ryzom/common/src/game_share/crypt_sha512.cpp

   1 /*
   2  * public domain sha512 crypt implementation
   3  *
   4  * original sha crypt design: http://people.redhat.com/drepper/SHA-crypt.txt
   5  * in this implementation at least 32bit int is assumed,
   6  * key length is limited, the $6$ prefix is mandatory, '\n' and ':' is rejected
   7  * in the salt and rounds= setting must contain a valid iteration count,
   8  * on error "*" is returned.
   9  */
  10
  11 #include <nel/misc/types_nl.h>
  12
  13 #include <ctype.h>
  14 #include <stdlib.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17
  18 /* public domain sha512 implementation based on fips180-3 */
  19 /* >=2^64 bits messages are not supported (about 2000 peta bytes) */
  20
  21 struct sha512 {
  22   uint64 len;     /* processed message length */
  23   uint64 h[8];    /* hash state */
  24   uint8 buf[128]; /* message block buffer */
  25 };
  26
  27 static uint64 ror(uint64 n, int k) { return (n >> k) | (n << (64-k)); }
  28 #define Ch(x,y,z)  (z ^ (x & (y ^ z)))
  29 #define Maj(x,y,z) ((x & y) | (z & (x | y)))
  30 #define S0(x)      (ror(x,28) ^ ror(x,34) ^ ror(x,39))
  31 #define S1(x)      (ror(x,14) ^ ror(x,18) ^ ror(x,41))
  32 #define R0(x)      (ror(x,1) ^ ror(x,8) ^ (x>>7))
  33 #define R1(x)      (ror(x,19) ^ ror(x,61) ^ (x>>6))
  34
  35 static const uint64 K[80] = {
  36   0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
  37   0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, 0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
  38   0xd807aa98a3030242ULL, 0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
  39   0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
  40   0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, 0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
  41   0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
  42   0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
  43   0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, 0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
  44   0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
  45   0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
  46   0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, 0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
  47   0xd192e819d6ef5218ULL, 0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
  48   0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
  49   0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, 0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
  50   0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
  51   0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
  52   0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, 0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
  53   0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
  54   0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
  55   0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, 0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
  56 };
  57
  58 static void processblock(struct sha512 *s, const uint8 *buf)
  59 {
  60   uint64 W[80], t1, t2, a, b, c, d, e, f, g, h;
  61   int i;
  62
  63   for (i = 0; i < 16; i++) {
  64     W[i] = (uint64)buf[8*i]<<56;
  65     W[i] |= (uint64)buf[8*i+1]<<48;
  66     W[i] |= (uint64)buf[8*i+2]<<40;
  67     W[i] |= (uint64)buf[8*i+3]<<32;
  68     W[i] |= (uint64)buf[8*i+4]<<24;
  69     W[i] |= (uint64)buf[8*i+5]<<16;
  70     W[i] |= (uint64)buf[8*i+6]<<8;
  71     W[i] |= buf[8*i+7];
  72   }
  73   for (; i < 80; i++)
  74     W[i] = R1(W[i-2]) + W[i-7] + R0(W[i-15]) + W[i-16];
  75   a = s->h[0];
  76   b = s->h[1];
  77   c = s->h[2];
  78   d = s->h[3];
  79   e = s->h[4];
  80   f = s->h[5];
  81   g = s->h[6];
  82   h = s->h[7];
  83   for (i = 0; i < 80; i++) {
  84     t1 = h + S1(e) + Ch(e,f,g) + K[i] + W[i];
  85     t2 = S0(a) + Maj(a,b,c);
  86     h = g;
  87     g = f;
  88     f = e;
  89     e = d + t1;
  90     d = c;
  91     c = b;
  92     b = a;
  93     a = t1 + t2;
  94   }
  95   s->h[0] += a;
  96   s->h[1] += b;
  97   s->h[2] += c;
  98   s->h[3] += d;
  99   s->h[4] += e;
 100   s->h[5] += f;
 101   s->h[6] += g;
 102   s->h[7] += h;
 103 }
 104
 105 static void pad(struct sha512 *s)
 106 {
 107   unsigned r = s->len % 128;
 108
 109   s->buf[r++] = 0x80;
 110   if (r > 112) {
 111     memset(s->buf + r, 0, 128 - r);
 112     r = 0;
 113     processblock(s, s->buf);
 114   }
 115   memset(s->buf + r, 0, 120 - r);
 116   s->len *= 8;
 117   s->buf[120] = s->len >> 56;
 118   s->buf[121] = s->len >> 48;
 119   s->buf[122] = s->len >> 40;
 120   s->buf[123] = s->len >> 32;
 121   s->buf[124] = s->len >> 24;
 122   s->buf[125] = s->len >> 16;
 123   s->buf[126] = s->len >> 8;
 124   s->buf[127] = s->len;
 125   processblock(s, s->buf);
 126 }
 127
 128 static void sha512_init(struct sha512 *s)
 129 {
 130   s->len = 0;
 131   s->h[0] = 0x6a09e667f3bcc908ULL;
 132   s->h[1] = 0xbb67ae8584caa73bULL;
 133   s->h[2] = 0x3c6ef372fe94f82bULL;
 134   s->h[3] = 0xa54ff53a5f1d36f1ULL;
 135   s->h[4] = 0x510e527fade682d1ULL;
 136   s->h[5] = 0x9b05688c2b3e6c1fULL;
 137   s->h[6] = 0x1f83d9abfb41bd6bULL;
 138   s->h[7] = 0x5be0cd19137e2179ULL;
 139 }
 140
 141 static void sha512_sum(struct sha512 *s, uint8 *md)
 142 {
 143   int i;
 144
 145   pad(s);
 146   for (i = 0; i < 8; i++) {
 147     md[8*i] = s->h[i] >> 56;
 148     md[8*i+1] = s->h[i] >> 48;
 149     md[8*i+2] = s->h[i] >> 40;
 150     md[8*i+3] = s->h[i] >> 32;
 151     md[8*i+4] = s->h[i] >> 24;
 152     md[8*i+5] = s->h[i] >> 16;
 153     md[8*i+6] = s->h[i] >> 8;
 154     md[8*i+7] = s->h[i];
 155   }
 156 }
 157
 158 static void sha512_update(struct sha512 *s, const void *m, unsigned long len)
 159 {
 160   const uint8 *p = (uint8 *)m;
 161   unsigned r = s->len % 128;
 162
 163   s->len += len;
 164   if (r) {
 165     if (len < 128 - r) {
 166       memcpy(s->buf + r, p, len);
 167       return;
 168     }
 169     memcpy(s->buf + r, p, 128 - r);
 170     len -= 128 - r;
 171     p += 128 - r;
 172     processblock(s, s->buf);
 173   }
 174   for (; len >= 128; len -= 128, p += 128)
 175     processblock(s, p);
 176   memcpy(s->buf, p, len);
 177 }
 178
 179 static const unsigned char b64[] =
 180   "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 181
 182 static char *to64(char *s, unsigned int u, int n)
 183 {
 184   while (--n >= 0) {
 185     *s++ = b64[u % 64];
 186     u /= 64;
 187   }
 188   return s;
 189 }
 190
 191 /* key limit is not part of the original design, added for DoS protection.
 192  * rounds limit has been lowered (versus the reference/spec), also for DoS
 193  * protection. runtime is O(klen^2 + klen*rounds) */
 194 #define KEY_MAX 256
 195 #define SALT_MAX 16
 196 #define ROUNDS_DEFAULT 5000
 197 #define ROUNDS_MIN 1000
 198 #define ROUNDS_MAX 9999999
 199
 200 /* hash n bytes of the repeated md message digest */
 201 static void hashmd(struct sha512 *s, unsigned int n, const void *md)
 202 {
 203   unsigned int i;
 204
 205   for (i = n; i > 64; i -= 64)
 206     sha512_update(s, md, 64);
 207   sha512_update(s, md, i);
 208 }
 209
 210 static char *sha512crypt(const char *key, const char *setting, char *output)
 211 {
 212   struct sha512 ctx;
 213   unsigned char md[64], kmd[64], smd[64];
 214   unsigned int i, r, klen, slen;
 215   char rounds[20] = "";
 216   const char *salt;
 217   char *p;
 218
 219   /* reject large keys */
 220   for (i = 0; i <= KEY_MAX && key[i]; i++);
 221   if (i > KEY_MAX)
 222     return 0;
 223   klen = i;
 224
 225   /* setting: $6$rounds=n$salt$ (rounds=n$ and closing $ are optional) */
 226   if (strncmp(setting, "$6$", 3) != 0)
 227     return 0;
 228   salt = setting + 3;
 229
 230   r = ROUNDS_DEFAULT;
 231   if (strncmp(salt, "rounds=", sizeof "rounds=" - 1) == 0) {
 232     unsigned long u;
 233     char *end;
 234
 235     /*
 236      * this is a deviation from the reference:
 237      * bad rounds setting is rejected if it is
 238      * - empty
 239      * - unterminated (missing '$')
 240      * - begins with anything but a decimal digit
 241      * the reference implementation treats these bad
 242      * rounds as part of the salt or parse them with
 243      * strtoul semantics which may cause problems
 244      * including non-portable hashes that depend on
 245      * the host's value of ULONG_MAX.
 246      */
 247     salt += sizeof "rounds=" - 1;
 248     if (!isdigit(*salt))
 249       return 0;
 250     u = strtoul(salt, &end, 10);
 251     if (*end != '$')
 252       return 0;
 253     salt = end+1;
 254     if (u < ROUNDS_MIN)
 255       r = ROUNDS_MIN;
 256     else if (u > ROUNDS_MAX)
 257       r = ROUNDS_MAX;
 258     else
 259       r = u;
 260     /* needed when rounds is zero prefixed or out of bounds */
 261     sprintf(rounds, "rounds=%u$", r);
 262   }
 263
 264   for (i = 0; i < SALT_MAX && salt[i] && salt[i] != '$'; i++)
 265     /* reject characters that interfere with /etc/shadow parsing */
 266     if (salt[i] == '\n' || salt[i] == ':')
 267       return 0;
 268   slen = i;
 269
 270   /* B = sha(key salt key) */
 271   sha512_init(&ctx);
 272   sha512_update(&ctx, key, klen);
 273   sha512_update(&ctx, salt, slen);
 274   sha512_update(&ctx, key, klen);
 275   sha512_sum(&ctx, md);
 276
 277   /* A = sha(key salt repeat-B alternate-B-key) */
 278   sha512_init(&ctx);
 279   sha512_update(&ctx, key, klen);
 280   sha512_update(&ctx, salt, slen);
 281   hashmd(&ctx, klen, md);
 282   for (i = klen; i > 0; i >>= 1)
 283     if (i & 1)
 284       sha512_update(&ctx, md, sizeof md);
 285     else
 286       sha512_update(&ctx, key, klen);
 287   sha512_sum(&ctx, md);
 288
 289   /* DP = sha(repeat-key), this step takes O(klen^2) time */
 290   sha512_init(&ctx);
 291   for (i = 0; i < klen; i++)
 292     sha512_update(&ctx, key, klen);
 293   sha512_sum(&ctx, kmd);
 294
 295   /* DS = sha(repeat-salt) */
 296   sha512_init(&ctx);
 297   for (i = 0; i < 16u + md[0]; i++)
 298     sha512_update(&ctx, salt, slen);
 299   sha512_sum(&ctx, smd);
 300
 301   /* iterate A = f(A,DP,DS), this step takes O(rounds*klen) time */
 302   for (i = 0; i < r; i++) {
 303     sha512_init(&ctx);
 304     if (i % 2)
 305       hashmd(&ctx, klen, kmd);
 306     else
 307       sha512_update(&ctx, md, sizeof md);
 308     if (i % 3)
 309       sha512_update(&ctx, smd, slen);
 310     if (i % 7)
 311       hashmd(&ctx, klen, kmd);
 312     if (i % 2)
 313       sha512_update(&ctx, md, sizeof md);
 314     else
 315       hashmd(&ctx, klen, kmd);
 316     sha512_sum(&ctx, md);
 317   }
 318
 319   /* output is $6$rounds=n$salt$hash */
 320   p = output;
 321   p += sprintf(p, "$6$%s%.*s$", rounds, slen, salt);
 322 #if 1
 323   static const unsigned char perm[][3] = {
 324         { 0,  21, 42 },
 325         { 22, 43,  1 },
 326         { 44,  2, 23 },
 327         {  3, 24, 45 },
 328         { 25, 46,  4 },
 329         { 47,  5, 26 },
 330         {  6, 27, 48 },
 331         { 28, 49,  7 },
 332         { 50,  8, 29 },
 333         {  9, 30, 51 },
 334         { 31, 52, 10 },
 335         { 53, 11, 32 },
 336         { 12, 33, 54 },
 337         { 34, 55, 13 },
 338         { 56, 14, 35 },
 339         { 15, 36, 57 },
 340         { 37, 58, 16 },
 341         { 59, 17, 38 },
 342         { 18, 39, 60 },
 343         { 40, 61, 19 },
 344         { 62, 20, 41 }
 345   };
 346   for (i=0; i<21; i++) p = to64(p,
 347                                 (md[perm[i][0]]<<16)|(md[perm[i][1]]<<8)|md[perm[i][2]], 4);
 348 #else
 349   p = to64(p, (md[0]<<16)|(md[21]<<8)|md[42], 4);
 350   p = to64(p, (md[22]<<16)|(md[43]<<8)|md[1], 4);
 351   p = to64(p, (md[44]<<16)|(md[2]<<8)|md[23], 4);
 352   p = to64(p, (md[3]<<16)|(md[24]<<8)|md[45], 4);
 353   p = to64(p, (md[25]<<16)|(md[46]<<8)|md[4], 4);
 354   p = to64(p, (md[47]<<16)|(md[5]<<8)|md[26], 4);
 355   p = to64(p, (md[6]<<16)|(md[27]<<8)|md[48], 4);
 356   p = to64(p, (md[28]<<16)|(md[49]<<8)|md[7], 4);
 357   p = to64(p, (md[50]<<16)|(md[8]<<8)|md[29], 4);
 358   p = to64(p, (md[9]<<16)|(md[30]<<8)|md[51], 4);
 359   p = to64(p, (md[31]<<16)|(md[52]<<8)|md[10], 4);
 360   p = to64(p, (md[53]<<16)|(md[11]<<8)|md[32], 4);
 361   p = to64(p, (md[12]<<16)|(md[33]<<8)|md[54], 4);
 362   p = to64(p, (md[34]<<16)|(md[55]<<8)|md[13], 4);
 363   p = to64(p, (md[56]<<16)|(md[14]<<8)|md[35], 4);
 364   p = to64(p, (md[15]<<16)|(md[36]<<8)|md[57], 4);
 365   p = to64(p, (md[37]<<16)|(md[58]<<8)|md[16], 4);
 366   p = to64(p, (md[59]<<16)|(md[17]<<8)|md[38], 4);
 367   p = to64(p, (md[18]<<16)|(md[39]<<8)|md[60], 4);
 368   p = to64(p, (md[40]<<16)|(md[61]<<8)|md[19], 4);
 369   p = to64(p, (md[62]<<16)|(md[20]<<8)|md[41], 4);
 370 #endif
 371   p = to64(p, md[63], 2);
 372   *p = 0;
 373   return output;
 374 }
 375
 376 std::string __crypt_sha512(const char *key, const char *setting, char *output)
 377 {
 378   static const char testkey[] = "Xy01@#\x01\x02\x80\x7f\xff\r\n\x81\t !";
 379   static const char testsetting[] = "$6$rounds=1234$abc0123456789$";
 380   static const char testhash[] = "$6$rounds=1234$abc0123456789$BCpt8zLrc/RcyuXmCDOE1ALqMXB2MH6n1g891HhFj8.w7LxGv.FTkqq6Vxc/km3Y0jE0j24jY5PIv/oOu6reg1";
 381   char testbuf[128];
 382   char *p, *q;
 383
 384   p = sha512crypt(key, setting, output);
 385
 386   /* self test and stack cleanup */
 387   q = sha512crypt(testkey, testsetting, testbuf);
 388   if (!p || q != testbuf || memcmp(testbuf, testhash, sizeof(testhash)))
 389     return "*";
 390
 391   return p;
 392 }