/// <summary>
/// Initializes a new instance of the <see cref="DistinguishedName"/> class.
/// </summary>
/// <param name="input">A pointer to a buffer that's used to initialize the object.</param>
/// <param name="length">The length of the buffer.</param>
/// <exception cref="CertificateException">Could not decode the buffer.</exception>
internal DistinguishedName(IntPtr input, int length) : this()
{
int size = 0;
SspiProvider.CryptDecodeObject(SecurityConstants.PKCS_7_ASN_ENCODING | SecurityConstants.X509_ASN_ENCODING, new IntPtr(SecurityConstants.X509_UNICODE_NAME), input, length, 0, IntPtr.Zero, ref size);
if (size <= 0)
{
throw new CertificateException("Unable to decode the name of the certificate.");
}
IntPtr buffer = Marshal.AllocHGlobal(size);
if (SspiProvider.CryptDecodeObject(SecurityConstants.PKCS_7_ASN_ENCODING | SecurityConstants.X509_ASN_ENCODING, new IntPtr(SecurityConstants.X509_UNICODE_NAME), input, length, 0, buffer, ref size) == 0)
{
throw new CertificateException("Unable to decode the name of the certificate.");
}
try {
CertificateNameInfo cni = (CertificateNameInfo)Marshal.PtrToStructure(buffer, typeof(CertificateNameInfo));
Initialize(cni);
} catch (CertificateException ce) {
throw ce;
} catch (Exception e) {
throw new CertificateException("Could not get the certificate distinguished name.", e);
} finally {
if (buffer != IntPtr.Zero)
{
Marshal.FreeHGlobal(buffer);
}
}
}