// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace System.Security.Cryptography
{
    public class DSASignatureFormatter : AsymmetricSignatureFormatter
    {
        private DSA? _dsaKey;
 
        public DSASignatureFormatter() { }
 
        public DSASignatureFormatter(AsymmetricAlgorithm key) : this()
        {
            ArgumentNullException.ThrowIfNull(key);
 
            _dsaKey = (DSA)key;
        }
 
        public override void SetKey(AsymmetricAlgorithm key)
        {
            ArgumentNullException.ThrowIfNull(key);
 
            _dsaKey = (DSA)key;
        }
 
        public override void SetHashAlgorithm(string strName)
        {
            if (!strName.Equals(HashAlgorithmNames.SHA1, StringComparison.InvariantCultureIgnoreCase))
            {
                // To match desktop, throw here
                throw new CryptographicUnexpectedOperationException(SR.Cryptography_InvalidOperation);
            }
        }
 
        public override byte[] CreateSignature(byte[] rgbHash)
        {
            ArgumentNullException.ThrowIfNull(rgbHash);
 
            if (_dsaKey == null)
                throw new CryptographicUnexpectedOperationException(SR.Cryptography_FormatterMissingKey);
 
            return _dsaKey.CreateSignature(rgbHash);
        }
    }
}