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 6283fc9f069c6f3755b043a62f445e9c0aadac14..71aabeea1bd73bca46c8a1657273dbedbffad4e0 100644 (file)
--- a/crypto/rsa/rsa_sign.c
+++ b/crypto/rsa/rsa_sign.c
@@ -62,7 +62,6 @@
 #include <openssl/rsa.h>
 #include <openssl/objects.h>
 #include <openssl/x509.h>
-#include <openssl/engine.h>
 
 /* Size of an SSL signature: MD5+SHA1 */
 #define SSL_SIG_LENGTH 36
@@ -77,9 +76,11 @@ int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
        const unsigned char *s = NULL;
        X509_ALGOR algor;
        ASN1_OCTET_STRING digest;
-       if(rsa->flags & RSA_FLAG_SIGN_VER)
-             return ENGINE_get_RSA(rsa->engine)->rsa_sign(type,
-                       m, m_len, sigret, siglen, rsa);
+       if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign)
+               {
+               return rsa->meth->rsa_sign(type, m, m_len,
+                       sigret, siglen, rsa);
+               }
        /* Special case: SSL signature, just check the length */
        if(type == NID_md5_sha1) {
                if(m_len != SSL_SIG_LENGTH) {
@@ -112,7 +113,7 @@ int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
                i=i2d_X509_SIG(&sig,NULL);
        }
        j=RSA_size(rsa);
-       if ((i-RSA_PKCS1_PADDING) > j)
+       if (i > (j-RSA_PKCS1_PADDING_SIZE))
                {
                RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
                return(0);
@@ -135,7 +136,7 @@ int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
                *siglen=i;
 
        if(type != NID_md5_sha1) {
-               memset(tmps,0,(unsigned int)j+1);
+               OPENSSL_cleanse(tmps,(unsigned int)j+1);
                OPENSSL_free(tmps);
        }
        return(ret);
@@ -145,7 +146,7 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
             unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
        {
        int i,ret=0,sigtype;
-       unsigned char *p,*s;
+       unsigned char *s;
        X509_SIG *sig=NULL;
 
        if (siglen != (unsigned int)RSA_size(rsa))
@@ -154,9 +155,11 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
                return(0);
                }
 
-       if(rsa->flags & RSA_FLAG_SIGN_VER)
-           return ENGINE_get_RSA(rsa->engine)->rsa_verify(dtype,
-                       m, m_len, sigbuf, siglen, rsa);
+       if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
+               {
+               return rsa->meth->rsa_verify(dtype, m, m_len,
+                       sigbuf, siglen, rsa);
+               }
 
        s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
        if (s == NULL)
@@ -166,7 +169,7 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
                }
        if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
                        RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
-                       return(0);
+                       goto err;
        }
        i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
 
@@ -178,10 +181,27 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
                                RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
                else ret = 1;
        } else {
-               p=s;
+               const unsigned char *p=s;
                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);
 
 
@@ -198,7 +218,7 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
                                (sigtype == NID_md2WithRSAEncryption)))
                                {
                                /* ok, we will let it through */
-#if !defined(OPENSSL_NO_STDIO) && !defined(WIN16)
+#if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
                                fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
 #endif
                                }
@@ -219,8 +239,11 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
        }
 err:
        if (sig != NULL) X509_SIG_free(sig);
-       memset(s,0,(unsigned int)siglen);
-       OPENSSL_free(s);
+       if (s != NULL)
+               {
+               OPENSSL_cleanse(s,(unsigned int)siglen);
+               OPENSSL_free(s);
+               }
        return(ret);
        }