/* * 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 #include #include #include #include /* public domain sha512 implementation based on fips180-3 */ /* >=2^64 bits messages are not supported (about 2000 peta bytes) */ struct sha512 { uint64 len; /* processed message length */ uint64 h[8]; /* hash state */ uint8 buf[128]; /* message block buffer */ }; static uint64 ror(uint64 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 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 *buf) { uint64 W[80], t1, t2, a, b, c, d, e, f, g, h; int i; for (i = 0; i < 16; i++) { W[i] = (uint64)buf[8*i]<<56; W[i] |= (uint64)buf[8*i+1]<<48; W[i] |= (uint64)buf[8*i+2]<<40; W[i] |= (uint64)buf[8*i+3]<<32; W[i] |= (uint64)buf[8*i+4]<<24; W[i] |= (uint64)buf[8*i+5]<<16; W[i] |= (uint64)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 *md) { 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 *p = (uint8 *)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 const 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 9999999 /* 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; }