package net.i2p.data;
/*
* free (adj.): unencumbered; not under the control of others
* Written by jrandom in 2003 and released into the public domain
* with no warranty of any kind, either expressed or implied.
* It probably won't make your computer catch on fire, or eat
* your children, but it might. Use at your own risk.
*
*/
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import net.i2p.crypto.SigType;
/**
* Defines the SigningPublicKey as defined by the I2P data structure spec.
* A signing public key is by default 128 byte Integer. The public key represents only the
* exponent, not the primes, which are constant and defined in the crypto spec.
* This key varies from the PrivateKey in its usage (verifying signatures, not encrypting)
*
* As of release 0.9.8, keys of arbitrary length and type are supported.
* See SigType.
*
* @author jrandom
*/
public class SigningPublicKey extends SimpleDataStructure {
private static final SigType DEF_TYPE = SigType.DSA_SHA1;
public final static int KEYSIZE_BYTES = DEF_TYPE.getPubkeyLen();
private static final int CACHE_SIZE = 1024;
private static final SDSCache<SigningPublicKey> _cache = new SDSCache<SigningPublicKey>(SigningPublicKey.class, KEYSIZE_BYTES, CACHE_SIZE);
private final SigType _type;
/**
* Pull from cache or return new.
* Deprecated - used only by deprecated Destination.readBytes(data, off)
*
* @throws ArrayIndexOutOfBoundsException if not enough bytes, FIXME should throw DataFormatException
* @since 0.8.3
*/
public static SigningPublicKey create(byte[] data, int off) {
return _cache.get(data, off);
}
/**
* Pull from cache or return new
* @since 0.8.3
*/
public static SigningPublicKey create(InputStream in) throws IOException {
return _cache.get(in);
}
public SigningPublicKey() {
this(DEF_TYPE);
}
/**
* @param type if null, type is unknown
* @since 0.9.8
*/
public SigningPublicKey(SigType type) {
super();
_type = type;
}
public SigningPublicKey(byte data[]) {
this(DEF_TYPE, data);
}
/**
* @param type if null, type is unknown
* @since 0.9.8
*/
public SigningPublicKey(SigType type, byte data[]) {
super();
_type = type;
if (type != null || data == null)
setData(data);
else
_data = data; // bypass length check
}
/** constructs from base64
* @param base64Data a string of base64 data (the output of .toBase64() called
* on a prior instance of SigningPublicKey
*/
public SigningPublicKey(String base64Data) throws DataFormatException {
this();
fromBase64(base64Data);
}
/**
* @return if type unknown, the length of the data, or 128 if no data
*/
public int length() {
if (_type != null)
return _type.getPubkeyLen();
if (_data != null)
return _data.length;
return KEYSIZE_BYTES;
}
/**
* @return null if unknown
* @since 0.9.8
*/
public SigType getType() {
return _type;
}
/**
* Up-convert this from an untyped (type 0) SPK to a typed SPK based on the Key Cert given.
* The type of the returned key will be null if the kcert sigtype is null.
*
* @throws IllegalArgumentException if this is already typed to a different type
* @since 0.9.12
*/
public SigningPublicKey toTypedKey(KeyCertificate kcert) {
if (_data == null)
throw new IllegalStateException();
SigType newType = kcert.getSigType();
if (_type == newType)
return this;
if (_type != SigType.DSA_SHA1)
throw new IllegalArgumentException("Cannot convert " + _type + " to " + newType);
// unknown type, keep the 128 bytes of data
if (newType == null)
return new SigningPublicKey(null, _data);
int newLen = newType.getPubkeyLen();
if (newLen == SigType.DSA_SHA1.getPubkeyLen())
return new SigningPublicKey(newType, _data);
byte[] newData = new byte[newLen];
if (newLen < SigType.DSA_SHA1.getPubkeyLen()) {
// right-justified
System.arraycopy(_data, _data.length - newLen, newData, 0, newLen);
} else {
// full 128 bytes + fragment in kcert
System.arraycopy(_data, 0, newData, 0, _data.length);
System.arraycopy(kcert.getPayload(), KeyCertificate.HEADER_LENGTH, newData, _data.length, newLen - _data.length);
}
return new SigningPublicKey(newType, newData);
}
/**
* Get the portion of this (type 0) SPK that is really padding based on the Key Cert type given,
* if any
*
* @return leading padding length > 0 or null if no padding or type is unknown
* @throws IllegalArgumentException if this is already typed to a different type
* @since 0.9.12
*/
public byte[] getPadding(KeyCertificate kcert) {
if (_data == null)
throw new IllegalStateException();
SigType newType = kcert.getSigType();
if (_type == newType || newType == null)
return null;
if (_type != SigType.DSA_SHA1)
throw new IllegalStateException("Cannot convert " + _type + " to " + newType);
int newLen = newType.getPubkeyLen();
if (newLen >= SigType.DSA_SHA1.getPubkeyLen())
return null;
int padLen = SigType.DSA_SHA1.getPubkeyLen() - newLen;
byte[] pad = new byte[padLen];
System.arraycopy(_data, 0, pad, 0, padLen);
return pad;
}
/**
* Write the data up to a max of 128 bytes.
* If longer, the rest will be written in the KeyCertificate.
* @since 0.9.12
*/
public void writeTruncatedBytes(OutputStream out) throws DataFormatException, IOException {
// we don't use _type here so we can write the data even for unknown type
//if (_type.getPubkeyLen() <= KEYSIZE_BYTES)
if (_data == null) throw new DataFormatException("No data to write out");
if (_data.length <= KEYSIZE_BYTES)
out.write(_data);
else
out.write(_data, 0, KEYSIZE_BYTES);
}
/**
* @since 0.9.8
*/
@Override
public String toString() {
StringBuilder buf = new StringBuilder(64);
buf.append('[').append(getClass().getSimpleName()).append(' ').append(_type).append(": ");
if (_data == null) {
buf.append("null");
} else {
buf.append("size: ").append(Integer.toString(length()));
}
buf.append(']');
return buf.toString();
}
/**
* @since 0.9.17
*/
public static void clearCache() {
_cache.clear();
}
/**
* @since 0.9.17
*/
@Override
public int hashCode() {
return DataHelper.hashCode(_type) ^ super.hashCode();
}
/**
* @since 0.9.17
*/
@Override
public boolean equals(Object obj) {
if (obj == this) return true;
if (obj == null || !(obj instanceof SigningPublicKey)) return false;
SigningPublicKey s = (SigningPublicKey) obj;
return _type == s._type && Arrays.equals(_data, s._data);
}
}