public static ECDiffieHellmanKey CreatePrivate(
ReadOnlySpan <byte> fingerprint,
ReadOnlySpan <byte> password,
ReadOnlySpan <byte> source,
out int publicKeySize)
{
var ecParameters = ReadOpenPgpECParameters(source, out publicKeySize);
// TODO: Validation
byte kdfSize = source[publicKeySize];
var kdfParameters = source.Slice(publicKeySize + 1, kdfSize).ToArray();
byte[] paramsArray = new byte[source.Length - publicKeySize];
try
{
S2kBasedEncryption.DecryptSecretKey(password, source.Slice(publicKeySize + kdfSize + 1), paramsArray, out int bytesWritten);
Debug.Assert(bytesWritten != 0);
ecParameters.D = MPInteger.ReadInteger(paramsArray, out int dConsumed).ToArray();
return(new ECDiffieHellmanKey(CreateECDiffieHellman(ecParameters), kdfParameters, fingerprint.ToArray()));
}
finally
{
CryptographicOperations.ZeroMemory(paramsArray);
CryptographicOperations.ZeroMemory(ecParameters.D);
}
}
public static DsaKey CreatePrivate(
ReadOnlySpan <byte> password,
ReadOnlySpan <byte> source,
out int publicKeySize)
{
var dsaParameters = ReadOpenPgpPublicKey(source, out publicKeySize);
byte[] xArray = new byte[source.Length - publicKeySize];
try
{
S2kBasedEncryption.DecryptSecretKey(password, source.Slice(publicKeySize), xArray, out int bytesWritten);
dsaParameters.X = MPInteger.ReadInteger(xArray, out int xConsumed).ToArray();
// Make sure Q, X have the same length (DSA implementation on Windows requires it)
int qxLength = Math.Max(dsaParameters.X.Length, dsaParameters.Q !.Length);
ResizeArrayIfNeeded(ref dsaParameters.Q, qxLength);
ResizeArrayIfNeeded(ref dsaParameters.X, qxLength);
return(new DsaKey(DSA.Create(dsaParameters)));
}
finally
{
CryptographicOperations.ZeroMemory(xArray);
CryptographicOperations.ZeroMemory(dsaParameters.X);
}
}
public bool TryDecryptSessionInfo(ReadOnlySpan <byte> encryptedSessionData, Span <byte> sessionData, out int bytesWritten)
{
var pEnc = MPInteger.ReadInteger(encryptedSessionData, out int pointBytesRead);
encryptedSessionData = encryptedSessionData.Slice(pointBytesRead);
int keyLen = encryptedSessionData[0];
var keyEnc = encryptedSessionData.Slice(1, keyLen);
var publicParams = ecdh.PublicKey.ExportParameters();
var publicPoint = DecodePoint(pEnc);
var otherEcdh = CreateECDiffieHellman(new ECParameters {
Curve = publicParams.Curve, Q = publicPoint
});
var derivedKey = ecdh.DeriveKeyFromHash(
otherEcdh.PublicKey,
PgpUtilities.GetHashAlgorithmName(this.hashAlgorithm),
new byte[] { 0, 0, 0, 1 },
CreateUserKeyingMaterial(publicParams.Curve.Oid));
derivedKey = derivedKey.AsSpan(0, PgpUtilities.GetKeySize(this.symmetricAlgorithm) / 8).ToArray();
var C = SymmetricKeyWrap.AESKeyWrapDecrypt(derivedKey, keyEnc.ToArray());
var data = UnpadSessionData(C);
if (sessionData.Length >= data.Length)
{
data.CopyTo(sessionData);
bytesWritten = data.Length;
return(true);
}
bytesWritten = 0;
return(false);
}
public bool VerifySignature(
ReadOnlySpan <byte> rgbHash,
ReadOnlySpan <byte> rgbSignature,
PgpHashAlgorithm hashAlgorithm)
{
var signature = MPInteger.ReadInteger(rgbSignature, out var _);
return(rsa.VerifyHash(rgbHash, signature, PgpUtilities.GetHashAlgorithmName(hashAlgorithm), RSASignaturePadding.Pkcs1));
}
public static RSAParameters ReadOpenPgpPublicKey(ReadOnlySpan <byte> source, out int bytesRead)
{
var rsaParameters = new RSAParameters();
rsaParameters.Modulus = MPInteger.ReadInteger(source, out int modulusConsumed).ToArray();
source = source.Slice(modulusConsumed);
rsaParameters.Exponent = MPInteger.ReadInteger(source, out int exponentConsumed).ToArray();
bytesRead = modulusConsumed + exponentConsumed;
return(rsaParameters);
}
private static ElGamalParameters ReadOpenPgpPublicKey(ReadOnlySpan <byte> source, out int bytesRead)
{
var elgamalParameters = new ElGamalParameters();
elgamalParameters.P = MPInteger.ReadInteger(source, out int pConsumed).ToArray();
source = source.Slice(pConsumed);
elgamalParameters.G = MPInteger.ReadInteger(source, out int gConsumed).ToArray();
source = source.Slice(gConsumed);
elgamalParameters.Y = MPInteger.ReadInteger(source, out int yConsumed).ToArray();
bytesRead = pConsumed + gConsumed + yConsumed;
return(elgamalParameters);
}
public bool TryDecryptSessionInfo(ReadOnlySpan <byte> encryptedSessionData, Span <byte> sessionData, out int bytesWritten)
{
var mp = MPInteger.ReadInteger(encryptedSessionData, out var _);
var data = rsa.Decrypt(mp.ToArray(), RSAEncryptionPadding.Pkcs1);
if (sessionData.Length >= data.Length)
{
data.CopyTo(sessionData);
bytesWritten = data.Length;
return(true);
}
bytesWritten = 0;
return(false);
}
public bool VerifySignature(
ReadOnlySpan <byte> rgbHash,
ReadOnlySpan <byte> rgbSignature,
PgpHashAlgorithm hashAlgorithm)
{
var asnWriter = new AsnWriter(AsnEncodingRules.DER);
using (var scope = asnWriter.PushSequence())
{
asnWriter.WriteIntegerUnsigned(MPInteger.ReadInteger(rgbSignature, out int rConsumed));
asnWriter.WriteIntegerUnsigned(MPInteger.ReadInteger(rgbSignature.Slice(rConsumed), out var _));
}
return(dsa.VerifySignature(rgbHash, asnWriter.Encode(), DSASignatureFormat.Rfc3279DerSequence));
}
public bool TryDecryptSessionInfo(ReadOnlySpan <byte> encryptedSessionData, Span <byte> sessionData, out int bytesWritten)
{
var g = MPInteger.ReadInteger(encryptedSessionData, out var gBytesRead);
var p = MPInteger.ReadInteger(encryptedSessionData.Slice(gBytesRead), out var _);
var halfLength = Math.Max(g.Length, p.Length);
var inputData = new byte[halfLength * 2];
g.CopyTo(inputData.AsSpan(halfLength - g.Length));
p.CopyTo(inputData.AsSpan(inputData.Length - p.Length));
var data = elGamal.Decrypt(inputData, RSAEncryptionPadding.Pkcs1);
if (sessionData.Length >= data.Length)
{
data.CopyTo(sessionData);
bytesWritten = data.Length;
return(true);
}
bytesWritten = 0;
return(false);
}
public new static EdDsaKey CreatePrivate(
ReadOnlySpan <byte> password,
ReadOnlySpan <byte> source,
out int publicKeySize)
{
var ecParameters = ReadOpenPgpECParameters(source, out publicKeySize);
byte[] paramsArray = new byte[source.Length - publicKeySize];
try
{
S2kBasedEncryption.DecryptSecretKey(password, source.Slice(publicKeySize), paramsArray, out int bytesWritten);
Debug.Assert(bytesWritten != 0);
ecParameters.D = MPInteger.ReadInteger(paramsArray, out int dConsumed).ToArray();
return(new EdDsaKey(CreateEdDsa(ecParameters)));
}
finally
{
CryptographicOperations.ZeroMemory(paramsArray);
CryptographicOperations.ZeroMemory(ecParameters.D);
}
}
private static DSAParameters ReadOpenPgpPublicKey(ReadOnlySpan <byte> source, out int bytesRead)
{
var dsaParameters = new DSAParameters();
dsaParameters.P = MPInteger.ReadInteger(source, out int pConsumed).ToArray();
source = source.Slice(pConsumed);
dsaParameters.Q = MPInteger.ReadInteger(source, out int qConsumed).ToArray();
source = source.Slice(qConsumed);
dsaParameters.G = MPInteger.ReadInteger(source, out int gConsumed).ToArray();
source = source.Slice(gConsumed);
dsaParameters.Y = MPInteger.ReadInteger(source, out int yConsumed).ToArray();
bytesRead = pConsumed + qConsumed + gConsumed + yConsumed;
// Make sure P, G, Y have the same length (DSA implementation on Windows requires it)
int pgyLength = Math.Max(Math.Max(dsaParameters.P !.Length, dsaParameters.G !.Length), dsaParameters.Y !.Length);
ResizeArrayIfNeeded(ref dsaParameters.P, pgyLength);
ResizeArrayIfNeeded(ref dsaParameters.G, pgyLength);
ResizeArrayIfNeeded(ref dsaParameters.Y, pgyLength);
return(dsaParameters);
}
public static ElGamalKey CreatePrivate(
ReadOnlySpan <byte> password,
ReadOnlySpan <byte> source,
out int bytesRead)
{
var elgamalParameters = ReadOpenPgpPublicKey(source, out bytesRead);
byte[] xArray = new byte[source.Length - bytesRead];
try
{
S2kBasedEncryption.DecryptSecretKey(password, source.Slice(bytesRead), xArray, out int bytesWritten);
elgamalParameters.X = MPInteger.ReadInteger(xArray, out int xConsumed).ToArray();
bytesRead = source.Length;
return(new ElGamalKey(ElGamal.Create(elgamalParameters)));
}
finally
{
CryptographicOperations.ZeroMemory(xArray);
CryptographicOperations.ZeroMemory(elgamalParameters.X);
}
}
protected static ECParameters ReadOpenPgpECParameters(ReadOnlySpan <byte> source, out int bytesRead)
{
ECParameters ecParameters = new ECParameters();
int oidLength = source[0];
// TODO: Validate oidLength
var oidBytes = new byte[oidLength + 2];
oidBytes[0] = 6;
oidBytes[1] = (byte)oidLength;
source.Slice(1, oidLength).CopyTo(oidBytes.AsSpan(2));
var oid = new Oid(AsnDecoder.ReadObjectIdentifier(oidBytes, AsnEncodingRules.DER, out _));
ecParameters.Curve = ECCurve.CreateFromOid(oid);
var pointBytes = MPInteger.ReadInteger(source.Slice(oidLength + 1), out bytesRead);
bytesRead += oidLength + 1;
ecParameters.Q = DecodePoint(pointBytes);
return(ecParameters);
}
public static RsaKey CreatePrivate(
ReadOnlySpan <byte> password,
ReadOnlySpan <byte> source,
out int publicKeyBytes,
int version = 4)
{
var rsaParameters = ReadOpenPgpPublicKey(source, out publicKeyBytes);
byte[] paramsArray = new byte[source.Length - publicKeyBytes];
try
{
S2kBasedEncryption.DecryptSecretKey(password, source.Slice(publicKeyBytes), paramsArray, out int bytesWritten, version);
Debug.Assert(bytesWritten != 0);
int halfModulusLength = (rsaParameters.Modulus !.Length + 1) / 2;
rsaParameters.D = new byte[rsaParameters.Modulus.Length];
rsaParameters.P = new byte[halfModulusLength];
rsaParameters.Q = new byte[halfModulusLength];
rsaParameters.DP = new byte[halfModulusLength];
rsaParameters.DQ = new byte[halfModulusLength];
rsaParameters.InverseQ = new byte[halfModulusLength];
var privateSource = new ReadOnlySpan <byte>(paramsArray);
var d = MPInteger.ReadInteger(privateSource, out int dConsumed);
privateSource = privateSource.Slice(dConsumed);
var p = MPInteger.ReadInteger(privateSource, out int pConsumed);
privateSource = privateSource.Slice(pConsumed);
var q = MPInteger.ReadInteger(privateSource, out int qConsumed);
//source = source.Slice(qConsumed);
// Technically InverseQ follows but it's often incorrect
// FIXME: These BigIntegers cannot be cleared from memory
var D = new BigInteger(d, isBigEndian: true, isUnsigned: true);
var P = new BigInteger(p, isBigEndian: true, isUnsigned: true);
var Q = new BigInteger(q, isBigEndian: true, isUnsigned: true);
var DP = BigInteger.Remainder(D, P - BigInteger.One);
var DQ = BigInteger.Remainder(D, Q - BigInteger.One);
// Lot of the public keys in the test suite have this wrong (switched P/Q)
var InverseQ = BigInteger.ModPow(Q, P - BigInteger.One - BigInteger.One, P);
d.CopyTo(rsaParameters.D.AsSpan(rsaParameters.D.Length - d.Length));
p.CopyTo(rsaParameters.P.AsSpan(rsaParameters.P.Length - p.Length));
q.CopyTo(rsaParameters.Q.AsSpan(rsaParameters.Q.Length - q.Length));
DP.TryWriteBytes(rsaParameters.DP.AsSpan(rsaParameters.DP.Length - DP.GetByteCount(isUnsigned: true)), out var _, isBigEndian: true, isUnsigned: true);
DQ.TryWriteBytes(rsaParameters.DQ.AsSpan(rsaParameters.DQ.Length - DQ.GetByteCount(isUnsigned: true)), out var _, isBigEndian: true, isUnsigned: true);
InverseQ.TryWriteBytes(rsaParameters.InverseQ.AsSpan(rsaParameters.InverseQ.Length - InverseQ.GetByteCount(isUnsigned: true)), out var _, isBigEndian: true, isUnsigned: true);
return(new RsaKey(RSA.Create(rsaParameters)));
}
finally
{
CryptographicOperations.ZeroMemory(paramsArray);
CryptographicOperations.ZeroMemory(rsaParameters.D);
CryptographicOperations.ZeroMemory(rsaParameters.P);
CryptographicOperations.ZeroMemory(rsaParameters.Q);
CryptographicOperations.ZeroMemory(rsaParameters.DP);
CryptographicOperations.ZeroMemory(rsaParameters.DQ);
CryptographicOperations.ZeroMemory(rsaParameters.InverseQ);
}
}
public static void EncryptSecretKey(
ReadOnlySpan <byte> password,
S2kParameters s2kParameters,
ReadOnlySpan <byte> source,
Span <byte> destination,
int version = 4)
{
if (password.Length == 0)
{
destination[0] = (byte)S2kUsageTag.None;
source.CopyTo(destination.Slice(1));
return;
}
using var c = PgpUtilities.GetSymmetricAlgorithm(s2kParameters.EncryptionAlgorithm);
int keySizeInBytes = (c.KeySize + 7) / 8;
Span <byte> keyBytes = stackalloc byte[keySizeInBytes];
if (version <= 3)
{
MakeKey(password, PgpHashAlgorithm.MD5, Array.Empty <byte>(), 0, keyBytes);
destination[0] = (byte)s2kParameters.EncryptionAlgorithm;
c.GenerateIV();
c.IV.CopyTo(destination.Slice(1));
int bytesWritten = 13 + ((c.BlockSize + 7) / 8);
destination = destination.Slice(bytesWritten);
c.Key = keyBytes.ToArray();
int checksum = 0;
foreach (var b in source)
{
checksum += b;
}
for (int i = 0; i < 4; i++)
{
using var encryptor = new ZeroPaddedCryptoTransform(c.CreateEncryptor());
destination[0] = source[0];
destination[1] = source[1];
var mpInteger = MPInteger.ReadInteger(source, out int bytesConsumed).ToArray();
source = source.Slice(bytesConsumed);
var data = encryptor.TransformFinalBlock(mpInteger, 0, mpInteger.Length);
data.AsSpan().CopyTo(destination.Slice(2));
destination = destination.Slice(2 + data.Length);
CryptographicOperations.ZeroMemory(mpInteger);
if (i != 4)
{
c.IV = data.AsSpan(data.Length - (c.BlockSize / 8)).ToArray();
}
}
destination[0] = (byte)(checksum >> 8);
destination[1] = (byte)(checksum);
}
else
{
var salt = new byte[8];
RandomNumberGenerator.Fill(salt);
byte rawIterationCount = 0x60;
int iterationCount = (16 + (rawIterationCount & 15)) << ((rawIterationCount >> 4) + 6);
MakeKey(password, s2kParameters.HashAlgorithm, salt, iterationCount, keyBytes);
destination[0] = (byte)s2kParameters.UsageTag;
destination[1] = (byte)s2kParameters.EncryptionAlgorithm;
destination[2] = 3; // Salted & iterated
destination[3] = (byte)s2kParameters.HashAlgorithm;
salt.CopyTo(destination.Slice(4));
destination[12] = rawIterationCount;
c.GenerateIV();
c.IV.CopyTo(destination.Slice(13));
int bytesWritten = 13 + ((c.BlockSize + 7) / 8);
destination = destination.Slice(bytesWritten);
c.Key = keyBytes.ToArray();
using var encryptor = new ZeroPaddedCryptoTransform(c.CreateEncryptor());
byte[] checksumBytes;
if (s2kParameters.UsageTag == S2kUsageTag.Sha1)
{
using var sha1 = IncrementalHash.CreateHash(HashAlgorithmName.SHA1);
sha1.AppendData(source);
checksumBytes = sha1.GetHashAndReset();
}
else
{
int checksum = 0;
foreach (var b in source)
{
checksum += b;
}
checksumBytes = new byte[] { (byte)(checksum >> 8), (byte)checksum };
}
var decSource = new byte[source.Length + checksumBytes.Length];
source.CopyTo(decSource);
checksumBytes.CopyTo(decSource, source.Length);
var data = encryptor.TransformFinalBlock(decSource, 0, decSource.Length);
data.AsSpan().CopyTo(destination);
CryptographicOperations.ZeroMemory(data);
CryptographicOperations.ZeroMemory(decSource);
}
}
