From 72033fde7be9e6f215078d63a9630872f95cd9c8 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bodo=20M=C3=B6ller?= Date: Fri, 2 Dec 2011 12:40:25 +0000 Subject: [PATCH] Fix ecdsatest.c. Submitted by: Emilia Kasper --- CHANGES | 3 ++ crypto/ecdsa/ecdsatest.c | 85 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 81 insertions(+), 7 deletions(-) diff --git a/CHANGES b/CHANGES index e03f7477cd..3771698bfd 100644 --- a/CHANGES +++ b/CHANGES @@ -4,6 +4,9 @@ Changes between 0.9.8r and 0.9.8s [xx XXX xxxx] + *) Fix spurious failures in ecdsatest.c. + [Emilia Käsper (Google)] + *) Fix the BIO_f_buffer() implementation (which was mixing different interpretations of the '..._len' fields). [Adam Langley (Google)] diff --git a/crypto/ecdsa/ecdsatest.c b/crypto/ecdsa/ecdsatest.c index 90de68c851..54d775ad45 100644 --- a/crypto/ecdsa/ecdsatest.c +++ b/crypto/ecdsa/ecdsatest.c @@ -286,9 +286,12 @@ int test_builtin(BIO *out) size_t crv_len = 0, n = 0; EC_KEY *eckey = NULL, *wrong_eckey = NULL; EC_GROUP *group; + ECDSA_SIG *ecdsa_sig = NULL; unsigned char digest[20], wrong_digest[20]; - unsigned char *signature = NULL; - unsigned int sig_len; + unsigned char *signature = NULL; + unsigned char *sig_ptr; + unsigned char *raw_buf = NULL; + unsigned int sig_len, degree, r_len, s_len, bn_len, buf_len; int nid, ret = 0; /* fill digest values with some random data */ @@ -338,7 +341,8 @@ int test_builtin(BIO *out) if (EC_KEY_set_group(eckey, group) == 0) goto builtin_err; EC_GROUP_free(group); - if (EC_GROUP_get_degree(EC_KEY_get0_group(eckey)) < 160) + degree = EC_GROUP_get_degree(EC_KEY_get0_group(eckey)); + if (degree < 160) /* drop the curve */ { EC_KEY_free(eckey); @@ -414,26 +418,89 @@ int test_builtin(BIO *out) } BIO_printf(out, "."); (void)BIO_flush(out); - /* modify a single byte of the signature */ - offset = signature[10] % sig_len; - dirt = signature[11]; - signature[offset] ^= dirt ? dirt : 1; + /* wrong length */ + if (ECDSA_verify(0, digest, 20, signature, sig_len - 1, + eckey) == 1) + { + BIO_printf(out, " failed\n"); + goto builtin_err; + } + BIO_printf(out, "."); + (void)BIO_flush(out); + + /* 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 ((ecdsa_sig = d2i_ECDSA_SIG(NULL, &sig_ptr, sig_len)) == NULL) + { + BIO_printf(out, " failed\n"); + goto builtin_err; + } + + /* Store the two BIGNUMs in raw_buf. */ + r_len = BN_num_bytes(ecdsa_sig->r); + s_len = BN_num_bytes(ecdsa_sig->s); + bn_len = (degree + 7) / 8; + if ((r_len > bn_len) || (s_len > bn_len)) + { + BIO_printf(out, " failed\n"); + goto builtin_err; + } + buf_len = 2 * bn_len; + if ((raw_buf = OPENSSL_malloc(buf_len)) == NULL) + goto builtin_err; + /* Pad the bignums with leading zeroes. */ + memset(raw_buf, 0, buf_len); + BN_bn2bin(ecdsa_sig->r, raw_buf + bn_len - r_len); + BN_bn2bin(ecdsa_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 ((BN_bin2bn(raw_buf, bn_len, ecdsa_sig->r) == NULL) || + (BN_bin2bn(raw_buf + bn_len, bn_len, ecdsa_sig->s) == NULL)) + goto builtin_err; + + sig_ptr = signature; + sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr); if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) == 1) { BIO_printf(out, " failed\n"); goto builtin_err; } + /* Sanity check: undo the modification and verify signature. */ + raw_buf[offset] ^= dirt; + if ((BN_bin2bn(raw_buf, bn_len, ecdsa_sig->r) == NULL) || + (BN_bin2bn(raw_buf + bn_len, bn_len, ecdsa_sig->s) == NULL)) + goto builtin_err; + + sig_ptr = signature; + sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr); + if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) != 1) + { + BIO_printf(out, " failed\n"); + goto builtin_err; + } BIO_printf(out, "."); (void)BIO_flush(out); BIO_printf(out, " ok\n"); /* cleanup */ + /* clean bogus errors */ + 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; + OPENSSL_free(raw_buf); + raw_buf = NULL; } ret = 1; @@ -442,8 +509,12 @@ builtin_err: EC_KEY_free(eckey); if (wrong_eckey) EC_KEY_free(wrong_eckey); + if (ecdsa_sig) + ECDSA_SIG_free(ecdsa_sig); if (signature) OPENSSL_free(signature); + if (raw_buf) + OPENSSL_free(raw_buf); if (curves) OPENSSL_free(curves); -- 2.25.1