Errata #11 (markus):

Enforce blinding on RSA operations involving private keys.

millert@ markus@ ok

2 files changed, 30 insertions, 5 deletions

diff --git a/src/lib/libssl/src/crypto/rsa/rsa_eay.c b/src/lib/libssl/src/crypto/rsa/rsa_eay.c
index 0eda816081..a3f549d8e6 100644
--- a/src/lib/libssl/src/crypto/rsa/rsa_eay.c
+++ b/src/lib/libssl/src/crypto/rsa/rsa_eay.c
@@ -193,6 +193,25 @@ err:
         return(r);
         }
 
+static int rsa_eay_blinding(RSA *rsa, BN_CTX *ctx)
+        {
+        int ret = 1;
+        CRYPTO_w_lock(CRYPTO_LOCK_RSA);
+        /* Check again inside the lock - the macro's check is racey */
+        if(rsa->blinding == NULL)
+                ret = RSA_blinding_on(rsa, ctx);
+        CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
+        return ret;
+        }
+
+#define BLINDING_HELPER(rsa, ctx, err_instr) \
+        do { \
+                if(((rsa)->flags & RSA_FLAG_BLINDING) && \
+                                ((rsa)->blinding == NULL) && \
+                                !rsa_eay_blinding(rsa, ctx)) \
+                        err_instr \
+        } while(0)
+
 /* signing */
 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
              unsigned char *to, RSA *rsa, int padding)
@@ -237,8 +256,8 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
                 goto err;
                 }
 
-        if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
-                RSA_blinding_on(rsa,ctx);
+        BLINDING_HELPER(rsa, ctx, goto err;);
+
         if (rsa->flags & RSA_FLAG_BLINDING)
                 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
 
@@ -316,8 +335,8 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
                 goto err;
                 }
 
-        if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
-                RSA_blinding_on(rsa,ctx);
+        BLINDING_HELPER(rsa, ctx, goto err;);
+
         if (rsa->flags & RSA_FLAG_BLINDING)
                 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
 
diff --git a/src/lib/libssl/src/crypto/rsa/rsa_lib.c b/src/lib/libssl/src/crypto/rsa/rsa_lib.c
index 93235744f7..37fff8bce3 100644
--- a/src/lib/libssl/src/crypto/rsa/rsa_lib.c
+++ b/src/lib/libssl/src/crypto/rsa/rsa_lib.c
@@ -70,7 +70,13 @@ static const RSA_METHOD *default_RSA_meth=NULL;
 
 RSA *RSA_new(void)
         {
-        return(RSA_new_method(NULL));
+        RSA *r=RSA_new_method(NULL);
+
+#ifndef OPENSSL_NO_FORCE_RSA_BLINDING
+        r->flags|=RSA_FLAG_BLINDING;
+#endif
+
+        return r;
         }
 
 void RSA_set_default_method(const RSA_METHOD *meth)