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-rw-r--r--sha2.c367
1 files changed, 367 insertions, 0 deletions
diff --git a/sha2.c b/sha2.c
new file mode 100644
index 0000000..84667a8
--- /dev/null
+++ b/sha2.c
@@ -0,0 +1,367 @@
+#include "sha2.h"
+#include <string.h> // memcpy
+
+// extract bytes from uint32_t
+// (used in sha256_fini() and sha224_fini())
+#define WB(ctx, i) \
+ ((ctx)->h[i] >> 24) & 0xff, \
+ ((ctx)->h[i] >> 16) & 0xff, \
+ ((ctx)->h[i] >> 8) & 0xff, \
+ ((ctx)->h[i]) & 0xff
+
+// sha256 initial hash values
+// (first 32 bits of the fractional parts of the square roots of the
+// first 8 primes 2..19):
+static const uint32_t SHA256_INIT[8] = {
+ 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+ 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
+};
+
+// round constants
+// (first 32 bits of the fractional parts of the cube roots of the first
+// 64 primes 2..311):
+static const uint32_t 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,
+};
+
+// rotate right
+// (src: https://blog.regehr.org/archives/1063)
+static inline uint32_t
+rr(const uint32_t v, const size_t n) {
+ return (v << (32 - n)) | (v >> n);
+}
+
+void sha256_init(sha256_t * const ctx) {
+ ctx->buf_len = 0;
+ ctx->num_bytes = 0;
+ memcpy(ctx->h, SHA256_INIT, sizeof(SHA256_INIT));
+}
+
+// WI: decode buffer data as 32-bit words (used for the first 16 words)
+#define WI(i) ( \
+ (((uint32_t) ctx->buf[4 * (i) + 0]) << 24) | \
+ (((uint32_t) ctx->buf[4 * (i) + 1]) << 16) | \
+ (((uint32_t) ctx->buf[4 * (i) + 2]) << 8) | \
+ ((uint32_t) ctx->buf[4 * (i) + 3]) \
+)
+
+// WE: expand first 16 buffer words into remaining 48 words
+#define WE(i) do { \
+ const uint32_t w2 = w[(i) - 2], \
+ w7 = w[(i) - 7], \
+ w15 = w[(i) - 15], \
+ w16 = w[(i) - 16], \
+ s0 = rr(w15, 7) ^ rr(w15, 18) ^ (w15 >> 3), \
+ s1 = rr(w2, 17) ^ rr(w2, 19) ^ (w2 >> 10); \
+ w[i] = w16 + s0 + w7 + s1; \
+} while (0)
+
+// WC: compress word
+#define WC(i) do { \
+ const uint32_t s1 = rr(hs[4], 6) ^ rr(hs[4], 11) ^ rr(hs[4], 25), \
+ ch = (hs[4] & hs[5]) ^ ((~(hs[4])) & hs[6]), \
+ t0 = hs[7] + s1 + ch + K[i] + w[i], \
+ s0 = rr(hs[0], 2) ^ rr(hs[0], 13) ^ rr(hs[0], 22), \
+ mj = (hs[0] & hs[1]) ^ (hs[0] & hs[2]) ^ (hs[1] & hs[2]), \
+ t1 = s0 + mj; \
+\
+ hs[7] = hs[6]; \
+ hs[6] = hs[5]; \
+ hs[5] = hs[4]; \
+ hs[4] = hs[3] + t0; \
+ hs[3] = hs[2]; \
+ hs[2] = hs[1]; \
+ hs[1] = hs[0]; \
+ hs[0] = t0 + t1; \
+} while (0)
+
+static void
+sha256_block(sha256_t * const ctx) {
+ // init first 16 words from buffer
+ uint32_t w[64] = {
+ WI(0), WI(1), WI(2), WI(3), WI(4), WI(5), WI(6), WI(7),
+ WI(8), WI(9), WI(10), WI(11), WI(12), WI(13), WI(14), WI(15),
+ 0,
+ };
+
+ // Extend the first 16 words into the remaining 48 words w[16..63] of
+ // the message schedule array
+ //
+ // for i from 16 to 63
+ // s0 := (w[i-15] rr 7) xor (w[i-15] rr 18) xor (w[i-15] rs 3)
+ // s1 := (w[i- 2] rr 17) xor (w[i- 2] rr 19) xor (w[i- 2] rs 10)
+ // w[i] := w[i-16] + s0 + w[i-7] + s1
+ //
+ // for (size_t i = 16; i < 64; i++) {
+ // const uint32_t w2 = w[i - 2],
+ // w7 = w[i - 7],
+ // w15 = w[i - 15],
+ // w16 = w[i - 16],
+ // s0 = rr(w15, 7) ^ rr(w15, 18) ^ (w15 >> 3),
+ // s1 = rr(w2, 17) ^ rr(w2, 19) ^ (w2 >> 10);
+ // w[i] = w16 + s0 + w7 + s1;
+ // }
+ //
+ // // fully unrolled version:
+ // WE(24); WE(25); WE(26); WE(27); WE(28); WE(29); WE(30); WE(31);
+ // WE(32); WE(33); WE(34); WE(35); WE(36); WE(37); WE(38); WE(39);
+ // WE(40); WE(41); WE(42); WE(43); WE(44); WE(45); WE(46); WE(47);
+ // WE(48); WE(49); WE(50); WE(51); WE(52); WE(53); WE(54); WE(55);
+ // WE(56); WE(57); WE(58); WE(59); WE(60); WE(61); WE(62); WE(63);
+ //
+ // partially unrolled:
+ // for (size_t we_i = 16; we_i < 64; we_i += 16) {
+ // WE(we_i + 0); WE(we_i + 1); WE(we_i + 2); WE(we_i + 3);
+ // WE(we_i + 4); WE(we_i + 5); WE(we_i + 6); WE(we_i + 7);
+ // WE(we_i + 8); WE(we_i + 9); WE(we_i + 10); WE(we_i + 11);
+ // WE(we_i + 12); WE(we_i + 13); WE(we_i + 14); WE(we_i + 15);
+ // }
+ for (size_t i = 16; i < 64; i++) {
+ WE(i);
+ }
+
+ // Initialize working variables to current hash value
+ uint32_t hs[8] = {
+ ctx->h[0], ctx->h[1], ctx->h[2], ctx->h[3],
+ ctx->h[4], ctx->h[5], ctx->h[6], ctx->h[7],
+ };
+
+ // Compression function main loop
+ //
+ // for i from 0 to 63
+ // S1 := (e rightrotate 6) xor (e rightrotate 11) xor (e rightrotate 25)
+ // ch := (e and f) xor ((not e) and g)
+ // temp1 := h + S1 + ch + k[i] + w[i]
+ // S0 := (a rightrotate 2) xor (a rightrotate 13) xor (a rightrotate 22)
+ // maj := (a and b) xor (a and c) xor (b and c)
+ // temp2 := S0 + maj
+ //
+ // h := g
+ // g := f
+ // f := e
+ // e := d + temp1
+ // d := c
+ // c := b
+ // b := a
+ // a := temp1 + temp2
+ //
+ // for (size_t i = 0; i < 64; i++) {
+ // const uint32_t s1 = rr(hs[4], 6) ^ rr(hs[4], 11) ^ rr(hs[4], 25),
+ // ch = (hs[4] & hs[5]) ^ ((~(hs[4])) & hs[6]),
+ // t0 = hs[7] + s1 + ch + K[i] + w[i],
+ // s0 = rr(hs[0], 2) ^ rr(hs[0], 13) ^ rr(hs[0], 22),
+ // mj = (hs[0] & hs[1]) ^ (hs[0] & hs[2]) ^ (hs[1] & hs[2]),
+ // t1 = s0 + mj;
+
+ // hs[7] = hs[6];
+ // hs[6] = hs[5];
+ // hs[5] = hs[4];
+ // hs[4] = hs[3] + t0;
+ // hs[3] = hs[2];
+ // hs[2] = hs[1];
+ // hs[1] = hs[0];
+ // hs[0] = t0 + t1;
+ // }
+ //
+ // // fully unrolled version:
+ // WC(0); WC(1); WC(2); WC(3); WC(4); WC(5); WC(6); WC(7);
+ // WC(8); WC(9); WC(10); WC(11); WC(12); WC(13); WC(14); WC(15);
+ // WC(16); WC(17); WC(18); WC(19); WC(20); WC(21); WC(22); WC(23);
+ // WC(24); WC(25); WC(26); WC(27); WC(28); WC(29); WC(30); WC(31);
+ // WC(32); WC(33); WC(34); WC(35); WC(36); WC(37); WC(38); WC(39);
+ // WC(40); WC(41); WC(42); WC(43); WC(44); WC(45); WC(46); WC(47);
+ // WC(48); WC(49); WC(50); WC(51); WC(52); WC(53); WC(54); WC(55);
+ // WC(56); WC(57); WC(58); WC(59); WC(60); WC(61); WC(62); WC(63);
+ //
+ // partially unrolled:
+ for (size_t i = 0; i < 64; i += 16) {
+ WC(i + 0); WC(i + 1); WC(i + 2); WC(i + 3);
+ WC(i + 4); WC(i + 5); WC(i + 6); WC(i + 7);
+ WC(i + 8); WC(i + 9); WC(i + 10); WC(i + 11);
+ WC(i + 12); WC(i + 13); WC(i + 14); WC(i + 15);
+ }
+
+ // Add the compressed chunk to the current hash value
+ ctx->h[0] += hs[0];
+ ctx->h[1] += hs[1];
+ ctx->h[2] += hs[2];
+ ctx->h[3] += hs[3];
+ ctx->h[4] += hs[4];
+ ctx->h[5] += hs[5];
+ ctx->h[6] += hs[6];
+ ctx->h[7] += hs[7];
+}
+
+#undef WI
+#undef WE
+#undef WC
+
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+
+void sha256_push(
+ sha256_t * const ctx,
+ const uint8_t * const src,
+ const size_t src_len
+) {
+ const size_t buf_left = 64 - ctx->buf_len;
+
+ if (src_len >= buf_left) {
+ // fill remaining buffer
+ memcpy(ctx->buf + ctx->buf_len, src, buf_left);
+ sha256_block(ctx);
+ ctx->buf_len = 0;
+
+ const size_t new_src_len = src_len - buf_left;
+ const size_t num_blocks = new_src_len / 64;
+
+ // process chunks
+ for (size_t i = 0; i < num_blocks; i++) {
+ memcpy(ctx->buf, src + buf_left + (64 * i), 64);
+ sha256_block(ctx);
+ }
+
+ // copy remaining bytes to buffer
+ const size_t new_buf_len = (new_src_len - 64 * num_blocks);
+ memcpy(ctx->buf, src + buf_left + (64 * num_blocks), new_buf_len);
+ ctx->buf_len = new_buf_len;
+ } else {
+ memcpy(ctx->buf + ctx->buf_len, src, src_len);
+ ctx->buf_len += src_len;
+ }
+
+ // update byte count
+ ctx->num_bytes += src_len;
+}
+
+static void
+sha256_push_u64(
+ sha256_t * const ctx,
+ const uint64_t val
+) {
+ const uint8_t buf[8] = {
+ ((val >> 56) & 0xff),
+ ((val >> 48) & 0xff),
+ ((val >> 40) & 0xff),
+ ((val >> 32) & 0xff),
+ ((val >> 24) & 0xff),
+ ((val >> 16) & 0xff),
+ ((val >> 8) & 0xff),
+ ((val) & 0xff),
+ };
+
+ sha256_push(ctx, buf, sizeof(buf));
+}
+
+// end of stream padding
+static const uint8_t PADDING[65] = {
+ 128,
+ 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, 0,
+};
+
+static void
+sha256_push_footer(
+ sha256_t * const ctx
+) {
+ const uint64_t num_bytes = ctx->num_bytes;
+ const size_t pad_len = (65 - ((num_bytes + 1 + 8) % 64));
+
+ // push padding
+ sha256_push(ctx, PADDING, pad_len);
+
+ // push length (in bits)
+ sha256_push_u64(ctx, num_bytes * 8);
+}
+
+void sha256_fini(
+ sha256_t * const ctx,
+ uint8_t * const out
+) {
+ // push footer
+ sha256_push_footer(ctx);
+
+ // extract hash
+ const uint8_t hash[32] = {
+ WB(ctx, 0), WB(ctx, 1), WB(ctx, 2), WB(ctx, 3),
+ WB(ctx, 4), WB(ctx, 5), WB(ctx, 6), WB(ctx, 7),
+ };
+
+ memcpy(out, hash, sizeof(hash));
+}
+
+void sha256(
+ const uint8_t * const src,
+ const size_t src_len,
+ uint8_t * const dst
+) {
+ sha256_t ctx;
+ sha256_init(&ctx);
+ sha256_push(&ctx, src, src_len);
+ sha256_fini(&ctx, dst);
+}
+
+// sha224 initial hash values
+// (the second 32 bits of the fractional parts of the square roots of
+// the 9th through 16th primes 23..53)
+static const uint32_t SHA224_INIT[8] = {
+ 0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939,
+ 0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4
+};
+
+void sha224_init(sha224_t * const ctx) {
+ ctx->ctx.buf_len = 0;
+ ctx->ctx.num_bytes = 0;
+ memcpy(ctx->ctx.h, SHA224_INIT, sizeof(SHA224_INIT));
+}
+
+void sha224_push(
+ sha224_t * const sha224_ctx,
+ const uint8_t * const src,
+ const size_t src_len
+) {
+ sha256_t * const ctx = (sha256_t * const) sha224_ctx;
+ sha256_push(ctx, src, src_len);
+}
+
+void sha224_fini(
+ sha224_t * const sha224_ctx,
+ uint8_t * const out
+) {
+ sha256_t * const ctx = (sha256_t * const) sha224_ctx;
+
+ // push footer
+ sha256_push_footer(ctx);
+
+ // extract hash
+ const uint8_t hash[28] = {
+ WB(ctx, 0), WB(ctx, 1), WB(ctx, 2), WB(ctx, 3),
+ WB(ctx, 4), WB(ctx, 5), WB(ctx, 6),
+ };
+
+ memcpy(out, hash, sizeof(hash));
+}
+
+void sha224(
+ const uint8_t * const src,
+ const size_t src_len,
+ uint8_t * const dst
+) {
+ sha224_t ctx;
+ sha224_init(&ctx);
+ sha224_push(&ctx, src, src_len);
+ sha224_fini(&ctx, dst);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 16:32:27 +0000