another.im-ios/Monal/Classes/AESGcm.m

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2024-11-18 14:53:52 +00:00
//
// AESGcm.m
// Monal
//
// Created by Anurodh Pokharel on 4/19/19.
// Copyright © 2019 Monal.im. All rights reserved.
//
#import "MLConstants.h"
#import "AESGcm.h"
#import <monalxmpp/monalxmpp-Swift.h>
@class MLCrypto;
@implementation AESGcm
+(MLEncryptedPayload*) encrypt:(NSData*) body keySize:(int) keySize
{
NSData* gcmKey = [self genKey:keySize];
if(!gcmKey)
{
return nil;
}
return [self encrypt:body withKey:gcmKey];
}
+(MLEncryptedPayload*) encrypt:(NSData*) body withKey:(NSData*) gcmKey
{
MLCrypto* crypto = [MLCrypto new];
EncryptedPayload* payload = [crypto encryptGCMWithKey:gcmKey decryptedContent:body];
if(payload == nil)
{
return nil;
}
NSMutableData* combinedKey = [NSMutableData dataWithData:gcmKey];
[combinedKey appendData:payload.tag];
if(combinedKey == nil)
{
return nil;
}
return [[MLEncryptedPayload alloc] initWithBody:payload.body key:combinedKey iv:payload.iv authTag:payload.tag];
}
+(NSData*) genIV
{
MLCrypto* crypto = [MLCrypto new];
return [crypto genIV];
}
+(NSData*) genKey:(int) keySize
{
uint8_t randomBytes[keySize];
if(SecRandomCopyBytes(kSecRandomDefault, keySize, randomBytes) != 0)
return nil;
return [[NSData alloc] initWithBytes:randomBytes length:keySize];
}
+(NSData*) decrypt:(NSData*) body withKey:(NSData*) key andIv:(NSData*) iv withAuth:(NSData* _Nullable) auth
{
MLCrypto* crypto = [MLCrypto new];
NSMutableData* combined = [NSMutableData new];
[combined appendData:iv];
[combined appendData:body];
[combined appendData:auth]; //if auth is nil assume it already was apended to body
NSData* toReturn = [crypto decryptGCMWithKey:key encryptedContent:combined];
return toReturn;
}
@end