diff options
Diffstat (limited to 'crypto/md5.c')
| -rw-r--r-- | crypto/md5.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/crypto/md5.c b/crypto/md5.c new file mode 100644 index 00000000..9155c99e --- /dev/null +++ b/crypto/md5.c @@ -0,0 +1,245 @@ +/* + * MD5 implementation for PuTTY. Written directly from the spec by + * Simon Tatham. + */ + +#include <assert.h> +#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"), +}; |