/// <summary>
/// Read private key parameters.
/// </summary>
/// <param name="passphrase">passphrase for decrypt the key file</param>
/// <param name="keyPair">key pair</param>
/// <param name="comment">comment or empty if it didn't exist</param>
public void Load(string passphrase, out KeyPair keyPair, out string comment)
{
PEMKeyType keyType;
String base64Text;
bool encrypted = false;
CipherAlgorithm? encryption = null;
byte[] iv = null;
int keySize = 0;
int ivSize = 0;
using (StreamReader sreader = GetStreamReader()) {
string line = sreader.ReadLine();
if (line == null)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected eof)");
if (line == PrivateKeyFileHeader.SSH2_OPENSSH_HEADER_RSA)
keyType = PEMKeyType.RSA;
else if (line == PrivateKeyFileHeader.SSH2_OPENSSH_HEADER_DSA)
keyType = PEMKeyType.DSA;
else if (line == PrivateKeyFileHeader.SSH2_OPENSSH_HEADER_ECDSA)
keyType = PEMKeyType.ECDSA;
else
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected key type)");
string footer = line.Replace("BEGIN", "END");
StringBuilder buf = new StringBuilder();
comment = String.Empty;
while (true) {
line = sreader.ReadLine();
if (line == null)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected eof)");
if (line == footer)
break;
if (line.IndexOf(':') >= 0) {
if (line.StartsWith("Proc-Type:")) {
string[] w = line.Substring("Proc-Type:".Length).Trim().Split(',');
if (w.Length < 1)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid Proc-Type)");
if (w[0] != "4")
throw new SSHException(Strings.GetString("UnsupportedPrivateKeyFormat")
+ " (" + Strings.GetString("Reason_UnsupportedProcType") + ")");
if (w.Length >= 2 && w[1] == "ENCRYPTED")
encrypted = true;
}
else if (line.StartsWith("DEK-Info:")) {
string[] w = line.Substring("DEK-Info:".Length).Trim().Split(',');
if (w.Length < 2)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid DEK-Info)");
switch (w[0]) {
case "DES-EDE3-CBC":
encryption = CipherAlgorithm.TripleDES;
ivSize = 8;
keySize = 24;
break;
case "AES-128-CBC":
encryption = CipherAlgorithm.AES128;
ivSize = 16;
keySize = 16;
break;
default:
throw new SSHException(Strings.GetString("UnsupportedPrivateKeyFormat")
+ " (" + Strings.GetString("Reason_UnsupportedEncryptionType") + ")");
}
iv = HexToByteArray(w[1]);
if (iv == null || iv.Length != ivSize)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid IV)");
}
}
else
buf.Append(line);
}
base64Text = buf.ToString();
}
byte[] keydata = Base64.Decode(Encoding.ASCII.GetBytes(base64Text));
if (encrypted) {
if (!encryption.HasValue || iv == null)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (missing encryption type or IV)");
byte[] key = PassphraseToKey(passphrase, iv, keySize);
Cipher cipher = CipherFactory.CreateCipher(SSHProtocol.SSH2, encryption.Value, key, iv);
if (keydata.Length % cipher.BlockSize != 0)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid key data size)");
cipher.Decrypt(keydata, 0, keydata.Length, keydata, 0);
}
using (MemoryStream keyDataStream = new MemoryStream(keydata, false)) {
BERReader reader = new BERReader(keyDataStream);
if (!reader.ReadSequence())
throw new SSHException(Strings.GetString("WrongPassphrase"));
if (keyType == PEMKeyType.RSA) {
/* from OpenSSL rsa_asn1.c
*
* ASN1_SIMPLE(RSA, version, LONG),
* ASN1_SIMPLE(RSA, n, BIGNUM),
* ASN1_SIMPLE(RSA, e, BIGNUM),
* ASN1_SIMPLE(RSA, d, BIGNUM),
* ASN1_SIMPLE(RSA, p, BIGNUM),
* ASN1_SIMPLE(RSA, q, BIGNUM),
* ASN1_SIMPLE(RSA, dmp1, BIGNUM),
* ASN1_SIMPLE(RSA, dmq1, BIGNUM),
* ASN1_SIMPLE(RSA, iqmp, BIGNUM)
*/
BigInteger v, n, e, d, p, q, dmp1, dmq1, iqmp;
if (!reader.ReadInteger(out v) ||
!reader.ReadInteger(out n) ||
!reader.ReadInteger(out e) ||
!reader.ReadInteger(out d) ||
!reader.ReadInteger(out p) ||
!reader.ReadInteger(out q) ||
!reader.ReadInteger(out dmp1) ||
!reader.ReadInteger(out dmq1) ||
!reader.ReadInteger(out iqmp)) {
throw new SSHException(Strings.GetString("WrongPassphrase"));
}
BigInteger u = p.ModInverse(q); // inverse of p mod q
keyPair = new RSAKeyPair(e, d, n, u, p, q);
}
else if (keyType == PEMKeyType.DSA) {
/* from OpenSSL dsa_asn1.c
*
* ASN1_SIMPLE(DSA, version, LONG),
* ASN1_SIMPLE(DSA, p, BIGNUM),
* ASN1_SIMPLE(DSA, q, BIGNUM),
* ASN1_SIMPLE(DSA, g, BIGNUM),
* ASN1_SIMPLE(DSA, pub_key, BIGNUM),
* ASN1_SIMPLE(DSA, priv_key, BIGNUM)
*/
BigInteger v, p, q, g, y, x;
if (!reader.ReadInteger(out v) ||
!reader.ReadInteger(out p) ||
!reader.ReadInteger(out q) ||
!reader.ReadInteger(out g) ||
!reader.ReadInteger(out y) ||
!reader.ReadInteger(out x)) {
throw new SSHException(Strings.GetString("WrongPassphrase"));
}
keyPair = new DSAKeyPair(p, g, q, y, x);
}
else if (keyType == PEMKeyType.ECDSA) {
/* from OpenSSL ec_asn1.c
*
* ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
* ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
* ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
* ------
* ASN1_SIMPLE(ECPKPARAMETERS, value.named_curve, ASN1_OBJECT),
* ------
* ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
*/
int len;
byte[] privateKey;
byte[] publicKey;
string namedCurve;
BigInteger v;
if (!reader.ReadInteger(out v) ||
!reader.ReadOctetString(out privateKey) ||
!reader.ReadTag(BERReader.TagClass.ContextSpecific, true, 0, out len) ||
!reader.ReadObjectIdentifier(out namedCurve) ||
!reader.ReadTag(BERReader.TagClass.ContextSpecific, true, 1, out len) ||
!reader.ReadBitString(out publicKey)) {
throw new SSHException(Strings.GetString("WrongPassphrase"));
}
EllipticCurve curve = EllipticCurve.FindByOID(namedCurve);
if (curve == null) {
throw new SSHException(Strings.GetString("UnsupportedEllipticCurveInKeyPair"));
}
ECPoint ecPublicKeyPoint;
if (!ECPoint.Parse(publicKey, curve, out ecPublicKeyPoint)) {
throw new SSHException(Strings.GetString("KeysAreBroken"));
}
var ecKeyPair = new ECDSAKeyPair(curve, new ECDSAPublicKey(curve, ecPublicKeyPoint), new BigInteger(privateKey));
if (!ecKeyPair.CheckKeyConsistency()) {
throw new SSHException(Strings.GetString("KeysAreBroken"));
}
keyPair = ecKeyPair;
}
else {
throw new SSHException("Unknown file type. This should not happen.");
}
}
}
// Tests key pair validation using test vectors from NIST CAVP.
// http://csrc.nist.gov/groups/STM/cavp/digital-signatures.html
internal static void TestKeyPair() {
using (var reader = new System.IO.StreamReader(@"186-3ecdsatestvectors\KeyPair.rsp")) {
EllipticCurve curve = null;
string ds = null;
BigInteger d = null;
BigInteger qx = null;
BigInteger qy = null;
int testCount = 0;
while (true) {
string line = reader.ReadLine();
if (line == null) {
break;
}
var match = System.Text.RegularExpressions.Regex.Match(line, @"\[([-\w]+)\]");
if (match.Success) {
string curveName = "nist" + match.Groups[1].Value.ToLowerInvariant().Replace("-", "");
curve = FindByName(curveName);
if (curve != null) {
Debug.WriteLine("Test " + curve.CurveName);
}
d = qx = qy = null;
ds = null;
testCount = 0;
continue;
}
if (line.StartsWith("d = ") && curve != null) {
ds = line.Substring(4).Trim();
d = new BigInteger(BigIntegerConverter.ParseHex(ds));
continue;
}
if (line.StartsWith("Qx = ") && curve != null) {
qx = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(5).Trim()));
continue;
}
if (line.StartsWith("Qy = ") && curve != null) {
qy = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(5).Trim()));
if (d != null && qx != null) {
var pk = new ECDSAPublicKey(curve, new ECPoint(qx, qy));
var kp = new ECDSAKeyPair(curve, pk, d);
if (!kp.CheckKeyConsistency()) {
throw new Exception("validation failed");
}
++testCount;
Debug.WriteLine("Pass #{0} : {1}", testCount, ds);
}
d = qx = qy = null;
ds = null;
}
}
}
}
