/// <summary>
/// 以指定的编码方式计算字符串指定模式的SHA值。
/// </summary>
/// <param name="input">需要计算SHA值的字符串。</param>
/// <param name="encoding">字符串的编码方式。</param>
/// <param name="mode">计算SHA的模式。</param>
/// <returns>字符串对应的SHA值。</returns>
/// <exception cref="ArgumentNullException">参数encoding为null时将抛出该异常。</exception>
/// <exception cref="ArgumentException">传入不能识别的ShaMode时将抛出该异常。</exception>
public static string ComputeSha(string input, Encoding encoding, ShaMode mode)
{
int length = Convert.ToInt32(mode);
if (string.IsNullOrEmpty(input))
{
return(string.Empty.PadLeft(length, '0'));
}
if (encoding == null)
{
throw new ArgumentNullException("encoding");
}
byte[] buffer = encoding.GetBytes(input);
StringBuilder builder = new StringBuilder(length);
using (HashAlgorithm provider = Encryption.CreateShaProvider(mode))
{
byte[] result = provider.ComputeHash(buffer);
for (int i = 0; i < result.Length; i++)
{
builder.Append(result[i].ToString("X2"));
}
}
return(builder.ToString());
}
/// <summary>
/// 计算IO流指定模式的SHA值。
/// </summary>
/// <param name="stream">需要计算SHA值的IO流。</param>
/// <param name="mode">计算SHA的模式。</param>
/// <returns>IO流对应的SHA值。</returns>
/// <exception cref="ArgumentNullException">参数stream为null时将抛出该异常。</exception>
/// <exception cref="ArgumentException">传入不能识别的ShaMode时将抛出该异常。</exception>
public static string ComputeSha(Stream stream, ShaMode mode)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
int length = Convert.ToInt32(mode);
StringBuilder builder = new StringBuilder(length);
using (HashAlgorithm provider = Encryption.CreateShaProvider(mode))
{
byte[] result = provider.ComputeHash(stream);
for (int i = 0; i < result.Length; i++)
{
builder.Append(result[i].ToString("X2"));
}
}
return(builder.ToString());
}
