Kaladaran/briar
0
0
Fork 0
mirror of https://code.briarproject.org/briar/briar.git synced 2026-02-12 10:49:06 +01:00
Code Issues Projects Releases Wiki Activity

Fixed some key derivation bugs and removed an unnecessary argument.

Browse Source 
CryptoComponentImpl needs some unit tests.
This commit is contained in:
akwizgran
2012-03-29 20:11:11 +01:00
parent 15d7fd5796
commit b01b17f2b1
3 changed files with 11 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
api/net/sf/briar/api/crypto/CryptoComponent.java
View File

@@ -19,7 +19,7 @@ public interface CryptoComponent {
byte[][] deriveInitialSecrets(byte[] ourPublicKey, byte[] theirPublicKey,
PrivateKey ourPrivateKey, int invitationCode, boolean initiator);
int deriveConfirmationCode(byte[] secret, boolean initiator);
int deriveConfirmationCode(byte[] secret);
byte[] deriveNextSecret(byte[] secret, int index, long connection);

22
components/net/sf/briar/crypto/CryptoComponentImpl.java
View File

@@ -104,14 +104,14 @@ class CryptoComponentImpl implements CryptoComponent {
if(secret.length != SECRET_KEY_BYTES)
throw new IllegalArgumentException();
// The label and context must leave a byte free for the counter
if(label.length + context.length + 4 > KEY_DERIVATION_IV_BYTES)
if(label.length + context.length + 2 >= KEY_DERIVATION_IV_BYTES)
throw new IllegalArgumentException();
// The IV contains the length-prefixed label and context
byte[] ivBytes = new byte[KEY_DERIVATION_IV_BYTES];
ByteUtils.writeUint8(label.length, ivBytes, 0);
System.arraycopy(label, 0, ivBytes, 2, label.length);
ByteUtils.writeUint8(context.length, ivBytes, label.length + 2);
System.arraycopy(context, 0, ivBytes, label.length + 4, context.length);
System.arraycopy(label, 0, ivBytes, 1, label.length);
ByteUtils.writeUint8(context.length, ivBytes, label.length + 1);
System.arraycopy(context, 0, ivBytes, label.length + 2, context.length);
// Use the secret and the IV to encrypt a blank plaintext
IvParameterSpec iv = new IvParameterSpec(ivBytes);
ErasableKey key = new ErasableKeyImpl(secret, SECRET_KEY_ALGO);
@@ -178,7 +178,7 @@ class CryptoComponentImpl implements CryptoComponent {
if(messageDigest.getDigestLength() < SECRET_KEY_BYTES)
throw new RuntimeException();
// All fields are length-prefixed
byte[] length = new byte[4];
byte[] length = new byte[1];
ByteUtils.writeUint8(rawSecret.length, length, 0);
messageDigest.update(length);
messageDigest.update(rawSecret);
@@ -213,19 +213,13 @@ class CryptoComponentImpl implements CryptoComponent {
return counterModeKdf(secret, NEXT, context);
}
public int deriveConfirmationCode(byte[] secret, boolean initiator) {
byte[] context = initiator ? INITIATOR : RESPONDER;
byte[] output = counterModeKdf(secret, CODE, context);
int code = extractCode(output);
public int deriveConfirmationCode(byte[] secret) {
byte[] output = counterModeKdf(secret, CODE, CODE);
int code = ByteUtils.readUint(output, CODE_BITS);
ByteUtils.erase(output);
return code;
}
private int extractCode(byte[] secret) {
// Convert the first CODE_BITS bits of the secret into an unsigned int
return ByteUtils.readUint(secret, CODE_BITS);
}
public KeyPair generateKeyPair() {
return keyPairGenerator.generateKeyPair();
}

4
components/net/sf/briar/plugins/InvitationStarterImpl.java
View File

@@ -158,8 +158,8 @@ class InvitationStarterImpl implements InvitationStarter {
callback.showFailure(INVALID_KEY);
return;
}
int initCode = crypto.deriveConfirmationCode(secrets[0], true);
int respCode = crypto.deriveConfirmationCode(secrets[1], false);
int initCode = crypto.deriveConfirmationCode(secrets[0]);
int respCode = crypto.deriveConfirmationCode(secrets[1]);
int ourCode = initiator ? initCode : respCode;
int theirCode = initiator ? respCode : initCode;
// Compare the confirmation codes