1 files changed, 46 insertions, 14 deletions

diff --git a/src/lib/libcrypto/cms/cms_enc.c b/src/lib/libcrypto/cms/cms_enc.c
index bab26235bd..f873ce3794 100644
--- a/src/lib/libcrypto/cms/cms_enc.c
+++ b/src/lib/libcrypto/cms/cms_enc.c
@@ -73,6 +73,8 @@ BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)
         const EVP_CIPHER *ciph;
         X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
         unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;
+        unsigned char *tkey = NULL;
+        size_t tkeylen;
 
         int ok = 0;
 
@@ -137,32 +139,57 @@ BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)
                                 CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
                 goto err;
                 }
-
-
-        if (enc && !ec->key)
+        tkeylen = EVP_CIPHER_CTX_key_length(ctx);
+        /* Generate random session key */
+        if (!enc || !ec->key)
                 {
-                /* Generate random key */
-                if (!ec->keylen)
-                        ec->keylen = EVP_CIPHER_CTX_key_length(ctx);
-                ec->key = OPENSSL_malloc(ec->keylen);
-                if (!ec->key)
+                tkey = OPENSSL_malloc(tkeylen);
+                if (!tkey)
                         {
                         CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
                                                         ERR_R_MALLOC_FAILURE);
                         goto err;
                         }
-                if (EVP_CIPHER_CTX_rand_key(ctx, ec->key) <= 0)
+                if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)
                         goto err;
-                keep_key = 1;
                 }
-        else if (ec->keylen != (unsigned int)EVP_CIPHER_CTX_key_length(ctx))
+
+        if (!ec->key)
+                {
+                ec->key = tkey;
+                ec->keylen = tkeylen;
+                tkey = NULL;
+                if (enc)
+                        keep_key = 1;
+                else
+                        ERR_clear_error();
+                
+                }
+
+        if (ec->keylen != tkeylen)
                 {
                 /* If necessary set key length */
                 if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0)
                         {
-                        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
-                                CMS_R_INVALID_KEY_LENGTH);
-                        goto err;
+                        /* Only reveal failure if debugging so we don't
+                         * leak information which may be useful in MMA.
+                         */
+                        if (enc || ec->debug)
+                                {
+                                CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
+                                                CMS_R_INVALID_KEY_LENGTH);
+                                goto err;
+                                }
+                        else
+                                {
+                                /* Use random key */
+                                OPENSSL_cleanse(ec->key, ec->keylen);
+                                OPENSSL_free(ec->key);
+                                ec->key = tkey;
+                                ec->keylen = tkeylen;
+                                tkey = NULL;
+                                ERR_clear_error();
+                                }
                         }
                 }
 
@@ -198,6 +225,11 @@ BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)
                 OPENSSL_free(ec->key);
                 ec->key = NULL;
                 }
+        if (tkey)
+                {
+                OPENSSL_cleanse(tkey, tkeylen);
+                OPENSSL_free(tkey);
+                }
         if (ok)
                 return b;
         BIO_free(b);