I2P_Developers/i2p.android.base
3
0
Fork 2
Code Issues 39 Pull Requests Actions 1 Packages Projects Releases Wiki Activity

* ElGamalAESEngine: Fixups required after SessionKey enforcement

Browse Source 
* SessionKey: Enforce data size and prevent reuse like the other SimpleDataStructures
This commit is contained in:
zzz
2011-06-02 13:33:03 +00:00
parent 94af6550fa
commit c5c4e3c7ce
2 changed files with 20 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
core/java/src/net/i2p/crypto/ElGamalAESEngine.java
View File

@ -91,14 +91,12 @@ public class ElGamalAESEngine {
SessionTag st = new SessionTag(tag);
SessionKey key = keyManager.consumeTag(st);
SessionKey foundKey = new SessionKey();
foundKey.setData(null);
SessionKey usedKey = new SessionKey();
Set foundTags = new HashSet();
byte decrypted[] = null;
boolean wasExisting = false;
if (key != null) {
//if (_log.shouldLog(Log.DEBUG)) _log.debug("Key is known for tag " + st);
usedKey.setData(key.getData());
long id = _context.random().nextLong();
if (_log.shouldLog(Log.DEBUG))
_log.debug(id + ": Decrypting existing session encrypted with tag: " + st.toString() + ": key: " + key.toBase64() + ": " + data.length + " bytes: " + Base64.encode(data, 0, 64));
@ -138,7 +136,7 @@ public class ElGamalAESEngine {
if (_log.shouldLog(Log.DEBUG))
_log.debug("Found key: " + foundKey.toBase64() + " tags: " + foundTags + " wasExisting? " + wasExisting);
keyManager.tagsReceived(foundKey, foundTags);
} else {
} else if (usedKey.getData() != null) {
if (_log.shouldLog(Log.DEBUG))
_log.debug("Used key: " + usedKey.toBase64() + " tags: " + foundTags + " wasExisting? " + wasExisting);
keyManager.tagsReceived(usedKey, foundTags);
@ -160,11 +158,12 @@ public class ElGamalAESEngine {
* the decryptAESBlock method & structure.
*
* @param foundTags set which is filled with any sessionTags found during decryption
* @param foundKey session key which may be filled with a new sessionKey found during decryption
* @param foundKey out parameter. Data must be unset when called; may be filled with a new sessionKey found during decryption
* @param usedKey out parameter. Data must be unset when called; usedKey.setData() will be called by this method on success.
*
* @return null if decryption fails
*/
byte[] decryptNewSession(byte data[], PrivateKey targetPrivateKey, Set foundTags, SessionKey usedKey,
private byte[] decryptNewSession(byte data[], PrivateKey targetPrivateKey, Set foundTags, SessionKey usedKey,
SessionKey foundKey) throws DataFormatException {
if (data == null) {
//if (_log.shouldLog(Log.WARN)) _log.warn("Data is null, unable to decrypt new session");
@ -231,11 +230,13 @@ public class ElGamalAESEngine {
* If anything doesn't match up in decryption, it falls back to decryptNewSession
*
* @param foundTags set which is filled with any sessionTags found during decryption
* @param foundKey session key which may be filled with a new sessionKey found during decryption
* @param foundKey out parameter. Data must be unset when called; may be filled with a new sessionKey found during decryption
* @param usedKey out parameter. Data must be unset when called; usedKey.setData() will be called by this method on success.
*
* @return decrypted data or null on failure
*
*/
byte[] decryptExistingSession(byte data[], SessionKey key, PrivateKey targetPrivateKey, Set foundTags,
private byte[] decryptExistingSession(byte data[], SessionKey key, PrivateKey targetPrivateKey, Set foundTags,
SessionKey usedKey, SessionKey foundKey) throws DataFormatException {
byte preIV[] = new byte[32];
System.arraycopy(data, 0, preIV, 0, preIV.length);
@ -243,8 +244,6 @@ public class ElGamalAESEngine {
byte iv[] = new byte[16];
System.arraycopy(ivHash.getData(), 0, iv, 0, 16);
usedKey.setData(key.getData());
//_log.debug("Pre IV for decryptExistingSession: " + DataHelper.toString(preIV, 32));
//_log.debug("SessionKey for decryptNewSession: " + DataHelper.toString(key.getData(), 32));
byte decrypted[] = decryptAESBlock(data, 32, data.length-32, key, iv, preIV, foundTags, foundKey);
@ -267,6 +266,7 @@ public class ElGamalAESEngine {
//if (_log.shouldLog(Log.DEBUG))
// _log.debug("Decrypt with an EXISTING session tag successfull, # tags read: " + foundTags.size(),
// new Exception("Decrypted by"));
usedKey.setData(key.getData());
return decrypted;
}
@ -287,14 +287,15 @@ public class ElGamalAESEngine {
* consume it, but if it is null, record the keys, etc as part of a new session.
*
* @param foundTags set which is filled with any sessionTags found during decryption
* @param foundKey session key which may be filled with a new sessionKey found during decryption
* @param foundKey out parameter. Data must be unset when called; may be filled with a new sessionKey found during decryption
* @return decrypted data or null on failure
*/
byte[] decryptAESBlock(byte encrypted[], SessionKey key, byte iv[],
private byte[] decryptAESBlock(byte encrypted[], SessionKey key, byte iv[],
byte sentTag[], Set foundTags, SessionKey foundKey) throws DataFormatException {
return decryptAESBlock(encrypted, 0, encrypted.length, key, iv, sentTag, foundTags, foundKey);
}
byte[] decryptAESBlock(byte encrypted[], int offset, int encryptedLen, SessionKey key, byte iv[],
private byte[] decryptAESBlock(byte encrypted[], int offset, int encryptedLen, SessionKey key, byte iv[],
byte sentTag[], Set foundTags, SessionKey foundKey) throws DataFormatException {
//_log.debug("iv for decryption: " + DataHelper.toString(iv, 16));
//_log.debug("decrypting AES block. encr.length = " + (encrypted == null? -1 : encrypted.length) + " sentTag: " + DataHelper.toString(sentTag, 32));
@ -448,7 +449,7 @@ public class ElGamalAESEngine {
* </pre>
*
*/
byte[] encryptNewSession(byte data[], PublicKey target, SessionKey key, Set tagsForDelivery,
private byte[] encryptNewSession(byte data[], PublicKey target, SessionKey key, Set tagsForDelivery,
SessionKey newKey, long paddedSize) {
//_log.debug("Encrypting to a NEW session");
byte elgSrcData[] = new byte[SessionKey.KEYSIZE_BYTES+32+158];
@ -511,7 +512,7 @@ public class ElGamalAESEngine {
* </pre>
*
*/
byte[] encryptExistingSession(byte data[], PublicKey target, SessionKey key, Set tagsForDelivery,
private byte[] encryptExistingSession(byte data[], PublicKey target, SessionKey key, Set tagsForDelivery,
SessionTag currentTag, SessionKey newKey, long paddedSize) {
//_log.debug("Encrypting to an EXISTING session");
byte rawTag[] = currentTag.getData();
@ -543,11 +544,12 @@ public class ElGamalAESEngine {
* </pre>
*
*/
final byte[] encryptAESBlock(byte data[], SessionKey key, byte[] iv, Set tagsForDelivery, SessionKey newKey,
private final byte[] encryptAESBlock(byte data[], SessionKey key, byte[] iv, Set tagsForDelivery, SessionKey newKey,
long paddedSize) {
return encryptAESBlock(data, key, iv, tagsForDelivery, newKey, paddedSize, 0);
}
final byte[] encryptAESBlock(byte data[], SessionKey key, byte[] iv, Set tagsForDelivery, SessionKey newKey,
private final byte[] encryptAESBlock(byte data[], SessionKey key, byte[] iv, Set tagsForDelivery, SessionKey newKey,
long paddedSize, int prefixBytes) {
//_log.debug("iv for encryption: " + DataHelper.toString(iv, 16));
//_log.debug("Encrypting AES");
@ -616,6 +618,7 @@ public class ElGamalAESEngine {
context.random().nextBytes(rv);
return rv;
}
final static int getPaddingSize(int curSize, long minPaddedSize) {
int diff = 0;
if (curSize < minPaddedSize) {

2
core/java/src/net/i2p/data/SessionKey.java
View File

@ -41,7 +41,7 @@ public class SessionKey extends SimpleDataStructure {
*/
@Override
public void setData(byte[] data) {
_data = data;
super.setData(data);
_preparedKey = null;
}