/* ====================================================================
* 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
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*
* 1. Redistributions of source code must retain the above copyright
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* 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/)"
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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
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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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 <gtest/gtest.h>
#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>
#include "../ec/internal.h"
#include "../../test/file_test.h"
static bssl::UniquePtr<BIGNUM> HexToBIGNUM(const char *hex) {
BIGNUM *bn = nullptr;
BN_hex2bn(&bn, hex);
return bssl::UniquePtr<BIGNUM>(bn);
}
// Though we do not support secp160r1, it is reachable from the deprecated
// custom curve APIs and has some unique properties (n is larger than p with the
// difference crossing a word boundary on 32-bit), so test it explicitly.
static bssl::UniquePtr<EC_GROUP> NewSecp160r1Group() {
static const char kP[] = "ffffffffffffffffffffffffffffffff7fffffff";
static const char kA[] = "ffffffffffffffffffffffffffffffff7ffffffc";
static const char kB[] = "1c97befc54bd7a8b65acf89f81d4d4adc565fa45";
static const char kX[] = "4a96b5688ef573284664698968c38bb913cbfc82";
static const char kY[] = "23a628553168947d59dcc912042351377ac5fb32";
static const char kN[] = "0100000000000000000001f4c8f927aed3ca752257";
bssl::UniquePtr<BIGNUM> p = HexToBIGNUM(kP), a = HexToBIGNUM(kA),
b = HexToBIGNUM(kB), x = HexToBIGNUM(kX),
y = HexToBIGNUM(kY), n = HexToBIGNUM(kN);
if (!p || !a || !b || !x || !y || !n) {
return nullptr;
}
bssl::UniquePtr<EC_GROUP> group(
EC_GROUP_new_curve_GFp(p.get(), a.get(), b.get(), nullptr));
if (!group) {
return nullptr;
}
bssl::UniquePtr<EC_POINT> g(EC_POINT_new(group.get()));
if (!g ||
!EC_POINT_set_affine_coordinates_GFp(group.get(), g.get(), x.get(),
y.get(), nullptr) ||
!EC_GROUP_set_generator(group.get(), g.get(), n.get(), BN_value_one())) {
return nullptr;
}
return group;
}
enum API {
kEncodedAPI,
kRawAPI,
};
// VerifyECDSASig checks that verifying |ecdsa_sig| gives |expected_result|.
static void VerifyECDSASig(API api, const uint8_t *digest, size_t digest_len,
const ECDSA_SIG *ecdsa_sig, EC_KEY *eckey,
int expected_result) {
switch (api) {
case kEncodedAPI: {
uint8_t *der;
size_t der_len;
ASSERT_TRUE(ECDSA_SIG_to_bytes(&der, &der_len, ecdsa_sig));
bssl::UniquePtr<uint8_t> delete_der(der);
EXPECT_EQ(expected_result,
ECDSA_verify(0, digest, digest_len, der, der_len, eckey));
break;
}
case kRawAPI:
EXPECT_EQ(expected_result,
ECDSA_do_verify(digest, digest_len, ecdsa_sig, eckey));
break;
default:
FAIL() << "Unknown API type.";
}
}
// TestTamperedSig verifies that signature verification fails when a valid
// signature is tampered with. |ecdsa_sig| must be a valid signature, which will
// be modified.
static void TestTamperedSig(API api, const uint8_t *digest,
size_t digest_len, ECDSA_SIG *ecdsa_sig,
EC_KEY *eckey, const BIGNUM *order) {
SCOPED_TRACE(api);
// 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);
ASSERT_LE(r_len, bn_len);
ASSERT_LE(s_len, bn_len);
size_t buf_len = 2 * bn_len;
std::vector<uint8_t> raw_buf(buf_len);
// Pad the bignums with leading zeroes.
ASSERT_TRUE(BN_bn2bin_padded(raw_buf.data(), bn_len, ecdsa_sig->r));
ASSERT_TRUE(BN_bn2bin_padded(raw_buf.data() + bn_len, bn_len, ecdsa_sig->s));
// 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.
ASSERT_TRUE(BN_bin2bn(raw_buf.data(), bn_len, ecdsa_sig->r));
ASSERT_TRUE(BN_bin2bn(raw_buf.data() + bn_len, bn_len, ecdsa_sig->s));
VerifyECDSASig(api, digest, digest_len, ecdsa_sig, eckey, 0);
// Sanity check: Undo the modification and verify signature.
raw_buf[offset] ^= dirt;
ASSERT_TRUE(BN_bin2bn(raw_buf.data(), bn_len, ecdsa_sig->r));
ASSERT_TRUE(BN_bin2bn(raw_buf.data() + bn_len, bn_len, ecdsa_sig->s));
VerifyECDSASig(api, digest, digest_len, ecdsa_sig, eckey, 1);
}
TEST(ECDSATest, BuiltinCurves) {
// Fill digest values with some random data.
uint8_t digest[20], wrong_digest[20];
ASSERT_TRUE(RAND_bytes(digest, 20));
ASSERT_TRUE(RAND_bytes(wrong_digest, 20));
static const struct {
int nid;
const char *name;
} kCurves[] = {
{ NID_secp224r1, "secp224r1" },
{ NID_X9_62_prime256v1, "secp256r1" },
{ NID_secp384r1, "secp384r1" },
{ NID_secp521r1, "secp521r1" },
{ NID_secp160r1, "secp160r1" },
};
for (const auto &curve : kCurves) {
SCOPED_TRACE(curve.name);
bssl::UniquePtr<EC_GROUP> group;
if (curve.nid == NID_secp160r1) {
group = NewSecp160r1Group();
} else {
group.reset(EC_GROUP_new_by_curve_name(curve.nid));
}
ASSERT_TRUE(group);
const BIGNUM *order = EC_GROUP_get0_order(group.get());
// Create a new ECDSA key.
bssl::UniquePtr<EC_KEY> eckey(EC_KEY_new());
ASSERT_TRUE(eckey);
ASSERT_TRUE(EC_KEY_set_group(eckey.get(), group.get()));
ASSERT_TRUE(EC_KEY_generate_key(eckey.get()));
// Create a second key.
bssl::UniquePtr<EC_KEY> wrong_eckey(EC_KEY_new());
ASSERT_TRUE(wrong_eckey);
ASSERT_TRUE(EC_KEY_set_group(wrong_eckey.get(), group.get()));
ASSERT_TRUE(EC_KEY_generate_key(wrong_eckey.get()));
// Check the key.
EXPECT_TRUE(EC_KEY_check_key(eckey.get()));
// Test ASN.1-encoded signatures.
// Create a signature.
unsigned sig_len = ECDSA_size(eckey.get());
std::vector<uint8_t> signature(sig_len);
ASSERT_TRUE(
ECDSA_sign(0, digest, 20, signature.data(), &sig_len, eckey.get()));
signature.resize(sig_len);
// Verify the signature.
EXPECT_TRUE(ECDSA_verify(0, digest, 20, signature.data(), signature.size(),
eckey.get()));
// Verify the signature with the wrong key.
EXPECT_FALSE(ECDSA_verify(0, digest, 20, signature.data(), signature.size(),
wrong_eckey.get()));
ERR_clear_error();
// Verify the signature using the wrong digest.
EXPECT_FALSE(ECDSA_verify(0, wrong_digest, 20, signature.data(),
signature.size(), eckey.get()));
ERR_clear_error();
// Verify a truncated signature.
EXPECT_FALSE(ECDSA_verify(0, digest, 20, signature.data(),
signature.size() - 1, eckey.get()));
ERR_clear_error();
// Verify a tampered signature.
bssl::UniquePtr<ECDSA_SIG> ecdsa_sig(
ECDSA_SIG_from_bytes(signature.data(), signature.size()));
ASSERT_TRUE(ecdsa_sig);
TestTamperedSig(kEncodedAPI, digest, 20, ecdsa_sig.get(), eckey.get(),
order);
// Test ECDSA_SIG signing and verification.
// Create a signature.
ecdsa_sig.reset(ECDSA_do_sign(digest, 20, eckey.get()));
ASSERT_TRUE(ecdsa_sig);
// Verify the signature using the correct key.
EXPECT_TRUE(ECDSA_do_verify(digest, 20, ecdsa_sig.get(), eckey.get()));
// Verify the signature with the wrong key.
EXPECT_FALSE(
ECDSA_do_verify(digest, 20, ecdsa_sig.get(), wrong_eckey.get()));
ERR_clear_error();
// Verify the signature using the wrong digest.
EXPECT_FALSE(
ECDSA_do_verify(wrong_digest, 20, ecdsa_sig.get(), eckey.get()));
ERR_clear_error();
// Verify a tampered signature.
TestTamperedSig(kRawAPI, digest, 20, ecdsa_sig.get(), eckey.get(), order);
}
}
static size_t BitsToBytes(size_t bits) {
return (bits / 8) + (7 + (bits % 8)) / 8;
}
TEST(ECDSATest, MaxSigLen) {
static const size_t kBits[] = {224, 256, 384, 521, 10000};
for (size_t bits : kBits) {
SCOPED_TRACE(bits);
size_t order_len = BitsToBytes(bits);
// Create the largest possible |ECDSA_SIG| of the given constraints.
bssl::UniquePtr<ECDSA_SIG> sig(ECDSA_SIG_new());
ASSERT_TRUE(sig);
std::vector<uint8_t> bytes(order_len, 0xff);
ASSERT_TRUE(BN_bin2bn(bytes.data(), bytes.size(), sig->r));
ASSERT_TRUE(BN_bin2bn(bytes.data(), bytes.size(), sig->s));
// Serialize it.
uint8_t *der;
size_t der_len;
ASSERT_TRUE(ECDSA_SIG_to_bytes(&der, &der_len, sig.get()));
OPENSSL_free(der);
EXPECT_EQ(der_len, ECDSA_SIG_max_len(order_len));
}
}
static bssl::UniquePtr<EC_GROUP> GetCurve(FileTest *t, const char *key) {
std::string curve_name;
if (!t->GetAttribute(&curve_name, key)) {
return nullptr;
}
if (curve_name == "P-224") {
return bssl::UniquePtr<EC_GROUP>(EC_GROUP_new_by_curve_name(NID_secp224r1));
}
if (curve_name == "P-256") {
return bssl::UniquePtr<EC_GROUP>(
EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
}
if (curve_name == "P-384") {
return bssl::UniquePtr<EC_GROUP>(EC_GROUP_new_by_curve_name(NID_secp384r1));
}
if (curve_name == "P-521") {
return bssl::UniquePtr<EC_GROUP>(EC_GROUP_new_by_curve_name(NID_secp521r1));
}
if (curve_name == "secp160r1") {
return NewSecp160r1Group();
}
ADD_FAILURE() << "Unknown curve: " << curve_name;
return nullptr;
}
static bssl::UniquePtr<EC_GROUP> MakeCustomClone(const EC_GROUP *group) {
bssl::UniquePtr<BN_CTX> ctx(BN_CTX_new());
bssl::UniquePtr<BIGNUM> p(BN_new()), a(BN_new()), b(BN_new()), x(BN_new()),
y(BN_new());
if (!ctx || !p || !a || !b || !x || !y ||
!EC_GROUP_get_curve_GFp(group, p.get(), a.get(), b.get(), ctx.get()) ||
!EC_POINT_get_affine_coordinates_GFp(
group, EC_GROUP_get0_generator(group), x.get(), y.get(), ctx.get())) {
return nullptr;
}
bssl::UniquePtr<EC_GROUP> ret(
EC_GROUP_new_curve_GFp(p.get(), a.get(), b.get(), ctx.get()));
if (!ret) {
return nullptr;
}
bssl::UniquePtr<EC_POINT> g(EC_POINT_new(ret.get()));
if (!g ||
!EC_POINT_set_affine_coordinates_GFp(ret.get(), g.get(), x.get(), y.get(),
ctx.get()) ||
!EC_GROUP_set_generator(ret.get(), g.get(), EC_GROUP_get0_order(group),
BN_value_one())) {
return nullptr;
}
return ret;
}
static bssl::UniquePtr<BIGNUM> GetBIGNUM(FileTest *t, const char *key) {
std::vector<uint8_t> bytes;
if (!t->GetBytes(&bytes, key)) {
return nullptr;
}
return bssl::UniquePtr<BIGNUM>(BN_bin2bn(bytes.data(), bytes.size(), nullptr));
}
TEST(ECDSATest, VerifyTestVectors) {
FileTestGTest("crypto/fipsmodule/ecdsa/ecdsa_verify_tests.txt",
[](FileTest *t) {
for (bool custom_group : {false, true}) {
SCOPED_TRACE(custom_group);
bssl::UniquePtr<EC_GROUP> group = GetCurve(t, "Curve");
ASSERT_TRUE(group);
if (custom_group) {
group = MakeCustomClone(group.get());
ASSERT_TRUE(group);
}
bssl::UniquePtr<BIGNUM> x = GetBIGNUM(t, "X");
ASSERT_TRUE(x);
bssl::UniquePtr<BIGNUM> y = GetBIGNUM(t, "Y");
ASSERT_TRUE(y);
bssl::UniquePtr<BIGNUM> r = GetBIGNUM(t, "R");
ASSERT_TRUE(r);
bssl::UniquePtr<BIGNUM> s = GetBIGNUM(t, "S");
ASSERT_TRUE(s);
std::vector<uint8_t> digest;
ASSERT_TRUE(t->GetBytes(&digest, "Digest"));
bssl::UniquePtr<EC_KEY> key(EC_KEY_new());
ASSERT_TRUE(key);
bssl::UniquePtr<EC_POINT> pub_key(EC_POINT_new(group.get()));
ASSERT_TRUE(pub_key);
bssl::UniquePtr<ECDSA_SIG> sig(ECDSA_SIG_new());
ASSERT_TRUE(sig);
ASSERT_TRUE(EC_KEY_set_group(key.get(), group.get()));
ASSERT_TRUE(EC_POINT_set_affine_coordinates_GFp(
group.get(), pub_key.get(), x.get(), y.get(), nullptr));
ASSERT_TRUE(EC_KEY_set_public_key(key.get(), pub_key.get()));
ASSERT_TRUE(BN_copy(sig->r, r.get()));
ASSERT_TRUE(BN_copy(sig->s, s.get()));
EXPECT_EQ(
t->HasAttribute("Invalid") ? 0 : 1,
ECDSA_do_verify(digest.data(), digest.size(), sig.get(), key.get()));
}
});
}
TEST(ECDSATest, SignTestVectors) {
FileTestGTest("crypto/fipsmodule/ecdsa/ecdsa_sign_tests.txt",
[](FileTest *t) {
for (bool custom_group : {false, true}) {
SCOPED_TRACE(custom_group);
bssl::UniquePtr<EC_GROUP> group = GetCurve(t, "Curve");
ASSERT_TRUE(group);
if (custom_group) {
group = MakeCustomClone(group.get());
ASSERT_TRUE(group);
}
bssl::UniquePtr<BIGNUM> priv_key = GetBIGNUM(t, "Private");
ASSERT_TRUE(priv_key);
bssl::UniquePtr<BIGNUM> x = GetBIGNUM(t, "X");
ASSERT_TRUE(x);
bssl::UniquePtr<BIGNUM> y = GetBIGNUM(t, "Y");
ASSERT_TRUE(y);
bssl::UniquePtr<BIGNUM> k = GetBIGNUM(t, "K");
ASSERT_TRUE(k);
bssl::UniquePtr<BIGNUM> r = GetBIGNUM(t, "R");
ASSERT_TRUE(r);
bssl::UniquePtr<BIGNUM> s = GetBIGNUM(t, "S");
ASSERT_TRUE(s);
std::vector<uint8_t> digest;
ASSERT_TRUE(t->GetBytes(&digest, "Digest"));
bssl::UniquePtr<EC_KEY> key(EC_KEY_new());
ASSERT_TRUE(key);
bssl::UniquePtr<EC_POINT> pub_key(EC_POINT_new(group.get()));
ASSERT_TRUE(pub_key);
ASSERT_TRUE(EC_KEY_set_group(key.get(), group.get()));
ASSERT_TRUE(EC_KEY_set_private_key(key.get(), priv_key.get()));
ASSERT_TRUE(EC_POINT_set_affine_coordinates_GFp(
group.get(), pub_key.get(), x.get(), y.get(), nullptr));
ASSERT_TRUE(EC_KEY_set_public_key(key.get(), pub_key.get()));
ASSERT_TRUE(EC_KEY_check_key(key.get()));
// Set the fixed k for testing purposes.
key->fixed_k = k.release();
bssl::UniquePtr<ECDSA_SIG> sig(
ECDSA_do_sign(digest.data(), digest.size(), key.get()));
ASSERT_TRUE(sig);
EXPECT_EQ(0, BN_cmp(r.get(), sig->r));
EXPECT_EQ(0, BN_cmp(s.get(), sig->s));
}
});
}