From 48672163702ae1382acf8cdfae208031b533a05c Mon Sep 17 00:00:00 2001 From: simon Date: Tue, 4 Apr 2000 14:47:22 +0000 Subject: [PATCH] Replace MD5 implementation with my own code git-svn-id: svn://svn.tartarus.org/sgt/putty@437 cda61777-01e9-0310-a592-d414129be87e --- ssh.h | 11 +- sshmd5.c | 403 ++++++++++++++++++++++++++++----------------------------------- 2 files changed, 184 insertions(+), 230 deletions(-) diff --git a/ssh.h b/ssh.h index f758174f..1e2291e8 100644 --- a/ssh.h +++ b/ssh.h @@ -28,13 +28,18 @@ typedef unsigned int uint32; unsigned long crc32(const void *s, size_t len); +typedef struct { + uint32 h[4]; +} MD5_Core_State; + struct MD5Context { #ifdef MSCRYPTOAPI unsigned long hHash; #else - uint32 buf[4]; - uint32 bits[2]; - unsigned char in[64]; + MD5_Core_State core; + unsigned char block[BLKSIZE]; + int blkused; + uint32 lenhi, lenlo; #endif }; diff --git a/sshmd5.c b/sshmd5.c index c242b839..43c274c3 100644 --- a/sshmd5.c +++ b/sshmd5.c @@ -1,249 +1,198 @@ -/* This code has been heavily hacked by Tatu Ylonen to - make it compile on machines like Cray that don't have a 32 bit integer - type. */ -/* - * This code implements the MD5 message-digest algorithm. - * The algorithm is due to Ron Rivest. This code was - * written by Colin Plumb in 1993, no copyright is claimed. - * This code is in the public domain; do with it what you wish. - * - * Equivalent code is available from RSA Data Security, Inc. - * This code has been tested against that, and is equivalent, - * except that you don't need to include two pages of legalese - * with every copy. - * - * To compute the message digest of a chunk of bytes, declare an - * MD5Context structure, pass it to MD5Init, call MD5Update as - * needed on buffers full of bytes, and then call MD5Final, which - * will fill a supplied 16-byte array with the digest. - */ - #include "ssh.h" -#define GET_32BIT_LSB_FIRST(cp) \ - (((unsigned long)(unsigned char)(cp)[0]) | \ - ((unsigned long)(unsigned char)(cp)[1] << 8) | \ - ((unsigned long)(unsigned char)(cp)[2] << 16) | \ - ((unsigned long)(unsigned char)(cp)[3] << 24)) - -#define PUT_32BIT_LSB_FIRST(cp, value) do { \ - (cp)[0] = (value); \ - (cp)[1] = (value) >> 8; \ - (cp)[2] = (value) >> 16; \ - (cp)[3] = (value) >> 24; } while (0) - -void MD5Transform(uint32 buf[4], const unsigned char in[64]); - /* - * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious - * initialization constants. + * MD5 implementation for PuTTY. Written directly from the spec by + * Simon Tatham. */ -void MD5Init(struct MD5Context *ctx) -{ - ctx->buf[0] = 0x67452301; - ctx->buf[1] = 0xefcdab89; - ctx->buf[2] = 0x98badcfe; - ctx->buf[3] = 0x10325476; - - ctx->bits[0] = 0; - ctx->bits[1] = 0; -} -/* - * Update context to reflect the concatenation of another buffer full - * of bytes. +/* ---------------------------------------------------------------------- + * Core MD5 algorithm: processes 16-word blocks into a message digest. */ -void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len) -{ - uint32 t; - /* Update bitcount */ +#define F(x,y,z) ( ((x) & (y)) | ((~(x)) & (z)) ) +#define G(x,y,z) ( ((x) & (z)) | ((~(z)) & (y)) ) +#define H(x,y,z) ( (x) ^ (y) ^ (z) ) +#define I(x,y,z) ( (y) ^ ( (x) | ~(z) ) ) - t = ctx->bits[0]; - if ((ctx->bits[0] = (t + ((uint32)len << 3)) & 0xffffffff) < t) - ctx->bits[1]++; /* Carry from low to high */ - ctx->bits[1] += len >> 29; +#define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) ) - t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */ +#define subround(f,w,x,y,z,k,s,ti) \ + w = x + rol(w + f(x,y,z) + block[k] + ti, s) - /* Handle any leading odd-sized chunks */ +typedef struct { + uint32 h[4]; +} MD5_Core_State; - if (t) { - unsigned char *p = ctx->in + t; +void MD5_Core_Init(MD5_Core_State *s) { + s->h[0] = 0x67452301; + s->h[1] = 0xefcdab89; + s->h[2] = 0x98badcfe; + s->h[3] = 0x10325476; +} - t = 64 - t; - if (len < t) { - memcpy(p, buf, len); - return; - } - memcpy(p, buf, t); - MD5Transform(ctx->buf, ctx->in); - buf += t; - len -= t; - } - /* Process data in 64-byte chunks */ +void MD5_Block(MD5_Core_State *s, uint32 *block) { + uint32 a,b,c,d; + + a = s->h[0]; b = s->h[1]; c = s->h[2]; d = s->h[3]; + + subround(F, a, b, c, d, 0, 7, 0xd76aa478); + subround(F, d, a, b, c, 1, 12, 0xe8c7b756); + subround(F, c, d, a, b, 2, 17, 0x242070db); + subround(F, b, c, d, a, 3, 22, 0xc1bdceee); + subround(F, a, b, c, d, 4, 7, 0xf57c0faf); + subround(F, d, a, b, c, 5, 12, 0x4787c62a); + subround(F, c, d, a, b, 6, 17, 0xa8304613); + subround(F, b, c, d, a, 7, 22, 0xfd469501); + subround(F, a, b, c, d, 8, 7, 0x698098d8); + subround(F, d, a, b, c, 9, 12, 0x8b44f7af); + subround(F, c, d, a, b, 10, 17, 0xffff5bb1); + subround(F, b, c, d, a, 11, 22, 0x895cd7be); + subround(F, a, b, c, d, 12, 7, 0x6b901122); + subround(F, d, a, b, c, 13, 12, 0xfd987193); + subround(F, c, d, a, b, 14, 17, 0xa679438e); + subround(F, b, c, d, a, 15, 22, 0x49b40821); + subround(G, a, b, c, d, 1, 5, 0xf61e2562); + subround(G, d, a, b, c, 6, 9, 0xc040b340); + subround(G, c, d, a, b, 11, 14, 0x265e5a51); + subround(G, b, c, d, a, 0, 20, 0xe9b6c7aa); + subround(G, a, b, c, d, 5, 5, 0xd62f105d); + subround(G, d, a, b, c, 10, 9, 0x02441453); + subround(G, c, d, a, b, 15, 14, 0xd8a1e681); + subround(G, b, c, d, a, 4, 20, 0xe7d3fbc8); + subround(G, a, b, c, d, 9, 5, 0x21e1cde6); + subround(G, d, a, b, c, 14, 9, 0xc33707d6); + subround(G, c, d, a, b, 3, 14, 0xf4d50d87); + subround(G, b, c, d, a, 8, 20, 0x455a14ed); + subround(G, a, b, c, d, 13, 5, 0xa9e3e905); + subround(G, d, a, b, c, 2, 9, 0xfcefa3f8); + subround(G, c, d, a, b, 7, 14, 0x676f02d9); + subround(G, b, c, d, a, 12, 20, 0x8d2a4c8a); + subround(H, a, b, c, d, 5, 4, 0xfffa3942); + subround(H, d, a, b, c, 8, 11, 0x8771f681); + subround(H, c, d, a, b, 11, 16, 0x6d9d6122); + subround(H, b, c, d, a, 14, 23, 0xfde5380c); + subround(H, a, b, c, d, 1, 4, 0xa4beea44); + subround(H, d, a, b, c, 4, 11, 0x4bdecfa9); + subround(H, c, d, a, b, 7, 16, 0xf6bb4b60); + subround(H, b, c, d, a, 10, 23, 0xbebfbc70); + subround(H, a, b, c, d, 13, 4, 0x289b7ec6); + subround(H, d, a, b, c, 0, 11, 0xeaa127fa); + subround(H, c, d, a, b, 3, 16, 0xd4ef3085); + subround(H, b, c, d, a, 6, 23, 0x04881d05); + subround(H, a, b, c, d, 9, 4, 0xd9d4d039); + subround(H, d, a, b, c, 12, 11, 0xe6db99e5); + subround(H, c, d, a, b, 15, 16, 0x1fa27cf8); + subround(H, b, c, d, a, 2, 23, 0xc4ac5665); + subround(I, a, b, c, d, 0, 6, 0xf4292244); + subround(I, d, a, b, c, 7, 10, 0x432aff97); + subround(I, c, d, a, b, 14, 15, 0xab9423a7); + subround(I, b, c, d, a, 5, 21, 0xfc93a039); + subround(I, a, b, c, d, 12, 6, 0x655b59c3); + subround(I, d, a, b, c, 3, 10, 0x8f0ccc92); + subround(I, c, d, a, b, 10, 15, 0xffeff47d); + subround(I, b, c, d, a, 1, 21, 0x85845dd1); + subround(I, a, b, c, d, 8, 6, 0x6fa87e4f); + subround(I, d, a, b, c, 15, 10, 0xfe2ce6e0); + subround(I, c, d, a, b, 6, 15, 0xa3014314); + subround(I, b, c, d, a, 13, 21, 0x4e0811a1); + subround(I, a, b, c, d, 4, 6, 0xf7537e82); + subround(I, d, a, b, c, 11, 10, 0xbd3af235); + subround(I, c, d, a, b, 2, 15, 0x2ad7d2bb); + subround(I, b, c, d, a, 9, 21, 0xeb86d391); + + s->h[0] += a; s->h[1] += b; s->h[2] += c; s->h[3] += d; +} - while (len >= 64) { - memcpy(ctx->in, buf, 64); - MD5Transform(ctx->buf, ctx->in); - buf += 64; - len -= 64; - } +/* ---------------------------------------------------------------------- + * Outer MD5 algorithm: take an arbitrary length byte string, + * convert it into 16-word blocks with the prescribed padding at + * the end, and pass those blocks to the core MD5 algorithm. + */ - /* Handle any remaining bytes of data. */ +#define BLKSIZE 64 - memcpy(ctx->in, buf, len); +void MD5Init(struct MD5Context *s) { + MD5_Core_Init(&s->core); + s->blkused = 0; + s->lenhi = s->lenlo = 0; } -/* - * Final wrapup - pad to 64-byte boundary with the bit pattern - * 1 0* (64-bit count of bits processed, MSB-first) - */ -void MD5Final(unsigned char digest[16], struct MD5Context *ctx) -{ - unsigned count; - unsigned char *p; - - /* Compute number of bytes mod 64 */ - count = (ctx->bits[0] >> 3) & 0x3F; - - /* Set the first char of padding to 0x80. This is safe since there is - always at least one byte free */ - p = ctx->in + count; - *p++ = 0x80; - - /* Bytes of padding needed to make 64 bytes */ - count = 64 - 1 - count; - - /* Pad out to 56 mod 64 */ - if (count < 8) { - /* Two lots of padding: Pad the first block to 64 bytes */ - memset(p, 0, count); - MD5Transform(ctx->buf, ctx->in); - - /* Now fill the next block with 56 bytes */ - memset(ctx->in, 0, 56); +void MD5Update(struct MD5Context *s, unsigned char const *p, + unsigned len) { + unsigned char *q = (unsigned char *)p; + uint32 wordblock[16]; + uint32 lenw = len; + int i; + + /* + * Update the length field. + */ + s->lenlo += lenw; + s->lenhi += (s->lenlo < lenw); + + if (s->blkused+len < BLKSIZE) { + /* + * Trivial case: just add to the block. + */ + memcpy(s->block + s->blkused, q, len); + s->blkused += len; } else { - /* Pad block to 56 bytes */ - memset(p, 0, count - 8); + /* + * We must complete and process at least one block. + */ + while (s->blkused + len >= BLKSIZE) { + memcpy(s->block + s->blkused, q, BLKSIZE - s->blkused); + q += BLKSIZE - s->blkused; + len -= BLKSIZE - s->blkused; + /* Now process the block. Gather bytes little-endian into words */ + for (i = 0; i < 16; i++) { + wordblock[i] = + ( ((uint32)s->block[i*4+3]) << 24 ) | + ( ((uint32)s->block[i*4+2]) << 16 ) | + ( ((uint32)s->block[i*4+1]) << 8 ) | + ( ((uint32)s->block[i*4+0]) << 0 ); + } + MD5_Block(&s->core, wordblock); + s->blkused = 0; + } + memcpy(s->block, q, len); + s->blkused = len; } - - /* Append length in bits and transform */ - PUT_32BIT_LSB_FIRST(ctx->in + 56, ctx->bits[0]); - PUT_32BIT_LSB_FIRST(ctx->in + 60, ctx->bits[1]); - - MD5Transform(ctx->buf, ctx->in); - PUT_32BIT_LSB_FIRST(digest, ctx->buf[0]); - PUT_32BIT_LSB_FIRST(digest + 4, ctx->buf[1]); - PUT_32BIT_LSB_FIRST(digest + 8, ctx->buf[2]); - PUT_32BIT_LSB_FIRST(digest + 12, ctx->buf[3]); - memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */ } -#ifndef ASM_MD5 - -/* The four core functions - F1 is optimized somewhat */ - -/* #define F1(x, y, z) (x & y | ~x & z) */ -#define F1(x, y, z) (z ^ (x & (y ^ z))) -#define F2(x, y, z) F1(z, x, y) -#define F3(x, y, z) (x ^ y ^ z) -#define F4(x, y, z) (y ^ (x | ~z)) - -/* This is the central step in the MD5 algorithm. */ -#define MD5STEP(f, w, x, y, z, data, s) \ - ( w += f(x, y, z) + data, w = w<>(32-s), w += x ) - -/* - * The core of the MD5 algorithm, this alters an existing MD5 hash to - * reflect the addition of 16 longwords of new data. MD5Update blocks - * the data and converts bytes into longwords for this routine. - */ -void MD5Transform(uint32 buf[4], const unsigned char inext[64]) -{ - register word32 a, b, c, d, i; - word32 in[16]; - - for (i = 0; i < 16; i++) - in[i] = GET_32BIT_LSB_FIRST(inext + 4 * i); - - a = buf[0]; - b = buf[1]; - c = buf[2]; - d = buf[3]; - - MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); - MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); - MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); - MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); - MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); - MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); - MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); - MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); - MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); - MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); - MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); - MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); - MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); - MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); - MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); - MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); - - MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); - MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); - MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); - MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); - MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); - MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); - MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); - MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); - MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); - MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); - MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); - MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); - MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); - MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); - MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); - MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); - - MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); - MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); - MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); - MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); - MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); - MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); - MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); - MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); - MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); - MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); - MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); - MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); - MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); - MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); - MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); - MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); - - MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); - MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); - MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); - MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); - MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); - MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); - MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); - MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); - MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); - MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); - MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); - MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); - MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); - MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); - MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); - MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); - - buf[0] += a; - buf[1] += b; - buf[2] += c; - buf[3] += d; +void MD5Final(unsigned char output[16], struct MD5Context *s) { + int i; + int pad; + unsigned char c[64]; + uint32 lenhi, lenlo; + + if (s->blkused >= 56) + pad = 56 + 64 - s->blkused; + else + pad = 56 - s->blkused; + + lenhi = (s->lenhi << 3) | (s->lenlo >> (32-3)); + lenlo = (s->lenlo << 3); + + memset(c, 0, pad); + c[0] = 0x80; + MD5_Bytes(s, &c, pad); + + c[7] = (lenhi >> 24) & 0xFF; + c[6] = (lenhi >> 16) & 0xFF; + c[5] = (lenhi >> 8) & 0xFF; + c[4] = (lenhi >> 0) & 0xFF; + c[3] = (lenlo >> 24) & 0xFF; + c[2] = (lenlo >> 16) & 0xFF; + c[1] = (lenlo >> 8) & 0xFF; + c[0] = (lenlo >> 0) & 0xFF; + + MD5_Bytes(s, &c, 8); + + for (i = 0; i < 4; i++) { + output[4*i+3] = (s->core.h[i] >> 24) & 0xFF; + output[4*i+2] = (s->core.h[i] >> 16) & 0xFF; + output[4*i+1] = (s->core.h[i] >> 8) & 0xFF; + output[4*i+0] = (s->core.h[i] >> 0) & 0xFF; + } } - -#endif -- 2.11.0