public RSAParameters ParseRSAPrivateKey()
{
RSAParameters parameters = new RSAParameters();
// Current value
byte[] value = null;
// Checkpoint
int position = _parser.CurrentPosition();
// Sanity Check
int length = 0;
// Ignore Sequence - PrivateKeyInfo
length = _parser.NextSequence();
if (length != _parser.RemainingBytes())
{
StringBuilder sb = new StringBuilder("Incorrect Sequence Size. ");
sb.AppendFormat("Specified: {0}, Remaining: {1}",
length.ToString(CultureInfo.InvariantCulture), _parser.RemainingBytes().ToString(CultureInfo.InvariantCulture));
throw new BerDecodeException(sb.ToString(), position);
}
// Checkpoint
position = _parser.CurrentPosition();
// Version
value = _parser.NextInteger();
if (0x00 != value[0])
{
StringBuilder sb = new StringBuilder("Incorrect PrivateKeyInfo Version. ");
BigInteger v = new BigInteger(value);
sb.AppendFormat("Expected: 0, Specified: {0}", v.ToString(10));
throw new BerDecodeException(sb.ToString(), position);
}
// Checkpoint
position = _parser.CurrentPosition();
// Ignore Sequence - AlgorithmIdentifier
length = _parser.NextSequence();
if (length > _parser.RemainingBytes())
{
StringBuilder sb = new StringBuilder("Incorrect AlgorithmIdentifier Size. ");
sb.AppendFormat("Specified: {0}, Remaining: {1}",
length.ToString(CultureInfo.InvariantCulture),
_parser.RemainingBytes().ToString(CultureInfo.InvariantCulture));
throw new BerDecodeException(sb.ToString(), position);
}
// Checkpoint
position = _parser.CurrentPosition();
// Grab the OID
value = _parser.NextOID();
byte[] oid = { 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01 };
if (!EqualOid(value, oid))
{
throw new BerDecodeException("Expected OID 1.2.840.113549.1.1.1", position);
}
// Optional Parameters
if (_parser.IsNextNull())
{
_parser.NextNull();
// Also OK: value = parser.Next();
}
else
{
// Gracefully skip the optional data
value = _parser.Next();
}
// Checkpoint
position = _parser.CurrentPosition();
// Ignore OctetString - PrivateKey
length = _parser.NextOctetString();
if (length > _parser.RemainingBytes())
{
StringBuilder sb = new StringBuilder("Incorrect PrivateKey Size. ");
sb.AppendFormat("Specified: {0}, Remaining: {1}",
length.ToString(CultureInfo.InvariantCulture),
_parser.RemainingBytes().ToString(CultureInfo.InvariantCulture));
throw new BerDecodeException(sb.ToString(), position);
}
// Checkpoint
position = _parser.CurrentPosition();
// Ignore Sequence - RSAPrivateKey
length = _parser.NextSequence();
if (length < _parser.RemainingBytes())
{
StringBuilder sb = new StringBuilder("Incorrect RSAPrivateKey Size. ");
sb.AppendFormat("Specified: {0}, Remaining: {1}",
length.ToString(CultureInfo.InvariantCulture),
_parser.RemainingBytes().ToString(CultureInfo.InvariantCulture));
throw new BerDecodeException(sb.ToString(), position);
}
// Checkpoint
position = _parser.CurrentPosition();
// Version
value = _parser.NextInteger();
if (0x00 != value[0])
{
StringBuilder sb = new StringBuilder("Incorrect RSAPrivateKey Version. ");
BigInteger v = new BigInteger(value);
sb.AppendFormat("Expected: 0, Specified: {0}", v.ToString(10));
throw new BerDecodeException(sb.ToString(), position);
}
parameters.Modulus = TrimLeadingZero(_parser.NextInteger());
parameters.Exponent = TrimLeadingZero(_parser.NextInteger());
parameters.D = TrimLeadingZero(_parser.NextInteger());
parameters.P = TrimLeadingZero(_parser.NextInteger());
parameters.Q = TrimLeadingZero(_parser.NextInteger());
parameters.DP = TrimLeadingZero(_parser.NextInteger());
parameters.DQ = TrimLeadingZero(_parser.NextInteger());
parameters.InverseQ = TrimLeadingZero(_parser.NextInteger());
Debug.Assert(0 == _parser.RemainingBytes());
return(parameters);
}
