From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date: Mon, 31 Jul 2017 18:38:26 +0000 (+0200)
Subject: Fix an information leak in the RSA padding check code.
X-Git-Tag: OpenSSL_1_0_2m~45
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=57ad215615071a7dc578e390de61ae163b15df9d;p=openssl

Fix an information leak in the RSA padding check code.
The memory blocks contain secret data and must be
cleared before returning to the system heap.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4063)
---

diff --git a/crypto/rsa/rsa_oaep.c b/crypto/rsa/rsa_oaep.c
index 19d28c6f0e..9a01b4afc1 100644
--- a/crypto/rsa/rsa_oaep.c
+++ b/crypto/rsa/rsa_oaep.c
@@ -237,10 +237,14 @@ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
     RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,
            RSA_R_OAEP_DECODING_ERROR);
  cleanup:
-    if (db != NULL)
+    if (db != NULL) {
+        OPENSSL_cleanse(db, dblen);
         OPENSSL_free(db);
-    if (em != NULL)
+    }
+    if (em != NULL) {
+        OPENSSL_cleanse(em, num);
         OPENSSL_free(em);
+    }
     return mlen;
 }
 
diff --git a/crypto/rsa/rsa_pk1.c b/crypto/rsa/rsa_pk1.c
index 017766ce71..50397c335a 100644
--- a/crypto/rsa/rsa_pk1.c
+++ b/crypto/rsa/rsa_pk1.c
@@ -264,8 +264,10 @@ int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen,
     memcpy(to, em + msg_index, mlen);
 
  err:
-    if (em != NULL)
+    if (em != NULL) {
+        OPENSSL_cleanse(em, num);
         OPENSSL_free(em);
+    }
     if (mlen == -1)
         RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,
                RSA_R_PKCS_DECODING_ERROR);