commit 1a5b5acc814fbd49f9b090809615063960f4db96
parent 0bd0fc1f03b21c8ee7abe98c231f4561b673d941
Author: MikoĊaj Lenczewski <mikolaj@lenczewski.org>
Date: Wed, 16 Sep 2026 00:03:29 +0100
Add sha256 implementation
Diffstat:
10 files changed, 545 insertions(+), 3 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -1,3 +1,6 @@
+bin/
+test/
+
**/.*.swp
imgui.ini
tags
diff --git a/NOTES.txt b/NOTES.txt
@@ -1,6 +1,18 @@
+https://jvns.ca/blog/2022/03/23/a-toy-version-of-tls/
https://datatracker.ietf.org/doc/html/rfc8446
https://tls13.xargs.org/
+
https://datatracker.ietf.org/doc/html/rfc2246
https://tls12.xargs.org/
+
https://datatracker.ietf.org/doc/html/rfc7748
https://x25519.xargs.org/
+
+# hmac and hkdf
+https://datatracker.ietf.org/doc/html/rfc2104
+https://datatracker.ietf.org/doc/html/rfc5869
+
+# aes-{128,256}-gcm, chacha20, and sha256/sha384
+https://datatracker.ietf.org/doc/html/rfc5116
+https://datatracker.ietf.org/doc/html/rfc8439
+https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf
diff --git a/build.sh b/build.sh
@@ -2,5 +2,14 @@
set -ex
-cc -o test-client test-client.c -std=c11 -O0 -g3 -Wall -Wextra
-cc -o test-server test-server.c -std=c11 -O0 -g3 -Wall -Wextra
+CC="${CC:-clang}"
+FLAGS="-std=c11 -O0 -g3 -Wall -Wextra -Wno-unused-parameter -Wno-format"
+
+mkdir -p bin test
+
+for src in test-*.c; do
+ cc -o test/$(basename -s .c $src) $src $FLAGS
+done
+
+cc -o bin/tls_client tls_client.c $FLAGS
+cc -o bin/tls_server tls_server.c $FLAGS
diff --git a/clean.sh b/clean.sh
@@ -2,4 +2,4 @@
set -ex
-rm -f test-client test-server
+rm -rf bin/
diff --git a/sha.c b/sha.c
@@ -0,0 +1,317 @@
+#include "sha.h"
+
+// sha constants
+// ===========================================================================
+
+static sha256_word_t const _sha256_constants[] = {
+ 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,
+};
+
+static sha512_word_t const _sha512_constants[] = {
+ 0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
+ 0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
+ 0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
+ 0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
+ 0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
+ 0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
+ 0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
+ 0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
+ 0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
+ 0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
+ 0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
+ 0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
+ 0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
+ 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
+ 0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
+ 0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
+ 0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
+ 0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
+ 0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
+ 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817,
+};
+
+// sha256
+// ===========================================================================
+
+void
+sha256_init(struct sha256_ctx *ctx)
+{
+ memset(ctx, 0, sizeof *ctx);
+
+ ctx->digest[0] = 0x6a09e667;
+ ctx->digest[1] = 0xbb67ae85;
+ ctx->digest[2] = 0x3c6ef372;
+ ctx->digest[3] = 0xa54ff53a;
+ ctx->digest[4] = 0x510e527f;
+ ctx->digest[5] = 0x9b05688c;
+ ctx->digest[6] = 0x1f83d9ab;
+ ctx->digest[7] = 0x5be0cd19;
+}
+
+static inline void
+_sha256_block(struct sha256_ctx *ctx)
+{
+ sha256_word_t a, b, c, d, e, f, g, h, t, t1, t2;
+
+ // load block words
+ for (t = 0; t < SHA256_BLOCK_WORDS; t++) {
+ ctx->schedule[t] = htobe32(ctx->schedule[t]);
+ }
+
+ // expand out block words into full schedule
+ for (; t < SHA256_SCHEDULE_WORDS; t++) {
+ ctx->schedule[t] = SHA256_s1(ctx->schedule[t - 2])
+ + ctx->schedule[t - 7]
+ + SHA256_s0(ctx->schedule[t - 15])
+ + ctx->schedule[t - 16];
+ }
+
+ // initialise working variables
+ a = ctx->digest[0];
+ b = ctx->digest[1];
+ c = ctx->digest[2];
+ d = ctx->digest[3];
+ e = ctx->digest[4];
+ f = ctx->digest[5];
+ g = ctx->digest[6];
+ h = ctx->digest[7];
+
+ // perform rounds of sha256 compression (as many as words in the schedule)
+ for (t = 0; t < SHA256_SCHEDULE_WORDS; t++) {
+ t1 = h
+ + SHA256_S1(e)
+ + SHA256_Ch(e, f, g)
+ + _sha256_constants[t]
+ + ctx->schedule[t];
+
+ t2 = SHA256_S0(a)
+ + SHA256_Maj(a, b, c);
+
+ h = g;
+ g = f;
+ f = e;
+ e = d + t1;
+ d = c;
+ c = b;
+ b = a;
+ a = t1 + t2;
+ }
+
+ // save intermediate hash
+ ctx->digest[0] += a;
+ ctx->digest[1] += b;
+ ctx->digest[2] += c;
+ ctx->digest[3] += d;
+ ctx->digest[4] += e;
+ ctx->digest[5] += f;
+ ctx->digest[6] += g;
+ ctx->digest[7] += h;
+}
+
+void
+sha256_push(struct sha256_ctx *ctx, void const *buf, size_t len)
+{
+ unsigned char const *ptr = buf, *end = ptr + len;
+ unsigned char *block = ((unsigned char *) ctx->schedule);
+
+ while (ptr < end) {
+ size_t idx = ctx->ctr++ & SHA256_BLOCK_MASK;
+ block[idx] = *ptr++;
+
+ if (idx == SHA256_BLOCK_MASK) { // filled a block; hash it
+ _sha256_block(ctx);
+ }
+ }
+}
+
+static inline void
+_sha256_digest_bswap(struct sha256_ctx *ctx, size_t words)
+{
+ for (size_t i = 0; i < words; i++)
+ ctx->digest[i] = htobe32(ctx->digest[i]);
+}
+
+void
+sha256_dgst(struct sha256_ctx *ctx)
+{
+ unsigned char *block = ((unsigned char *) ctx->schedule);
+ unsigned char *cur = block + (ctx->ctr & SHA256_BLOCK_MASK);
+ unsigned char *end = block + SHA256_BLOCK_SIZE;
+ unsigned char *len = end - (64 / CHAR_BIT);
+
+ // TODO: handle 64-bit overflow here
+ assert(ctx->ctr < (UINT64_MAX / CHAR_BIT));
+ uint64_t bits = ctx->ctr * CHAR_BIT;
+
+ // append the 1 bit
+ *cur++ = 0x80;
+
+ // can we fit our message bit length? if not, add an extra padding block
+ if (len < cur) {
+ memset(cur, 0, end - cur);
+ _sha256_block(ctx);
+
+ cur = block;
+ }
+
+ // pad out final block
+ memset(cur, 0, len - cur);
+
+ // write out message bit length
+ ((uint64_t *) len)[0] = htobe64(bits);
+
+ // hash final block
+ _sha256_block(ctx);
+
+ // write out internally host-endian hash as big-endian hash
+ _sha256_digest_bswap(ctx, SHA256_DIGEST_WORDS);
+}
+
+void
+sha256(void const *buf, size_t len, unsigned char digest[static SHA256_DIGEST_SIZE])
+{
+ struct sha256_ctx ctx;
+ sha256_init(&ctx);
+ sha256_push(&ctx, buf, len);
+ sha256_dgst(&ctx);
+
+ memcpy(digest, ctx.digest, SHA256_DIGEST_SIZE);
+}
+
+// sha 512
+// ===========================================================================
+
+void
+sha512_init(struct sha512_ctx *ctx)
+{
+ ctx->digest[0] = 0x6a09e667f3bcc908;
+ ctx->digest[1] = 0xbb67ae8584caa73b;
+ ctx->digest[2] = 0x3c6ef372fe94f82b;
+ ctx->digest[3] = 0xa54ff53a5f1d36f1;
+ ctx->digest[4] = 0x510e527fade682d1;
+ ctx->digest[5] = 0x9b05688c2b3e6c1f;
+ ctx->digest[6] = 0x1f83d9abfb41bd6b;
+ ctx->digest[7] = 0x5be0cd19137e2179;
+}
+
+static inline void
+_sha512_block()
+{
+}
+
+void
+sha512_push(struct sha512_ctx *ctx, void const *buf, size_t len)
+{
+}
+
+static inline void
+_sha512_digest_bswap(struct sha512_ctx *ctx, size_t len)
+{
+ for (size_t i = 0; i < len; i++)
+ ctx->digest[i] = htobe64(ctx->digest[i]);
+}
+
+void
+sha512_dgst(struct sha512_ctx *ctx)
+{
+}
+
+void
+sha512(void const *buf, size_t len, unsigned char digest[static SHA512_DIGEST_SIZE])
+{
+ struct sha512_ctx ctx;
+ sha512_init(&ctx);
+ sha512_push(&ctx, buf, len);
+ sha512_dgst(&ctx);
+
+ memcpy(digest, ctx.digest, SHA512_DIGEST_SIZE);
+}
+
+// sha 384
+// ===========================================================================
+
+void
+sha384_init(struct sha512_ctx *ctx)
+{
+ ctx->digest[0] = 0xcbbb9d5dc1059ed8;
+ ctx->digest[1] = 0x629a292a367cd507;
+ ctx->digest[2] = 0x9159015a3070dd17;
+ ctx->digest[3] = 0x152fecd8f70e5939;
+ ctx->digest[4] = 0x67332667ffc00b31;
+ ctx->digest[5] = 0x8eb44a8768581511;
+ ctx->digest[6] = 0xdb0c2e0d64f98fa7;
+ ctx->digest[7] = 0x47b5481dbefa4fa4;
+}
+
+void
+sha384_push(struct sha512_ctx *ctx, void const *buf, size_t len)
+{
+}
+
+void
+sha384_dgst(struct sha512_ctx *ctx)
+{
+}
+
+void
+sha384(void const *buf, size_t len, unsigned char digest[static SHA384_DIGEST_SIZE])
+{
+ struct sha512_ctx ctx;
+ sha384_init(&ctx);
+ sha384_push(&ctx, buf, len);
+ sha384_dgst(&ctx);
+
+ memcpy(digest, ctx.digest, SHA384_DIGEST_SIZE);
+}
+
+// sha512/256
+// ===========================================================================
+
+void
+sha512_256_init(struct sha512_ctx *ctx)
+{
+ ctx->digest[0] = 0x22312194fc2bf72c;
+ ctx->digest[1] = 0x9f555fa3c84c64c2;
+ ctx->digest[2] = 0x2393b86b6f53b151;
+ ctx->digest[3] = 0x963877195940eabd;
+ ctx->digest[4] = 0x96283ee2A88effe3;
+ ctx->digest[5] = 0xbe5e1e2553863992;
+ ctx->digest[6] = 0x2b0199fc2c85b8aa;
+ ctx->digest[7] = 0x0eb72ddc81c52ca2;
+}
+
+void
+sha512_256_push(struct sha512_ctx *ctx, void const *buf, size_t len)
+{
+}
+
+void
+sha512_256_dgst(struct sha512_ctx *ctx)
+{
+}
+
+void
+sha512_256(void const *buf, size_t len, unsigned char digest[static SHA512_256_DIGEST_SIZE])
+{
+ struct sha512_ctx ctx;
+ sha512_256_init(&ctx);
+ sha512_256_push(&ctx, buf, len);
+ sha512_256_dgst(&ctx);
+
+ memcpy(digest, ctx.digest, SHA512_256_DIGEST_SIZE);
+}
diff --git a/sha.h b/sha.h
@@ -0,0 +1,165 @@
+// https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf
+
+#ifndef SHA_H
+#define SHA_H
+
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE 1
+#endif
+
+#include <assert.h>
+#include <endian.h>
+#include <limits.h>
+#include <stdalign.h>
+#include <stdint.h>
+#include <string.h>
+
+// sha definitions and constants
+// ===========================================================================
+
+#define SHA_ALIGN 64 // align structures to a 64-byte/512-bit boundary
+
+typedef uint32_t sha256_word_t;
+
+#define SHA256_WORD_BITS 32
+#define SHA256_BLOCK_BITS 512
+#define SHA256_DIGEST_BITS 256
+#define SHA256_SCHEDULE_BITS 2048
+
+#define SHA256_BLOCK_WORDS (SHA256_BLOCK_BITS / SHA256_WORD_BITS)
+#define SHA256_BLOCK_SIZE (SHA256_BLOCK_BITS / CHAR_BIT)
+#define SHA256_BLOCK_MASK (SHA256_BLOCK_SIZE - 1)
+
+#define SHA256_DIGEST_WORDS (SHA256_DIGEST_BITS / SHA256_WORD_BITS)
+#define SHA256_DIGEST_SIZE (SHA256_DIGEST_BITS / CHAR_BIT)
+
+#define SHA256_SCHEDULE_WORDS (SHA256_SCHEDULE_BITS / SHA256_WORD_BITS)
+#define SHA256_SCHEDULE_SIZE (SHA256_SCHEDULE_BITS / CHAR_BIT)
+
+struct sha256_ctx {
+ alignas(SHA_ALIGN)
+ sha256_word_t schedule[SHA256_SCHEDULE_WORDS];
+ sha256_word_t digest[SHA256_DIGEST_WORDS];
+ size_t ctr;
+};
+
+typedef uint64_t sha512_word_t;
+
+#define SHA512_WORD_BITS 64
+#define SHA512_BLOCK_BITS 1024
+#define SHA512_DIGEST_BITS 512
+#define SHA512_SCHEDULE_BITS 5120
+
+#define SHA512_BLOCK_WORDS (SHA512_BLOCK_BITS / SHA512_WORD_BITS)
+#define SHA512_BLOCK_SIZE (SHA512_BLOCK_BITS / CHAR_BIT)
+#define SHA512_BLOCK_MASK (SHA512_BLOCK_SIZE - 1)
+
+#define SHA512_DIGEST_WORDS (SHA512_DIGEST_BITS / SHA512_WORD_BITS)
+#define SHA512_DIGEST_SIZE (SHA512_DIGEST_BITS / CHAR_BIT)
+
+#define SHA512_SCHEDULE_WORDS (SHA512_SCHEDULE_BITS / SHA512_WORD_BITS)
+#define SHA512_SCHEDULE_SIZE (SHA512_SCHEDULE_BITS / CHAR_BIT)
+
+struct sha512_ctx {
+ alignas(SHA_ALIGN)
+ sha512_word_t schedule[SHA512_SCHEDULE_WORDS];
+ sha512_word_t block[SHA512_BLOCK_WORDS];
+ sha512_word_t digest[SHA512_DIGEST_WORDS];
+ size_t ctr;
+};
+
+// sha384 re-uses the sha512 definitions
+#define SHA384_DIGEST_BITS 384
+#define SHA384_DIGEST_WORDS (SHA384_DIGEST_BITS / SHA512_WORD_BITS)
+#define SHA384_DIGEST_SIZE (SHA384_DIGEST_BITS / CHAR_BIT)
+
+// sha512/256 re-uses the sha512 definitions
+#define SHA512_256_DIGEST_BITS 256
+#define SHA512_256_DIGEST_WORDS (SHA512_256_DIGEST_BITS / SHA512_WORD_BITS)
+#define SHA512_256_DIGEST_SIZE (SHA512_256_DIGEST_BITS / CHAR_BIT)
+
+// sha operations
+// ===========================================================================
+
+#define SHA_ROTR32(x, n) (((x) >> (n)) | ((x) << (32 - (n))))
+#define SHA_ROTR64(x, n) (((x) >> (n)) | ((x) << (64 - (n))))
+#define SHA_SHR(x, n) ((x) >> (n))
+
+// sha functions
+// ===========================================================================
+
+#define SHA256_Ch(x, y, z) (((x) & (y)) ^ ((~(x)) & (z)))
+#define SHA256_Maj(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+#define SHA256_S0(x) (SHA_ROTR32((x), 2) ^ SHA_ROTR32((x), 13) ^ SHA_ROTR32((x), 22))
+#define SHA256_S1(x) (SHA_ROTR32((x), 6) ^ SHA_ROTR32((x), 11) ^ SHA_ROTR32((x), 25))
+#define SHA256_s0(x) (SHA_ROTR32((x), 7) ^ SHA_ROTR32((x), 18) ^ SHA_SHR((x), 3))
+#define SHA256_s1(x) (SHA_ROTR32((x), 17) ^ SHA_ROTR32((x), 19) ^ SHA_SHR((x), 10))
+
+#define SHA512_Ch(x, y, z) (((x) & (y)) ^ ((~(x)) & (z)))
+#define SHA512_Maj(x, y, z) (((x) ^ (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+#define SHA512_S0(x) (SHA_ROTR64((x), 28) ^ SHA_ROTR64((x), 34) ^ SHA_ROTR64((x), 39))
+#define SHA512_S1(x) (SHA_ROTR64((x), 14) ^ SHA_ROTR64((x), 18) ^ SHA_ROTR64((x), 41))
+#define SHA512_s0(x) (SHA_ROTR64((x), 1) ^ SHA_ROTR64((x), 8) ^ SHA_SHR((x), 7))
+#define SHA512_s1(x) (SHA_ROTR64((x), 19) ^ SHA_ROTR64((x), 61) ^ SHA_SHR((x), 6))
+
+// sha256
+// ===========================================================================
+
+void
+sha256_init(struct sha256_ctx *ctx);
+
+void
+sha256_push(struct sha256_ctx *ctx, void const *buf, size_t len);
+
+void
+sha256_dgst(struct sha256_ctx *ctx);
+
+void
+sha256(void const *buf, size_t len, unsigned char digest[static SHA256_DIGEST_SIZE]);
+
+// sha 512
+// ===========================================================================
+
+void
+sha512_init(struct sha512_ctx *ctx);
+
+void
+sha512_push(struct sha512_ctx *ctx, void const *buf, size_t len);
+
+void
+sha512_dgst(struct sha512_ctx *ctx);
+
+void
+sha512(void const *buf, size_t len, unsigned char digest[static SHA512_DIGEST_SIZE]);
+
+// sha 384
+// ===========================================================================
+
+void
+sha384_init(struct sha512_ctx *ctx);
+
+void
+sha384_push(struct sha512_ctx *ctx, void const *buf, size_t len);
+
+void
+sha384_dgst(struct sha512_ctx *ctx);
+
+void
+sha384(void const *buf, size_t len, unsigned char digest[static SHA384_DIGEST_SIZE]);
+
+// sha512/256
+// ===========================================================================
+
+void
+sha512_256_init(struct sha512_ctx *ctx);
+
+void
+sha512_256_push(struct sha512_ctx *ctx, void const *buf, size_t len);
+
+void
+sha512_256_dgst(struct sha512_ctx *ctx);
+
+void
+sha512_256(void const *buf, size_t len, unsigned char digest[static SHA512_256_DIGEST_SIZE]);
+
+#endif /* SHA_H */
diff --git a/sha.pdf b/sha.pdf
Binary files differ.
diff --git a/test-sha256.c b/test-sha256.c
@@ -0,0 +1,36 @@
+#include "sha.h"
+#include <stdio.h>
+
+int
+main(void)
+{
+ char msg[] = "abc";
+
+ uint8_t dgst[SHA256_DIGEST_SIZE];
+ sha256(msg, strlen(msg), dgst);
+
+ uint8_t expected[SHA256_DIGEST_SIZE] = {
+ 0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea,
+ 0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
+ 0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c,
+ 0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad,
+ };
+
+ printf("msg: \"%.*s\" (%lu bytes)\n", sizeof msg, msg, strlen(msg));
+
+ printf("dgst: ");
+ for (size_t i = 0; i < sizeof dgst; i++) {
+ printf("%.2x", dgst[i]);
+ }
+ printf("\n");
+
+ printf("exp.: ");
+ for (size_t i = 0; i < sizeof expected; i++) {
+ printf("%.2x", expected[i]);
+ }
+ printf("\n");
+
+ return memcmp(expected, dgst, SHA256_DIGEST_SIZE);
+}
+
+#include "sha.c"
diff --git a/test-client.c b/tls_client.c
diff --git a/test-server.c b/tls_server.c
