bool bp_pubkey_checklowS(const void *sig_, size_t sig_len)
{
secp256k1_ecdsa_signature sig;
secp256k1_context *ctx = get_secp256k1_context();
if (!ctx) {
return false;
}
if (!ecdsa_signature_parse_der_lax(ctx, &sig, sig_, sig_len)) {
return false;
}
return (!secp256k1_ecdsa_signature_normalize(ctx, NULL, &sig));
}
bool bp_verify(const struct bp_key *key, const void *data, size_t data_len,
const void *sig_, size_t sig_len)
{
if (32 != data_len) {
return false;
}
secp256k1_ecdsa_signature sig;
secp256k1_context *ctx = get_secp256k1_context();
if (!ctx) {
return false;
}
if (ecdsa_signature_parse_der_lax(ctx, &sig, sig_, sig_len)) {
secp256k1_ecdsa_signature_normalize(ctx, &sig, &sig);
return secp256k1_ecdsa_verify(ctx, &sig, data, &key->pubkey);
}
return false;
}
bool parse_signature(ec_signature& out, const der_signature& der_signature,
bool strict)
{
if (der_signature.empty())
return false;
bool valid;
secp256k1_ecdsa_signature parsed;
const auto context = verification.context();
if (strict)
valid = secp256k1_ecdsa_signature_parse_der(context, &parsed,
der_signature.data(), der_signature.size()) == 1;
else
valid = ecdsa_signature_parse_der_lax(context, &parsed,
der_signature.data(), der_signature.size()) == 1;
if (valid)
std::copy(std::begin(parsed.data), std::end(parsed.data), out.begin());
return valid;
}
void Sec256SignatureEx::Parse(RCSpan cbuf) {
if (!ecdsa_signature_parse_der_lax(g_sec256Ctx, &m_sig, cbuf.data(), cbuf.size()))
throw CryptoException(make_error_code(ExtErr::Crypto), "Invalid Signature");
secp256k1_ecdsa_signature_normalize(g_sec256Ctx, &m_sig, &m_sig);
}
