Line data    Source code

       1             : /*-
       2             :  * Copyright 2005,2007,2009 Colin Percival
       3             :  * All rights reserved.
       4             :  *
       5             :  * Redistribution and use in source and binary forms, with or without
       6             :  * modification, are permitted provided that the following conditions
       7             :  * are met:
       8             :  * 1. Redistributions of source code must retain the above copyright
       9             :  *    notice, this list of conditions and the following disclaimer.
      10             :  * 2. Redistributions in binary form must reproduce the above copyright
      11             :  *    notice, this list of conditions and the following disclaimer in the
      12             :  *    documentation and/or other materials provided with the distribution.
      13             :  *
      14             :  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
      15             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      16             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      17             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
      18             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      19             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      20             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      21             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      22             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      23             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      24             :  * SUCH DAMAGE.
      25             :  */
      26             : 
      27             : #include <zebra.h>
      28             : #include "sha256.h"
      29             : 
      30             : #if !HAVE_DECL_BE32DEC
      31      107008 : static inline uint32_t be32dec(const void *pp)
      32             : {
      33      107008 :         const uint8_t *p = (uint8_t const *)pp;
      34             : 
      35      107008 :         return ((uint32_t)(p[3]) + ((uint32_t)(p[2]) << 8)
      36      107008 :                 + ((uint32_t)(p[1]) << 16) + ((uint32_t)(p[0]) << 24));
      37             : }
      38             : #endif
      39             : 
      40             : #if !HAVE_DECL_BE32ENC
      41       39210 : static inline void be32enc(void *pp, uint32_t x)
      42             : {
      43       39210 :         uint8_t *p = (uint8_t *)pp;
      44             : 
      45       39210 :         p[3] = x & 0xff;
      46       39210 :         p[2] = (x >> 8) & 0xff;
      47       39210 :         p[1] = (x >> 16) & 0xff;
      48       39210 :         p[0] = (x >> 24) & 0xff;
      49             : }
      50             : #endif
      51             : 
      52             : /*
      53             :  * Encode a length len/4 vector of (uint32_t) into a length len vector of
      54             :  * (unsigned char) in big-endian form.  Assumes len is a multiple of 4.
      55             :  */
      56        7842 : static void be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
      57             : {
      58        7842 :         size_t i;
      59             : 
      60       47052 :         for (i = 0; i < len / 4; i++)
      61       39210 :                 be32enc(dst + i * 4, src[i]);
      62        7842 : }
      63             : 
      64             : /*
      65             :  * Decode a big-endian length len vector of (unsigned char) into a length
      66             :  * len/4 vector of (uint32_t).  Assumes len is a multiple of 4.
      67             :  */
      68        6688 : static void be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
      69             : {
      70        6688 :         size_t i;
      71             : 
      72      113696 :         for (i = 0; i < len / 4; i++)
      73      107008 :                 dst[i] = be32dec(src + i * 4);
      74        6688 : }
      75             : 
      76             : /* Elementary functions used by SHA256 */
      77             : #define Ch(x, y, z)     ((x & (y ^ z)) ^ z)
      78             : #define Maj(x, y, z)    ((x & (y | z)) | (y & z))
      79             : #define SHR(x, n)       (x >> n)
      80             : #define ROTR(x, n)      ((x >> n) | (x << (32 - n)))
      81             : #define S0(x)           (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
      82             : #define S1(x)           (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
      83             : #define s0(x)           (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
      84             : #define s1(x)           (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
      85             : 
      86             : /* SHA256 round function */
      87             : #define RND(a, b, c, d, e, f, g, h, k)                                         \
      88             :         t0 = h + S1(e) + Ch(e, f, g) + k;                                      \
      89             :         t1 = S0(a) + Maj(a, b, c);                                             \
      90             :         d += t0;                                                               \
      91             :         h = t0 + t1;
      92             : 
      93             : /* Adjusted round function for rotating state */
      94             : #define RNDr(S, W, i, k)                                                       \
      95             :         RND(S[(64 - i) % 8], S[(65 - i) % 8], S[(66 - i) % 8],                 \
      96             :             S[(67 - i) % 8], S[(68 - i) % 8], S[(69 - i) % 8],                 \
      97             :             S[(70 - i) % 8], S[(71 - i) % 8], W[i] + k)
      98             : 
      99             : /*
     100             :  * SHA256 block compression function.  The 256-bit state is transformed via
     101             :  * the 512-bit input block to produce a new state.
     102             :  */
     103        6688 : static void SHA256_Transform(uint32_t *state, const unsigned char block[64])
     104             : {
     105        6688 :         uint32_t W[64];
     106        6688 :         uint32_t S[8];
     107        6688 :         uint32_t t0, t1;
     108        6688 :         int i;
     109             : 
     110             :         /* 1. Prepare message schedule W. */
     111        6688 :         be32dec_vect(W, block, 64);
     112      334400 :         for (i = 16; i < 64; i++)
     113      321024 :                 W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
     114             : 
     115             :         /* 2. Initialize working variables. */
     116        6688 :         memcpy(S, state, 32);
     117             : 
     118             :         /* 3. Mix. */
     119        6688 :         RNDr(S, W, 0, 0x428a2f98);
     120        6688 :         RNDr(S, W, 1, 0x71374491);
     121        6688 :         RNDr(S, W, 2, 0xb5c0fbcf);
     122        6688 :         RNDr(S, W, 3, 0xe9b5dba5);
     123        6688 :         RNDr(S, W, 4, 0x3956c25b);
     124        6688 :         RNDr(S, W, 5, 0x59f111f1);
     125        6688 :         RNDr(S, W, 6, 0x923f82a4);
     126        6688 :         RNDr(S, W, 7, 0xab1c5ed5);
     127        6688 :         RNDr(S, W, 8, 0xd807aa98);
     128        6688 :         RNDr(S, W, 9, 0x12835b01);
     129        6688 :         RNDr(S, W, 10, 0x243185be);
     130        6688 :         RNDr(S, W, 11, 0x550c7dc3);
     131        6688 :         RNDr(S, W, 12, 0x72be5d74);
     132        6688 :         RNDr(S, W, 13, 0x80deb1fe);
     133        6688 :         RNDr(S, W, 14, 0x9bdc06a7);
     134        6688 :         RNDr(S, W, 15, 0xc19bf174);
     135        6688 :         RNDr(S, W, 16, 0xe49b69c1);
     136        6688 :         RNDr(S, W, 17, 0xefbe4786);
     137        6688 :         RNDr(S, W, 18, 0x0fc19dc6);
     138        6688 :         RNDr(S, W, 19, 0x240ca1cc);
     139        6688 :         RNDr(S, W, 20, 0x2de92c6f);
     140        6688 :         RNDr(S, W, 21, 0x4a7484aa);
     141        6688 :         RNDr(S, W, 22, 0x5cb0a9dc);
     142        6688 :         RNDr(S, W, 23, 0x76f988da);
     143        6688 :         RNDr(S, W, 24, 0x983e5152);
     144        6688 :         RNDr(S, W, 25, 0xa831c66d);
     145        6688 :         RNDr(S, W, 26, 0xb00327c8);
     146        6688 :         RNDr(S, W, 27, 0xbf597fc7);
     147        6688 :         RNDr(S, W, 28, 0xc6e00bf3);
     148        6688 :         RNDr(S, W, 29, 0xd5a79147);
     149        6688 :         RNDr(S, W, 30, 0x06ca6351);
     150        6688 :         RNDr(S, W, 31, 0x14292967);
     151        6688 :         RNDr(S, W, 32, 0x27b70a85);
     152        6688 :         RNDr(S, W, 33, 0x2e1b2138);
     153        6688 :         RNDr(S, W, 34, 0x4d2c6dfc);
     154        6688 :         RNDr(S, W, 35, 0x53380d13);
     155        6688 :         RNDr(S, W, 36, 0x650a7354);
     156        6688 :         RNDr(S, W, 37, 0x766a0abb);
     157        6688 :         RNDr(S, W, 38, 0x81c2c92e);
     158        6688 :         RNDr(S, W, 39, 0x92722c85);
     159        6688 :         RNDr(S, W, 40, 0xa2bfe8a1);
     160        6688 :         RNDr(S, W, 41, 0xa81a664b);
     161        6688 :         RNDr(S, W, 42, 0xc24b8b70);
     162        6688 :         RNDr(S, W, 43, 0xc76c51a3);
     163        6688 :         RNDr(S, W, 44, 0xd192e819);
     164        6688 :         RNDr(S, W, 45, 0xd6990624);
     165        6688 :         RNDr(S, W, 46, 0xf40e3585);
     166        6688 :         RNDr(S, W, 47, 0x106aa070);
     167        6688 :         RNDr(S, W, 48, 0x19a4c116);
     168        6688 :         RNDr(S, W, 49, 0x1e376c08);
     169        6688 :         RNDr(S, W, 50, 0x2748774c);
     170        6688 :         RNDr(S, W, 51, 0x34b0bcb5);
     171        6688 :         RNDr(S, W, 52, 0x391c0cb3);
     172        6688 :         RNDr(S, W, 53, 0x4ed8aa4a);
     173        6688 :         RNDr(S, W, 54, 0x5b9cca4f);
     174        6688 :         RNDr(S, W, 55, 0x682e6ff3);
     175        6688 :         RNDr(S, W, 56, 0x748f82ee);
     176        6688 :         RNDr(S, W, 57, 0x78a5636f);
     177        6688 :         RNDr(S, W, 58, 0x84c87814);
     178        6688 :         RNDr(S, W, 59, 0x8cc70208);
     179        6688 :         RNDr(S, W, 60, 0x90befffa);
     180        6688 :         RNDr(S, W, 61, 0xa4506ceb);
     181        6688 :         RNDr(S, W, 62, 0xbef9a3f7);
     182        6688 :         RNDr(S, W, 63, 0xc67178f2);
     183             : 
     184             :         /* 4. Mix local working variables into global state */
     185       60192 :         for (i = 0; i < 8; i++)
     186       53504 :                 state[i] += S[i];
     187             : 
     188             :         /* Clean the stack. */
     189        6688 :         explicit_bzero(W, 256);
     190        6688 :         explicit_bzero(S, 32);
     191        6688 :         explicit_bzero(&t0, sizeof(t0));
     192        6688 :         explicit_bzero(&t1, sizeof(t0));
     193        6688 : }
     194             : 
     195             : static unsigned char PAD[64] = {
     196             :         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     197             :         0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     198             :         0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
     199             : 
     200             : /* Add padding and terminating bit-count. */
     201        3921 : static void SHA256_Pad(SHA256_CTX *ctx)
     202             : {
     203        3921 :         unsigned char len[8];
     204        3921 :         uint32_t r, plen;
     205             : 
     206             :         /*
     207             :          * Convert length to a vector of bytes -- we do this now rather
     208             :          * than later because the length will change after we pad.
     209             :          */
     210        3921 :         be32enc_vect(len, ctx->count, 8);
     211             : 
     212             :         /* Add 1--64 bytes so that the resulting length is 56 mod 64 */
     213        3921 :         r = (ctx->count[1] >> 3) & 0x3f;
     214        3921 :         plen = (r < 56) ? (56 - r) : (120 - r);
     215        3921 :         SHA256_Update(ctx, PAD, (size_t)plen);
     216             : 
     217             :         /* Add the terminating bit-count */
     218        3921 :         SHA256_Update(ctx, len, 8);
     219        3921 : }
     220             : 
     221             : /* SHA-256 initialization.  Begins a SHA-256 operation. */
     222        3921 : void SHA256_Init(SHA256_CTX *ctx)
     223             : {
     224             : 
     225             :         /* Zero bits processed so far */
     226        3921 :         ctx->count[0] = ctx->count[1] = 0;
     227             : 
     228             :         /* Magic initialization constants */
     229        3921 :         ctx->state[0] = 0x6A09E667;
     230        3921 :         ctx->state[1] = 0xBB67AE85;
     231        3921 :         ctx->state[2] = 0x3C6EF372;
     232        3921 :         ctx->state[3] = 0xA54FF53A;
     233        3921 :         ctx->state[4] = 0x510E527F;
     234        3921 :         ctx->state[5] = 0x9B05688C;
     235        3921 :         ctx->state[6] = 0x1F83D9AB;
     236        3921 :         ctx->state[7] = 0x5BE0CD19;
     237        3921 : }
     238             : 
     239             : /* Add bytes into the hash */
     240       23526 : void SHA256_Update(SHA256_CTX *ctx, const void *in, size_t len)
     241             : {
     242       23526 :         uint32_t bitlen[2];
     243       23526 :         uint32_t r;
     244       23526 :         const unsigned char *src = in;
     245             : 
     246             :         /* Number of bytes left in the buffer from previous updates */
     247       23526 :         r = (ctx->count[1] >> 3) & 0x3f;
     248             : 
     249             :         /* Convert the length into a number of bits */
     250       23526 :         bitlen[1] = ((uint32_t)len) << 3;
     251       23526 :         bitlen[0] = (uint32_t)(len >> 29);
     252             : 
     253             :         /* Update number of bits */
     254       23526 :         if ((ctx->count[1] += bitlen[1]) < bitlen[1])
     255           0 :                 ctx->count[0]++;
     256       23526 :         ctx->count[0] += bitlen[0];
     257             : 
     258             :         /* Handle the case where we don't need to perform any transforms */
     259       23526 :         if (len < 64 - r) {
     260       16845 :                 memcpy(&ctx->buf[r], src, len);
     261       16845 :                 return;
     262             :         }
     263             : 
     264             :         /* Finish the current block */
     265        6681 :         memcpy(&ctx->buf[r], src, 64 - r);
     266        6681 :         SHA256_Transform(ctx->state, ctx->buf);
     267        6681 :         src += 64 - r;
     268        6681 :         len -= 64 - r;
     269             : 
     270             :         /* Perform complete blocks */
     271        6688 :         while (len >= 64) {
     272           7 :                 SHA256_Transform(ctx->state, src);
     273           7 :                 src += 64;
     274           7 :                 len -= 64;
     275             :         }
     276             : 
     277             :         /* Copy left over data into buffer */
     278        6681 :         memcpy(ctx->buf, src, len);
     279             : }
     280             : 
     281             : /*
     282             :  * SHA-256 finalization.  Pads the input data, exports the hash value,
     283             :  * and clears the context state.
     284             :  */
     285        3921 : void SHA256_Final(unsigned char digest[32], SHA256_CTX *ctx)
     286             : {
     287             : 
     288             :         /* Add padding */
     289        3921 :         SHA256_Pad(ctx);
     290             : 
     291             :         /* Write the hash */
     292        3921 :         be32enc_vect(digest, ctx->state, 32);
     293             : 
     294             :         /* Clear the context state */
     295        3921 :         explicit_bzero((void *)ctx, sizeof(*ctx));
     296        3921 : }
     297             : 
     298             : /* Initialize an HMAC-SHA256 operation with the given key. */
     299           0 : void HMAC__SHA256_Init(HMAC_SHA256_CTX *ctx, const void *_K, size_t Klen)
     300             : {
     301           0 :         unsigned char pad[64];
     302           0 :         unsigned char khash[32];
     303           0 :         const unsigned char *K = _K;
     304           0 :         size_t i;
     305             : 
     306             :         /* If Klen > 64, the key is really SHA256(K). */
     307           0 :         if (Klen > 64) {
     308           0 :                 SHA256_Init(&ctx->ictx);
     309           0 :                 SHA256_Update(&ctx->ictx, K, Klen);
     310           0 :                 SHA256_Final(khash, &ctx->ictx);
     311           0 :                 K = khash;
     312           0 :                 Klen = 32;
     313             :         }
     314             : 
     315             :         /* Inner SHA256 operation is SHA256(K xor [block of 0x36] || data). */
     316           0 :         SHA256_Init(&ctx->ictx);
     317           0 :         memset(pad, 0x36, 64);
     318           0 :         for (i = 0; i < Klen; i++)
     319           0 :                 pad[i] ^= K[i];
     320           0 :         SHA256_Update(&ctx->ictx, pad, 64);
     321             : 
     322             :         /* Outer SHA256 operation is SHA256(K xor [block of 0x5c] || hash). */
     323           0 :         SHA256_Init(&ctx->octx);
     324           0 :         memset(pad, 0x5c, 64);
     325           0 :         for (i = 0; i < Klen; i++)
     326           0 :                 pad[i] ^= K[i];
     327           0 :         SHA256_Update(&ctx->octx, pad, 64);
     328             : 
     329             :         /* Clean the stack. */
     330           0 :         explicit_bzero(khash, 32);
     331           0 : }
     332             : 
     333             : /* Add bytes to the HMAC-SHA256 operation. */
     334           0 : void HMAC__SHA256_Update(HMAC_SHA256_CTX *ctx, const void *in, size_t len)
     335             : {
     336             : 
     337             :         /* Feed data to the inner SHA256 operation. */
     338           0 :         SHA256_Update(&ctx->ictx, in, len);
     339           0 : }
     340             : 
     341             : /* Finish an HMAC-SHA256 operation. */
     342           0 : void HMAC__SHA256_Final(unsigned char digest[32], HMAC_SHA256_CTX *ctx)
     343             : {
     344           0 :         unsigned char ihash[32];
     345             : 
     346             :         /* Finish the inner SHA256 operation. */
     347           0 :         SHA256_Final(ihash, &ctx->ictx);
     348             : 
     349             :         /* Feed the inner hash to the outer SHA256 operation. */
     350           0 :         SHA256_Update(&ctx->octx, ihash, 32);
     351             : 
     352             :         /* Finish the outer SHA256 operation. */
     353           0 :         SHA256_Final(digest, &ctx->octx);
     354             : 
     355             :         /* Clean the stack. */
     356           0 :         explicit_bzero(ihash, 32);
     357           0 : }
     358             : 
     359             : /**
     360             :  * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen):
     361             :  * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and
     362             :  * write the output to buf.  The value dkLen must be at most 32 * (2^32 - 1).
     363             :  */
     364           0 : void PBKDF2_SHA256(const uint8_t *passwd, size_t passwdlen, const uint8_t *salt,
     365             :                    size_t saltlen, uint64_t c, uint8_t *buf, size_t dkLen)
     366             : {
     367           0 :         HMAC_SHA256_CTX PShctx, hctx;
     368           0 :         size_t i;
     369           0 :         uint8_t ivec[4];
     370           0 :         uint8_t U[32];
     371           0 :         uint8_t T[32];
     372           0 :         uint64_t j;
     373           0 :         int k;
     374           0 :         size_t clen;
     375             : 
     376             :         /* Compute HMAC state after processing P and S. */
     377           0 :         HMAC__SHA256_Init(&PShctx, passwd, passwdlen);
     378           0 :         HMAC__SHA256_Update(&PShctx, salt, saltlen);
     379             : 
     380             :         /* Iterate through the blocks. */
     381           0 :         for (i = 0; i * 32 < dkLen; i++) {
     382             :                 /* Generate INT(i + 1). */
     383           0 :                 be32enc(ivec, (uint32_t)(i + 1));
     384             : 
     385             :                 /* Compute U_1 = PRF(P, S || INT(i)). */
     386           0 :                 memcpy(&hctx, &PShctx, sizeof(HMAC_SHA256_CTX));
     387           0 :                 HMAC__SHA256_Update(&hctx, ivec, 4);
     388           0 :                 HMAC__SHA256_Final(U, &hctx);
     389             : 
     390             :                 /* T_i = U_1 ... */
     391           0 :                 memcpy(T, U, 32);
     392             : 
     393           0 :                 for (j = 2; j <= c; j++) {
     394             :                         /* Compute U_j. */
     395           0 :                         HMAC__SHA256_Init(&hctx, passwd, passwdlen);
     396           0 :                         HMAC__SHA256_Update(&hctx, U, 32);
     397           0 :                         HMAC__SHA256_Final(U, &hctx);
     398             : 
     399             :                         /* ... xor U_j ... */
     400           0 :                         for (k = 0; k < 32; k++)
     401           0 :                                 T[k] ^= U[k];
     402             :                 }
     403             : 
     404             :                 /* Copy as many bytes as necessary into buf. */
     405           0 :                 clen = dkLen - i * 32;
     406           0 :                 if (clen > 32)
     407             :                         clen = 32;
     408           0 :                 memcpy(&buf[i * 32], T, clen);
     409             :         }
     410             : 
     411             :         /* Clean PShctx, since we never called _Final on it. */
     412           0 :         explicit_bzero(&PShctx, sizeof(HMAC_SHA256_CTX));
     413           0 : }