crypto/fipsmodule/ecdsa/ecdsa_test.cc - boringssl - Git at Google

 /* ====================================================================
  * 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
  *    endorse or promote products derived from this software without
  *    prior written permission. For written permission, please contact
  *    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)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * 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"


 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" },
   };

   for (const auto &curve : kCurves) {
     SCOPED_TRACE(curve.name);

     int nid = curve.nid;
     bssl::UniquePtr<EC_GROUP> group(EC_GROUP_new_by_curve_name(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));
   }

   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));
     }
   });
 }
	/* ====================================================================
	* 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
	* endorse or promote products derived from this software without
	* prior written permission. For written permission, please contact
	* 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)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* 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"


	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" },
	};

	for (const auto &curve : kCurves) {
	SCOPED_TRACE(curve.name);

	int nid = curve.nid;
	bssl::UniquePtr<EC_GROUP> group(EC_GROUP_new_by_curve_name(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));
	}

	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));
	}
	});
	}