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DSAEngine: minor cleanup

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ElG KeyFactory: Use getParameters() instead of getParams()
to get the correct class back
SigUtil:
  Use split() in sigBytesToASN1();
  new public ASN1 methods
  Javadoc, args checking
This commit is contained in:
zzz
2016-01-24 13:28:03 +00:00
parent c9063f9d9b
commit 403044fc6c
3 changed files with 64 additions and 28 deletions
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5
core/java/src/net/i2p/crypto/DSAEngine.java
View File

@ -234,7 +234,7 @@ public class DSAEngine {
BigInteger s = new NativeBigInteger(1, sbytes);
BigInteger r = new NativeBigInteger(1, rbytes);
BigInteger y = new NativeBigInteger(1, verifyingKey.getData());
BigInteger w = null;
BigInteger w;
try {
w = s.modInverse(CryptoConstants.dsaq);
} catch (ArithmeticException ae) {
@ -402,8 +402,7 @@ public class DSAEngine {
long start = _context.clock().now();
BigInteger k;
boolean ok = false;
boolean ok;
do {
k = new BigInteger(160, _context.random());
ok = k.compareTo(CryptoConstants.dsaq) != 1;

67
core/java/src/net/i2p/crypto/SigUtil.java
View File

@ -549,9 +549,13 @@ public class SigUtil {
/**
* Split a byte array into two BigIntegers
* @param b length must be even
* @return array of two BigIntegers
* @since 0.9.9
*/
private static BigInteger[] split(byte[] b) {
private static NativeBigInteger[] split(byte[] b) {
if ((b.length & 0x01) != 0)
throw new IllegalArgumentException("length must be even");
int sublen = b.length / 2;
byte[] bx = new byte[sublen];
byte[] by = new byte[sublen];
@ -565,9 +569,12 @@ public class SigUtil {
/**
* Combine two BigIntegers of nominal length = len / 2
* @return array of exactly len bytes
* @since 0.9.9
*/
private static byte[] combine(BigInteger x, BigInteger y, int len)
throws InvalidKeyException {
if ((len & 0x01) != 0)
throw new InvalidKeyException("length must be even");
int sublen = len / 2;
byte[] b = new byte[len];
byte[] bx = rectify(x, sublen);
@ -609,7 +616,8 @@ public class SigUtil {
/**
* http://download.oracle.com/javase/1.5.0/docs/guide/security/CryptoSpec.html
* Signature Format ASN.1 sequence of two INTEGER values: r and s, in that order:
*<pre>
* Signature Format: ASN.1 sequence of two INTEGER values: r and s, in that order:
* SEQUENCE ::= { r INTEGER, s INTEGER }
*
* http://en.wikipedia.org/wiki/Abstract_Syntax_Notation_One
@ -619,6 +627,7 @@ public class SigUtil {
* 02 -- tag indicating INTEGER
* xx - length in octets
* xxxxxx - value
*</pre>
*
* Convert to BigInteger and back so we have the minimum length representation, as required.
* r and s are always non-negative.
@ -626,22 +635,43 @@ public class SigUtil {
* Only supports sigs up to about 252 bytes. See code to fix BER encoding for this before you
* add a SigType with bigger signatures.
*
* @param sig length must be even
* @throws IllegalArgumentException if too big
* @since 0.8.7, moved to SigUtil in 0.9.9
*/
private static byte[] sigBytesToASN1(byte[] sig) {
//System.out.println("pre TO asn1\n" + net.i2p.util.HexDump.dump(sig));
int len = sig.length;
int sublen = len / 2;
byte[] tmp = new byte[sublen];
BigInteger[] rs = split(sig);
return sigBytesToASN1(rs[0], rs[1]);
}
System.arraycopy(sig, 0, tmp, 0, sublen);
BigInteger r = new BigInteger(1, tmp);
/**
* http://download.oracle.com/javase/1.5.0/docs/guide/security/CryptoSpec.html
*<pre>
* Signature Format: ASN.1 sequence of two INTEGER values: r and s, in that order:
* SEQUENCE ::= { r INTEGER, s INTEGER }
*
* http://en.wikipedia.org/wiki/Abstract_Syntax_Notation_One
* 30 -- tag indicating SEQUENCE
* xx - length in octets
*
* 02 -- tag indicating INTEGER
* xx - length in octets
* xxxxxx - value
*</pre>
*
* r and s are always non-negative.
*
* Only supports sigs up to about 252 bytes. See code to fix BER encoding for this before you
* add a SigType with bigger signatures.
*
* @param sig length must be even
* @throws IllegalArgumentException if too big
* @since 0.9.25, split out from sigBytesToASN1(byte[])
*/
public static byte[] sigBytesToASN1(BigInteger r, BigInteger s) {
byte[] rb = r.toByteArray();
if (rb.length > 127)
throw new IllegalArgumentException("FIXME R length > 127");
System.arraycopy(sig, sublen, tmp, 0, sublen);
BigInteger s = new BigInteger(1, tmp);
byte[] sb = s.toByteArray();
if (sb.length > 127)
throw new IllegalArgumentException("FIXME S length > 127");
@ -676,7 +706,8 @@ public class SigUtil {
* See above.
* Only supports sigs up to about 252 bytes. See code to fix BER encoding for bigger than that.
*
* @return len bytes
* @param len must be even, twice the nominal length of each BigInteger
* @return len bytes, call split() on the result to get two BigIntegers
* @since 0.8.7, moved to SigUtil in 0.9.9
*/
private static byte[] aSN1ToSigBytes(byte[] asn, int len)
@ -722,6 +753,20 @@ public class SigUtil {
return rv;
}
/**
* See above.
* Only supports sigs up to about 252 bytes. See code to fix BER encoding for bigger than that.
*
* @param len nominal length of each BigInteger
* @return two BigIntegers
* @since 0.9.25
*/
public static NativeBigInteger[] aSN1ToBigInteger(byte[] asn, int len)
throws SignatureException {
byte[] sig = aSN1ToSigBytes(asn, len * 2);
return split(sig);
}
public static void clearCaches() {
synchronized(_ECPubkeyCache) {
_ECPubkeyCache.clear();

20
core/java/src/net/i2p/crypto/elgamal/KeyFactory.java
View File

@ -60,23 +60,15 @@ public class KeyFactory extends KeyFactorySpi {
throws InvalidKeySpecException {
if (keySpec.isAssignableFrom(ElGamalPublicKeySpec.class) && key instanceof ElGamalPublicKey) {
ElGamalPublicKey k = (ElGamalPublicKey) key;
// key.getParams() is a DHParameterSpec
DHParameterSpec dhp = k.getParams();
if (dhp != null) {
if (dhp.getP().equals(I2P_ELGAMAL_2048_SPEC.getP()) &&
dhp.getG().equals(I2P_ELGAMAL_2048_SPEC.getG()))
return (T) new ElGamalPrivateKeySpec(k.getY(), I2P_ELGAMAL_2048_SPEC);
return (T) new ElGamalPrivateKeySpec(k.getY(), new ElGamalParameterSpec(dhp.getP(), dhp.getG()));
ElGamalParameterSpec egp = k.getParameters();
if (egp != null) {
return (T) new ElGamalPrivateKeySpec(k.getY(), egp);
}
} else if (keySpec.isAssignableFrom(ElGamalPrivateKeySpec.class) && key instanceof ElGamalPrivateKey) {
ElGamalPrivateKey k = (ElGamalPrivateKey) key;
// key.getParams() is a DHParameterSpec
DHParameterSpec dhp = k.getParams();
if (dhp != null) {
if (dhp.getP().equals(I2P_ELGAMAL_2048_SPEC.getP()) &&
dhp.getG().equals(I2P_ELGAMAL_2048_SPEC.getG()))
return (T) new ElGamalPrivateKeySpec(k.getX(), I2P_ELGAMAL_2048_SPEC);
return (T) new ElGamalPrivateKeySpec(k.getX(), new ElGamalParameterSpec(dhp.getP(), dhp.getG()));
ElGamalParameterSpec egp = k.getParameters();
if (egp != null) {
return (T) new ElGamalPrivateKeySpec(k.getX(), egp);
}
}
throw new InvalidKeySpecException("not implemented yet " + key + " " + keySpec);