From 062e58118f35e04a9a899e2957545e7593ca5dfc Mon Sep 17 00:00:00 2001 From: ben Date: Wed, 31 Aug 2005 21:48:22 +0000 Subject: [PATCH] SHA-256 implementation, for use in future KEX algorithms, in particular diffie-hellman-group-exchange-sha256, which the last DHGEX draft defined. Code lifted from Simon's "crypto" directory, with changes to make it look more like sshsh512.c. git-svn-id: svn://svn.tartarus.org/sgt/putty@6252 cda61777-01e9-0310-a592-d414129be87e --- Recipe | 2 +- ssh.h | 11 +++ sshsh256.c | 269 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 281 insertions(+), 1 deletion(-) create mode 100644 sshsh256.c diff --git a/Recipe b/Recipe index a82a969c..6b9f200f 100644 --- a/Recipe +++ b/Recipe @@ -213,7 +213,7 @@ NONSSH = telnet raw rlogin ldisc pinger # SSH back end (putty, plink, pscp, psftp). SSH = ssh sshcrc sshdes sshmd5 sshrsa sshrand sshsha sshblowf + sshdh sshcrcda sshpubk sshzlib sshdss x11fwd portfwd - + sshaes sshsh512 sshbn wildcard pinger ssharcf + + sshaes sshsh256 sshsh512 sshbn wildcard pinger ssharcf WINSSH = SSH winnoise winpgntc UXSSH = SSH uxnoise uxagentc MACSSH = SSH macnoise diff --git a/ssh.h b/ssh.h index 09ee167a..45405d3e 100644 --- a/ssh.h +++ b/ssh.h @@ -122,6 +122,16 @@ void SHA_Simple(void *p, int len, unsigned char *output); void hmac_sha1_simple(void *key, int keylen, void *data, int datalen, unsigned char *output); +typedef struct { + uint32 h[8]; + unsigned char block[64]; + int blkused; + uint32 lenhi, lenlo; +} SHA256_State; +void SHA256_Init(SHA256_State * s); +void SHA256_Bytes(SHA256_State * s, const void *p, int len); +void SHA256_Final(SHA256_State * s, unsigned char *output); +void SHA256_Simple(const void *p, int len, unsigned char *output); typedef struct { uint64 h[8]; @@ -245,6 +255,7 @@ extern const struct ssh2_ciphers ssh2_aes; extern const struct ssh2_ciphers ssh2_blowfish; extern const struct ssh2_ciphers ssh2_arcfour; extern const struct ssh_hash ssh_sha1; +extern const struct ssh_hash ssh_sha256; extern const struct ssh_kex ssh_diffiehellman_group1; extern const struct ssh_kex ssh_diffiehellman_group14; extern const struct ssh_kex ssh_diffiehellman_gex; diff --git a/sshsh256.c b/sshsh256.c new file mode 100644 index 00000000..70c2d7d3 --- /dev/null +++ b/sshsh256.c @@ -0,0 +1,269 @@ +/* + * SHA-256 algorithm as described at + * + * http://csrc.nist.gov/cryptval/shs.html + */ + +#include "ssh.h" + +/* ---------------------------------------------------------------------- + * Core SHA256 algorithm: processes 16-word blocks into a message digest. + */ + +#define ror(x,y) ( ((x) << (32-y)) | (((uint32)(x)) >> (y)) ) +#define shr(x,y) ( (((uint32)(x)) >> (y)) ) +#define Ch(x,y,z) ( ((x) & (y)) ^ (~(x) & (z)) ) +#define Maj(x,y,z) ( ((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)) ) +#define bigsigma0(x) ( ror((x),2) ^ ror((x),13) ^ ror((x),22) ) +#define bigsigma1(x) ( ror((x),6) ^ ror((x),11) ^ ror((x),25) ) +#define smallsigma0(x) ( ror((x),7) ^ ror((x),18) ^ shr((x),3) ) +#define smallsigma1(x) ( ror((x),17) ^ ror((x),19) ^ shr((x),10) ) + +void SHA256_Core_Init(SHA256_State *s) { + s->h[0] = 0x6a09e667; + s->h[1] = 0xbb67ae85; + s->h[2] = 0x3c6ef372; + s->h[3] = 0xa54ff53a; + s->h[4] = 0x510e527f; + s->h[5] = 0x9b05688c; + s->h[6] = 0x1f83d9ab; + s->h[7] = 0x5be0cd19; +} + +void SHA256_Block(SHA256_State *s, uint32 *block) { + uint32 w[80]; + uint32 a,b,c,d,e,f,g,h; + static const int k[] = { + 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, + 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, + 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, + 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, + 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, + 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, + 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, + 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, + 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, + 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, + 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, + 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, + 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, + 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, + 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, + 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2, + }; + + int t; + + for (t = 0; t < 16; t++) + w[t] = block[t]; + + for (t = 16; t < 64; t++) + w[t] = smallsigma1(w[t-2]) + w[t-7] + smallsigma0(w[t-15]) + w[t-16]; + + a = s->h[0]; b = s->h[1]; c = s->h[2]; d = s->h[3]; + e = s->h[4]; f = s->h[5]; g = s->h[6]; h = s->h[7]; + + for (t = 0; t < 64; t+=8) { + uint32 t1, t2; + +#define ROUND(j,a,b,c,d,e,f,g,h) \ + t1 = h + bigsigma1(e) + Ch(e,f,g) + k[j] + w[j]; \ + t2 = bigsigma0(a) + Maj(a,b,c); \ + d = d + t1; h = t1 + t2; + + ROUND(t+0, a,b,c,d,e,f,g,h); + ROUND(t+1, h,a,b,c,d,e,f,g); + ROUND(t+2, g,h,a,b,c,d,e,f); + ROUND(t+3, f,g,h,a,b,c,d,e); + ROUND(t+4, e,f,g,h,a,b,c,d); + ROUND(t+5, d,e,f,g,h,a,b,c); + ROUND(t+6, c,d,e,f,g,h,a,b); + ROUND(t+7, b,c,d,e,f,g,h,a); + } + + s->h[0] += a; s->h[1] += b; s->h[2] += c; s->h[3] += d; + s->h[4] += e; s->h[5] += f; s->h[6] += g; s->h[7] += h; +} + +/* ---------------------------------------------------------------------- + * Outer SHA256 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 SHA256 algorithm. + */ + +#define BLKSIZE 64 + +void SHA256_Init(SHA256_State *s) { + SHA256_Core_Init(s); + s->blkused = 0; + s->lenhi = s->lenlo = 0; +} + +void SHA256_Bytes(SHA256_State *s, const void *p, int 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 && s->blkused+len < BLKSIZE) { + /* + * Trivial case: just add to the block. + */ + memcpy(s->block + s->blkused, q, len); + s->blkused += len; + } else { + /* + * 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 big-endian into words */ + for (i = 0; i < 16; i++) { + wordblock[i] = + ( ((uint32)s->block[i*4+0]) << 24 ) | + ( ((uint32)s->block[i*4+1]) << 16 ) | + ( ((uint32)s->block[i*4+2]) << 8 ) | + ( ((uint32)s->block[i*4+3]) << 0 ); + } + SHA256_Block(s, wordblock); + s->blkused = 0; + } + memcpy(s->block, q, len); + s->blkused = len; + } +} + +void SHA256_Final(SHA256_State *s, unsigned char *digest) { + 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; + SHA256_Bytes(s, &c, pad); + + c[0] = (lenhi >> 24) & 0xFF; + c[1] = (lenhi >> 16) & 0xFF; + c[2] = (lenhi >> 8) & 0xFF; + c[3] = (lenhi >> 0) & 0xFF; + c[4] = (lenlo >> 24) & 0xFF; + c[5] = (lenlo >> 16) & 0xFF; + c[6] = (lenlo >> 8) & 0xFF; + c[7] = (lenlo >> 0) & 0xFF; + + SHA256_Bytes(s, &c, 8); + + for (i = 0; i < 8; i++) { + digest[i*4+0] = (s->h[i] >> 24) & 0xFF; + digest[i*4+1] = (s->h[i] >> 16) & 0xFF; + digest[i*4+2] = (s->h[i] >> 8) & 0xFF; + digest[i*4+3] = (s->h[i] >> 0) & 0xFF; + } +} + +void SHA256_Simple(const void *p, int len, unsigned char *output) { + SHA256_State s; + + SHA256_Init(&s); + SHA256_Bytes(&s, p, len); + SHA256_Final(&s, output); +} + +/* + * Thin abstraction for things where hashes are pluggable. + */ + +static void *sha256_init(void) +{ + SHA256_State *s; + + s = snew(SHA256_State); + SHA256_Init(s); + return s; +} + +static void sha256_bytes(void *handle, void *p, int len) +{ + SHA256_State *s = handle; + + SHA256_Bytes(s, p, len); +} + +static void sha256_final(void *handle, unsigned char *output) +{ + SHA256_State *s = handle; + + SHA256_Final(s, output); + sfree(s); +} + +const struct ssh_hash ssh_sha256 = { + sha256_init, sha256_bytes, sha256_final, 32 +}; + +#ifdef TEST + +#include +#include +#include + +int main(void) { + unsigned char digest[32]; + int i, j, errors; + + struct { + const char *teststring; + unsigned char digest[32]; + } tests[] = { + { "abc", { + 0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea, + 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23, + 0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c, + 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad, + } }, + { "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", { + 0x24, 0x8d, 0x6a, 0x61, 0xd2, 0x06, 0x38, 0xb8, + 0xe5, 0xc0, 0x26, 0x93, 0x0c, 0x3e, 0x60, 0x39, + 0xa3, 0x3c, 0xe4, 0x59, 0x64, 0xff, 0x21, 0x67, + 0xf6, 0xec, 0xed, 0xd4, 0x19, 0xdb, 0x06, 0xc1, + } }, + }; + + errors = 0; + + for (i = 0; i < sizeof(tests) / sizeof(*tests); i++) { + SHA256_Simple(tests[i].teststring, + strlen(tests[i].teststring), digest); + for (j = 0; j < 32; j++) { + if (digest[j] != tests[i].digest[j]) { + fprintf(stderr, + "\"%s\" digest byte %d should be 0x%02x, is 0x%02x\n", + tests[i].teststring, j, tests[i].digest[j], digest[j]); + errors++; + } + } + } + + printf("%d errors\n", errors); + + return 0; +} + +#endif -- 2.11.0