/** * $Id: md5.c,v 1.2 2008/03/24 20:59:12 mascarenhas Exp $ * Hash function MD5 * @author Marcela Ozorio Suarez, Roberto I. */ #include #include "md5.h" #define WORD 32 #define MASK 0xFFFFFFFF #if __STDC_VERSION__ >= 199901L #include typedef uint32_t WORD32; #else typedef unsigned int WORD32; #endif /** * md5 hash function. * @param message: aribtary string. * @param len: message length. * @param output: buffer to receive the hash value. Its size must be * (at least) HASHSIZE. */ void md5 (const char *message, long len, char *output); /* ** Realiza a rotacao no sentido horario dos bits da variavel 'D' do tipo WORD32. ** Os bits sao deslocados de 'num' posicoes */ #define rotate(D, num) (D<>(WORD-num)) /*Macros que definem operacoes relizadas pelo algoritmo md5 */ #define F(x, y, z) (((x) & (y)) | ((~(x)) & (z))) #define G(x, y, z) (((x) & (z)) | ((y) & (~(z)))) #define H(x, y, z) ((x) ^ (y) ^ (z)) #define I(x, y, z) ((y) ^ ((x) | (~(z)))) /*vetor de numeros utilizados pelo algoritmo md5 para embaralhar bits */ static const WORD32 T[64]={ 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501, 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be, 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8, 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1, 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 }; static void word32tobytes (const WORD32 *input, char *output) { int j = 0; while (j<4*4) { WORD32 v = *input++; output[j++] = (char)(v & 0xff); v >>= 8; output[j++] = (char)(v & 0xff); v >>= 8; output[j++] = (char)(v & 0xff); v >>= 8; output[j++] = (char)(v & 0xff); } } static void inic_digest(WORD32 *d) { d[0] = 0x67452301; d[1] = 0xEFCDAB89; d[2] = 0x98BADCFE; d[3] = 0x10325476; } /*funcao que implemeta os quatro passos principais do algoritmo MD5 */ static void digest(const WORD32 *m, WORD32 *d) { int j; /*MD5 PASSO1 */ for (j=0; j<4*4; j+=4) { d[0] = d[0]+ F(d[1], d[2], d[3])+ m[j] + T[j]; d[0]=rotate(d[0], 7); d[0]+=d[1]; d[3] = d[3]+ F(d[0], d[1], d[2])+ m[(j)+1] + T[j+1]; d[3]=rotate(d[3], 12); d[3]+=d[0]; d[2] = d[2]+ F(d[3], d[0], d[1])+ m[(j)+2] + T[j+2]; d[2]=rotate(d[2], 17); d[2]+=d[3]; d[1] = d[1]+ F(d[2], d[3], d[0])+ m[(j)+3] + T[j+3]; d[1]=rotate(d[1], 22); d[1]+=d[2]; } /*MD5 PASSO2 */ for (j=0; j<4*4; j+=4) { d[0] = d[0]+ G(d[1], d[2], d[3])+ m[(5*j+1)&0x0f] + T[(j-1)+17]; d[0] = rotate(d[0],5); d[0]+=d[1]; d[3] = d[3]+ G(d[0], d[1], d[2])+ m[((5*(j+1)+1)&0x0f)] + T[(j+0)+17]; d[3] = rotate(d[3], 9); d[3]+=d[0]; d[2] = d[2]+ G(d[3], d[0], d[1])+ m[((5*(j+2)+1)&0x0f)] + T[(j+1)+17]; d[2] = rotate(d[2], 14); d[2]+=d[3]; d[1] = d[1]+ G(d[2], d[3], d[0])+ m[((5*(j+3)+1)&0x0f)] + T[(j+2)+17]; d[1] = rotate(d[1], 20); d[1]+=d[2]; } /*MD5 PASSO3 */ for (j=0; j<4*4; j+=4) { d[0] = d[0]+ H(d[1], d[2], d[3])+ m[(3*j+5)&0x0f] + T[(j-1)+33]; d[0] = rotate(d[0], 4); d[0]+=d[1]; d[3] = d[3]+ H(d[0], d[1], d[2])+ m[(3*(j+1)+5)&0x0f] + T[(j+0)+33]; d[3] = rotate(d[3], 11); d[3]+=d[0]; d[2] = d[2]+ H(d[3], d[0], d[1])+ m[(3*(j+2)+5)&0x0f] + T[(j+1)+33]; d[2] = rotate(d[2], 16); d[2]+=d[3]; d[1] = d[1]+ H(d[2], d[3], d[0])+ m[(3*(j+3)+5)&0x0f] + T[(j+2)+33]; d[1] = rotate(d[1], 23); d[1]+=d[2]; } /*MD5 PASSO4 */ for (j=0; j<4*4; j+=4) { d[0] = d[0]+ I(d[1], d[2], d[3])+ m[(7*j)&0x0f] + T[(j-1)+49]; d[0] = rotate(d[0], 6); d[0]+=d[1]; d[3] = d[3]+ I(d[0], d[1], d[2])+ m[(7*(j+1))&0x0f] + T[(j+0)+49]; d[3] = rotate(d[3], 10); d[3]+=d[0]; d[2] = d[2]+ I(d[3], d[0], d[1])+ m[(7*(j+2))&0x0f] + T[(j+1)+49]; d[2] = rotate(d[2], 15); d[2]+=d[3]; d[1] = d[1]+ I(d[2], d[3], d[0])+ m[(7*(j+3))&0x0f] + T[(j+2)+49]; d[1] = rotate(d[1], 21); d[1]+=d[2]; } } static void bytestoword32 (WORD32 *x, const char *pt) { int i; for (i=0; i<16; i++) { int j=i*4; x[i] = (((WORD32)(unsigned char)pt[j+3] << 8 | (WORD32)(unsigned char)pt[j+2]) << 8 | (WORD32)(unsigned char)pt[j+1]) << 8 | (WORD32)(unsigned char)pt[j]; } } static void put_length(WORD32 *x, long len) { /* in bits! */ x[14] = (WORD32)((len<<3) & MASK); x[15] = (WORD32)(len>>(32-3) & 0x7); } /* ** returned status: * 0 - normal message (full 64 bytes) * 1 - enough room for 0x80, but not for message length (two 4-byte words) * 2 - enough room for 0x80 plus message length (at least 9 bytes free) */ static int converte (WORD32 *x, const char *pt, int num, int old_status) { int new_status = 0; char buff[64]; if (num<64) { memcpy(buff, pt, num); /* to avoid changing original string */ memset(buff+num, 0, 64-num); if (old_status == 0) buff[num] = '\200'; new_status = 1; pt = buff; } bytestoword32(x, pt); if (num <= (64 - 9)) new_status = 2; return new_status; } void md5 (const char *message, long len, char *output) { WORD32 d[4]; int status = 0; long i = 0; inic_digest(d); while (status != 2) { WORD32 d_old[4]; WORD32 wbuff[16]; int numbytes = (len-i >= 64) ? 64 : len-i; /*salva os valores do vetor digest*/ d_old[0]=d[0]; d_old[1]=d[1]; d_old[2]=d[2]; d_old[3]=d[3]; status = converte(wbuff, message+i, numbytes, status); if (status == 2) put_length(wbuff, len); digest(wbuff, d); d[0]+=d_old[0]; d[1]+=d_old[1]; d[2]+=d_old[2]; d[3]+=d_old[3]; i += numbytes; } word32tobytes(d, output); }