/* ====================================================================
* Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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* openssl-core@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <openssl/ecdsa.h>
#include <vector>
#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <openssl/ec.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/nid.h>
#include <openssl/rand.h>
enum Api {
kEncodedApi,
kRawApi,
};
// VerifyECDSASig returns true on success, false on failure.
static bool VerifyECDSASig(Api api, const uint8_t *digest,
size_t digest_len, const ECDSA_SIG *ecdsa_sig,
EC_KEY *eckey, int expected_result) {
int actual_result;
switch (api) {
case kEncodedApi: {
uint8_t *der;
size_t der_len;
if (!ECDSA_SIG_to_bytes(&der, &der_len, ecdsa_sig)) {
return false;
}
bssl::UniquePtr<uint8_t> delete_der(der);
actual_result = ECDSA_verify(0, digest, digest_len, der, der_len, eckey);
break;
}
case kRawApi:
actual_result = ECDSA_do_verify(digest, digest_len, ecdsa_sig, eckey);
break;
default:
return false;
}
return expected_result == actual_result;
}
// TestTamperedSig verifies that signature verification fails when a valid
// signature is tampered with. |ecdsa_sig| must be a valid signature, which will
// be modified. TestTamperedSig returns true on success, false on failure.
static bool TestTamperedSig(FILE *out, Api api, const uint8_t *digest,
size_t digest_len, ECDSA_SIG *ecdsa_sig,
EC_KEY *eckey, const BIGNUM *order) {
// Modify a single byte of the signature: to ensure we don't
// garble the ASN1 structure, we read the raw signature and
// modify a byte in one of the bignums directly.
// Store the two BIGNUMs in raw_buf.
size_t r_len = BN_num_bytes(ecdsa_sig->r);
size_t s_len = BN_num_bytes(ecdsa_sig->s);
size_t bn_len = BN_num_bytes(order);
if (r_len > bn_len || s_len > bn_len) {
return false;
}
size_t buf_len = 2 * bn_len;
std::vector<uint8_t> raw_buf(buf_len);
// Pad the bignums with leading zeroes.
if (!BN_bn2bin_padded(raw_buf.data(), bn_len, ecdsa_sig->r) ||
!BN_bn2bin_padded(raw_buf.data() + bn_len, bn_len, ecdsa_sig->s)) {
return false;
}
// Modify a single byte in the buffer.
size_t offset = raw_buf[10] % buf_len;
uint8_t dirt = raw_buf[11] ? raw_buf[11] : 1;
raw_buf[offset] ^= dirt;
// Now read the BIGNUMs back in from raw_buf.
if (BN_bin2bn(raw_buf.data(), bn_len, ecdsa_sig->r) == NULL ||
BN_bin2bn(raw_buf.data() + bn_len, bn_len, ecdsa_sig->s) == NULL ||
!VerifyECDSASig(api, digest, digest_len, ecdsa_sig, eckey, 0)) {
return false;
}
// Sanity check: Undo the modification and verify signature.
raw_buf[offset] ^= dirt;
if (BN_bin2bn(raw_buf.data(), bn_len, ecdsa_sig->r) == NULL ||
BN_bin2bn(raw_buf.data() + bn_len, bn_len, ecdsa_sig->s) == NULL ||
!VerifyECDSASig(api, digest, digest_len, ecdsa_sig, eckey, 1)) {
return false;
}
return true;
}
static bool TestBuiltin(FILE *out) {
// Fill digest values with some random data.
uint8_t digest[20], wrong_digest[20];
if (!RAND_bytes(digest, 20) || !RAND_bytes(wrong_digest, 20)) {
fprintf(out, "ERROR: unable to get random data\n");
return false;
}
static const struct {
int nid;
const char *name;
} kCurves[] = {
{ NID_secp224r1, "secp224r1" },
{ NID_X9_62_prime256v1, "secp256r1" },
{ NID_secp384r1, "secp384r1" },
{ NID_secp521r1, "secp521r1" },
{ NID_undef, NULL }
};
// Create and verify ECDSA signatures with every available curve.
fputs("\ntesting ECDSA_sign(), ECDSA_verify(), ECDSA_do_sign(), and "
"ECDSA_do_verify() with some internal curves:\n", out);
for (size_t n = 0; kCurves[n].nid != NID_undef; n++) {
fprintf(out, "%s: ", kCurves[n].name);
int nid = kCurves[n].nid;
bssl::UniquePtr<EC_GROUP> group(EC_GROUP_new_by_curve_name(nid));
if (!group) {
fprintf(out, " failed\n");
return false;
}
const BIGNUM *order = EC_GROUP_get0_order(group.get());
if (BN_num_bits(order) < 160) {
// Too small to test.
fprintf(out, " skipped\n");
continue;
}
// Create a new ECDSA key.
bssl::UniquePtr<EC_KEY> eckey(EC_KEY_new());
if (!eckey || !EC_KEY_set_group(eckey.get(), group.get()) ||
!EC_KEY_generate_key(eckey.get())) {
fprintf(out, " failed\n");
return false;
}
// Create a second key.
bssl::UniquePtr<EC_KEY> wrong_eckey(EC_KEY_new());
if (!wrong_eckey || !EC_KEY_set_group(wrong_eckey.get(), group.get()) ||
!EC_KEY_generate_key(wrong_eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Check the key.
if (!EC_KEY_check_key(eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Test ASN.1-encoded signatures.
// Create a signature.
unsigned sig_len = ECDSA_size(eckey.get());
std::vector<uint8_t> signature(sig_len);
if (!ECDSA_sign(0, digest, 20, signature.data(), &sig_len, eckey.get())) {
fprintf(out, " failed\n");
return false;
}
signature.resize(sig_len);
fprintf(out, ".");
fflush(out);
// Verify the signature.
if (!ECDSA_verify(0, digest, 20, signature.data(), signature.size(),
eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify the signature with the wrong key.
if (ECDSA_verify(0, digest, 20, signature.data(), signature.size(),
wrong_eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify the signature using the wrong digest.
if (ECDSA_verify(0, wrong_digest, 20, signature.data(), signature.size(),
eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify a truncated signature.
if (ECDSA_verify(0, digest, 20, signature.data(), signature.size() - 1,
eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify a tampered signature.
bssl::UniquePtr<ECDSA_SIG> ecdsa_sig(ECDSA_SIG_from_bytes(
signature.data(), signature.size()));
if (!ecdsa_sig ||
!TestTamperedSig(out, kEncodedApi, digest, 20, ecdsa_sig.get(),
eckey.get(), order)) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Test ECDSA_SIG signing and verification.
// Create a signature.
ecdsa_sig.reset(ECDSA_do_sign(digest, 20, eckey.get()));
if (!ecdsa_sig) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify the signature using the correct key.
if (!ECDSA_do_verify(digest, 20, ecdsa_sig.get(), eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify the signature with the wrong key.
if (ECDSA_do_verify(digest, 20, ecdsa_sig.get(), wrong_eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify the signature using the wrong digest.
if (ECDSA_do_verify(wrong_digest, 20, ecdsa_sig.get(), eckey.get())) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
// Verify a tampered signature.
if (!TestTamperedSig(out, kRawApi, digest, 20, ecdsa_sig.get(), eckey.get(),
order)) {
fprintf(out, " failed\n");
return false;
}
fprintf(out, ".");
fflush(out);
fprintf(out, " ok\n");
// Clear bogus errors.
ERR_clear_error();
}
return true;
}
static bool TestECDSA_SIG_max_len(size_t order_len) {
/* Create the largest possible |ECDSA_SIG| of the given constraints. */
bssl::UniquePtr<ECDSA_SIG> sig(ECDSA_SIG_new());
if (!sig) {
return false;
}
std::vector<uint8_t> bytes(order_len, 0xff);
if (!BN_bin2bn(bytes.data(), bytes.size(), sig->r) ||
!BN_bin2bn(bytes.data(), bytes.size(), sig->s)) {
return false;
}
/* Serialize it. */
uint8_t *der;
size_t der_len;
if (!ECDSA_SIG_to_bytes(&der, &der_len, sig.get())) {
return false;
}
bssl::UniquePtr<uint8_t> delete_der(der);
size_t max_len = ECDSA_SIG_max_len(order_len);
if (max_len != der_len) {
fprintf(stderr, "ECDSA_SIG_max_len(%u) returned %u, wanted %u\n",
static_cast<unsigned>(order_len), static_cast<unsigned>(max_len),
static_cast<unsigned>(der_len));
return false;
}
return true;
}
static size_t BitsToBytes(size_t bits) {
return (bits / 8) + (7 + (bits % 8)) / 8;
}
int main(void) {
CRYPTO_library_init();
if (!TestBuiltin(stdout) ||
!TestECDSA_SIG_max_len(BitsToBytes(224)) ||
!TestECDSA_SIG_max_len(BitsToBytes(256)) ||
!TestECDSA_SIG_max_len(BitsToBytes(384)) ||
!TestECDSA_SIG_max_len(BitsToBytes(521)) ||
!TestECDSA_SIG_max_len(BitsToBytes(10000))) {
printf("\nECDSA test failed\n");
ERR_print_errors_fp(stdout);
return 1;
}
printf("\nPASS\n");
return 0;
}