signalapp/SignalProtocolKit
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Check identity in encrypt/decrypt

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// FREEBIE
This commit is contained in:
Michael Kirk 2017-05-30 14:26:55 -07:00
parent d0bd4d56c0
commit a4cbfbcbef
1 changed files with 32 additions and 1 deletions
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33
AxolotlKit/Classes/SessionCipher.m
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@ -35,6 +35,7 @@ static dispatch_queue_t _sessionCipherDispatchQueue;
@property (nonatomic, readonly) NSString *recipientId;
@property (nonatomic, readonly) int deviceId;
@property (nonatomic, readonly) id<IdentityKeyStore> identityKeyStore;
@property (nonatomic, readonly) id<SessionStore> sessionStore;
@property (nonatomic, readonly) SessionBuilder *sessionBuilder;
@property (nonatomic, readonly) id<PreKeyStore> prekeyStore;
@ -66,6 +67,7 @@ static dispatch_queue_t _sessionCipherDispatchQueue;
_recipientId = recipientId;
_deviceId = deviceId;
_sessionStore = sessionStore;
_identityKeyStore = identityKeyStore;
_sessionBuilder = [[SessionBuilder alloc] initWithSessionStore:sessionStore
preKeyStore:preKeyStore
signedPreKeyStore:signedPreKeyStore
@ -112,6 +114,20 @@ static dispatch_queue_t _sessionCipherDispatchQueue;
int previousCounter = sessionState.previousCounter;
int sessionVersion = sessionState.version;
if (![self.identityKeyStore isTrustedIdentityKey:sessionState.remoteIdentityKey
recipientId:self.recipientId
direction:TSMessageDirectionOutgoing]) {
DDLogWarn(
@"%@ Previously known identity key for while encrypting for recipient: %@", self.tag, self.recipientId);
@throw [NSException exceptionWithName:UntrustedIdentityKeyException
reason:@"There is a previously known identity key."
userInfo:@{}];
}
if ([self.identityKeyStore saveRemoteIdentity:sessionState.remoteIdentityKey recipientId:self.recipientId]) {
[sessionRecord removePreviousSessionStates];
}
NSData *ciphertextBody = [AES_CBC encryptCBCMode:paddedMessage withKey:messageKeys.cipherKey withIV:messageKeys.iv];
id<CipherMessage> cipherMessage =
@ -176,7 +192,22 @@ static dispatch_queue_t _sessionCipherDispatchQueue;
SessionRecord *sessionRecord = [self.sessionStore loadSession:self.recipientId deviceId:self.deviceId];
NSData *plaintext = [self decryptWithSessionRecord:sessionRecord whisperMessage:message];
if (![self.identityKeyStore isTrustedIdentityKey:sessionRecord.sessionState.remoteIdentityKey
recipientId:self.recipientId
direction:TSMessageDirectionIncoming]) {
DDLogWarn(
@"%@ Previously known identity key for while decrypting from recipient: %@", self.tag, self.recipientId);
@throw [NSException exceptionWithName:UntrustedIdentityKeyException
reason:@"There is a previously known identity key."
userInfo:@{}];
}
if ([self.identityKeyStore saveRemoteIdentity:sessionRecord.sessionState.remoteIdentityKey
recipientId:self.recipientId]) {
[sessionRecord removePreviousSessionStates];
}
[self.sessionStore storeSession:self.recipientId deviceId:self.deviceId session:sessionRecord];
return plaintext;