/// <summary>Extracts the binary data from a PEM file.</summary>
internal static byte[] GetDERFromPEM(string sPEM)
{
UInt32 dwSkip, dwFlags;
UInt32 dwBinarySize = 0;
if (!RSACryptoServiceProviderExtensions.CryptStringToBinary(sPEM, (UInt32)sPEM.Length, CRYPT_STRING_FLAGS.CRYPT_STRING_BASE64HEADER, null, ref dwBinarySize, out dwSkip, out dwFlags))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
byte[] decodedData = new byte[dwBinarySize];
if (!RSACryptoServiceProviderExtensions.CryptStringToBinary(sPEM, (UInt32)sPEM.Length, CRYPT_STRING_FLAGS.CRYPT_STRING_BASE64HEADER, decodedData, ref dwBinarySize, out dwSkip, out dwFlags))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
return(decodedData);
}
/// <summary>Converts DER binary format to a CAPI CRYPT_PRIVATE_KEY_INFO structure.</summary>
internal static byte[] GetPrivateKeyDER(byte[] DERData)
{
byte[] data = null;
UInt32 dwRSAPrivateKeyBlobSize = 0;
IntPtr pRSAPrivateKeyBlob = IntPtr.Zero;
if (RSACryptoServiceProviderExtensions.CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.PKCS_RSA_PRIVATE_KEY),
DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwRSAPrivateKeyBlobSize))
{
data = new byte[dwRSAPrivateKeyBlobSize];
if (!RSACryptoServiceProviderExtensions.CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.PKCS_RSA_PRIVATE_KEY),
DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwRSAPrivateKeyBlobSize))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
else
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
return(data);
}
/// <summary>Converts DER binary format to a CAPI CERT_PUBLIC_KEY_INFO structure containing an RSA key.</summary>
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 (RSACryptoServiceProviderExtensions.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 (RSACryptoServiceProviderExtensions.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);
}
/// <summary>Returns a public key blob from an RSA public key.</summary>
internal static byte[] GetPublicKeyBlobFromRSA(byte[] RSAData)
{
byte[] data = null;
UInt32 dwCertPublicKeyBlobSize = 0;
if (RSACryptoServiceProviderExtensions.CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING,
new IntPtr((int)CRYPT_OUTPUT_TYPES.RSA_CSP_PUBLICKEYBLOB), RSAData, (UInt32)RSAData.Length, CRYPT_DECODE_FLAGS.NONE,
data, ref dwCertPublicKeyBlobSize))
{
data = new byte[dwCertPublicKeyBlobSize];
if (!RSACryptoServiceProviderExtensions.CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING,
new IntPtr((int)CRYPT_OUTPUT_TYPES.RSA_CSP_PUBLICKEYBLOB), RSAData, (UInt32)RSAData.Length, CRYPT_DECODE_FLAGS.NONE,
data, ref dwCertPublicKeyBlobSize))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
else
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
return(data);
}
/// <summary>Extension method which initializes an RSACryptoServiceProvider from a PEM private key string.</summary>
public static void LoadPrivateKeyPEM(this RSACryptoServiceProvider provider, string sPEM)
{
byte[] DERData = RSACryptoServiceProviderExtensions.GetDERFromPEM(sPEM);
RSACryptoServiceProviderExtensions.LoadPrivateKeyDER(provider, DERData);
}
/// <summary>Extension method which initializes an RSACryptoServiceProvider from a DER private key blob.</summary>
public static void LoadPrivateKeyDER(this RSACryptoServiceProvider provider, byte[] DERData)
{
byte[] privateKeyBlob = RSACryptoServiceProviderExtensions.GetPrivateKeyDER(DERData);
provider.ImportCspBlob(privateKeyBlob);
}
/// <summary>Extension method which initializes an RSACryptoServiceProvider from a DER public key blob.</summary>
public static void LoadPublicKeyDER(this RSACryptoServiceProvider provider, byte[] DERData)
{
byte[] RSAData = RSACryptoServiceProviderExtensions.GetRSAFromDER(DERData);
byte[] publicKeyBlob = RSACryptoServiceProviderExtensions.GetPublicKeyBlobFromRSA(RSAData);
provider.ImportCspBlob(publicKeyBlob);
}
