openssl/test/ecdsatest.c
Matt Caswell 9fc8f18f59 Use order not degree to calculate a buffer size in ecdsatest
Otherwise this can result in an incorrect calculation of the maximum
encoded integer length, meaning an insufficient buffer size is allocated.

Thanks to Billy Brumley for helping to track this down.

Fixes #8209

Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8237)
2019-02-15 09:54:59 +00:00

409 lines
13 KiB
C

/*
* Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_EC is defined */
#include "testutil.h"
#ifndef OPENSSL_NO_EC
# include <openssl/crypto.h>
# include <openssl/bio.h>
# include <openssl/evp.h>
# include <openssl/bn.h>
# include <openssl/ec.h>
# ifndef OPENSSL_NO_ENGINE
# include <openssl/engine.h>
# endif
# include <openssl/sha.h>
# include <openssl/err.h>
# include <openssl/rand.h>
/* functions to change the RAND_METHOD */
static int fbytes(unsigned char *buf, int num);
static RAND_METHOD fake_rand;
static const RAND_METHOD *old_rand;
static int change_rand(void)
{
/* save old rand method */
if (!TEST_ptr(old_rand = RAND_get_rand_method()))
return 0;
fake_rand = *old_rand;
/* use own random function */
fake_rand.bytes = fbytes;
/* set new RAND_METHOD */
if (!TEST_true(RAND_set_rand_method(&fake_rand)))
return 0;
return 1;
}
static int restore_rand(void)
{
if (!TEST_true(RAND_set_rand_method(old_rand)))
return 0;
return 1;
}
static int fbytes_counter = 0, use_fake = 0;
static const char *numbers[8] = {
"651056770906015076056810763456358567190100156695615665659",
"6140507067065001063065065565667405560006161556565665656654",
"8763001015071075675010661307616710783570106710677817767166"
"71676178726717",
"7000000175690566466555057817571571075705015757757057795755"
"55657156756655",
"1275552191113212300012030439187146164646146646466749494799",
"1542725565216523985789236956265265265235675811949404040041",
"1456427555219115346513212300075341203043918714616464614664"
"64667494947990",
"1712787255652165239672857892369562652652652356758119494040"
"40041670216363"
};
static int fbytes(unsigned char *buf, int num)
{
int ret = 0;
BIGNUM *tmp = NULL;
if (use_fake == 0)
return old_rand->bytes(buf, num);
use_fake = 0;
if (fbytes_counter >= 8)
return 0;
if (!TEST_ptr(tmp = BN_new()))
return 0;
if (!TEST_true(BN_dec2bn(&tmp, numbers[fbytes_counter]))) {
BN_free(tmp);
return 0;
}
fbytes_counter++;
if (TEST_int_eq(BN_num_bytes(tmp), num)
&& TEST_true(BN_bn2bin(tmp, buf)))
ret = 1;
BN_free(tmp);
return ret;
}
/* some tests from the X9.62 draft */
static int x9_62_test_internal(int nid, const char *r_in, const char *s_in)
{
int ret = 0;
const char message[] = "abc";
unsigned char digest[SHA_DIGEST_LENGTH];
unsigned int dgst_len = 0;
EVP_MD_CTX *md_ctx;
EC_KEY *key = NULL;
ECDSA_SIG *signature = NULL;
BIGNUM *r = NULL, *s = NULL;
BIGNUM *kinv = NULL, *rp = NULL;
const BIGNUM *sig_r, *sig_s;
if (!TEST_ptr(md_ctx = EVP_MD_CTX_new()))
goto x962_int_err;
/* get the message digest */
if (!TEST_true(EVP_DigestInit(md_ctx, EVP_sha1()))
|| !TEST_true(EVP_DigestUpdate(md_ctx, (const void *)message, 3))
|| !TEST_true(EVP_DigestFinal(md_ctx, digest, &dgst_len)))
goto x962_int_err;
TEST_info("testing %s", OBJ_nid2sn(nid));
/* create the key */
if (!TEST_ptr(key = EC_KEY_new_by_curve_name(nid)))
goto x962_int_err;
use_fake = 1;
if (!TEST_true(EC_KEY_generate_key(key)))
goto x962_int_err;
/* create the signature */
use_fake = 1;
/* Use ECDSA_sign_setup to avoid use of ECDSA nonces */
if (!TEST_true(ECDSA_sign_setup(key, NULL, &kinv, &rp)))
goto x962_int_err;
if (!TEST_ptr(signature =
ECDSA_do_sign_ex(digest, SHA_DIGEST_LENGTH, kinv, rp, key)))
goto x962_int_err;
/* compare the created signature with the expected signature */
if (!TEST_ptr(r = BN_new()) || !TEST_ptr(s = BN_new()))
goto x962_int_err;
if (!TEST_true(BN_dec2bn(&r, r_in)) || !TEST_true(BN_dec2bn(&s, s_in)))
goto x962_int_err;
ECDSA_SIG_get0(signature, &sig_r, &sig_s);
if (!TEST_BN_eq(sig_r, r)
|| !TEST_BN_eq(sig_s, s))
goto x962_int_err;
/* verify the signature */
if (!TEST_int_eq(ECDSA_do_verify(digest, SHA_DIGEST_LENGTH,
signature, key), 1))
goto x962_int_err;
ret = 1;
x962_int_err:
EC_KEY_free(key);
ECDSA_SIG_free(signature);
BN_free(r);
BN_free(s);
EVP_MD_CTX_free(md_ctx);
BN_clear_free(kinv);
BN_clear_free(rp);
return ret;
}
static int x9_62_tests(void)
{
int ret = 0;
/* set own rand method */
if (!change_rand())
goto x962_err;
if (!TEST_true(x9_62_test_internal(NID_X9_62_prime192v1,
"3342403536405981729393488334694600415596881826869351677613",
"5735822328888155254683894997897571951568553642892029982342")))
goto x962_err;
if (!TEST_true(x9_62_test_internal(NID_X9_62_prime239v1,
"3086361431751678114926225473006680188549593787585317781474"
"62058306432176",
"3238135532097973577080787768312505059318910517550078427819"
"78505179448783")))
goto x962_err;
# ifndef OPENSSL_NO_EC2M
if (!TEST_true(x9_62_test_internal(NID_X9_62_c2tnb191v1,
"87194383164871543355722284926904419997237591535066528048",
"308992691965804947361541664549085895292153777025772063598")))
goto x962_err;
if (!TEST_true(x9_62_test_internal(NID_X9_62_c2tnb239v1,
"2159633321041961198501834003903461262881815148684178964245"
"5876922391552",
"1970303740007316867383349976549972270528498040721988191026"
"49413465737174")))
goto x962_err;
# endif
ret = 1;
x962_err:
if (!TEST_true(restore_rand()))
ret = 0;
return ret;
}
static int test_builtin(void)
{
EC_builtin_curve *curves = NULL;
size_t crv_len = 0, n = 0;
EC_KEY *eckey = NULL, *wrong_eckey = NULL;
EC_GROUP *group;
ECDSA_SIG *ecdsa_sig = NULL, *modified_sig = NULL;
unsigned char digest[SHA512_DIGEST_LENGTH];
unsigned char wrong_digest[SHA512_DIGEST_LENGTH];
unsigned char *signature = NULL;
const unsigned char *sig_ptr;
unsigned char *sig_ptr2;
unsigned char *raw_buf = NULL;
const BIGNUM *sig_r, *sig_s;
BIGNUM *modified_r = NULL, *modified_s = NULL;
BIGNUM *unmodified_r = NULL, *unmodified_s = NULL;
unsigned int sig_len, order, r_len, s_len, bn_len, buf_len;
int nid, ret = 0;
/* fill digest values with some random data */
if (!TEST_true(RAND_bytes(digest, SHA512_DIGEST_LENGTH))
|| !TEST_true(RAND_bytes(wrong_digest, SHA512_DIGEST_LENGTH)))
goto builtin_err;
/* create and verify a ecdsa signature with every available curve */
/* get a list of all internal curves */
crv_len = EC_get_builtin_curves(NULL, 0);
if (!TEST_ptr(curves = OPENSSL_malloc(sizeof(*curves) * crv_len))
|| !TEST_true(EC_get_builtin_curves(curves, crv_len)))
goto builtin_err;
/* now create and verify a signature for every curve */
for (n = 0; n < crv_len; n++) {
unsigned char dirt, offset;
nid = curves[n].nid;
if (nid == NID_ipsec4 || nid == NID_ipsec3)
continue;
/* create new ecdsa key (== EC_KEY) */
if (!TEST_ptr(eckey = EC_KEY_new())
|| !TEST_ptr(group = EC_GROUP_new_by_curve_name(nid))
|| !TEST_true(EC_KEY_set_group(eckey, group)))
goto builtin_err;
EC_GROUP_free(group);
order = EC_GROUP_order_bits(EC_KEY_get0_group(eckey));
TEST_info("testing %s", OBJ_nid2sn(nid));
/* create key */
if (!TEST_true(EC_KEY_generate_key(eckey)))
goto builtin_err;
/* create second key */
if (!TEST_ptr(wrong_eckey = EC_KEY_new())
|| !TEST_ptr(group = EC_GROUP_new_by_curve_name(nid))
|| !TEST_true(EC_KEY_set_group(wrong_eckey, group)))
goto builtin_err;
EC_GROUP_free(group);
if (!TEST_true(EC_KEY_generate_key(wrong_eckey)))
goto builtin_err;
/* check key */
if (!TEST_true(EC_KEY_check_key(eckey)))
goto builtin_err;
/* create signature */
sig_len = ECDSA_size(eckey);
if (!TEST_ptr(signature = OPENSSL_malloc(sig_len))
|| !TEST_true(ECDSA_sign(0, digest, SHA512_DIGEST_LENGTH,
signature, &sig_len, eckey)))
goto builtin_err;
/* verify signature */
if (!TEST_int_eq(ECDSA_verify(0, digest, SHA512_DIGEST_LENGTH,
signature, sig_len, eckey),
1))
goto builtin_err;
/* verify signature with the wrong key */
if (!TEST_int_ne(ECDSA_verify(0, digest, SHA512_DIGEST_LENGTH,
signature, sig_len, wrong_eckey),
1))
goto builtin_err;
/* wrong digest */
if (!TEST_int_ne(ECDSA_verify(0, wrong_digest, SHA512_DIGEST_LENGTH,
signature, sig_len, eckey),
1))
goto builtin_err;
/* wrong length */
if (!TEST_int_ne(ECDSA_verify(0, digest, SHA512_DIGEST_LENGTH,
signature, sig_len - 1, eckey),
1))
goto builtin_err;
/*
* 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.
*/
sig_ptr = signature;
if (!TEST_ptr(ecdsa_sig = d2i_ECDSA_SIG(NULL, &sig_ptr, sig_len)))
goto builtin_err;
ECDSA_SIG_get0(ecdsa_sig, &sig_r, &sig_s);
/* Store the two BIGNUMs in raw_buf. */
r_len = BN_num_bytes(sig_r);
s_len = BN_num_bytes(sig_s);
bn_len = (order + 7) / 8;
if (!TEST_false(r_len > bn_len)
|| !TEST_false(s_len > bn_len))
goto builtin_err;
buf_len = 2 * bn_len;
if (!TEST_ptr(raw_buf = OPENSSL_zalloc(buf_len)))
goto builtin_err;
BN_bn2bin(sig_r, raw_buf + bn_len - r_len);
BN_bn2bin(sig_s, raw_buf + buf_len - s_len);
/* Modify a single byte in the buffer. */
offset = raw_buf[10] % buf_len;
dirt = raw_buf[11] ? raw_buf[11] : 1;
raw_buf[offset] ^= dirt;
/* Now read the BIGNUMs back in from raw_buf. */
if (!TEST_ptr(modified_sig = ECDSA_SIG_new()))
goto builtin_err;
if (!TEST_ptr(modified_r = BN_bin2bn(raw_buf, bn_len, NULL))
|| !TEST_ptr(modified_s = BN_bin2bn(raw_buf + bn_len,
bn_len, NULL))
|| !TEST_true(ECDSA_SIG_set0(modified_sig,
modified_r, modified_s))) {
BN_free(modified_r);
BN_free(modified_s);
goto builtin_err;
}
sig_ptr2 = signature;
sig_len = i2d_ECDSA_SIG(modified_sig, &sig_ptr2);
if (!TEST_false(ECDSA_verify(0, digest, SHA512_DIGEST_LENGTH,
signature, sig_len, eckey)))
goto builtin_err;
/* Sanity check: undo the modification and verify signature. */
raw_buf[offset] ^= dirt;
if (!TEST_ptr(unmodified_r = BN_bin2bn(raw_buf, bn_len, NULL))
|| !TEST_ptr(unmodified_s = BN_bin2bn(raw_buf + bn_len,
bn_len, NULL))
|| !TEST_true(ECDSA_SIG_set0(modified_sig, unmodified_r,
unmodified_s))) {
BN_free(unmodified_r);
BN_free(unmodified_s);
goto builtin_err;
}
sig_ptr2 = signature;
sig_len = i2d_ECDSA_SIG(modified_sig, &sig_ptr2);
if (!TEST_true(ECDSA_verify(0, digest, SHA512_DIGEST_LENGTH,
signature, sig_len, eckey)))
goto builtin_err;
/* cleanup */
ERR_clear_error();
OPENSSL_free(signature);
signature = NULL;
EC_KEY_free(eckey);
eckey = NULL;
EC_KEY_free(wrong_eckey);
wrong_eckey = NULL;
ECDSA_SIG_free(ecdsa_sig);
ecdsa_sig = NULL;
ECDSA_SIG_free(modified_sig);
modified_sig = NULL;
OPENSSL_free(raw_buf);
raw_buf = NULL;
}
ret = 1;
builtin_err:
EC_KEY_free(eckey);
EC_KEY_free(wrong_eckey);
ECDSA_SIG_free(ecdsa_sig);
ECDSA_SIG_free(modified_sig);
OPENSSL_free(signature);
OPENSSL_free(raw_buf);
OPENSSL_free(curves);
return ret;
}
#endif
int setup_tests(void)
{
#ifdef OPENSSL_NO_EC
TEST_note("Elliptic curves are disabled.");
#else
ADD_TEST(x9_62_tests);
ADD_TEST(test_builtin);
#endif
return 1;
}