diff options
Diffstat (limited to 'src/crypt/crypt_sha512.c')
| -rw-r--r-- | src/crypt/crypt_sha512.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/src/crypt/crypt_sha512.c b/src/crypt/crypt_sha512.c new file mode 100644 index 00000000..2c0de698 --- /dev/null +++ b/src/crypt/crypt_sha512.c @@ -0,0 +1,371 @@ +/* + * public domain sha512 crypt implementation + * + * original sha crypt design: http://people.redhat.com/drepper/SHA-crypt.txt + * in this implementation at least 32bit int is assumed, + * key length is limited, the $6$ prefix is mandatory, '\n' and ':' is rejected + * in the salt and rounds= setting must contain a valid iteration count, + * on error "*" is returned. + */ +#include <ctype.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <stdint.h> + +/* public domain sha512 implementation based on fips180-3 */ +/* >=2^64 bits messages are not supported (about 2000 peta bytes) */ + +struct sha512 { + uint64_t len; /* processed message length */ + uint64_t h[8]; /* hash state */ + uint8_t buf[128]; /* message block buffer */ +}; + +static uint64_t ror(uint64_t n, int k) { return (n >> k) | (n << (64-k)); } +#define Ch(x,y,z) (z ^ (x & (y ^ z))) +#define Maj(x,y,z) ((x & y) | (z & (x | y))) +#define S0(x) (ror(x,28) ^ ror(x,34) ^ ror(x,39)) +#define S1(x) (ror(x,14) ^ ror(x,18) ^ ror(x,41)) +#define R0(x) (ror(x,1) ^ ror(x,8) ^ (x>>7)) +#define R1(x) (ror(x,19) ^ ror(x,61) ^ (x>>6)) + +static const uint64_t K[80] = { +0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL, +0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, 0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, +0xd807aa98a3030242ULL, 0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL, +0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL, +0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, 0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, +0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL, +0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL, +0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, 0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, +0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL, +0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, 0x92722c851482353bULL, +0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, 0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, +0xd192e819d6ef5218ULL, 0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL, +0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL, +0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, 0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, +0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL, +0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL, +0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, 0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, +0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL, +0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL, +0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, 0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL +}; + +static void processblock(struct sha512 *s, const uint8_t *buf) +{ + uint64_t W[80], t1, t2, a, b, c, d, e, f, g, h; + int i; + + for (i = 0; i < 16; i++) { + W[i] = (uint64_t)buf[8*i]<<56; + W[i] |= (uint64_t)buf[8*i+1]<<48; + W[i] |= (uint64_t)buf[8*i+2]<<40; + W[i] |= (uint64_t)buf[8*i+3]<<32; + W[i] |= (uint64_t)buf[8*i+4]<<24; + W[i] |= (uint64_t)buf[8*i+5]<<16; + W[i] |= (uint64_t)buf[8*i+6]<<8; + W[i] |= buf[8*i+7]; + } + for (; i < 80; i++) + W[i] = R1(W[i-2]) + W[i-7] + R0(W[i-15]) + W[i-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 (i = 0; i < 80; i++) { + t1 = h + S1(e) + Ch(e,f,g) + K[i] + W[i]; + t2 = S0(a) + Maj(a,b,c); + h = g; + g = f; + f = e; + e = d + t1; + d = c; + c = b; + b = a; + a = t1 + t2; + } + 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; +} + +static void pad(struct sha512 *s) +{ + unsigned r = s->len % 128; + + s->buf[r++] = 0x80; + if (r > 112) { + memset(s->buf + r, 0, 128 - r); + r = 0; + processblock(s, s->buf); + } + memset(s->buf + r, 0, 120 - r); + s->len *= 8; + s->buf[120] = s->len >> 56; + s->buf[121] = s->len >> 48; + s->buf[122] = s->len >> 40; + s->buf[123] = s->len >> 32; + s->buf[124] = s->len >> 24; + s->buf[125] = s->len >> 16; + s->buf[126] = s->len >> 8; + s->buf[127] = s->len; + processblock(s, s->buf); +} + +static void sha512_init(struct sha512 *s) +{ + s->len = 0; + s->h[0] = 0x6a09e667f3bcc908ULL; + s->h[1] = 0xbb67ae8584caa73bULL; + s->h[2] = 0x3c6ef372fe94f82bULL; + s->h[3] = 0xa54ff53a5f1d36f1ULL; + s->h[4] = 0x510e527fade682d1ULL; + s->h[5] = 0x9b05688c2b3e6c1fULL; + s->h[6] = 0x1f83d9abfb41bd6bULL; + s->h[7] = 0x5be0cd19137e2179ULL; +} + +static void sha512_sum(struct sha512 *s, uint8_t md[20]) +{ + int i; + + pad(s); + for (i = 0; i < 8; i++) { + md[8*i] = s->h[i] >> 56; + md[8*i+1] = s->h[i] >> 48; + md[8*i+2] = s->h[i] >> 40; + md[8*i+3] = s->h[i] >> 32; + md[8*i+4] = s->h[i] >> 24; + md[8*i+5] = s->h[i] >> 16; + md[8*i+6] = s->h[i] >> 8; + md[8*i+7] = s->h[i]; + } +} + +static void sha512_update(struct sha512 *s, const void *m, unsigned long len) +{ + const uint8_t *p = m; + unsigned r = s->len % 128; + + s->len += len; + if (r) { + if (len < 128 - r) { + memcpy(s->buf + r, p, len); + return; + } + memcpy(s->buf + r, p, 128 - r); + len -= 128 - r; + p += 128 - r; + processblock(s, s->buf); + } + for (; len >= 128; len -= 128, p += 128) + processblock(s, p); + memcpy(s->buf, p, len); +} + +static unsigned char b64[] = +"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; + +static char *to64(char *s, unsigned int u, int n) +{ + while (--n >= 0) { + *s++ = b64[u % 64]; + u /= 64; + } + return s; +} + +/* key limit is not part of the original design, added for DoS protection. + * rounds limit has been lowered (versus the reference/spec), also for DoS + * protection. runtime is O(klen^2 + klen*rounds) */ +#define KEY_MAX 256 +#define SALT_MAX 16 +#define ROUNDS_DEFAULT 5000 +#define ROUNDS_MIN 1000 +#define ROUNDS_MAX 20000 + +/* hash n bytes of the repeated md message digest */ +static void hashmd(struct sha512 *s, unsigned int n, const void *md) +{ + unsigned int i; + + for (i = n; i > 64; i -= 64) + sha512_update(s, md, 64); + sha512_update(s, md, i); +} + +static char *sha512crypt(const char *key, const char *setting, char *output) +{ + struct sha512 ctx; + unsigned char md[64], kmd[64], smd[64]; + unsigned int i, r, klen, slen; + char rounds[20] = ""; + const char *salt; + char *p; + + /* reject large keys */ + for (i = 0; i <= KEY_MAX && key[i]; i++); + if (i > KEY_MAX) + return 0; + klen = i; + + /* setting: $6$rounds=n$salt$ (rounds=n$ and closing $ are optional) */ + if (strncmp(setting, "$6$", 3) != 0) + return 0; + salt = setting + 3; + + r = ROUNDS_DEFAULT; + if (strncmp(salt, "rounds=", sizeof "rounds=" - 1) == 0) { + unsigned long u; + char *end; + + /* + * this is a deviation from the reference: + * bad rounds setting is rejected if it is + * - empty + * - unterminated (missing '$') + * - begins with anything but a decimal digit + * the reference implementation treats these bad + * rounds as part of the salt or parse them with + * strtoul semantics which may cause problems + * including non-portable hashes that depend on + * the host's value of ULONG_MAX. + */ + salt += sizeof "rounds=" - 1; + if (!isdigit(*salt)) + return 0; + u = strtoul(salt, &end, 10); + if (*end != '$') + return 0; + salt = end+1; + if (u < ROUNDS_MIN) + r = ROUNDS_MIN; + else if (u > ROUNDS_MAX) + r = ROUNDS_MAX; + else + r = u; + /* needed when rounds is zero prefixed or out of bounds */ + sprintf(rounds, "rounds=%u$", r); + } + + for (i = 0; i < SALT_MAX && salt[i] && salt[i] != '$'; i++) + /* reject characters that interfere with /etc/shadow parsing */ + if (salt[i] == '\n' || salt[i] == ':') + return 0; + slen = i; + + /* B = sha(key salt key) */ + sha512_init(&ctx); + sha512_update(&ctx, key, klen); + sha512_update(&ctx, salt, slen); + sha512_update(&ctx, key, klen); + sha512_sum(&ctx, md); + + /* A = sha(key salt repeat-B alternate-B-key) */ + sha512_init(&ctx); + sha512_update(&ctx, key, klen); + sha512_update(&ctx, salt, slen); + hashmd(&ctx, klen, md); + for (i = klen; i > 0; i >>= 1) + if (i & 1) + sha512_update(&ctx, md, sizeof md); + else + sha512_update(&ctx, key, klen); + sha512_sum(&ctx, md); + + /* DP = sha(repeat-key), this step takes O(klen^2) time */ + sha512_init(&ctx); + for (i = 0; i < klen; i++) + sha512_update(&ctx, key, klen); + sha512_sum(&ctx, kmd); + + /* DS = sha(repeat-salt) */ + sha512_init(&ctx); + for (i = 0; i < 16 + md[0]; i++) + sha512_update(&ctx, salt, slen); + sha512_sum(&ctx, smd); + + /* iterate A = f(A,DP,DS), this step takes O(rounds*klen) time */ + for (i = 0; i < r; i++) { + sha512_init(&ctx); + if (i % 2) + hashmd(&ctx, klen, kmd); + else + sha512_update(&ctx, md, sizeof md); + if (i % 3) + sha512_update(&ctx, smd, slen); + if (i % 7) + hashmd(&ctx, klen, kmd); + if (i % 2) + sha512_update(&ctx, md, sizeof md); + else + hashmd(&ctx, klen, kmd); + sha512_sum(&ctx, md); + } + + /* output is $6$rounds=n$salt$hash */ + p = output; + p += sprintf(p, "$6$%s%.*s$", rounds, slen, salt); +#if 1 + static const unsigned char perm[][3] = { + 0,21,42,22,43,1,44,2,23,3,24,45,25,46,4, + 47,5,26,6,27,48,28,49,7,50,8,29,9,30,51, + 31,52,10,53,11,32,12,33,54,34,55,13,56,14,35, + 15,36,57,37,58,16,59,17,38,18,39,60,40,61,19, + 62,20,41 }; + for (i=0; i<21; i++) p = to64(p, + (md[perm[i][0]]<<16)|(md[perm[i][1]]<<8)|md[perm[i][2]], 4); +#else + p = to64(p, (md[0]<<16)|(md[21]<<8)|md[42], 4); + p = to64(p, (md[22]<<16)|(md[43]<<8)|md[1], 4); + p = to64(p, (md[44]<<16)|(md[2]<<8)|md[23], 4); + p = to64(p, (md[3]<<16)|(md[24]<<8)|md[45], 4); + p = to64(p, (md[25]<<16)|(md[46]<<8)|md[4], 4); + p = to64(p, (md[47]<<16)|(md[5]<<8)|md[26], 4); + p = to64(p, (md[6]<<16)|(md[27]<<8)|md[48], 4); + p = to64(p, (md[28]<<16)|(md[49]<<8)|md[7], 4); + p = to64(p, (md[50]<<16)|(md[8]<<8)|md[29], 4); + p = to64(p, (md[9]<<16)|(md[30]<<8)|md[51], 4); + p = to64(p, (md[31]<<16)|(md[52]<<8)|md[10], 4); + p = to64(p, (md[53]<<16)|(md[11]<<8)|md[32], 4); + p = to64(p, (md[12]<<16)|(md[33]<<8)|md[54], 4); + p = to64(p, (md[34]<<16)|(md[55]<<8)|md[13], 4); + p = to64(p, (md[56]<<16)|(md[14]<<8)|md[35], 4); + p = to64(p, (md[15]<<16)|(md[36]<<8)|md[57], 4); + p = to64(p, (md[37]<<16)|(md[58]<<8)|md[16], 4); + p = to64(p, (md[59]<<16)|(md[17]<<8)|md[38], 4); + p = to64(p, (md[18]<<16)|(md[39]<<8)|md[60], 4); + p = to64(p, (md[40]<<16)|(md[61]<<8)|md[19], 4); + p = to64(p, (md[62]<<16)|(md[20]<<8)|md[41], 4); +#endif + p = to64(p, md[63], 2); + *p = 0; + return output; +} + +char *__crypt_sha512(const char *key, const char *setting, char *output) +{ + static const char testkey[] = "Xy01@#\x01\x02\x80\x7f\xff\r\n\x81\t !"; + static const char testsetting[] = "$6$rounds=1234$abc0123456789$"; + static const char testhash[] = "$6$rounds=1234$abc0123456789$BCpt8zLrc/RcyuXmCDOE1ALqMXB2MH6n1g891HhFj8.w7LxGv.FTkqq6Vxc/km3Y0jE0j24jY5PIv/oOu6reg1"; + char testbuf[128]; + char *p, *q; + + p = sha512crypt(key, setting, output); + /* self test and stack cleanup */ + q = sha512crypt(testkey, testsetting, testbuf); + if (!p || q != testbuf || memcmp(testbuf, testhash, sizeof testhash)) + return "*"; + return p; +} |