cipher: raise CipherError for unsupported algorithm name

Raise OpenSSL::Cipher::CipherError instead of ArgumentError or
RuntimeError for consistency.

Author: rhenium

ext/openssl/ossl_cipher.c

@@ -65,8 +65,8 @@ ossl_evp_get_cipherbyname(VALUE obj)
 	StringValueCStr(obj);
 	cipher = EVP_get_cipherbyname(RSTRING_PTR(obj));
 	if (!cipher)
-	    ossl_raise(rb_eArgError,
-		       "unsupported cipher algorithm: %"PRIsVALUE, obj);
+	    ossl_raise(eCipherError, "unsupported cipher algorithm: %"PRIsVALUE,
+                       obj);
 
 	return cipher;
     }
@@ -114,17 +114,13 @@ ossl_cipher_initialize(VALUE self, VALUE str)
 {
     EVP_CIPHER_CTX *ctx;
     const EVP_CIPHER *cipher;
-    char *name;
 
-    name = StringValueCStr(str);
     GetCipherInit(self, ctx);
     if (ctx) {
 	ossl_raise(rb_eRuntimeError, "Cipher already initialized!");
     }
+    cipher = ossl_evp_get_cipherbyname(str);
     AllocCipher(self, ctx);
-    if (!(cipher = EVP_get_cipherbyname(name))) {
-	ossl_raise(rb_eRuntimeError, "unsupported cipher algorithm (%"PRIsVALUE")", str);
-    }
     if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, -1) != 1)
 	ossl_raise(eCipherError, NULL);
 

test/openssl/test_cipher.rb

@@ -112,6 +112,9 @@ def test_initialize
     cipher = OpenSSL::Cipher.new("DES-EDE3-CBC")
     assert_raise(RuntimeError) { cipher.__send__(:initialize, "DES-EDE3-CBC") }
     assert_raise(RuntimeError) { OpenSSL::Cipher.allocate.final }
+    assert_raise(OpenSSL::Cipher::CipherError) {
+      OpenSSL::Cipher.new("no such algorithm")
+    }
   end
 
   def test_ctr_if_exists
@@ -368,7 +371,7 @@ def test_aes_keywrap_pad
 
     begin
       cipher = OpenSSL::Cipher.new("id-aes192-wrap-pad").encrypt
-    rescue OpenSSL::Cipher::CipherError, RuntimeError
+    rescue OpenSSL::Cipher::CipherError
       omit "id-aes192-wrap-pad is not supported: #$!"
     end
     cipher.key = kek