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-rw-r--r--lib/sha256.c449
1 files changed, 449 insertions, 0 deletions
diff --git a/lib/sha256.c b/lib/sha256.c
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+/*
+ * BIRD Library -- SHA-256 and SHA-224 Hash Functions,
+ * HMAC-SHA-256 and HMAC-SHA-224 Functions
+ *
+ * (c) 2015 CZ.NIC z.s.p.o.
+ *
+ * Based on the code from libgcrypt-1.6.0, which is
+ * (c) 2003, 2006, 2008, 2009 Free Software Foundation, Inc.
+ *
+ * Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include "lib/sha256.h"
+#include "lib/unaligned.h"
+
+
+// #define SHA256_UNROLLED
+
+void
+sha256_init(struct sha256_context *ctx)
+{
+ ctx->h0 = 0x6a09e667;
+ ctx->h1 = 0xbb67ae85;
+ ctx->h2 = 0x3c6ef372;
+ ctx->h3 = 0xa54ff53a;
+ ctx->h4 = 0x510e527f;
+ ctx->h5 = 0x9b05688c;
+ ctx->h6 = 0x1f83d9ab;
+ ctx->h7 = 0x5be0cd19;
+
+ ctx->nblocks = 0;
+ ctx->count = 0;
+}
+
+void
+sha224_init(struct sha224_context *ctx)
+{
+ ctx->h0 = 0xc1059ed8;
+ ctx->h1 = 0x367cd507;
+ ctx->h2 = 0x3070dd17;
+ ctx->h3 = 0xf70e5939;
+ ctx->h4 = 0xffc00b31;
+ ctx->h5 = 0x68581511;
+ ctx->h6 = 0x64f98fa7;
+ ctx->h7 = 0xbefa4fa4;
+
+ ctx->nblocks = 0;
+ ctx->count = 0;
+}
+
+/* (4.2) same as SHA-1's F1. */
+static inline u32
+f1(u32 x, u32 y, u32 z)
+{
+ return (z ^ (x & (y ^ z)));
+}
+
+/* (4.3) same as SHA-1's F3 */
+static inline u32
+f3(u32 x, u32 y, u32 z)
+{
+ return ((x & y) | (z & (x|y)));
+}
+
+/* Bitwise rotation of an uint to the right */
+static inline u32 ror(u32 x, int n)
+{
+ return ((x >> (n&(32-1))) | (x << ((32-n)&(32-1))));
+}
+
+/* (4.4) */
+static inline u32
+sum0(u32 x)
+{
+ return (ror(x, 2) ^ ror(x, 13) ^ ror(x, 22));
+}
+
+/* (4.5) */
+static inline u32
+sum1(u32 x)
+{
+ return (ror(x, 6) ^ ror(x, 11) ^ ror(x, 25));
+}
+
+/*
+ Transform the message X which consists of 16 32-bit-words. See FIPS
+ 180-2 for details. */
+#define S0(x) (ror((x), 7) ^ ror((x), 18) ^ ((x) >> 3)) /* (4.6) */
+#define S1(x) (ror((x), 17) ^ ror((x), 19) ^ ((x) >> 10)) /* (4.7) */
+#define R(a,b,c,d,e,f,g,h,k,w) \
+ do \
+ { \
+ t1 = (h) + sum1((e)) + f1((e),(f),(g)) + (k) + (w); \
+ t2 = sum0((a)) + f3((a),(b),(c)); \
+ h = g; \
+ g = f; \
+ f = e; \
+ e = d + t1; \
+ d = c; \
+ c = b; \
+ b = a; \
+ a = t1 + t2; \
+ } while (0)
+
+/*
+ The SHA-256 core: Transform the message X which consists of 16
+ 32-bit-words. See FIPS 180-2 for details.
+ */
+static uint
+sha256_transform(struct sha256_context *ctx, const byte *data)
+{
+ static const u32 K[64] = {
+ 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+ 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+ 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+ 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+ 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+ 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+ 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+ 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+ 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+ 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+ 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+ 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+ 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+ 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+ 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+ 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+ };
+
+ u32 a,b,c,d,e,f,g,h,t1,t2;
+ u32 w[64];
+ int i;
+
+ a = ctx->h0;
+ b = ctx->h1;
+ c = ctx->h2;
+ d = ctx->h3;
+ e = ctx->h4;
+ f = ctx->h5;
+ g = ctx->h6;
+ h = ctx->h7;
+
+ for (i = 0; i < 16; i++)
+ w[i] = get_u32(data + i * 4);
+
+ for (; i < 64; i++)
+ w[i] = S1(w[i-2]) + w[i-7] + S0(w[i-15]) + w[i-16];
+
+ for (i = 0; i < 64;)
+ {
+#ifndef SHA256_UNROLLED
+ R(a,b,c,d,e,f,g,h,K[i],w[i]);
+ i++;
+#else /* Unrolled */
+ t1 = h + sum1(e) + f1(e, f, g) + K[i] + w[i];
+ t2 = sum0(a) + f3(a, b, c);
+ d += t1;
+ h = t1 + t2;
+
+ t1 = g + sum1(d) + f1(d, e, f) + K[i+1] + w[i+1];
+ t2 = sum0(h) + f3(h, a, b);
+ c += t1;
+ g = t1 + t2;
+
+ t1 = f + sum1(c) + f1(c, d, e) + K[i+2] + w[i+2];
+ t2 = sum0(g) + f3(g, h, a);
+ b += t1;
+ f = t1 + t2;
+
+ t1 = e + sum1(b) + f1(b, c, d) + K[i+3] + w[i+3];
+ t2 = sum0(f) + f3(f, g, h);
+ a += t1;
+ e = t1 + t2;
+
+ t1 = d + sum1(a) + f1(a, b, c) + K[i+4] + w[i+4];
+ t2 = sum0(e) + f3(e, f, g);
+ h += t1;
+ d = t1 + t2;
+
+ t1 = c + sum1(h) + f1(h, a, b) + K[i+5] + w[i+5];
+ t2 = sum0(d) + f3(d, e, f);
+ g += t1;
+ c = t1 + t2;
+
+ t1 = b + sum1(g) + f1(g, h, a) + K[i+6] + w[i+6];
+ t2 = sum0(c) + f3(c, d, e);
+ f += t1;
+ b = t1 + t2;
+
+ t1 = a + sum1(f) + f1(f, g, h) + K[i+7] + w[i+7];
+ t2 = sum0(b) + f3(b, c, d);
+ e += t1;
+ a = t1 + t2;
+
+ i += 8;
+#endif
+ }
+
+ ctx->h0 += a;
+ ctx->h1 += b;
+ ctx->h2 += c;
+ ctx->h3 += d;
+ ctx->h4 += e;
+ ctx->h5 += f;
+ ctx->h6 += g;
+ ctx->h7 += h;
+
+ return /*burn_stack*/ 74*4+32;
+}
+#undef S0
+#undef S1
+#undef R
+
+/* Common function to write a chunk of data to the transform function
+ of a hash algorithm. Note that the use of the term "block" does
+ not imply a fixed size block. Note that we explicitly allow to use
+ this function after the context has been finalized; the result does
+ not have any meaning but writing after finalize is sometimes
+ helpful to mitigate timing attacks. */
+void
+sha256_update(struct sha256_context *ctx, const byte *buf, size_t len)
+{
+ if (ctx->count)
+ {
+ /* Fill rest of internal buffer */
+ for (; len && ctx->count < SHA256_BLOCK_SIZE; len--)
+ ctx->buf[ctx->count++] = *buf++;
+
+ if (ctx->count < SHA256_BLOCK_SIZE)
+ return;
+
+ /* Process data from internal buffer */
+ sha256_transform(ctx, ctx->buf);
+ ctx->nblocks++;
+ ctx->count = 0;
+ }
+
+ if (!len)
+ return;
+
+ /* Process data from input buffer */
+ while (len >= SHA256_BLOCK_SIZE)
+ {
+ sha256_transform(ctx, buf);
+ ctx->nblocks++;
+ buf += SHA256_BLOCK_SIZE;
+ len -= SHA256_BLOCK_SIZE;
+ }
+
+ /* Copy remaining data to internal buffer */
+ memcpy(ctx->buf, buf, len);
+ ctx->count = len;
+}
+
+/*
+ * The routine finally terminates the computation and returns the digest. The
+ * handle is prepared for a new cycle, but adding bytes to the handle will the
+ * destroy the returned buffer.
+ *
+ * Returns: 32 bytes with the message the digest. 28 bytes for SHA-224.
+ */
+byte *
+sha256_final(struct sha256_context *ctx)
+{
+ u32 t, th, msb, lsb;
+
+ sha256_update(ctx, NULL, 0); /* flush */
+
+ t = ctx->nblocks;
+ th = 0;
+
+ /* multiply by 64 to make a byte count */
+ lsb = t << 6;
+ msb = (th << 6) | (t >> 26);
+ /* add the count */
+ t = lsb;
+ if ((lsb += ctx->count) < t)
+ msb++;
+ /* multiply by 8 to make a bit count */
+ t = lsb;
+ lsb <<= 3;
+ msb <<= 3;
+ msb |= t >> 29;
+
+ if (ctx->count < 56)
+ {
+ /* enough room */
+ ctx->buf[ctx->count++] = 0x80; /* pad */
+ while (ctx->count < 56)
+ ctx->buf[ctx->count++] = 0; /* pad */
+ }
+ else
+ {
+ /* need one extra block */
+ ctx->buf[ctx->count++] = 0x80; /* pad character */
+ while (ctx->count < 64)
+ ctx->buf[ctx->count++] = 0;
+ sha256_update(ctx, NULL, 0); /* flush */;
+ memset(ctx->buf, 0, 56 ); /* fill next block with zeroes */
+ }
+
+ /* append the 64 bit count */
+ put_u32(ctx->buf + 56, msb);
+ put_u32(ctx->buf + 60, lsb);
+ sha256_transform(ctx, ctx->buf);
+
+ byte *p = ctx->buf;
+#define X(a) do { put_u32(p, ctx->h##a); p += 4; } while(0)
+ X(0);
+ X(1);
+ X(2);
+ X(3);
+ X(4);
+ X(5);
+ X(6);
+ X(7);
+#undef X
+
+ return ctx->buf;
+}
+
+
+/*
+ * SHA256-HMAC
+ */
+
+static void
+sha256_hash_buffer(byte *outbuf, const byte *buffer, size_t length)
+{
+ struct sha256_context ctx;
+
+ sha256_init(&ctx);
+ sha256_update(&ctx, buffer, length);
+ memcpy(outbuf, sha256_final(&ctx), SHA256_SIZE);
+}
+
+void
+sha256_hmac_init(struct sha256_hmac_context *ctx, const byte *key, size_t keylen)
+{
+ byte keybuf[SHA256_BLOCK_SIZE], buf[SHA256_BLOCK_SIZE];
+
+ /* Hash the key if necessary */
+ if (keylen <= SHA256_BLOCK_SIZE)
+ {
+ memcpy(keybuf, key, keylen);
+ memset(keybuf + keylen, 0, SHA256_BLOCK_SIZE - keylen);
+ }
+ else
+ {
+ sha256_hash_buffer(keybuf, key, keylen);
+ memset(keybuf + SHA256_SIZE, 0, SHA256_BLOCK_SIZE - SHA256_SIZE);
+ }
+
+ /* Initialize the inner digest */
+ sha256_init(&ctx->ictx);
+ int i;
+ for (i = 0; i < SHA256_BLOCK_SIZE; i++)
+ buf[i] = keybuf[i] ^ 0x36;
+ sha256_update(&ctx->ictx, buf, SHA256_BLOCK_SIZE);
+
+ /* Initialize the outer digest */
+ sha256_init(&ctx->octx);
+ for (i = 0; i < SHA256_BLOCK_SIZE; i++)
+ buf[i] = keybuf[i] ^ 0x5c;
+ sha256_update(&ctx->octx, buf, SHA256_BLOCK_SIZE);
+}
+
+void
+sha256_hmac_update(struct sha256_hmac_context *ctx, const byte *buf, size_t buflen)
+{
+ /* Just update the inner digest */
+ sha256_update(&ctx->ictx, buf, buflen);
+}
+
+byte *
+sha256_hmac_final(struct sha256_hmac_context *ctx)
+{
+ /* Finish the inner digest */
+ byte *isha = sha256_final(&ctx->ictx);
+
+ /* Finish the outer digest */
+ sha256_update(&ctx->octx, isha, SHA256_SIZE);
+ return sha256_final(&ctx->octx);
+}
+
+
+/*
+ * SHA224-HMAC
+ */
+
+static void
+sha224_hash_buffer(byte *outbuf, const byte *buffer, size_t length)
+{
+ struct sha224_context ctx;
+
+ sha224_init(&ctx);
+ sha224_update(&ctx, buffer, length);
+ memcpy(outbuf, sha224_final(&ctx), SHA224_SIZE);
+}
+
+void
+sha224_hmac_init(struct sha224_hmac_context *ctx, const byte *key, size_t keylen)
+{
+ byte keybuf[SHA224_BLOCK_SIZE], buf[SHA224_BLOCK_SIZE];
+
+ /* Hash the key if necessary */
+ if (keylen <= SHA224_BLOCK_SIZE)
+ {
+ memcpy(keybuf, key, keylen);
+ memset(keybuf + keylen, 0, SHA224_BLOCK_SIZE - keylen);
+ }
+ else
+ {
+ sha224_hash_buffer(keybuf, key, keylen);
+ memset(keybuf + SHA224_SIZE, 0, SHA224_BLOCK_SIZE - SHA224_SIZE);
+ }
+
+ /* Initialize the inner digest */
+ sha224_init(&ctx->ictx);
+ int i;
+ for (i = 0; i < SHA224_BLOCK_SIZE; i++)
+ buf[i] = keybuf[i] ^ 0x36;
+ sha224_update(&ctx->ictx, buf, SHA224_BLOCK_SIZE);
+
+ /* Initialize the outer digest */
+ sha224_init(&ctx->octx);
+ for (i = 0; i < SHA224_BLOCK_SIZE; i++)
+ buf[i] = keybuf[i] ^ 0x5c;
+ sha224_update(&ctx->octx, buf, SHA224_BLOCK_SIZE);
+}
+
+void
+sha224_hmac_update(struct sha224_hmac_context *ctx, const byte *buf, size_t buflen)
+{
+ /* Just update the inner digest */
+ sha256_update(&ctx->ictx, buf, buflen);
+}
+
+byte *
+sha224_hmac_final(struct sha224_hmac_context *ctx)
+{
+ /* Finish the inner digest */
+ byte *isha = sha224_final(&ctx->ictx);
+
+ /* Finish the outer digest */
+ sha224_update(&ctx->octx, isha, SHA224_SIZE);
+ return sha224_final(&ctx->octx);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 06:00:14 +0000