internal static byte[] GetRSAFromDER(byte[] DERData)
{
byte[] data = null;
byte[] publicKey = null;
CERT_PUBLIC_KEY_INFO info;
UInt32 dwCertPublicKeyInfoSize = 0;
IntPtr pCertPublicKeyInfo = IntPtr.Zero;
if (RSACryptoServiceProviderExtension.CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.X509_PUBLIC_KEY_INFO),
DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwCertPublicKeyInfoSize))
{
data = new byte[dwCertPublicKeyInfoSize];
if (RSACryptoServiceProviderExtension.CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.X509_PUBLIC_KEY_INFO),
DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwCertPublicKeyInfoSize))
{
GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
try
{
info = (CERT_PUBLIC_KEY_INFO)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(CERT_PUBLIC_KEY_INFO));
publicKey = new byte[info.PublicKey.cbData];
Marshal.Copy(info.PublicKey.pbData, publicKey, 0, publicKey.Length);
}
finally
{
handle.Free();
}
}
else
throw new Win32Exception(Marshal.GetLastWin32Error());
}
else
throw new Win32Exception(Marshal.GetLastWin32Error());
return publicKey;
}