public override RSAParameters ExportParameters(bool includePrivateParameters)
{
SecKeyPair keys = GetKeys();
SafeSecKeyRefHandle keyHandle = includePrivateParameters ? keys.PrivateKey : keys.PublicKey;
if (keyHandle == null)
{
throw new CryptographicException(SR.Cryptography_OpenInvalidHandle);
}
DerSequenceReader keyReader = Interop.AppleCrypto.SecKeyExport(keyHandle, includePrivateParameters);
RSAParameters parameters = new RSAParameters();
if (includePrivateParameters)
{
keyReader.ReadPkcs8Blob(ref parameters);
}
else
{
// When exporting a key handle opened from a certificate, it seems to
// export as a PKCS#1 blob instead of an X509 SubjectPublicKeyInfo blob.
// So, check for that.
if (keyReader.PeekTag() == (byte)DerSequenceReader.DerTag.Integer)
{
keyReader.ReadPkcs1PublicBlob(ref parameters);
}
else
{
keyReader.ReadSubjectPublicKeyInfo(ref parameters);
}
}
return(parameters);
}
internal static void ReadSubjectPublicKeyInfo(this DerSequenceReader keyInfo, ref RSAParameters parameters)
{
// SubjectPublicKeyInfo::= SEQUENCE {
// algorithm AlgorithmIdentifier,
// subjectPublicKey BIT STRING }
DerSequenceReader algorithm = keyInfo.ReadSequence();
string algorithmOid = algorithm.ReadOidAsString();
if (algorithmOid != RsaOid)
{
throw new CryptographicException();
}
byte[] subjectPublicKeyBytes = keyInfo.ReadBitString();
DerSequenceReader subjectPublicKey = new DerSequenceReader(subjectPublicKeyBytes);
subjectPublicKey.ReadPkcs1PublicBlob(ref parameters);
}
