1 files changed, 261 insertions, 0 deletions
diff --git a/xcode/OLMKit/OLMSession.m b/xcode/OLMKit/OLMSession.m
new file mode 100644
index 0000000..41aef7e
--- /dev/null
+++ b/xcode/OLMKit/OLMSession.m
@@ -0,0 +1,261 @@
+//
+//  OLMSession.m
+//  olm
+//
+//  Created by Chris Ballinger on 4/8/16.
+//
+//
+
+#import "OLMSession.h"
+#import "OLMUtility.h"
+#import "OLMAccount_Private.h"
+#import "OLMSession_Private.h"
+#include "olm/olm.h"
+
+@implementation OLMSession
+
+- (void) dealloc {
+    olm_clear_session(_session);
+    free(_session);
+}
+
+- (BOOL) initializeSessionMemory {
+    size_t size = olm_session_size();
+    _session = malloc(size);
+    NSParameterAssert(_session != nil);
+    if (!_session) {
+        return NO;
+    }
+    _session = olm_session(_session);
+    NSParameterAssert(_session != nil);
+    if (!_session) {
+        return NO;
+    }
+    return YES;
+}
+
+- (instancetype) init {
+    self = [super init];
+    if (!self) {
+        return nil;
+    }
+    BOOL success = [self initializeSessionMemory];
+    if (!success) {
+        return nil;
+    }
+    return self;
+}
+
+- (instancetype) initWithAccount:(OLMAccount*)account {
+    self = [self init];
+    if (!self) {
+        return nil;
+    }
+    NSParameterAssert(account != nil &&  account.account != NULL);
+    if (account == nil || account.account == NULL) {
+        return nil;
+    }
+    _account = account;
+    return self;
+}
+
+- (instancetype) initOutboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey theirOneTimeKey:(NSString*)theirOneTimeKey {
+    self = [self initWithAccount:account];
+    if (!self) {
+        return nil;
+    }
+    NSMutableData *random = [OLMUtility randomBytesOfLength:olm_create_outbound_session_random_length(_session)];
+    NSData *idKey = [theirIdentityKey dataUsingEncoding:NSUTF8StringEncoding];
+    NSData *otKey = [theirOneTimeKey dataUsingEncoding:NSUTF8StringEncoding];
+    size_t result = olm_create_outbound_session(_session, account.account, idKey.bytes, idKey.length, otKey.bytes, otKey.length, random.mutableBytes, random.length);
+    if (result == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_create_outbound_session error: %s", error);
+        return nil;
+    }
+    return self;
+}
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account oneTimeKeyMessage:(NSString*)oneTimeKeyMessage {
+    self = [self initWithAccount:account];
+    if (!self) {
+        return nil;
+    }
+    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
+    size_t result = olm_create_inbound_session(_session, account.account, otk.mutableBytes, oneTimeKeyMessage.length);
+    if (result == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_create_inbound_session error: %s", error);
+        return nil;
+    }
+    return self;
+}
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString*)oneTimeKeyMessage {
+    self = [self initWithAccount:account];
+    if (!self) {
+        return nil;
+    }
+    NSData *idKey = [theirIdentityKey dataUsingEncoding:NSUTF8StringEncoding];
+    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
+    size_t result = olm_create_inbound_session_from(_session, account.account, idKey.bytes, idKey.length, otk.mutableBytes, otk.length);
+    if (result == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_create_inbound_session_from error: %s", error);
+        return nil;
+    }
+    return self;
+}
+
+- (NSString*) sessionIdentifier {
+    size_t length = olm_session_id_length(_session);
+    NSMutableData *idData = [NSMutableData dataWithLength:length];
+    if (!idData) {
+        return nil;
+    }
+    size_t result = olm_session_id(_session, idData.mutableBytes, idData.length);
+    if (result == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_session_id error: %s", error);
+        return nil;
+    }
+    NSString *idString = [[NSString alloc] initWithData:idData encoding:NSUTF8StringEncoding];
+    return idString;
+}
+
+- (OLMMessage*) encryptMessage:(NSString*)message {
+    size_t messageType = olm_encrypt_message_type(_session);
+    size_t randomLength = olm_encrypt_random_length(_session);
+    NSMutableData *random = [OLMUtility randomBytesOfLength:randomLength];
+    NSData *plaintextData = [message dataUsingEncoding:NSUTF8StringEncoding];
+    size_t ciphertextLength = olm_encrypt_message_length(_session, plaintextData.length);
+    NSMutableData *ciphertext = [NSMutableData dataWithLength:ciphertextLength];
+    if (!ciphertext) {
+        return nil;
+    }
+    size_t result = olm_encrypt(_session, plaintextData.bytes, plaintextData.length, random.mutableBytes, random.length, ciphertext.mutableBytes, ciphertext.length);
+    if (result == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_encrypt error: %s", error);
+        return nil;
+    }
+    NSString *ciphertextString = [[NSString alloc] initWithData:ciphertext encoding:NSUTF8StringEncoding];
+    OLMMessage *encryptedMessage = [[OLMMessage alloc] initWithCiphertext:ciphertextString type:messageType];
+    return encryptedMessage;
+}
+
+- (NSString*) decryptMessage:(OLMMessage*)message {
+    NSParameterAssert(message != nil);
+    NSData *messageData = [message.ciphertext dataUsingEncoding:NSUTF8StringEncoding];
+    if (!messageData) {
+        return nil;
+    }
+    NSMutableData *mutMessage = messageData.mutableCopy;
+    size_t maxPlaintextLength = olm_decrypt_max_plaintext_length(_session, message.type, mutMessage.mutableBytes, mutMessage.length);
+    if (maxPlaintextLength == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_decrypt_max_plaintext_length error: %s", error);
+        return nil;
+    }
+    // message buffer is destroyed by olm_decrypt_max_plaintext_length
+    mutMessage = messageData.mutableCopy;
+    NSMutableData *plaintextData = [NSMutableData dataWithLength:maxPlaintextLength];
+    size_t plaintextLength = olm_decrypt(_session, message.type, mutMessage.mutableBytes, mutMessage.length, plaintextData.mutableBytes, plaintextData.length);
+    if (plaintextLength == olm_error()) {
+        const char *error = olm_session_last_error(_session);
+        NSAssert(NO, @"olm_decrypt error: %s", error);
+        return nil;
+    }
+    plaintextData.length = plaintextLength;
+    NSString *plaintext = [[NSString alloc] initWithData:plaintextData encoding:NSUTF8StringEncoding];
+    return plaintext;
+}
+
+#pragma mark OLMSerializable
+
+/** Initializes from encrypted serialized data. Will throw error if invalid key or invalid base64. */
+- (instancetype) initWithSerializedData:(NSString*)serializedData key:(NSData*)key error:(NSError**)error {
+    self = [self init];
+    if (!self) {
+        return nil;
+    }
+    NSParameterAssert(key.length > 0);
+    NSParameterAssert(serializedData.length > 0);
+    if (key.length == 0 || serializedData.length == 0) {
+        if (error) {
+            *error = [NSError errorWithDomain:@"org.matrix.olm" code:0 userInfo:@{NSLocalizedDescriptionKey: @"Bad length."}];
+        }
+        return nil;
+    }
+    NSMutableData *pickle = [serializedData dataUsingEncoding:NSUTF8StringEncoding].mutableCopy;
+    size_t result = olm_unpickle_session(_session, key.bytes, key.length, pickle.mutableBytes, pickle.length);
+    if (result == olm_error()) {
+        const char *olm_error = olm_session_last_error(_session);
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        if (error && errorString) {
+            *error = [NSError errorWithDomain:@"org.matrix.olm" code:0 userInfo:@{NSLocalizedDescriptionKey: errorString}];
+        }
+        return nil;
+    }
+    return self;
+}
+
+/** Serializes and encrypts object data, outputs base64 blob */
+- (NSString*) serializeDataWithKey:(NSData*)key error:(NSError**)error {
+    NSParameterAssert(key.length > 0);
+    size_t length = olm_pickle_session_length(_session);
+    NSMutableData *pickled = [NSMutableData dataWithLength:length];
+    size_t result = olm_pickle_session(_session, key.bytes, key.length, pickled.mutableBytes, pickled.length);
+    if (result == olm_error()) {
+        const char *olm_error = olm_session_last_error(_session);
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        if (error && errorString) {
+            *error = [NSError errorWithDomain:@"org.matrix.olm" code:0 userInfo:@{NSLocalizedDescriptionKey: errorString}];
+        }
+        return nil;
+    }
+    NSString *pickleString = [[NSString alloc] initWithData:pickled encoding:NSUTF8StringEncoding];
+    return pickleString;
+}
+
+#pragma mark NSSecureCoding
+
++ (BOOL) supportsSecureCoding {
+    return YES;
+}
+
+#pragma mark NSCoding
+
+- (id)initWithCoder:(NSCoder *)decoder {
+    NSString *version = [decoder decodeObjectOfClass:[NSString class] forKey:@"version"];
+    
+    NSError *error = nil;
+    
+    if ([version isEqualToString:@"1"]) {
+        NSString *pickle = [decoder decodeObjectOfClass:[NSString class] forKey:@"pickle"];
+        NSData *key = [decoder decodeObjectOfClass:[NSData class] forKey:@"key"];
+        
+        self = [self initWithSerializedData:pickle key:key error:&error];
+    }
+    
+    NSParameterAssert(error == nil);
+    NSParameterAssert(self != nil);
+    if (!self) {
+        return nil;
+    }
+    
+    return self;
+}
+
+- (void)encodeWithCoder:(NSCoder *)encoder {
+    NSData *key = [OLMUtility randomBytesOfLength:32];
+    NSError *error = nil;
+    NSString *pickle = [self serializeDataWithKey:key error:&error];
+    NSParameterAssert(pickle.length > 0 && error == nil);
+    
+    [encoder encodeObject:pickle forKey:@"pickle"];
+    [encoder encodeObject:key forKey:@"key"];
+    [encoder encodeObject:@"1" forKey:@"version"];
+}
+
+@end