OLMKit: add Short Authentication String verification

(cherry picked from commit 3e954ca2729d3333ea853c878602d1696f616573)

1 files changed, 59 insertions, 0 deletions

diff --git a/xcode/OLMKit/OLMSAS.h b/xcode/OLMKit/OLMSAS.h
new file mode 100644
index 0000000..454c8e0
--- /dev/null
+++ b/xcode/OLMKit/OLMSAS.h
@@ -0,0 +1,59 @@
+/*
+ Copyright 2019 New Vector 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>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ Short Authentication String verification utility class.
+ */
+@interface OLMSAS : NSObject
+
+/**
+ Get the public key of the SAS object.
+ */
+- (NSString * _Nullable)publicKey;
+
+/**
+ Set the public key of other user.
+
+ @param theirPublicKey the other user's public key.
+ @return error the error if any.
+ */
+- (NSError* _Nullable)setTheirPublicKey:(NSString*)theirPublicKey;
+
+/**
+ Generate bytes to use for the short authentication string.
+
+ @param info extra information to mix in when generating the bytes, as per the Matrix spec.
+ @param length the size of the output buffer. For hex-based SAS as in the Matrix spec, this will be 5.
+ @return generated bytes
+ */
+- (NSData *)generateBytes:(NSString*)info length:(NSUInteger)length;
+
+/**
+ Generate a message authentication code (MAC) based on the shared secret.
+
+ @param input the message to produce the authentication code for.
+ @param info extra information to mix in when generating the MAC, as per the Matrix spec.
+ @param error the error if any.
+ @return the MAC.
+ */
+- (NSString *)calculateMac:(NSString*)input info:(NSString*)info error:(NSError* _Nullable *)error; // TODO: NSError?
+
+@end
+
+NS_ASSUME_NONNULL_END