Partial support for importing EC keys

3 files changed, 167 insertions, 6 deletions

diff --git a/lib/src/main/java/com/trilead/ssh2/crypto/PEMDecoder.java b/lib/src/main/java/com/trilead/ssh2/crypto/PEMDecoder.java
index bb14464..430307e 100644
--- a/lib/src/main/java/com/trilead/ssh2/crypto/PEMDecoder.java
+++ b/lib/src/main/java/com/trilead/ssh2/crypto/PEMDecoder.java
@@ -14,6 +14,10 @@ import java.security.PrivateKey;
 import java.security.PublicKey;
 import java.security.spec.DSAPrivateKeySpec;
 import java.security.spec.DSAPublicKeySpec;
+import java.security.spec.ECParameterSpec;
+import java.security.spec.ECPoint;
+import java.security.spec.ECPrivateKeySpec;
+import java.security.spec.ECPublicKeySpec;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.RSAPrivateCrtKeySpec;
 import java.security.spec.RSAPrivateKeySpec;
@@ -24,6 +28,7 @@ import com.trilead.ssh2.crypto.cipher.BlockCipher;
 import com.trilead.ssh2.crypto.cipher.CBCMode;
 import com.trilead.ssh2.crypto.cipher.DES;
 import com.trilead.ssh2.crypto.cipher.DESede;
+import com.trilead.ssh2.signature.ECDSASHA2Verify;
 
 /**
  * PEM Support.
@@ -35,6 +40,7 @@ public class PEMDecoder
 {
 	public static final int PEM_RSA_PRIVATE_KEY = 1;
 	public static final int PEM_DSA_PRIVATE_KEY = 2;
+	public static final int PEM_EC_PRIVATE_KEY = 3;
 
 	private static final int hexToInt(char c)
 	{
@@ -173,6 +179,12 @@ public class PEMDecoder
 				ps.pemType = PEM_RSA_PRIVATE_KEY;
 				break;
 			}
+
+			if (line.startsWith("-----BEGIN EC PRIVATE KEY-----")) {
+				endLine = "-----END EC PRIVATE KEY-----";
+				ps.pemType = PEM_EC_PRIVATE_KEY;
+				break;
+			}
 		}
 
 		while (true)
@@ -420,9 +432,72 @@ public class PEMDecoder
 			PublicKey pubKey;
 			PrivateKey privKey;
 			try {
-			KeyFactory kf = KeyFactory.getInstance("RSA");
-			pubKey = kf.generatePublic(pubSpec);
-			privKey = kf.generatePrivate(privSpec);
+				KeyFactory kf = KeyFactory.getInstance("RSA");
+				pubKey = kf.generatePublic(pubSpec);
+				privKey = kf.generatePrivate(privSpec);
+			} catch (NoSuchAlgorithmException ex) {
+				IOException ioex = new IOException();
+				ioex.initCause(ex);
+				throw ioex;
+			} catch (InvalidKeySpecException ex) {
+				IOException ioex = new IOException("invalid keyspec");
+				ioex.initCause(ex);
+				throw ioex;
+			}
+
+			return new KeyPair(pubKey, privKey);
+		}
+
+		if (ps.pemType == PEM_EC_PRIVATE_KEY) {
+			SimpleDERReader dr = new SimpleDERReader(ps.data);
+
+			byte[] seq = dr.readSequenceAsByteArray();
+
+			if (dr.available() != 0)
+				throw new IOException("Padding in EC PRIVATE KEY DER stream.");
+
+			dr.resetInput(seq);
+
+			BigInteger version = dr.readInt();
+
+			if ((version.compareTo(BigInteger.ONE) != 0))
+				throw new IOException("Wrong version (" + version + ") in EC PRIVATE KEY DER stream.");
+
+			byte[] privateBytes = dr.readOctetString();
+
+			String curveOid = null;
+			byte[] publicBytes = null;
+			while (dr.available() > 0) {
+				int type = dr.readConstructedType();
+				SimpleDERReader cr = dr.readConstructed();
+				switch (type) {
+				case 0:
+					curveOid = cr.readOid();
+					break;
+				case 1:
+					publicBytes = cr.readOctetString();
+					break;
+				}
+			}
+
+			ECParameterSpec params = ECDSASHA2Verify.getCurveForOID(curveOid);
+			if (params == null)
+				throw new IOException("invalid OID");
+
+			BigInteger s = new BigInteger(privateBytes);
+			byte[] publicBytesSlice = new byte[publicBytes.length - 1];
+			System.arraycopy(publicBytes, 1, publicBytesSlice, 0, publicBytesSlice.length);
+			ECPoint w = ECDSASHA2Verify.decodeECPoint(publicBytesSlice, params.getCurve());
+
+			ECPrivateKeySpec privSpec = new ECPrivateKeySpec(s, params);
+			ECPublicKeySpec pubSpec = new ECPublicKeySpec(w, params);
+
+			PublicKey pubKey;
+			PrivateKey privKey;
+			try {
+				KeyFactory kf = KeyFactory.getInstance("EC");
+				pubKey = kf.generatePublic(pubSpec);
+				privKey = kf.generatePrivate(privSpec);
 			} catch (NoSuchAlgorithmException ex) {
 				IOException ioex = new IOException();
 				ioex.initCause(ex);
diff --git a/lib/src/main/java/com/trilead/ssh2/crypto/SimpleDERReader.java b/lib/src/main/java/com/trilead/ssh2/crypto/SimpleDERReader.java
index 9f626ad..ff8112a 100644
--- a/lib/src/main/java/com/trilead/ssh2/crypto/SimpleDERReader.java
+++ b/lib/src/main/java/com/trilead/ssh2/crypto/SimpleDERReader.java
@@ -12,6 +12,8 @@ import java.math.BigInteger;
  */
 public class SimpleDERReader
 {
+	private static final int CONSTRUCTED = 0x20;
+
 	byte[] buffer;
 	int pos;
 	int count;
@@ -123,6 +125,30 @@ public class SimpleDERReader
 		return bi;
 	}
 
+	public int readConstructedType() throws IOException {
+		int type = readByte() & 0xff;
+
+		if ((type & CONSTRUCTED) != CONSTRUCTED)
+			throw new IOException("Expected constructed type, but was " + type);
+
+		return type & 0x1f;
+	}
+
+	public SimpleDERReader readConstructed() throws IOException
+	{
+		int len = readLength();
+
+		if ((len < 0) || len > available())
+			throw new IOException("Illegal len in DER object (" + len  + ")");
+
+		SimpleDERReader cr = new SimpleDERReader(buffer, pos, len);
+
+		pos += len;
+		count -= len;
+
+		return cr;
+	}
+
 	public byte[] readSequenceAsByteArray() throws IOException
 	{
 		int type = readByte() & 0xff;
@@ -139,12 +165,55 @@ public class SimpleDERReader
 
 		return b;
 	}
-	
+
+	public String readOid() throws IOException
+	{
+		int type = readByte() & 0xff;
+
+		if (type != 0x06)
+		   throw new IOException("Expected DER OID, but found type " + type);
+
+		int len = readLength();
+
+		if ((len < 1) || len > available())
+			throw new IOException("Illegal len in DER object (" + len  + ")");
+
+		byte[] b = readBytes(len);
+
+		long value = 0;
+
+		StringBuilder sb = new StringBuilder(64);
+		switch(b[0] / 40) {
+		case 0:
+			sb.append('0');
+			break;
+		case 1:
+			sb.append('1');
+			b[0] -= 40;
+			break;
+		default:
+			sb.append('2');
+			b[0] -= 80;
+			break;
+		}
+
+		for (int i = 0; i < len; i++) {
+			value = (value << 7) + (b[i] & 0x7F);
+			if ((b[i] & 0x80) == 0) {
+				sb.append('.');
+				sb.append(value);
+				value = 0;
+			}
+		}
+
+		return sb.toString();
+	}
+
 	public byte[] readOctetString() throws IOException
 	{
 		int type = readByte() & 0xff;
-		
-		if (type != 0x04)
+
+		if (type != 0x04 && type != 0x03)
 			throw new IOException("Expected DER Octetstring, but found type " + type);
 		
 		int len = readLength();
diff --git a/lib/src/main/java/com/trilead/ssh2/signature/ECDSASHA2Verify.java b/lib/src/main/java/com/trilead/ssh2/signature/ECDSASHA2Verify.java
index 7b4f6af..49028e6 100644
--- a/lib/src/main/java/com/trilead/ssh2/signature/ECDSASHA2Verify.java
+++ b/lib/src/main/java/com/trilead/ssh2/signature/ECDSASHA2Verify.java
@@ -38,8 +38,11 @@ public class ECDSASHA2Verify {
 	public static final String ECDSA_SHA2_PREFIX = "ecdsa-sha2-";
 
 	private static final String NISTP256 = "nistp256";
+	private static final String NISTP256_OID = "1.2.840.10045.3.1.7";
 	private static final String NISTP384 = "nistp384";
+	private static final String NISTP384_OID = "1.3.132.0.34";
 	private static final String NISTP521 = "nistp521";
+	private static final String NISTP521_OID = "1.3.132.0.35";
 
 	private static final Map<String, ECParameterSpec> CURVES = new TreeMap<String, ECParameterSpec>();
 	static {
@@ -55,6 +58,13 @@ public class ECDSASHA2Verify {
 		CURVE_SIZES.put(521, NISTP521);
 	}
 
+	private static final Map<String, String> CURVE_OIDS = new TreeMap<String, String>();
+	static {
+		CURVE_OIDS.put(NISTP256_OID, NISTP256);
+		CURVE_OIDS.put(NISTP384_OID, NISTP256);
+		CURVE_OIDS.put(NISTP521_OID, NISTP256);
+	}
+
 	public static int[] getCurveSizes() {
 		int[] keys = new int[CURVE_SIZES.size()];
 		int i = 0;
@@ -156,6 +166,13 @@ public class ECDSASHA2Verify {
 		return params.getCurve().getField().getFieldSize();
 	}
 
+	public static ECParameterSpec getCurveForOID(String oid) {
+		String name = CURVE_OIDS.get(oid);
+		if (name == null)
+			return null;
+		return CURVES.get(name);
+	}
+
 	public static byte[] decodeSSHECDSASignature(byte[] sig) throws IOException {
 		byte[] rsArray = null;