Merge branch 'topic/cipher-no-initialize-null-key'

* topic/cipher-no-initialize-null-key:
  cipher: don't set dummy encryption key in Cipher#initialize

1 files changed, 13 insertions, 12 deletions

diff --git a/ext/openssl/ossl_cipher.c b/ext/openssl/ossl_cipher.c
index 57bc3cfa..0ad75592 100644
--- a/ext/openssl/ossl_cipher.c
+++ b/ext/openssl/ossl_cipher.c
@@ -36,7 +36,7 @@
  */
 VALUE cCipher;
 VALUE eCipherError;
-static ID id_auth_tag_len;
+static ID id_auth_tag_len, id_key_set;
 
 static VALUE ossl_cipher_alloc(VALUE klass);
 static void ossl_cipher_free(void *ptr);
@@ -118,7 +118,6 @@ ossl_cipher_initialize(VALUE self, VALUE str)
     EVP_CIPHER_CTX *ctx;
     const EVP_CIPHER *cipher;
     char *name;
-    unsigned char dummy_key[EVP_MAX_KEY_LENGTH] = { 0 };
 
     name = StringValueCStr(str);
     GetCipherInit(self, ctx);
@@ -129,16 +128,7 @@ ossl_cipher_initialize(VALUE self, VALUE str)
     if (!(cipher = EVP_get_cipherbyname(name))) {
 	ossl_raise(rb_eRuntimeError, "unsupported cipher algorithm (%"PRIsVALUE")", str);
     }
-    /*
-     * EVP_CipherInit_ex() allows to specify NULL to key and IV, however some
-     * ciphers don't handle well (OpenSSL's bug). [Bug #2768]
-     *
-     * The EVP which has EVP_CIPH_RAND_KEY flag (such as DES3) allows
-     * uninitialized key, but other EVPs (such as AES) does not allow it.
-     * Calling EVP_CipherUpdate() without initializing key causes SEGV so we
-     * set the data filled with "\0" as the key by default.
-     */
-    if (EVP_CipherInit_ex(ctx, cipher, NULL, dummy_key, NULL, -1) != 1)
+    if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, -1) != 1)
 	ossl_raise(eCipherError, NULL);
 
     return self;
@@ -251,6 +241,9 @@ ossl_cipher_init(int argc, VALUE *argv, VALUE self, int mode)
 	ossl_raise(eCipherError, NULL);
     }
 
+    if (p_key)
+	rb_ivar_set(self, id_key_set, Qtrue);
+
     return self;
 }
 
@@ -337,6 +330,8 @@ ossl_cipher_pkcs5_keyivgen(int argc, VALUE *argv, VALUE self)
     OPENSSL_cleanse(key, sizeof key);
     OPENSSL_cleanse(iv, sizeof iv);
 
+    rb_ivar_set(self, id_key_set, Qtrue);
+
     return Qnil;
 }
 
@@ -387,6 +382,9 @@ ossl_cipher_update(int argc, VALUE *argv, VALUE self)
 
     rb_scan_args(argc, argv, "11", &data, &str);
 
+    if (!RTEST(rb_attr_get(self, id_key_set)))
+	ossl_raise(eCipherError, "key not set");
+
     StringValue(data);
     in = (unsigned char *)RSTRING_PTR(data);
     if ((in_len = RSTRING_LEN(data)) == 0)
@@ -488,6 +486,8 @@ ossl_cipher_set_key(VALUE self, VALUE key)
     if (EVP_CipherInit_ex(ctx, NULL, NULL, (unsigned char *)RSTRING_PTR(key), NULL, -1) != 1)
 	ossl_raise(eCipherError, NULL);
 
+    rb_ivar_set(self, id_key_set, Qtrue);
+
     return key;
 }
 
@@ -1082,4 +1082,5 @@ Init_ossl_cipher(void)
     rb_define_method(cCipher, "padding=", ossl_cipher_set_padding, 1);
 
     id_auth_tag_len = rb_intern_const("auth_tag_len");
+    id_key_set = rb_intern_const("key_set");
 }