Fix ecdsatest.c.
[openssl.git] / crypto / ecdsa / ecdsatest.c
index 0a138c3bde0e57441a0868e40d0cf20615e833c5..fdadbd9614459844212a925f140dc819bb558714 100644 (file)
@@ -105,7 +105,7 @@ int test_builtin(BIO *);
 /* functions to change the RAND_METHOD */
 int change_rand(void);
 int restore_rand(void);
-int fbytes(unsigned char *buf, size_t num);
+int fbytes(unsigned char *buf, int num);
 
 RAND_METHOD    fake_rand;
 const RAND_METHOD *old_rand;
@@ -137,7 +137,7 @@ int restore_rand(void)
                return 1;
        }
 
-static int fbytes_counter = 0;
+static int fbytes_counter = 0, use_fake = 0;
 static const char *numbers[8] = {
        "651056770906015076056810763456358567190100156695615665659",
        "6140507067065001063065065565667405560006161556565665656654",
@@ -152,11 +152,16 @@ static const char *numbers[8] = {
        "1712787255652165239672857892369562652652652356758119494040"
        "40041670216363"};
 
-int fbytes(unsigned char *buf, size_t num)
+int fbytes(unsigned char *buf, int num)
        {
        int     ret;
        BIGNUM  *tmp = NULL;
 
+       if (use_fake == 0)
+               return old_rand->bytes(buf, num);
+
+       use_fake = 0;
+
        if (fbytes_counter >= 8)
                return 0;
        tmp = BN_new();
@@ -168,10 +173,9 @@ int fbytes(unsigned char *buf, size_t num)
                return 0;
                }
        fbytes_counter ++;
-       ret = BN_bn2bin(tmp, buf);      
-       if (ret == 0 || ret != num)
+       if (num != BN_num_bytes(tmp) || !BN_bn2bin(tmp, buf))
                ret = 0;
-       else
+       else 
                ret = 1;
        if (tmp)
                BN_free(tmp);
@@ -192,19 +196,22 @@ int x9_62_test_internal(BIO *out, int nid, const char *r_in, const char *s_in)
 
        EVP_MD_CTX_init(&md_ctx);
        /* get the message digest */
-       EVP_DigestInit(&md_ctx, EVP_ecdsa());
-       EVP_DigestUpdate(&md_ctx, (const void*)message, 3);
-       EVP_DigestFinal(&md_ctx, digest, &dgst_len);
+       if (!EVP_DigestInit(&md_ctx, EVP_ecdsa())
+           || !EVP_DigestUpdate(&md_ctx, (const void*)message, 3)
+           || !EVP_DigestFinal(&md_ctx, digest, &dgst_len))
+               goto x962_int_err;
 
        BIO_printf(out, "testing %s: ", OBJ_nid2sn(nid));
        /* create the key */
        if ((key = EC_KEY_new_by_curve_name(nid)) == NULL)
                goto x962_int_err;
+       use_fake = 1;
        if (!EC_KEY_generate_key(key))
                goto x962_int_err;
        BIO_printf(out, ".");
        (void)BIO_flush(out);
        /* create the signature */
+       use_fake = 1;
        signature = ECDSA_do_sign(digest, 20, key);
        if (signature == NULL)
                goto x962_int_err;
@@ -263,6 +270,7 @@ int x9_62_tests(BIO *out)
                "3238135532097973577080787768312505059318910517550078427819"
                "78505179448783"))
                goto x962_err;
+#ifndef OPENSSL_NO_EC2M
        if (!x9_62_test_internal(out, NID_X9_62_c2tnb191v1,
                "87194383164871543355722284926904419997237591535066528048",
                "308992691965804947361541664549085895292153777025772063598"))
@@ -273,7 +281,7 @@ int x9_62_tests(BIO *out)
                "1970303740007316867383349976549972270528498040721988191026"
                "49413465737174"))
                goto x962_err;
-
+#endif
        ret = 1;
 x962_err:
        if (!restore_rand())
@@ -287,9 +295,12 @@ 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 */
@@ -339,7 +350,8 @@ 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);
@@ -415,26 +427,89 @@ 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;        
@@ -443,8 +518,12 @@ 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);