/* md5.c - MD5 Message-Digest Algorithm * Copyright (C) 1995, 1996, 1998, 1999, * 2000, 2001 Free Software Foundation, Inc. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2, or (at your option) any * later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * According to the definition of MD5 in RFC 1321 from April 1992. * NOTE: This is *not* the same file as the one from glibc. */ /* Written by Ulrich Drepper , 1995. */ /* Heavily modified for GnuPG by */ #include #include #include #include #include "types.h" #ifdef WORDS_BIGENDIAN #define BIG_ENDIAN_HOST #endif //#define DIM(v) (sizeof(v)/sizeof((v)[0])) #define wipememory2(_ptr,_set,_len) do { volatile char *_vptr=(volatile char *)(_ptr); size_t _vlen=(_len); while(_vlen) { *_vptr=(_set); _vptr++; _vlen--; } } while(0) #define wipememory(_ptr,_len) wipememory2(_ptr,0,_len) #define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) ) typedef struct { u32 A,B,C,D; /* chaining variables */ u32 nblocks; byte buf[64]; int count; } MD5_CONTEXT; void md5_init( MD5_CONTEXT *ctx ) { ctx->A = 0x67452301; ctx->B = 0xefcdab89; ctx->C = 0x98badcfe; ctx->D = 0x10325476; ctx->nblocks = 0; ctx->count = 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)) static void burn_stack (int bytes) { char buf[128]; wipememory(buf,sizeof buf); bytes -= sizeof buf; if (bytes > 0) burn_stack (bytes); } /**************** * transform n*64 bytes */ static void /*transform( MD5_CONTEXT *ctx, const void *buffer, size_t len )*/ transform( MD5_CONTEXT *ctx, byte *data ) { u32 correct_words[16]; u32 A = ctx->A; u32 B = ctx->B; u32 C = ctx->C; u32 D = ctx->D; u32 *cwp = correct_words; #ifdef BIG_ENDIAN_HOST { int i; byte *p2, *p1; for(i=0, p1=data, p2=(byte*)correct_words; i < 16; i++, p2 += 4 ) { p2[3] = *p1++; p2[2] = *p1++; p2[1] = *p1++; p2[0] = *p1++; } } #else memcpy( correct_words, data, 64 ); #endif #define OP(a, b, c, d, s, T) \ do \ { \ a += FF (b, c, d) + (*cwp++) + T; \ a = rol(a, s); \ a += b; \ } \ while (0) /* Before we start, one word about the strange constants. They are defined in RFC 1321 as T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64 */ /* Round 1. */ 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); #undef OP #define OP(f, a, b, c, d, k, s, T) \ do \ { \ a += f (b, c, d) + correct_words[k] + T; \ a = rol(a, s); \ a += b; \ } \ while (0) /* Round 2. */ 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); /* Round 3. */ 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); /* Round 4. */ 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); /* Put checksum in context given as argument. */ ctx->A += A; ctx->B += B; ctx->C += C; ctx->D += D; } /* The routine updates the message-digest context to * account for the presence of each of the characters inBuf[0..inLen-1] * in the message whose digest is being computed. */ void md5_write( MD5_CONTEXT *hd, byte *inbuf, size_t inlen) { if( hd->count == 64 ) { /* flush the buffer */ transform( hd, hd->buf ); burn_stack (80+6*sizeof(void*)); hd->count = 0; hd->nblocks++; } if( !inbuf ) return; if( hd->count ) { for( ; inlen && hd->count < 64; inlen-- ) hd->buf[hd->count++] = *inbuf++; md5_write( hd, NULL, 0 ); if( !inlen ) return; } while( inlen >= 64 ) { transform( hd, inbuf ); hd->count = 0; hd->nblocks++; inlen -= 64; inbuf += 64; } burn_stack (80+6*sizeof(void*)); for( ; inlen && hd->count < 64; inlen-- ) hd->buf[hd->count++] = *inbuf++; } /* The routine final terminates the message-digest computation and * ends with the desired message digest in mdContext->digest[0...15]. * The handle is prepared for a new MD5 cycle. * Returns 16 bytes representing the digest. */ void md5_final( MD5_CONTEXT *hd ) { u32 t, msb, lsb; byte *p; md5_write(hd, NULL, 0); /* flush */; t = hd->nblocks; /* multiply by 64 to make a byte count */ lsb = t << 6; msb = t >> 26; /* add the count */ t = lsb; if( (lsb += hd->count) < t ) msb++; /* multiply by 8 to make a bit count */ t = lsb; lsb <<= 3; msb <<= 3; msb |= t >> 29; if( hd->count < 56 ) { /* enough room */ hd->buf[hd->count++] = 0x80; /* pad */ while( hd->count < 56 ) hd->buf[hd->count++] = 0; /* pad */ } else { /* need one extra block */ hd->buf[hd->count++] = 0x80; /* pad character */ while( hd->count < 64 ) hd->buf[hd->count++] = 0; md5_write(hd, NULL, 0); /* flush */; memset(hd->buf, 0, 56 ); /* fill next block with zeroes */ } /* append the 64 bit count */ hd->buf[56] = lsb ; hd->buf[57] = lsb >> 8; hd->buf[58] = lsb >> 16; hd->buf[59] = lsb >> 24; hd->buf[60] = msb ; hd->buf[61] = msb >> 8; hd->buf[62] = msb >> 16; hd->buf[63] = msb >> 24; transform( hd, hd->buf ); burn_stack (80+6*sizeof(void*)); p = hd->buf; #ifdef BIG_ENDIAN_HOST #define X(a) do { *p++ = hd-> a ; *p++ = hd-> a >> 8; \ *p++ = hd-> a >> 16; *p++ = hd-> a >> 24; } while(0) #else /* little endian */ #define X(a) do { *(u32*)p = hd-> a ; p += 4; } while(0) #endif X(A); X(B); X(C); X(D); #undef X } static byte * md5_read( MD5_CONTEXT *hd ) { return hd->buf; }