summaryrefslogtreecommitdiffstats
path: root/lib/sha256.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/sha256.c')
-rw-r--r--lib/sha256.c413
1 files changed, 413 insertions, 0 deletions
diff --git a/lib/sha256.c b/lib/sha256.c
new file mode 100644
index 0000000..f1727b6
--- /dev/null
+++ b/lib/sha256.c
@@ -0,0 +1,413 @@
+/*-
+ * Copyright 2005,2007,2009 Colin Percival
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <zebra.h>
+#include "sha256.h"
+
+#if !HAVE_DECL_BE32DEC
+static inline uint32_t be32dec(const void *pp)
+{
+ const uint8_t *p = (uint8_t const *)pp;
+
+ return ((uint32_t)(p[3]) + ((uint32_t)(p[2]) << 8)
+ + ((uint32_t)(p[1]) << 16) + ((uint32_t)(p[0]) << 24));
+}
+#endif
+
+#if !HAVE_DECL_BE32ENC
+static inline void be32enc(void *pp, uint32_t x)
+{
+ uint8_t *p = (uint8_t *)pp;
+
+ p[3] = x & 0xff;
+ p[2] = (x >> 8) & 0xff;
+ p[1] = (x >> 16) & 0xff;
+ p[0] = (x >> 24) & 0xff;
+}
+#endif
+
+/*
+ * Encode a length len/4 vector of (uint32_t) into a length len vector of
+ * (unsigned char) in big-endian form. Assumes len is a multiple of 4.
+ */
+static void be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len / 4; i++)
+ be32enc(dst + i * 4, src[i]);
+}
+
+/*
+ * Decode a big-endian length len vector of (unsigned char) into a length
+ * len/4 vector of (uint32_t). Assumes len is a multiple of 4.
+ */
+static void be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len / 4; i++)
+ dst[i] = be32dec(src + i * 4);
+}
+
+/* Elementary functions used by SHA256 */
+#define Ch(x, y, z) ((x & (y ^ z)) ^ z)
+#define Maj(x, y, z) ((x & (y | z)) | (y & z))
+#define SHR(x, n) (x >> n)
+#define ROTR(x, n) ((x >> n) | (x << (32 - n)))
+#define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
+#define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
+
+/* SHA256 round function */
+#define RND(a, b, c, d, e, f, g, h, k) \
+ t0 = h + S1(e) + Ch(e, f, g) + k; \
+ t1 = S0(a) + Maj(a, b, c); \
+ d += t0; \
+ h = t0 + t1;
+
+/* Adjusted round function for rotating state */
+#define RNDr(S, W, i, k) \
+ RND(S[(64 - i) % 8], S[(65 - i) % 8], S[(66 - i) % 8], \
+ S[(67 - i) % 8], S[(68 - i) % 8], S[(69 - i) % 8], \
+ S[(70 - i) % 8], S[(71 - i) % 8], W[i] + k)
+
+/*
+ * SHA256 block compression function. The 256-bit state is transformed via
+ * the 512-bit input block to produce a new state.
+ */
+static void SHA256_Transform(uint32_t *state, const unsigned char block[64])
+{
+ uint32_t W[64];
+ uint32_t S[8];
+ uint32_t t0, t1;
+ int i;
+
+ /* 1. Prepare message schedule W. */
+ be32dec_vect(W, block, 64);
+ for (i = 16; i < 64; i++)
+ W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
+
+ /* 2. Initialize working variables. */
+ memcpy(S, state, 32);
+
+ /* 3. Mix. */
+ RNDr(S, W, 0, 0x428a2f98);
+ RNDr(S, W, 1, 0x71374491);
+ RNDr(S, W, 2, 0xb5c0fbcf);
+ RNDr(S, W, 3, 0xe9b5dba5);
+ RNDr(S, W, 4, 0x3956c25b);
+ RNDr(S, W, 5, 0x59f111f1);
+ RNDr(S, W, 6, 0x923f82a4);
+ RNDr(S, W, 7, 0xab1c5ed5);
+ RNDr(S, W, 8, 0xd807aa98);
+ RNDr(S, W, 9, 0x12835b01);
+ RNDr(S, W, 10, 0x243185be);
+ RNDr(S, W, 11, 0x550c7dc3);
+ RNDr(S, W, 12, 0x72be5d74);
+ RNDr(S, W, 13, 0x80deb1fe);
+ RNDr(S, W, 14, 0x9bdc06a7);
+ RNDr(S, W, 15, 0xc19bf174);
+ RNDr(S, W, 16, 0xe49b69c1);
+ RNDr(S, W, 17, 0xefbe4786);
+ RNDr(S, W, 18, 0x0fc19dc6);
+ RNDr(S, W, 19, 0x240ca1cc);
+ RNDr(S, W, 20, 0x2de92c6f);
+ RNDr(S, W, 21, 0x4a7484aa);
+ RNDr(S, W, 22, 0x5cb0a9dc);
+ RNDr(S, W, 23, 0x76f988da);
+ RNDr(S, W, 24, 0x983e5152);
+ RNDr(S, W, 25, 0xa831c66d);
+ RNDr(S, W, 26, 0xb00327c8);
+ RNDr(S, W, 27, 0xbf597fc7);
+ RNDr(S, W, 28, 0xc6e00bf3);
+ RNDr(S, W, 29, 0xd5a79147);
+ RNDr(S, W, 30, 0x06ca6351);
+ RNDr(S, W, 31, 0x14292967);
+ RNDr(S, W, 32, 0x27b70a85);
+ RNDr(S, W, 33, 0x2e1b2138);
+ RNDr(S, W, 34, 0x4d2c6dfc);
+ RNDr(S, W, 35, 0x53380d13);
+ RNDr(S, W, 36, 0x650a7354);
+ RNDr(S, W, 37, 0x766a0abb);
+ RNDr(S, W, 38, 0x81c2c92e);
+ RNDr(S, W, 39, 0x92722c85);
+ RNDr(S, W, 40, 0xa2bfe8a1);
+ RNDr(S, W, 41, 0xa81a664b);
+ RNDr(S, W, 42, 0xc24b8b70);
+ RNDr(S, W, 43, 0xc76c51a3);
+ RNDr(S, W, 44, 0xd192e819);
+ RNDr(S, W, 45, 0xd6990624);
+ RNDr(S, W, 46, 0xf40e3585);
+ RNDr(S, W, 47, 0x106aa070);
+ RNDr(S, W, 48, 0x19a4c116);
+ RNDr(S, W, 49, 0x1e376c08);
+ RNDr(S, W, 50, 0x2748774c);
+ RNDr(S, W, 51, 0x34b0bcb5);
+ RNDr(S, W, 52, 0x391c0cb3);
+ RNDr(S, W, 53, 0x4ed8aa4a);
+ RNDr(S, W, 54, 0x5b9cca4f);
+ RNDr(S, W, 55, 0x682e6ff3);
+ RNDr(S, W, 56, 0x748f82ee);
+ RNDr(S, W, 57, 0x78a5636f);
+ RNDr(S, W, 58, 0x84c87814);
+ RNDr(S, W, 59, 0x8cc70208);
+ RNDr(S, W, 60, 0x90befffa);
+ RNDr(S, W, 61, 0xa4506ceb);
+ RNDr(S, W, 62, 0xbef9a3f7);
+ RNDr(S, W, 63, 0xc67178f2);
+
+ /* 4. Mix local working variables into global state */
+ for (i = 0; i < 8; i++)
+ state[i] += S[i];
+
+ /* Clean the stack. */
+ explicit_bzero(W, 256);
+ explicit_bzero(S, 32);
+ explicit_bzero(&t0, sizeof(t0));
+ explicit_bzero(&t1, sizeof(t0));
+}
+
+static unsigned char PAD[64] = {
+ 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+/* Add padding and terminating bit-count. */
+static void SHA256_Pad(SHA256_CTX *ctx)
+{
+ unsigned char len[8];
+ uint32_t r, plen;
+
+ /*
+ * Convert length to a vector of bytes -- we do this now rather
+ * than later because the length will change after we pad.
+ */
+ be32enc_vect(len, ctx->count, 8);
+
+ /* Add 1--64 bytes so that the resulting length is 56 mod 64 */
+ r = (ctx->count[1] >> 3) & 0x3f;
+ plen = (r < 56) ? (56 - r) : (120 - r);
+ SHA256_Update(ctx, PAD, (size_t)plen);
+
+ /* Add the terminating bit-count */
+ SHA256_Update(ctx, len, 8);
+}
+
+/* SHA-256 initialization. Begins a SHA-256 operation. */
+void SHA256_Init(SHA256_CTX *ctx)
+{
+
+ /* Zero bits processed so far */
+ ctx->count[0] = ctx->count[1] = 0;
+
+ /* Magic initialization constants */
+ ctx->state[0] = 0x6A09E667;
+ ctx->state[1] = 0xBB67AE85;
+ ctx->state[2] = 0x3C6EF372;
+ ctx->state[3] = 0xA54FF53A;
+ ctx->state[4] = 0x510E527F;
+ ctx->state[5] = 0x9B05688C;
+ ctx->state[6] = 0x1F83D9AB;
+ ctx->state[7] = 0x5BE0CD19;
+}
+
+/* Add bytes into the hash */
+void SHA256_Update(SHA256_CTX *ctx, const void *in, size_t len)
+{
+ uint32_t bitlen[2];
+ uint32_t r;
+ const unsigned char *src = in;
+
+ /* Number of bytes left in the buffer from previous updates */
+ r = (ctx->count[1] >> 3) & 0x3f;
+
+ /* Convert the length into a number of bits */
+ bitlen[1] = ((uint32_t)len) << 3;
+ bitlen[0] = (uint32_t)(len >> 29);
+
+ /* Update number of bits */
+ if ((ctx->count[1] += bitlen[1]) < bitlen[1])
+ ctx->count[0]++;
+ ctx->count[0] += bitlen[0];
+
+ /* Handle the case where we don't need to perform any transforms */
+ if (len < 64 - r) {
+ memcpy(&ctx->buf[r], src, len);
+ return;
+ }
+
+ /* Finish the current block */
+ memcpy(&ctx->buf[r], src, 64 - r);
+ SHA256_Transform(ctx->state, ctx->buf);
+ src += 64 - r;
+ len -= 64 - r;
+
+ /* Perform complete blocks */
+ while (len >= 64) {
+ SHA256_Transform(ctx->state, src);
+ src += 64;
+ len -= 64;
+ }
+
+ /* Copy left over data into buffer */
+ memcpy(ctx->buf, src, len);
+}
+
+/*
+ * SHA-256 finalization. Pads the input data, exports the hash value,
+ * and clears the context state.
+ */
+void SHA256_Final(unsigned char digest[32], SHA256_CTX *ctx)
+{
+
+ /* Add padding */
+ SHA256_Pad(ctx);
+
+ /* Write the hash */
+ be32enc_vect(digest, ctx->state, 32);
+
+ /* Clear the context state */
+ explicit_bzero((void *)ctx, sizeof(*ctx));
+}
+
+/* Initialize an HMAC-SHA256 operation with the given key. */
+void HMAC__SHA256_Init(HMAC_SHA256_CTX *ctx, const void *_K, size_t Klen)
+{
+ unsigned char pad[64];
+ unsigned char khash[32];
+ const unsigned char *K = _K;
+ size_t i;
+
+ /* If Klen > 64, the key is really SHA256(K). */
+ if (Klen > 64) {
+ SHA256_Init(&ctx->ictx);
+ SHA256_Update(&ctx->ictx, K, Klen);
+ SHA256_Final(khash, &ctx->ictx);
+ K = khash;
+ Klen = 32;
+ }
+
+ /* Inner SHA256 operation is SHA256(K xor [block of 0x36] || data). */
+ SHA256_Init(&ctx->ictx);
+ memset(pad, 0x36, 64);
+ for (i = 0; i < Klen; i++)
+ pad[i] ^= K[i];
+ SHA256_Update(&ctx->ictx, pad, 64);
+
+ /* Outer SHA256 operation is SHA256(K xor [block of 0x5c] || hash). */
+ SHA256_Init(&ctx->octx);
+ memset(pad, 0x5c, 64);
+ for (i = 0; i < Klen; i++)
+ pad[i] ^= K[i];
+ SHA256_Update(&ctx->octx, pad, 64);
+
+ /* Clean the stack. */
+ explicit_bzero(khash, 32);
+}
+
+/* Add bytes to the HMAC-SHA256 operation. */
+void HMAC__SHA256_Update(HMAC_SHA256_CTX *ctx, const void *in, size_t len)
+{
+
+ /* Feed data to the inner SHA256 operation. */
+ SHA256_Update(&ctx->ictx, in, len);
+}
+
+/* Finish an HMAC-SHA256 operation. */
+void HMAC__SHA256_Final(unsigned char digest[32], HMAC_SHA256_CTX *ctx)
+{
+ unsigned char ihash[32];
+
+ /* Finish the inner SHA256 operation. */
+ SHA256_Final(ihash, &ctx->ictx);
+
+ /* Feed the inner hash to the outer SHA256 operation. */
+ SHA256_Update(&ctx->octx, ihash, 32);
+
+ /* Finish the outer SHA256 operation. */
+ SHA256_Final(digest, &ctx->octx);
+
+ /* Clean the stack. */
+ explicit_bzero(ihash, 32);
+}
+
+/**
+ * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen):
+ * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and
+ * write the output to buf. The value dkLen must be at most 32 * (2^32 - 1).
+ */
+void PBKDF2_SHA256(const uint8_t *passwd, size_t passwdlen, const uint8_t *salt,
+ size_t saltlen, uint64_t c, uint8_t *buf, size_t dkLen)
+{
+ HMAC_SHA256_CTX PShctx, hctx;
+ size_t i;
+ uint8_t ivec[4];
+ uint8_t U[32];
+ uint8_t T[32];
+ uint64_t j;
+ int k;
+ size_t clen;
+
+ /* Compute HMAC state after processing P and S. */
+ HMAC__SHA256_Init(&PShctx, passwd, passwdlen);
+ HMAC__SHA256_Update(&PShctx, salt, saltlen);
+
+ /* Iterate through the blocks. */
+ for (i = 0; i * 32 < dkLen; i++) {
+ /* Generate INT(i + 1). */
+ be32enc(ivec, (uint32_t)(i + 1));
+
+ /* Compute U_1 = PRF(P, S || INT(i)). */
+ memcpy(&hctx, &PShctx, sizeof(HMAC_SHA256_CTX));
+ HMAC__SHA256_Update(&hctx, ivec, 4);
+ HMAC__SHA256_Final(U, &hctx);
+
+ /* T_i = U_1 ... */
+ memcpy(T, U, 32);
+
+ for (j = 2; j <= c; j++) {
+ /* Compute U_j. */
+ HMAC__SHA256_Init(&hctx, passwd, passwdlen);
+ HMAC__SHA256_Update(&hctx, U, 32);
+ HMAC__SHA256_Final(U, &hctx);
+
+ /* ... xor U_j ... */
+ for (k = 0; k < 32; k++)
+ T[k] ^= U[k];
+ }
+
+ /* Copy as many bytes as necessary into buf. */
+ clen = dkLen - i * 32;
+ if (clen > 32)
+ clen = 32;
+ memcpy(&buf[i * 32], T, clen);
+ }
+
+ /* Clean PShctx, since we never called _Final on it. */
+ explicit_bzero(&PShctx, sizeof(HMAC_SHA256_CTX));
+}