Copied TCP impl from other project, basic Block implementation, randomx pow, signing via secp256k1

src/crypto/crypto.c

@@ -0,0 +1,77 @@
+#include <crypto/crypto.h>
+#include <string.h>
+
+static bool crypto_hash_to_32(const uint8_t* data, size_t len, uint8_t out32[32]) {
+    if (!data || !out32) {
+        return false;
+    }
+    return SHA256(data, len, out32) != NULL;
+}
+
+bool Crypto_VerifySignature(const uint8_t* data, size_t len, const uint8_t* signature, const uint8_t* publicKey) {
+    if (!data || !signature || !publicKey) {
+        return false;
+    }
+
+    uint8_t digest[32];
+    if (!crypto_hash_to_32(data, len, digest)) {
+        return false;
+    }
+
+    secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY);
+    if (!ctx) {
+        return false;
+    }
+
+    secp256k1_pubkey pubkey;
+    secp256k1_ecdsa_signature sig;
+
+    const int pub_ok = secp256k1_ec_pubkey_parse(ctx, &pubkey, publicKey, 33);
+    const int sig_ok = secp256k1_ecdsa_signature_parse_compact(ctx, &sig, signature);
+    const int verified = (pub_ok && sig_ok) ? secp256k1_ecdsa_verify(ctx, &sig, digest, &pubkey) : 0;
+
+    secp256k1_context_destroy(ctx);
+    return verified == 1;
+}
+
+void Crypto_SignData(const uint8_t* data, size_t len, const uint8_t* privateKey, uint8_t* outSignature) {
+    if (!data || !privateKey || !outSignature) {
+        return;
+    }
+
+    uint8_t digest[32];
+    if (!crypto_hash_to_32(data, len, digest)) {
+        memset(outSignature, 0, 64);
+        return;
+    }
+
+    secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
+    if (!ctx) {
+        memset(outSignature, 0, 64);
+        return;
+    }
+
+    if (!secp256k1_ec_seckey_verify(ctx, privateKey)) {
+        memset(outSignature, 0, 64);
+        secp256k1_context_destroy(ctx);
+        return;
+    }
+
+    secp256k1_ecdsa_signature sig;
+    const int sign_ok = secp256k1_ecdsa_sign(
+        ctx,
+        &sig,
+        digest,
+        privateKey,
+        secp256k1_nonce_function_default,
+        NULL
+    );
+    if (!sign_ok) {
+        memset(outSignature, 0, 64);
+        secp256k1_context_destroy(ctx);
+        return;
+    }
+
+    secp256k1_ecdsa_signature_serialize_compact(ctx, outSignature, &sig);
+    secp256k1_context_destroy(ctx);
+}