+ /* 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_ptr2 = signature;
+ sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2);