KEY_NAME (Transact-SQL)
Returns the name of the symmetric key from either a symmetric key GUID or cipher text.
.gif "Topic link icon")
Syntax
KEY_NAME ( ciphertext | key_guid )
Arguments
ciphertext
Is the text encrypted by the symmetric key. cyphertext is type varbinary(8000).key_guid
Is the GUID of the symmetric key. key_guid is type uniqueidentifier.
Returned Types
varchar(128)
Permissions
Beginning in SQL Server 2005, the visibility of metadata is limited to securables that a user either owns or on which the user has been granted some permission. For more information, see Metadata Visibility Configuration.
Examples
A. Displaying the name of a symmetric key using the key_guid
The master database contains a symmetric key named ##MS_ServiceMasterKey##. The following example gets the GUID of that key from the sys.symmetric_keys dynamic management view, assigns it to a variable, and then passes that variable to the KEY_NAME function to demonstrate how to return the name that corresponds to the GUID.
USE master
GO
DECLARE @guid uniqueidentifier ;
SELECT @guid = key_guid FROM sys.symmetric_keys
WHERE name = '##MS_ServiceMasterKey##' ;
-- Demonstration of passing a GUID to KEY_NAME to receive a name
SELECT KEY_NAME(@guid) AS [Name of Key];
PASSWORD = 'decryption_password'
B. Displaying the name of a symmetric key using the cipher text
The following example demonstrates the entire process of creating a symmetric key and populating data into a table. The example then shows how KEY_NAME returns the name of the key when passed the encrypted text.
-- Create a symmetric key
CREATE SYMMETRIC KEY TestSymKey
WITH ALGORITHM = AES_128,
KEY_SOURCE = 'The square of the hypotenuse is equal to the sum of the squares of the sides',
IDENTITY_VALUE = 'Pythagoras'
ENCRYPTION BY PASSWORD = 'pGFD4bb925DGvbd2439587y' ;
GO
-- Create a table for the demonstration
CREATE TABLE DemoKey
(IDCol int IDENTITY PRIMARY KEY,
SecretCol varbinary(256) NOT NULL)
GO
-- Open the symmetric key if not already open
OPEN SYMMETRIC KEY TestSymKey
DECRYPTION BY PASSWORD = 'pGFD4bb925DGvbd2439587y';
GO
-- Insert a row into the DemoKey table
DECLARE @key_GUID uniqueidentifier
SELECT @key_GUID = key_guid FROM sys.symmetric_keys
WHERE name LIKE 'TestSymKey' ;
INSERT INTO DemoKey(SecretCol)
VALUES ( ENCRYPTBYKEY (@key_GUID, 'EncryptedText'))
GO
-- Verify the DemoKey data
SELECT * FROM DemoKey
GO
-- Decrypt the data
DECLARE @ciphertext varbinary(256)
SELECT @ciphertext = SecretCol
FROM DemoKey WHERE IDCol = 1 ;
SELECT CAST (
DECRYPTBYKEY( @ciphertext)
AS varchar(100) ) AS SecretText ;
-- Use KEY_NAME to view the name of the key
SELECT KEY_NAME(@ciphertext) AS [Name of Key] ;