1 files changed, 121 insertions, 0 deletions
diff --git a/xcode/OLMKit/OLMUtility.m b/xcode/OLMKit/OLMUtility.m
new file mode 100644
index 0000000..936785a
--- /dev/null
+++ b/xcode/OLMKit/OLMUtility.m
@@ -0,0 +1,121 @@
+/*
+ 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