A, 12, 20, 0x8d2a4c8a); +# endif + + /* Round 3 */ +# if MD5_SIZE_VS_SPEED == 1 + for (i = 0; i < 4; i++) { + OP(FH, A, B, C, D, (int) (*pp++), 4, *pc++); + OP(FH, D, A, B, C, (int) (*pp++), 11, *pc++); + OP(FH, C, D, A, B, (int) (*pp++), 16, *pc++); + OP(FH, B, C, D, A, (int) (*pp++), 23, *pc++); + } +# else + OP(FH, A, B, C, D, 5, 4, 0xfffa3942); + OP(FH, D, A, B, C, 8, 11, 0x8771f681); + OP(FH, C, D, A, B, 11, 16, 0x6d9d6122); + OP(FH, B, C, D, A, 14, 23, 0xfde5380c); + OP(FH, A, B, C, D, 1, 4, 0xa4beea44); + OP(FH, D, A, B, C, 4, 11, 0x4bdecfa9); + OP(FH, C, D, A, B, 7, 16, 0xf6bb4b60); + OP(FH, B, C, D, A, 10, 23, 0xbebfbc70); + OP(FH, A, B, C, D, 13, 4, 0x289b7ec6); + OP(FH, D, A, B, C, 0, 11, 0xeaa127fa); + OP(FH, C, D, A, B, 3, 16, 0xd4ef3085); + OP(FH, B, C, D, A, 6, 23, 0x04881d05); + OP(FH, A, B, C, D, 9, 4, 0xd9d4d039); + OP(FH, D, A, B, C, 12, 11, 0xe6db99e5); + OP(FH, C, D, A, B, 15, 16, 0x1fa27cf8); + OP(FH, B, C, D, A, 2, 23, 0xc4ac5665); +# endif + + /* Round 4 */ +# if MD5_SIZE_VS_SPEED == 1 + for (i = 0; i < 4; i++) { + OP(FI, A, B, C, D, (int) (*pp++), 6, *pc++); + OP(FI, D, A, B, C, (int) (*pp++), 10, *pc++); + OP(FI, C, D, A, B, (int) (*pp++), 15, *pc++); + OP(FI, B, C, D, A, (int) (*pp++), 21, *pc++); + } +# else + OP(FI, A, B, C, D, 0, 6, 0xf4292244); + OP(FI, D, A, B, C, 7, 10, 0x432aff97); + OP(FI, C, D, A, B, 14, 15, 0xab9423a7); + OP(FI, B, C, D, A, 5, 21, 0xfc93a039); + OP(FI, A, B, C, D, 12, 6, 0x655b59c3); + OP(FI, D, A, B, C, 3, 10, 0x8f0ccc92); + OP(FI, C, D, A, B, 10, 15, 0xffeff47d); + OP(FI, B, C, D, A, 1, 21, 0x85845dd1); + OP(FI, A, B, C, D, 8, 6, 0x6fa87e4f); + OP(FI, D, A, B, C, 15, 10, 0xfe2ce6e0); + OP(FI, C, D, A, B, 6, 15, 0xa3014314); + OP(FI, B, C, D, A, 13, 21, 0x4e0811a1); + OP(FI, A, B, C, D, 4, 6, 0xf7537e82); + OP(FI, D, A, B, C, 11, 10, 0xbd3af235); + OP(FI, C, D, A, B, 2, 15, 0x2ad7d2bb); + OP(FI, B, C, D, A, 9, 21, 0xeb86d391); +# endif + /* Add checksum to the starting values */ + ctx->A = A_save + A; + ctx->B = B_save + B; + ctx->C = C_save + C; + ctx->D = D_save + D; +#endif +} + +/* Feed data through a temporary buffer to call md5_hash_aligned_block() + * with chunks of data that are 4-byte aligned and a multiple of 64 bytes. + * This function's internal buffer remembers previous data until it has 64 + * bytes worth to pass on. Call md5_end() to flush this buffer. */ +void FAST_FUNC md5_hash(md5_ctx_t *ctx, const void *buffer, size_t len) +{ + unsigned bufpos = ctx->total64 & 63; + unsigned remaining; + + /* RFC 1321 specifies the possible length of the file up to 2^64 bits. + * Here we only track the number of bytes. */ + ctx->total64 += len; +#if 0 + remaining = 64 - bufpos; + + /* Hash whole blocks */ + while (len >= remaining) { + memcpy(ctx->wbuffer + bufpos, buffer, remaining); + buffer = (const char *)buffer + remaining; + len -= remaining; + remaining = 64; + bufpos = 0; + md5_process_block64(ctx); + } + + /* Save last, partial blosk */ + memcpy(ctx->wbuffer + bufpos, buffer, len); +#else + /* Tiny bit smaller code */ + while (1) { + remaining = 64 - bufpos; + if (remaining > len) + remaining = len; + /* Copy data into aligned buffer */ + memcpy(ctx->wbuffer + bufpos, buffer, remaining); + len -= remaining; + buffer = (const char *)buffer + remaining; + bufpos += remaining; + /* clever way to do "if (bufpos != 64) break; ... ; bufpos = 0;" */ + bufpos -= 64; + if (bufpos != 0) + break; + /* Buffer is filled up, process it */ + md5_process_block64(ctx); + /*bufpos = 0; - already is */ + } +#endif +} + +/* Process the remaining bytes in the buffer and put result from CTX + * in first 16 bytes following RESBUF. The result is always in little + * endian byte order, so that a byte-wise output yields to the wanted + * ASCII representation of the message digest. + */ +void FAST_FUNC md5_end(md5_ctx_t *ctx, void *resbuf) +{ + unsigned bufpos = ctx->total64 & 63; + /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... */ + ctx->wbuffer[bufpos++] = 0x80; + + /* This loop iterates either once or twice, no more, no less */ + while (1) { + unsigned remaining = 64 - bufpos; + memset(ctx->wbuffer + bufpos, 0, remaining); + /* Do we have enough space for the length count? */ + if (remaining >= 8) { + /* Store the 64-bit counter of bits in the buffer in BE format */ + uint64_t t = ctx->total64 << 3; + unsigned i; + for (i = 0; i < 8; i++) { + ctx->wbuffer[56 + i] = t; + t >>= 8; + } + } + md5_process_block64(ctx); + if (remaining >= 8) + break; + bufpos = 0; + } + + /* The MD5 result is in little endian byte order. + * We (ab)use the fact that A-D are consecutive in memory. + */ +#if BB_BIG_ENDIAN + ctx->A = SWAP_LE32(ctx->A); + ctx->B = SWAP_LE32(ctx->B); + ctx->C = SWAP_LE32(ctx->C); + ctx->D = SWAP_LE32(ctx->D); +#endif + memcpy(resbuf, &ctx->A, sizeof(ctx->A) * 4); +} |