Avoid PKCS #1 v1.5 signature attack discovered by Daniel Bleichenbacher

[oweals/openssl.git] / crypto / rsa / rsa_sign.c

diff --git a/crypto/rsa/rsa_sign.c b/crypto/rsa/rsa_sign.c
index 230ec6d7ea2a981ead6a4a8fa45d1f38128298e5..71aabeea1bd73bca46c8a1657273dbedbffad4e0 100644 (file)
--- a/crypto/rsa/rsa_sign.c
+++ b/crypto/rsa/rsa_sign.c
@@ -185,6 +185,23 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
                sig=d2i_X509_SIG(NULL,&p,(long)i);
 
                if (sig == NULL) goto err;
+
+               /* Excess data can be used to create forgeries */
+               if(p != s+i)
+                       {
+                       RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
+                       goto err;
+                       }
+
+               /* Parameters to the signature algorithm can also be used to
+                  create forgeries */
+               if(sig->algor->parameter
+                  && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)
+                       {
+                       RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
+                       goto err;
+                       }
+
                sigtype=OBJ_obj2nid(sig->algor->algorithm);