Merge pull request #36 from matrix-org/manuroe/olmkit

OLMKit

xcode/OLMKit/OLMSerializable.h

+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+@protocol OLMSerializable <NSObject>
+
+/** Initializes from encrypted serialized data. Will throw error if invalid key or invalid base64. */
+- (instancetype) initWithSerializedData:(NSString*)serializedData key:(NSData*)key error:(NSError**)error;
+
+/** Serializes and encrypts object data, outputs base64 blob */
+- (NSString*) serializeDataWithKey:(NSData*)key error:(NSError**)error;
+
+@end

xcode/OLMKit/OLMSession.h

+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+#import "OLMSerializable.h"
+#import "OLMAccount.h"
+#import "OLMMessage.h"
+
+@interface OLMSession : NSObject <OLMSerializable, NSSecureCoding>
+
+- (instancetype) initOutboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey theirOneTimeKey:(NSString*)theirOneTimeKey error:(NSError**)error;
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error;
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error;
+
+- (NSString*) sessionIdentifier;
+
+- (BOOL) matchesInboundSession:(NSString*)oneTimeKeyMessage;
+
+- (BOOL) matchesInboundSessionFrom:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString *)oneTimeKeyMessage;
+
+/** UTF-8 plaintext -> base64 ciphertext */
+- (OLMMessage*) encryptMessage:(NSString*)message error:(NSError**)error;
+
+/** base64 ciphertext -> UTF-8 plaintext */
+- (NSString*) decryptMessage:(OLMMessage*)message error:(NSError**)error;
+
+@end

xcode/OLMKit/OLMSession.m

+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#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  error:(NSError**)error {
+    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);
+    [random resetBytesInRange:NSMakeRange(0, random.length)];
+    if (result == olm_error()) {
+        const char *olm_error = olm_session_last_error(_session);
+
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        NSLog(@"olm_create_outbound_session error: %@", errorString);
+
+        if (error && olm_error && errorString) {
+            *error = [NSError errorWithDomain:OLMErrorDomain
+                                         code:0
+                                     userInfo:@{
+                                                NSLocalizedDescriptionKey: errorString,
+                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_create_outbound_session error: %@", errorString]
+                                                }];
+        }
+
+        return nil;
+    }
+    return self;
+}
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error {
+    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 *olm_error = olm_session_last_error(_session);
+
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        NSLog(@"olm_create_inbound_session error: %@", errorString);
+
+        if (error && olm_error && errorString) {
+            *error = [NSError errorWithDomain:OLMErrorDomain
+                                         code:0
+                                     userInfo:@{
+                                                NSLocalizedDescriptionKey: errorString,
+                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_create_inbound_session error: %@", errorString]
+                                                }];
+        }
+
+        return nil;
+    }
+    return self;
+}
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error {
+    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 *olm_error = olm_session_last_error(_session);
+
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        NSLog(@"olm_create_inbound_session_from error: %@", errorString);
+
+        if (error && olm_error && errorString) {
+            *error = [NSError errorWithDomain:OLMErrorDomain
+                                         code:0
+                                     userInfo:@{
+                                                NSLocalizedDescriptionKey: errorString,
+                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_create_inbound_session_from error: %@", errorString]
+                                                }];
+        }
+
+        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);
+        NSLog(@"olm_session_id error: %s", error);
+        return nil;
+    }
+    NSString *idString = [[NSString alloc] initWithData:idData encoding:NSUTF8StringEncoding];
+    return idString;
+}
+
+- (BOOL)matchesInboundSession:(NSString *)oneTimeKeyMessage {
+    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
+
+    size_t result = olm_matches_inbound_session(_session, otk.mutableBytes, otk.length);
+    if (result == 1) {
+        return YES;
+    }
+    else {
+        if (result == olm_error()) {
+            const char *error = olm_session_last_error(_session);
+            NSLog(@"olm_matches_inbound_session error: %s", error);
+        }
+        return NO;
+    }
+}
+
+- (BOOL)matchesInboundSessionFrom:(NSString *)theirIdentityKey oneTimeKeyMessage:(NSString *)oneTimeKeyMessage {
+    NSData *idKey = [theirIdentityKey dataUsingEncoding:NSUTF8StringEncoding];
+    NSMutableData *otk = [NSMutableData dataWithData:[oneTimeKeyMessage dataUsingEncoding:NSUTF8StringEncoding]];
+
+    size_t result = olm_matches_inbound_session_from(_session,
+                                                     idKey.bytes, idKey.length,
+                                                     otk.mutableBytes, otk.length);
+    if (result == 1) {
+        return YES;
+    }
+    else {
+        if (result == olm_error()) {
+            const char *error = olm_session_last_error(_session);
+            NSLog(@"olm_matches_inbound_session error: %s", error);
+        }
+        return NO;
+    }
+}
+
+- (OLMMessage*) encryptMessage:(NSString*)message error:(NSError**)error {
+    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);
+    [random resetBytesInRange:NSMakeRange(0, random.length)];
+    if (result == olm_error()) {
+        const char *olm_error = olm_session_last_error(_session);
+
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        NSLog(@"olm_encrypt error: %@", errorString);
+
+        if (error && olm_error && errorString) {
+            *error = [NSError errorWithDomain:OLMErrorDomain
+                                         code:0
+                                     userInfo:@{
+                                                NSLocalizedDescriptionKey: errorString,
+                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_encrypt error: %@", errorString]
+                                                }];
+        }
+
+        return nil;
+    }
+    NSString *ciphertextString = [[NSString alloc] initWithData:ciphertext encoding:NSUTF8StringEncoding];
+    OLMMessage *encryptedMessage = [[OLMMessage alloc] initWithCiphertext:ciphertextString type:messageType];
+    return encryptedMessage;
+}
+
+- (NSString*) decryptMessage:(OLMMessage*)message error:(NSError**)error {
+    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 *olm_error = olm_session_last_error(_session);
+
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        NSLog(@"olm_decrypt_max_plaintext_length error: %@", errorString);
+
+        if (error && olm_error && errorString) {
+            *error = [NSError errorWithDomain:OLMErrorDomain
+                                         code:0
+                                     userInfo:@{
+                                                NSLocalizedDescriptionKey: errorString,
+                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_decrypt_max_plaintext_length error: %@", errorString]
+                                                }];
+        }
+
+        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 *olm_error = olm_session_last_error(_session);
+
+        NSString *errorString = [NSString stringWithUTF8String:olm_error];
+        NSLog(@"olm_decrypt error: %@", errorString);
+
+        if (error && olm_error && errorString) {
+            *error = [NSError errorWithDomain:OLMErrorDomain
+                                         code:0
+                                     userInfo:@{
+                                                NSLocalizedDescriptionKey: errorString,
+                                                NSLocalizedFailureReasonErrorKey: [NSString stringWithFormat:@"olm_decrypt error: %@", errorString]
+                                                }];
+        }
+
+        return nil;
+    }
+    plaintextData.length = plaintextLength;
+    NSString *plaintext = [[NSString alloc] initWithData:plaintextData encoding:NSUTF8StringEncoding];
+    [plaintextData resetBytesInRange:NSMakeRange(0, plaintextData.length)];
+    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:OLMErrorDomain 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:OLMErrorDomain 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:OLMErrorDomain 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

xcode/OLMKit/OLMSession_Private.h

+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#include "olm/olm.h"
+
+@interface OLMSession()
+
+@property (nonatomic) OlmSession *session;
+@property (nonatomic, strong) OLMAccount *account;
+
+@end

xcode/OLMKit/OLMUtility.h

+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+FOUNDATION_EXPORT NSString *const OLMErrorDomain;
+
+@interface OLMUtility : NSObject
+
+/**
+ Calculate the SHA-256 hash of the input and encodes it as base64.
+ 
+ @param message the message to hash.
+ @return the base64-encoded hash value.
+ */
+- (NSString*)sha256:(NSData*)message;
+
+/**
+ Verify an ed25519 signature.
+
+ @param signature the base64-encoded signature to be checked.
+ @param key the ed25519 key.
+ @param message the message which was signed.
+ @param the result error if there is a problem with the verification.
+ If the key was too small then the message will be "OLM.INVALID_BASE64".
+ If the signature was invalid then the message will be "OLM.BAD_MESSAGE_MAC".
+
+ @return YES if valid.
+ */
+- (BOOL)verifyEd25519Signature:(NSString*)signature key:(NSString*)key message:(NSData*)message error:(NSError**)error;
+
++ (NSMutableData*) randomBytesOfLength:(NSUInteger)length;
+
+@end

xcode/OLMKit/OLMUtility.m

+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import "OLMUtility.h"
+
+#include "olm/olm.h"
+
+NSString *const OLMErrorDomain = @"org.matrix.olm";
+
+@interface OLMUtility()
+
+@property (nonatomic) OlmUtility *utility;
+
+@end
+
+@implementation OLMUtility
+
+- (void) dealloc {
+    olm_clear_utility(_utility);
+    free(_utility);
+}
+
+- (BOOL) initializeUtilityMemory {
+    size_t utilitySize = olm_utility_size();
+    _utility = malloc(utilitySize);
+    NSParameterAssert(_utility != nil);
+    if (!_utility) {
+        return NO;
+    }
+    _utility = olm_utility(_utility);
+    NSParameterAssert(_utility != nil);
+    if (!_utility) {
+        return NO;
+    }
+    return YES;
+}
+
+- (instancetype) init {
+    self = [super init];
+    if (!self) {
+        return nil;
+    }
+    BOOL success = [self initializeUtilityMemory];
+    if (!success) {
+        return nil;
+    }
+    return self;
+}
+
+- (NSString *)sha256:(NSData *)message {
+    size_t length = olm_sha256_length(_utility);
+
+    NSMutableData *shaData = [NSMutableData dataWithLength:length];
+    if (!shaData) {
+        return nil;
+    }
+
+    size_t result = olm_sha256(_utility, message.bytes, message.length, shaData.mutableBytes, shaData.length);
+    if (result == olm_error()) {
+        const char *error = olm_utility_last_error(_utility);
+        NSLog(@"olm_sha256 error: %s", error);
+        return nil;
+    }
+    
+    NSString *sha = [[NSString alloc] initWithData:shaData encoding:NSUTF8StringEncoding];
+    return sha;
+}
+
+- (BOOL)verifyEd25519Signature:(NSString*)signature key:(NSString*)key message:(NSData*)message error:(NSError**)error {
+
+    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
+    NSData *signatureData = [signature dataUsingEncoding:NSUTF8StringEncoding];
+
+    size_t result = olm_ed25519_verify(_utility,
+                                       keyData.bytes, keyData.length,
+                                       message.bytes, message.length,
+                                       (void*)signatureData.bytes, signatureData.length
+                                       );
+
+    if (result == olm_error()) {
+        if (error) {
+            NSDictionary *userInfo = @{NSLocalizedFailureReasonErrorKey: [NSString stringWithUTF8String:olm_utility_last_error(_utility)]};
+
+            // @TODO
+            *error = [[NSError alloc] initWithDomain:@"OLMKitErrorDomain" code:0 userInfo:userInfo];
+        }
+        return NO;
+    }
+    else {
+        return YES;
+    }
+}
+
++ (NSMutableData*) randomBytesOfLength:(NSUInteger)length {
+    NSMutableData *randomData = [NSMutableData dataWithLength:length];
+    if (!randomData) {
+        return nil;
+    }
+    int result = SecRandomCopyBytes(kSecRandomDefault, randomData.length, randomData.mutableBytes);
+    if (result != 0) {
+        return nil;
+    }
+    return randomData;
+}
+
+@end

xcode/OLMKitTests/Info.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>BNDL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+</dict>
+</plist>

xcode/OLMKitTests/OLMKitGroupTests.m

+/*
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <XCTest/XCTest.h>
+
+#import <OLMKit/OLMKit.h>
+
+#include "olm/olm.h"
+
+@interface OLMKitGroupTests : XCTestCase
+
+@end
+
+@implementation OLMKitGroupTests
+
+- (void)setUp {
+    [super setUp];
+    // Put setup code here. This method is called before the invocation of each test method in the class.
+}
+
+- (void)tearDown {
+    // Put teardown code here. This method is called after the invocation of each test method in the class.
+    [super tearDown];
+}
+
+- (void)testAliceAndBob {
+    NSError *error;
+
+    OLMOutboundGroupSession *aliceSession = [[OLMOutboundGroupSession alloc] initOutboundGroupSession];
+    XCTAssertGreaterThan(aliceSession.sessionIdentifier.length, 0);
+    XCTAssertGreaterThan(aliceSession.sessionKey.length, 0);
+    XCTAssertEqual(aliceSession.messageIndex, 0);
+
+    // Store the session key before starting encrypting
+    NSString *sessionKey = aliceSession.sessionKey;
+
+    NSString *message = @"Hello!";
+    NSString *aliceToBobMsg = [aliceSession encryptMessage:message error:&error];
+
+    XCTAssertEqual(aliceSession.messageIndex, 1);
+    XCTAssertGreaterThanOrEqual(aliceToBobMsg.length, 0);
+    XCTAssertNil(error);
+
+    OLMInboundGroupSession *bobSession = [[OLMInboundGroupSession alloc] initInboundGroupSessionWithSessionKey:sessionKey error:&error];
+    XCTAssertEqualObjects(aliceSession.sessionIdentifier, bobSession.sessionIdentifier);
+    XCTAssertNil(error);
+
+    NSUInteger messageIndex;
+
+    NSString *plaintext = [bobSession decryptMessage:aliceToBobMsg messageIndex:&messageIndex error:&error];
+    XCTAssertEqualObjects(message, plaintext);
+
+    XCTAssertEqual(messageIndex, 0);
+    XCTAssertNil(error);
+}
+
+- (void)testOutboundGroupSessionSerialization {
+
+    OLMOutboundGroupSession *aliceSession = [[OLMOutboundGroupSession alloc] initOutboundGroupSession];
+
+    NSData *aliceData = [NSKeyedArchiver archivedDataWithRootObject:aliceSession];
+    OLMOutboundGroupSession *aliceSession2 = [NSKeyedUnarchiver unarchiveObjectWithData:aliceData];
+
+    XCTAssertEqualObjects(aliceSession2.sessionKey, aliceSession.sessionKey);
+    XCTAssertEqualObjects(aliceSession2.sessionIdentifier, aliceSession.sessionIdentifier);
+}
+
+- (void)testInboundGroupSessionSerialization {
+
+    OLMOutboundGroupSession *aliceSession = [[OLMOutboundGroupSession alloc] initOutboundGroupSession];
+
+    OLMInboundGroupSession *bobSession = [[OLMInboundGroupSession alloc] initInboundGroupSessionWithSessionKey:aliceSession.sessionKey error:nil];
+
+    NSData *bobData = [NSKeyedArchiver archivedDataWithRootObject:bobSession];
+    OLMInboundGroupSession *bobSession2 = [NSKeyedUnarchiver unarchiveObjectWithData:bobData];
+
+    XCTAssertEqualObjects(bobSession2.sessionIdentifier, aliceSession.sessionIdentifier);
+}
+
+@end

xcode/OLMKitTests/OLMKitTests.m

+/*
+Copyright 2016 Chris Ballinger
+Copyright 2016 OpenMarket Ltd
+Copyright 2016 Vector Creations Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#import <XCTest/XCTest.h>
+#import <OLMKit/OLMKit.h>
+
+@interface OLMKitTests : XCTestCase
+
+@end
+
+@implementation OLMKitTests
+
+- (void)setUp {
+    [super setUp];
+    // Put setup code here. This method is called before the invocation of each test method in the class.
+}
+
+- (void)tearDown {
+    // Put teardown code here. This method is called after the invocation of each test method in the class.
+    [super tearDown];
+}
+
+- (void)testAliceAndBob {
+    NSError *error;
+
+    OLMAccount *alice = [[OLMAccount alloc] initNewAccount];
+    OLMAccount *bob = [[OLMAccount alloc] initNewAccount];
+    [bob generateOneTimeKeys:5];
+    NSDictionary *bobIdKeys = bob.identityKeys;
+    NSString *bobIdKey = bobIdKeys[@"curve25519"];
+    NSDictionary *bobOneTimeKeys = bob.oneTimeKeys;
+    NSParameterAssert(bobIdKey != nil);
+    NSParameterAssert(bobOneTimeKeys != nil);
+    __block NSString *bobOneTimeKey = nil;
+    NSDictionary *bobOtkCurve25519 = bobOneTimeKeys[@"curve25519"];
+    [bobOtkCurve25519 enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
+        bobOneTimeKey = obj;
+    }];
+    XCTAssert([bobOneTimeKey isKindOfClass:[NSString class]]);
+    
+    OLMSession *aliceSession = [[OLMSession alloc] initOutboundSessionWithAccount:alice theirIdentityKey:bobIdKey theirOneTimeKey:bobOneTimeKey error:nil];
+    NSString *message = @"Hello!";
+    OLMMessage *aliceToBobMsg = [aliceSession encryptMessage:message error:&error];
+    XCTAssertNil(error);
+    
+    OLMSession *bobSession = [[OLMSession alloc] initInboundSessionWithAccount:bob oneTimeKeyMessage:aliceToBobMsg.ciphertext error:nil];
+    NSString *plaintext = [bobSession decryptMessage:aliceToBobMsg error:&error];
+    XCTAssertEqualObjects(message, plaintext);
+    XCTAssertNil(error);
+
+    XCTAssert([bobSession matchesInboundSession:aliceToBobMsg.ciphertext]);
+    XCTAssertFalse([aliceSession matchesInboundSession:@"ARandomOtkMessage"]);
+
+    NSString *aliceIdKey = alice.identityKeys[@"curve25519"];
+    XCTAssert([bobSession matchesInboundSessionFrom:aliceIdKey oneTimeKeyMessage:aliceToBobMsg.ciphertext]);
+    XCTAssertFalse([bobSession matchesInboundSessionFrom:@"ARandomIdKey" oneTimeKeyMessage:aliceToBobMsg.ciphertext]);
+    XCTAssertFalse([bobSession matchesInboundSessionFrom:aliceIdKey oneTimeKeyMessage:@"ARandomOtkMessage"]);
+
+    BOOL success = [bob removeOneTimeKeysForSession:bobSession];
+    XCTAssertTrue(success);
+}
+
+- (void) testBackAndForth {
+    OLMAccount *alice = [[OLMAccount alloc] initNewAccount];
+    OLMAccount *bob = [[OLMAccount alloc] initNewAccount];
+    [bob generateOneTimeKeys:1];
+    NSDictionary *bobIdKeys = bob.identityKeys;
+    NSString *bobIdKey = bobIdKeys[@"curve25519"];
+    NSDictionary *bobOneTimeKeys = bob.oneTimeKeys;
+    NSParameterAssert(bobIdKey != nil);
+    NSParameterAssert(bobOneTimeKeys != nil);
+    __block NSString *bobOneTimeKey = nil;
+    NSDictionary *bobOtkCurve25519 = bobOneTimeKeys[@"curve25519"];
+    [bobOtkCurve25519 enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
+        bobOneTimeKey = obj;
+    }];
+    XCTAssert([bobOneTimeKey isKindOfClass:[NSString class]]);
+    
+    OLMSession *aliceSession = [[OLMSession alloc] initOutboundSessionWithAccount:alice theirIdentityKey:bobIdKey theirOneTimeKey:bobOneTimeKey error:nil];
+    NSString *message = @"Hello I'm Alice!";
+    OLMMessage *aliceToBobMsg = [aliceSession encryptMessage:message error:nil];
+    
+    OLMSession *bobSession = [[OLMSession alloc] initInboundSessionWithAccount:bob oneTimeKeyMessage:aliceToBobMsg.ciphertext error:nil];
+    NSString *plaintext = [bobSession decryptMessage:aliceToBobMsg error:nil];
+    XCTAssertEqualObjects(message, plaintext);
+    BOOL success = [bob removeOneTimeKeysForSession:bobSession];
+    XCTAssertTrue(success);
+    
+    NSString *msg1 = @"Hello I'm Bob!";
+    NSString *msg2 = @"Isn't life grand?";
+    NSString *msg3 = @"Let's go to the opera.";
+    
+    OLMMessage *eMsg1 = [bobSession encryptMessage:msg1 error:nil];
+    OLMMessage *eMsg2 = [bobSession encryptMessage:msg2 error:nil];
+    OLMMessage *eMsg3 = [bobSession encryptMessage:msg3 error:nil];
+    
+    NSString *dMsg1 = [aliceSession decryptMessage:eMsg1 error:nil];
+    NSString *dMsg2 = [aliceSession decryptMessage:eMsg2 error:nil];
+    NSString *dMsg3 = [aliceSession decryptMessage:eMsg3 error:nil];
+    XCTAssertEqualObjects(msg1, dMsg1);
+    XCTAssertEqualObjects(msg2, dMsg2);
+    XCTAssertEqualObjects(msg3, dMsg3);
+}
+
+- (void) testAccountSerialization {
+    OLMAccount *bob = [[OLMAccount alloc] initNewAccount];
+    [bob generateOneTimeKeys:5];
+    NSDictionary *bobIdKeys = bob.identityKeys;
+    NSDictionary *bobOneTimeKeys = bob.oneTimeKeys;
+    
+    NSData *bobData = [NSKeyedArchiver archivedDataWithRootObject:bob];
+    
+    OLMAccount *bob2 = [NSKeyedUnarchiver unarchiveObjectWithData:bobData];
+    NSDictionary *bobIdKeys2 = bob2.identityKeys;
+    NSDictionary *bobOneTimeKeys2 = bob2.oneTimeKeys;
+    
+    XCTAssertEqualObjects(bobIdKeys, bobIdKeys2);
+    XCTAssertEqualObjects(bobOneTimeKeys, bobOneTimeKeys2);
+}
+
+- (void) testSessionSerialization {
+    NSError *error;
+
+    OLMAccount *alice = [[OLMAccount alloc] initNewAccount];
+    OLMAccount *bob = [[OLMAccount alloc] initNewAccount];
+    [bob generateOneTimeKeys:1];
+    NSDictionary *bobIdKeys = bob.identityKeys;
+    NSString *bobIdKey = bobIdKeys[@"curve25519"];
+    NSDictionary *bobOneTimeKeys = bob.oneTimeKeys;
+    NSParameterAssert(bobIdKey != nil);
+    NSParameterAssert(bobOneTimeKeys != nil);
+    __block NSString *bobOneTimeKey = nil;
+    NSDictionary *bobOtkCurve25519 = bobOneTimeKeys[@"curve25519"];
+    [bobOtkCurve25519 enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
+        bobOneTimeKey = obj;
+    }];
+    XCTAssert([bobOneTimeKey isKindOfClass:[NSString class]]);
+    
+    OLMSession *aliceSession = [[OLMSession alloc] initOutboundSessionWithAccount:alice theirIdentityKey:bobIdKey theirOneTimeKey:bobOneTimeKey error:nil];
+    NSString *message = @"Hello I'm Alice!";
+    OLMMessage *aliceToBobMsg = [aliceSession encryptMessage:message error:&error];
+    XCTAssertNil(error);
+
+    
+    OLMSession *bobSession = [[OLMSession alloc] initInboundSessionWithAccount:bob oneTimeKeyMessage:aliceToBobMsg.ciphertext error:nil];
+    NSString *plaintext = [bobSession decryptMessage:aliceToBobMsg error:nil];
+    XCTAssertEqualObjects(message, plaintext);
+    BOOL success = [bob removeOneTimeKeysForSession:bobSession];
+    XCTAssertTrue(success);
+    
+    NSString *msg1 = @"Hello I'm Bob!";
+    NSString *msg2 = @"Isn't life grand?";
+    NSString *msg3 = @"Let's go to the opera.";
+    
+    OLMMessage *eMsg1 = [bobSession encryptMessage:msg1 error:nil];
+    OLMMessage *eMsg2 = [bobSession encryptMessage:msg2 error:nil];
+    OLMMessage *eMsg3 = [bobSession encryptMessage:msg3 error:nil];
+    
+    NSData *aliceData = [NSKeyedArchiver archivedDataWithRootObject:aliceSession];
+    OLMSession *alice2 = [NSKeyedUnarchiver unarchiveObjectWithData:aliceData];
+    
+    NSString *dMsg1 = [alice2 decryptMessage:eMsg1 error:nil];
+    NSString *dMsg2 = [alice2 decryptMessage:eMsg2 error:nil];
+    NSString *dMsg3 = [alice2 decryptMessage:eMsg3 error:nil];
+    XCTAssertEqualObjects(msg1, dMsg1);
+    XCTAssertEqualObjects(msg2, dMsg2);
+    XCTAssertEqualObjects(msg3, dMsg3);
+}
+
+- (void)testEd25519Signing {
+
+    OLMUtility *olmUtility = [[OLMUtility alloc] init];
+    OLMAccount *alice = [[OLMAccount alloc] initNewAccount];
+
+    NSDictionary *aJSON = @{
+                            @"key1": @"value1",
+                            @"key2": @"value2"
+                            };
+    NSData *message = [NSKeyedArchiver archivedDataWithRootObject:aJSON];
+    NSString *signature = [alice signMessage:message];
+
+
+    NSString *aliceEd25519Key = alice.identityKeys[@"ed25519"];
+
+    NSError *error;
+    BOOL result = [olmUtility verifyEd25519Signature:signature key:aliceEd25519Key message:message error:&error];
+    XCTAssert(result);
+    XCTAssertNil(error);
+}
+
+@end

xcode/Podfile

+target "OLMKit" do
+pod 'OLMKit', :path => '../OLMKit.podspec'
+end
+
+target "OLMKitTests" do
+pod 'OLMKit', :path => '../OLMKit.podspec'
+end
\ No newline at end of file

xcode/Podfile.lock

+PODS:
+  - OLMKit (2.0.1):
+    - OLMKit/olmc (= 2.0.1)
+    - OLMKit/olmcpp (= 2.0.1)
+  - OLMKit/olmc (2.0.1)
+  - OLMKit/olmcpp (2.0.1)
+
+DEPENDENCIES:
+  - OLMKit (from `../OLMKit.podspec`)
+
+EXTERNAL SOURCES:
+  OLMKit:
+    :path: ../OLMKit.podspec
+
+SPEC CHECKSUMS:
+  OLMKit: 12a35a69f92c7facdd50b559128d1b4a17857ba7
+
+PODFILE CHECKSUM: 4e261dae61d833ec5585ced2473023b98909fd35
+
+COCOAPODS: 1.1.1

xcode/README.rst

+OLMKit
+======
+
+OLMKit exposes an Objective-C wrapper to libolm.
+
+The original work by Chris Ballinger can be found at https://github.com/chrisballinger/OLMKit.
+
+Installation
+------------
+You can embed OLMKit to your application project with CocoaPods. The pod for
+the latest OLMKit release is::
+
+    pod 'OLMKit'
+
+Development
+-----------
+Run `pod install` and open `OLMKit.xcworkspace`.
+
+The project contains only tests files. The libolm and the Objective-C wrapper source files are loaded via the OLMKit CocoaPods pod.
+
+To add a new source file, add it to the file system and run `pod update` to make CocoaPods insert it into OLMKit.xcworkspace. 
+
+Release
+-------
+See ../README.rst for the release of the CocoaPod.
+