/* * MD5 implementation for PuTTY. Written directly from the spec by * Simon Tatham. */ #include #include "ssh.h" static const uint32_t md5_initial_state[] = { 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, }; static const struct md5_round_constant { uint32_t addition, rotation, msg_index; } md5_round_constants[] = { { 0xd76aa478, 7, 0 }, { 0xe8c7b756, 12, 1 }, { 0x242070db, 17, 2 }, { 0xc1bdceee, 22, 3 }, { 0xf57c0faf, 7, 4 }, { 0x4787c62a, 12, 5 }, { 0xa8304613, 17, 6 }, { 0xfd469501, 22, 7 }, { 0x698098d8, 7, 8 }, { 0x8b44f7af, 12, 9 }, { 0xffff5bb1, 17, 10 }, { 0x895cd7be, 22, 11 }, { 0x6b901122, 7, 12 }, { 0xfd987193, 12, 13 }, { 0xa679438e, 17, 14 }, { 0x49b40821, 22, 15 }, { 0xf61e2562, 5, 1 }, { 0xc040b340, 9, 6 }, { 0x265e5a51, 14, 11 }, { 0xe9b6c7aa, 20, 0 }, { 0xd62f105d, 5, 5 }, { 0x02441453, 9, 10 }, { 0xd8a1e681, 14, 15 }, { 0xe7d3fbc8, 20, 4 }, { 0x21e1cde6, 5, 9 }, { 0xc33707d6, 9, 14 }, { 0xf4d50d87, 14, 3 }, { 0x455a14ed, 20, 8 }, { 0xa9e3e905, 5, 13 }, { 0xfcefa3f8, 9, 2 }, { 0x676f02d9, 14, 7 }, { 0x8d2a4c8a, 20, 12 }, { 0xfffa3942, 4, 5 }, { 0x8771f681, 11, 8 }, { 0x6d9d6122, 16, 11 }, { 0xfde5380c, 23, 14 }, { 0xa4beea44, 4, 1 }, { 0x4bdecfa9, 11, 4 }, { 0xf6bb4b60, 16, 7 }, { 0xbebfbc70, 23, 10 }, { 0x289b7ec6, 4, 13 }, { 0xeaa127fa, 11, 0 }, { 0xd4ef3085, 16, 3 }, { 0x04881d05, 23, 6 }, { 0xd9d4d039, 4, 9 }, { 0xe6db99e5, 11, 12 }, { 0x1fa27cf8, 16, 15 }, { 0xc4ac5665, 23, 2 }, { 0xf4292244, 6, 0 }, { 0x432aff97, 10, 7 }, { 0xab9423a7, 15, 14 }, { 0xfc93a039, 21, 5 }, { 0x655b59c3, 6, 12 }, { 0x8f0ccc92, 10, 3 }, { 0xffeff47d, 15, 10 }, { 0x85845dd1, 21, 1 }, { 0x6fa87e4f, 6, 8 }, { 0xfe2ce6e0, 10, 15 }, { 0xa3014314, 15, 6 }, { 0x4e0811a1, 21, 13 }, { 0xf7537e82, 6, 4 }, { 0xbd3af235, 10, 11 }, { 0x2ad7d2bb, 15, 2 }, { 0xeb86d391, 21, 9 }, }; typedef struct md5_block md5_block; struct md5_block { uint8_t block[64]; size_t used; uint64_t len; }; static inline void md5_block_setup(md5_block *blk) { blk->used = 0; blk->len = 0; } static inline bool md5_block_write( md5_block *blk, const void **vdata, size_t *len) { size_t blkleft = sizeof(blk->block) - blk->used; size_t chunk = *len < blkleft ? *len : blkleft; const uint8_t *p = *vdata; memcpy(blk->block + blk->used, p, chunk); *vdata = p + chunk; *len -= chunk; blk->used += chunk; blk->len += chunk; if (blk->used == sizeof(blk->block)) { blk->used = 0; return true; } return false; } static inline void md5_block_pad(md5_block *blk, BinarySink *bs) { uint64_t final_len = blk->len << 3; size_t pad = 63 & (55 - blk->used); put_byte(bs, 0x80); put_padding(bs, pad, 0); unsigned char buf[8]; PUT_64BIT_LSB_FIRST(buf, final_len); put_data(bs, buf, 8); smemclr(buf, 8); assert(blk->used == 0 && "Should have exactly hit a block boundary"); } static inline uint32_t rol(uint32_t x, unsigned y) { return (x << (31 & y)) | (x >> (31 & -y)); } static inline uint32_t Ch(uint32_t ctrl, uint32_t if1, uint32_t if0) { return if0 ^ (ctrl & (if1 ^ if0)); } /* Parameter functions for the four MD5 round types */ static inline uint32_t F(uint32_t x, uint32_t y, uint32_t z) { return Ch(x, y, z); } static inline uint32_t G(uint32_t x, uint32_t y, uint32_t z) { return Ch(z, x, y); } static inline uint32_t H(uint32_t x, uint32_t y, uint32_t z) { return x ^ y ^ z; } static inline uint32_t I(uint32_t x, uint32_t y, uint32_t z) { return y ^ (x | ~z); } static inline void md5_round( unsigned round_index, const uint32_t *message, uint32_t *a, uint32_t *b, uint32_t *c, uint32_t *d, uint32_t (*f)(uint32_t, uint32_t, uint32_t)) { struct md5_round_constant rc = md5_round_constants[round_index]; *a = *b + rol(*a + f(*b, *c, *d) + message[rc.msg_index] + rc.addition, rc.rotation); } static void md5_do_block(uint32_t *core, const uint8_t *block) { uint32_t message_words[16]; for (size_t i = 0; i < 16; i++) message_words[i] = GET_32BIT_LSB_FIRST(block + 4*i); uint32_t a = core[0], b = core[1], c = core[2], d = core[3]; size_t t = 0; for (size_t u = 0; u < 4; u++) { md5_round(t++, message_words, &a, &b, &c, &d, F); md5_round(t++, message_words, &d, &a, &b, &c, F); md5_round(t++, message_words, &c, &d, &a, &b, F); md5_round(t++, message_words, &b, &c, &d, &a, F); } for (size_t u = 0; u < 4; u++) { md5_round(t++, message_words, &a, &b, &c, &d, G); md5_round(t++, message_words, &d, &a, &b, &c, G); md5_round(t++, message_words, &c, &d, &a, &b, G); md5_round(t++, message_words, &b, &c, &d, &a, G); } for (size_t u = 0; u < 4; u++) { md5_round(t++, message_words, &a, &b, &c, &d, H); md5_round(t++, message_words, &d, &a, &b, &c, H); md5_round(t++, message_words, &c, &d, &a, &b, H); md5_round(t++, message_words, &b, &c, &d, &a, H); } for (size_t u = 0; u < 4; u++) { md5_round(t++, message_words, &a, &b, &c, &d, I); md5_round(t++, message_words, &d, &a, &b, &c, I); md5_round(t++, message_words, &c, &d, &a, &b, I); md5_round(t++, message_words, &b, &c, &d, &a, I); } core[0] += a; core[1] += b; core[2] += c; core[3] += d; smemclr(message_words, sizeof(message_words)); } typedef struct md5 { uint32_t core[4]; md5_block blk; BinarySink_IMPLEMENTATION; ssh_hash hash; } md5; static void md5_write(BinarySink *bs, const void *vp, size_t len); static ssh_hash *md5_new(const ssh_hashalg *alg) { md5 *s = snew(md5); s->hash.vt = alg; BinarySink_INIT(s, md5_write); BinarySink_DELEGATE_INIT(&s->hash, s); return &s->hash; } static void md5_reset(ssh_hash *hash) { md5 *s = container_of(hash, md5, hash); memcpy(s->core, md5_initial_state, sizeof(s->core)); md5_block_setup(&s->blk); } static void md5_copyfrom(ssh_hash *hcopy, ssh_hash *horig) { md5 *copy = container_of(hcopy, md5, hash); md5 *orig = container_of(horig, md5, hash); memcpy(copy, orig, sizeof(*copy)); BinarySink_COPIED(copy); BinarySink_DELEGATE_INIT(©->hash, copy); } static void md5_free(ssh_hash *hash) { md5 *s = container_of(hash, md5, hash); smemclr(s, sizeof(*s)); sfree(s); } static void md5_write(BinarySink *bs, const void *vp, size_t len) { md5 *s = BinarySink_DOWNCAST(bs, md5); while (len > 0) if (md5_block_write(&s->blk, &vp, &len)) md5_do_block(s->core, s->blk.block); } static void md5_digest(ssh_hash *hash, uint8_t *digest) { md5 *s = container_of(hash, md5, hash); md5_block_pad(&s->blk, BinarySink_UPCAST(s)); for (size_t i = 0; i < 4; i++) PUT_32BIT_LSB_FIRST(digest + 4*i, s->core[i]); } const ssh_hashalg ssh_md5 = { .new = md5_new, .reset = md5_reset, .copyfrom = md5_copyfrom, .digest = md5_digest, .free = md5_free, .hlen = 16, .blocklen = 64, HASHALG_NAMES_BARE("MD5"), };