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U S E R S ’ D ATA S E C U R I T YI N I O S A P P L I C A T I O N S
Odessa Innovation Week, WebCamp 2015
W H AT I S U S E R D ATA
Odessa Innovation Week, WebCamp 2015
User data is being generated during interactions with user
I T I S A D E V E L O P E R ’ S R E S P O N S I B I L I T Y T O P R O T E C T
S E N S I T I V E D ATA
Odessa Innovation Week, WebCamp 2015
U S E R D ATA S TAT E S
Odessa Innovation Week, WebCamp 2015
• Runtime data
• Stored data
• Transmitted data
W H AT C O U L D P O S S I B LY G O W R O N G ?
Odessa Innovation Week, WebCamp 2015
• Runtime data
• Stored data
• Transmitted data
C O U L D B E S T O L E N ,
M O D I F I E D O R D E L E T E D
W H AT S H O U L D W E D O ?
Odessa Innovation Week, WebCamp 2015
• Runtime data
• Stored data
• Transmitted data
encrypt storage
encrypt transport
use secure design
R U N T I M E D ATA
Odessa Innovation Week, WebCamp 2015
U I PA S T E B O A R D
• general Pasteboard is open for everyone
Odessa Innovation Week, WebCamp 2015
[[UIPasteboard generalPasteboard] setValue:@"1234 5689 3455 6604" forPasteboardType:@"card"];
• custom Pasteboards are open for current app and apps with same team ID
UIPasteboard * pasteboard = [UIPasteboard pasteboardWithName:@"my.app" create:YES];pasteboard.persistent = YES; [pasteboard setValue:@"1234 5689 3455 6604”forPasteboardType:@"card"];
U I PA S T E B O A R D
• prevent copying sensitive data
Odessa Innovation Week, WebCamp 2015
@implementation UITextView (DisableCopyPaste)- (BOOL)canPerformAction:(SEL)action withSender:(id)sender { [UIMenuController sharedMenuController].menuVisible = NO;
return NO; } @end
S N A P S H O T T I N G & S C R E E N S H O T T I N G
Odessa Innovation Week, WebCamp 2015
- (void)applicationWillResignActive:(UIApplication *)application { UIImageView * imageView = [[UIImageView alloc]initWithFrame:[self.window frame]]; [imageView setImage:[UIImage imageNamed:@"mySplash"]]; [self.window addSubview:imageView]; }
• hide any sensitive data before snapshotting
• or set your picture as snapshot
- (void)applicationWillResignActive:(UIApplication *)application { self.window.rootViewController.view.cardLabel.hidden = YES;
}
PA S S W O R D - P R O T E C T I O N
Odessa Innovation Week, WebCamp 2015
• ask password on app launching (if it’s really needed)
• ask password on entering ‘sensitive’ areas
• ask password to confirm some actions
• ask password on configuration screen
T O U C H I D
iOS8+
LocalAuthentication Framework
use as alternative to your application’s password
Odessa Innovation Week, WebCamp 2015
T O U C H I D
#import <LocalAuthentication/LocalAuthentication.h>
LAContext * myContext = [LAContext new];NSError * authError = nil;NSString * myLocalizedReasonString = @"Authenticate using your finger";if ([myContext canEvaluatePolicy:LAPolicyDevice OwnerAuthenticationWithBiometrics error:&authError]) { ...} else { NSLog(@"Authentication error %@", authError); }
Odessa Innovation Week, WebCamp 2015
T O U C H I D
[myContext evaluatePolicy: LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:myLocalizedReasonString reply:^(BOOL success, NSError * error) { if (success) { NSLog(@"User is authenticated successfully”); } else { NSLog(@"Authentication failed with error %@", error); } }];
Odessa Innovation Week, WebCamp 2015
T O U C H I Dswitch (error.code) { case LAErrorAuthenticationFailed: NSLog(@"Authentication Failed"); break; case LAErrorUserCancel: NSLog(@"User pressed Cancel button"); break; case LAErrorUserFallback: NSLog(@"User pressed \"Enter Password\""); [self showPassword]; break; default: NSLog(@"Touch ID is not configured"); [self showPassword]; break;}
Odessa Innovation Week, WebCamp 2015
S T O R E D D ATA
Odessa Innovation Week, WebCamp 2015
D O N O T S T O R E
• passwords
• keys
• any financial data
• logs!
Odessa Innovation Week, WebCamp 2015
P L A I N T E X T K E Y S A R E B A D
Odessa Innovation Week, WebCamp 2015
[Parse setApplicationId:@"GpvoqI7Ut29H...2JL1dyceOv0hV1" clientKey:@“sv8wcfIf0neo...y2m9YIwu0OxQr”];
static NSString *kMyAPIKey = @"mySecretApiKey";
P L A I N T E X T K E Y S A R E B A D
Odessa Innovation Week, WebCamp 2015
strings MyApp.app/MyApp > myapp.txt
P L A I N T E X T K E Y S A R E B A D
Odessa Innovation Week, WebCamp 2015
GpvoqI7Ut29...2JL1dyceOv0hV1 sv8wcfIf0neo...y2m9YIwu0OxQr application did finish launching window T@"UIWindow",&,N T@"UIWindow",&,N,V_window
[Parse setApplicationId:@"GpvoqI7Ut29H...2JL1dyceOv0hV1" clientKey:@“sv8wcfIf0neo...y2m9YIwu0OxQr”];
static NSString *kMyAPIKey = @"mySecretApiKey";
AV O I D P L A I N T E X T K E Y S
• store like hex strings
Odessa Innovation Week, WebCamp 2015
unsigned char myApiKey[] = { 0xAB, 0xAA, 0xBE, 0xDE, 0xEF };
• obfuscateNSString * key = [NSString stringWithFormat:@"%@%@%@%@", @"my", @"secret", @"Api", @“Key"]; NSString * key = [NSString stringWithFormat:@"%3$@%2$@%1$@%4$@", @"Api", @"secret", @"my", @"Key"];
NSString * format = [[[@"x3$yx2$z%1$yx4$@" stringByReplacingOccurrencesOfString:@"x" withString:@"%"] stringByReplacingOccurrencesOfString:@"y" withString:@"@"] stringByReplacingOccurrencesOfString:@"z" withString:@"@"];NSString * key = [NSString stringWithFormat:format, @"Api", @"secret", @"my", @"Key"];
"mySecretApiKey"
U S E E N C R Y P T E D K E Y S
1. take key in plain text
Odessa Innovation Week, WebCamp 2015
static NSString *kMyAPIKey = @"mySecretApiKey";
NSData * encryptedData = [RNEncryptor encryptData:kMyAPIKey withSettings:kRNCryptorAES256Settings password:[self calculatePassword] error:&error]; NSString * resultString = [[NSString alloc] initWithData:encryptedData
encoding:NSUTF8StringEncoding];
2. encrypt it
U S E E N C R Y P T E D K E Y S
3. hardcode encrypted key
Odessa Innovation Week, WebCamp 2015
static NSString *kMyAPIKeyEncrypted = @“789fae43c3e66113e48cebfafeef6806542c0c9062b78b686f515acb09b2c0a6";
NSData *decryptedData = [RNDecryptor decryptData:encryptedData withPassword:[self calculatePassword] error:&error];
NSString * resultString = [[NSString alloc] initWithData:encryptedData encoding:NSUTF8StringEncoding];
4. decrypt it before using
U S E E N C R Y P T E D K E Y S
5. use generated password, not static string
Odessa Innovation Week, WebCamp 2015
- (NSString * )calculatePassword { CGFloat result = (CGFloat) (1.0/23.0); return [NSString stringWithFormat:@"%.10f", result];}
@“0.0434782609” this password is calculated each time;
is not stored as string
W H E R E T O S T O R E S E N S I T I V E D ATA ?
• NSUserDefaults
• plist
• files
• database
• keychain
Odessa Innovation Week, WebCamp 2015
W H E R E T O S T O R E S E N S I T I V E D ATA ?
• NSUserDefaults
• plist
• files
• database
• keychain
Odessa Innovation Week, WebCamp 2015
U S E K E Y C H A I N
W H E R E T O S T O R E S E N S I T I V E D ATA ?
• NSUserDefaults
• plist
• files
• database
• keychain
Odessa Innovation Week, WebCamp 2015
O R U S E E N C R Y P T I O N !
E N C R Y P T A L L D ATA
C O M M O N C R Y P T O F R A M E W O R K
Odessa Innovation Week, WebCamp 2015
E N C R Y P T A L L D ATA#import <CommonCrypto/CommonCryptor.h> - (NSData *)AES256EncryptWithKey:(NSString*)key { char keyPtr[kCCKeySizeAES256 + 1]; // room for terminator (unused) bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding) [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [self length]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void* buffer = malloc(bufferSize); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL [self bytes], dataLength, /* input */ buffer, bufferSize, /* output */ &numBytesEncrypted); if (cryptStatus == kCCSuccess) { //the returned NSData takes ownership of the buffer and will free it on deallocation return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted]; } free(buffer); return nil; }
Odessa Innovation Week, WebCamp 2015
C O M M O N C R Y P T O
E N C R Y P T A L L D ATA#import <CommonCrypto/CommonCryptor.h> - (NSData *)AES256EncryptWithKey:(NSString*)key { char keyPtr[kCCKeySizeAES256 + 1]; // room for terminator (unused) bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding) [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [self length]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void* buffer = malloc(bufferSize); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL [self bytes], dataLength, /* input */ buffer, bufferSize, /* output */ &numBytesEncrypted); if (cryptStatus == kCCSuccess) { //the returned NSData takes ownership of the buffer and will free it on deallocation return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted]; } free(buffer); return nil; }
Odessa Innovation Week, WebCamp 2015
C O M M O N C R Y P T O
E N C R Y P T A L L D ATA
#import <RNCryptor/RNCryptor.h>NSData *data = [@"Data" dataUsingEncoding:NSUTF8StringEncoding];NSError *error;NSData *encryptedData = [RNEncryptor encryptData:data withSettings:kRNCryptorAES256Settings password:aPassword error:&error];
NSData *decryptedData = [RNDecryptor decryptData:encryptedData withPassword:aPassword error:&error];
Odessa Innovation Week, WebCamp 2015
https://github.com/RNCryptor/RNCryptor
U S E W R A P P E R S
E N C R Y P T A L L D ATA
#import "scell_seal.h"
NSData *data = [@"Data" dataUsingEncoding:NSUTF8StringEncoding];
TSCellSeal * cellSeal = [[TSCellSeal alloc] initWithKey:masterKeyData];NSData * encryptedMessage = [cellSeal wrapData:data context:nil error:&error];NSData * decryptedMessage = [cellSeal unwrapData:encryptedMessage context:nil error:&error];
Odessa Innovation Week, WebCamp 2015
https://github.com/cossacklabs/themis
U S E C O O L L I B R A R I E S
E N C R Y P T D ATA B A S E
SQLCipher (+FMDB)
https://github.com/sqlcipher/sqlcipher
CoreData
https://github.com/project-imas/encrypted-core-data
Odessa Innovation Week, WebCamp 2015
F I L E S P R O T E C T I O N
Odessa Innovation Week, WebCamp 2015
allows to encrypt NSFiles
Odessa Innovation Week, WebCamp 2015
* NSFileProtectionNone
* NSFileProtectionComplete Cannot be accessed while device locked.
* NSFileProtectionCompleteUnlessOpen Opens only when device is unlocked; can be accessed whenever
* NSFileProtectionCompleteUntilFirstUserAuthentication Opens only after device is booted; can be accessed whenever.
F I L E S P R O T E C T I O N
Odessa Innovation Week, WebCamp 2015
NSFileManager * fileManager = [NSFileManager defaultManager]; NSDictionary * attributes = @{ NSFileProtectionKey : NSFileProtectionComplete };[fileManager createFileAtPath:path contents:data attributes:attributes];[fileManager setAttributes:attributes ofItemAtPath:path error:&errorFolderProtect];
F I L E S P R O T E C T I O N
Odessa Innovation Week, WebCamp 2015
[SSKeychain setPassword:password forService:@"com.my.app" account:@"MyAppUserPasswordKey"];
S E C U R E K E Y C H A I N
https://github.com/soffes/sskeychain
S E C U R I T Y F R A M E W O R K O R U S E W R A P P E R S
D I S A B L E D E B U G G I N G Y O U R A P P S
Odessa Innovation Week, WebCamp 2015
typedef int (*ptrace_ptr_t)(int _request, pid_t _pid, caddr_t _addr, int _data); #if !defined(PT_DENY_ATTACH) #define PT_DENY_ATTACH 31#endif
void disable_gdb() { void* handle = dlopen(0, RTLD_GLOBAL | RTLD_NOW); ptrace_ptr_t ptrace_ptr = dlsym(handle, "ptrace"); ptrace_ptr(PT_DENY_ATTACH, 0, 0, 0); dlclose(handle); }
int main(int argc, char * argv[]) { #if !(DEBUG) // Don't interfere with Xcode debugging sessions. disable_gdb();#endif @autoreleasepool { return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); } } https://www.theiphonewiki.com/wiki/Bugging_Debuggers
T R A N S M I T T E D D ATA
Odessa Innovation Week, WebCamp 2015
S E N D I N G P L A I N T E X T D ATA
• plain text could be easily stolen or modified
• sending passwords as plain text is bad idea
Odessa Innovation Week, WebCamp 2015
S E N D I N G P L A I N T E X T D ATA
• plain text could be easily stolen or modified
• sending passwords as plain text is bad idea
Odessa Innovation Week, WebCamp 2015
U S E H T T P S !
Odessa Innovation Week, WebCamp 2015
U S I N G H T T P S
Odessa Innovation Week, WebCamp 2015
HTTPs protects only POST requests (do not use GET*)
* https://blog.httpwatch.com/2009/02/20/how-secure-are-query-strings-over-https/
U S I N G H T T P S : B A D P R A C T I C E S
• allowing self-signed certificates
Odessa Innovation Week, WebCamp 2015
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge { [challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge]; }
[AFSecurityPolicy setAllowInvalidCertificates:YES]; [AFSecurityPolicy setValidatesDomainName:NO];
• allowing invalid certificates
U S I N G H T T P S : B A D P R A C T I C E S
• allowing self-signed certificates
Odessa Innovation Week, WebCamp 2015
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge { [challenge.sender continueWithoutCredentialForAuthenticationChallenge:challenge]; }
[AFSecurityPolicy setAllowInvalidCertificates:YES]; [AFSecurityPolicy setValidatesDomainName:NO];
• allowing invalid certificates
A F N E T W O R K I N G B U G S 2 . 5 . 1 - 2 . 5 . 2
H T T P S
O N I O S 9 H T T P I S T U R N E D O F F !
Odessa Innovation Week, WebCamp 2015
(as required by App Transport Security)
H T T P S
O N I O S 9 H T T P I S T U R N E D O F F !
Odessa Innovation Week, WebCamp 2015
you should disable ATS to use HTTP
(as required by App Transport Security)
H T T P S
O N I O S 9 H T T P I S T U R N E D O F F !
Odessa Innovation Week, WebCamp 2015
you should disable ATS to use HTTP
(as required by App Transport Security)
U S I N G H T T P S : B A D P R A C T I C E S
H T T P S D O E S N ’ T M E A N T O U S E P L A I N T E X T
Odessa Innovation Week, WebCamp 2015
U S I N G H T T P S : B A D P R A C T I C E S
H T T P S D O E S N ’ T M E A N T O U S E P L A I N T E X T
Odessa Innovation Week, WebCamp 2015
anyone can generate fake SSL certificate and your app will trust him
MitM attacks lead to stolen or modified data
H T T P S I S N O T S O S E C U R E
A L L D ATA S H O U L D B E E N C R Y P T E D
Odessa Innovation Week, WebCamp 2015
For messaging you should use special crypto, not just encrypting data like for storage.
E N C R Y P T I N G C O M M U N I C AT I O N
Odessa Innovation Week, WebCamp 2015
Communication is sequence of messages
E N C R Y P T I N G C O M M U N I C AT I O N
Odessa Innovation Week, WebCamp 2015
Communication is sequence of messages
When sequence get’s recorded, it is easier to crack the key based on captured data
E N C R Y P T I N G C O M M U N I C AT I O N
Odessa Innovation Week, WebCamp 2015
Communication is sequence of messages
When sequence get’s recorded, it is easier to crack the key based on captured data
Your keys should be ephemeral, your exchange should be sequence aware, authenticated and content-
validating
E N C R Y P T I N G C O M M U N I C AT I O N
Odessa Innovation Week, WebCamp 2015
Communication is sequence of messages
When sequence get’s recorded, it is easier to crack the key based on captured data
Your keys should be ephemeral, your exchange should be sequence aware, authenticated and content-
validating
E N D T O E N D
P E R F E C T F O R WA R D S E C R E C Y
P R O N E T O T I M I N G AT TA C K S
AUTHENT ICATE MESSAGES
U S E K E Y A G R E E M E N T P R O T O C O L
E N C R Y P T I N G C O M M U N I C AT I O N
Odessa Innovation Week, WebCamp 2015
Communication is sequence of messages
When sequence get’s recorded, it is easier to crack the key based on captured data
Your keys should be ephemeral, your exchange should be sequence aware, authenticated and content-
validating
E N D T O E N D
P E R F E C T F O R WA R D S E C R E C Y
P R O N E T O T I M I N G AT TA C K S
AUTHENT ICATE MESSAGES
U S E K E Y A G R E E M E N T P R O T O C O L
E N C R Y P T I N G C O M M U N I C AT I O N
Odessa Innovation Week, WebCamp 2015
Themis (Secure Message / Secure Session) (https://github.com/cossacklabs/themis)
OTRKit (https://github.com/ChatSecure/OTRKit)
libsodium / NaCL (https://github.com/mochtu/libsodium-ios)
T H E R E ’ S A L I B F O R T H AT !
M O R E T O R E A D
Odessa Innovation Week, WebCamp 2015
• The Mobile Application Hacker's Handbook • https://books.google.com.ua/books?
id=UgVhBgAAQBAJ
• Secure Developing on iOS • https://www.isecpartners.com/media/11221/
secure_development_on_ios.pdf
M O R E T O R E A D
Odessa Innovation Week, WebCamp 2015
• Security Coding Guide • https://developer.apple.com/library/ios/
documentation/Security/Conceptual/SecureCodingGuide/Introduction.html#//apple_ref/doc/uid/TP40002477-SW1
M O R E T O R E A D
Odessa Innovation Week, WebCamp 2015
• Designing Secure User Interfaces • https://developer.apple.com/library/ios/
documentation/Security/Conceptual/SecureCodingGuide/Articles/AppInterfaces.html#//apple_ref/doc/uid/TP40002862-SW1
M O R E T O R E A D
Odessa Innovation Week, WebCamp 2015
• https://www.theiphonewiki.com/wiki/Bugging_Debuggers
• http://www.splinter.com.au/2014/09/16/storing-secret-keys/
• http://priyaaank.tumblr.com/post/81172916565/validating-ssl-certificates-in-mobile-apps
• https://www.venafi.com/blog/post/ssl-vulnerabilities-in-your-mobile-apps-what-could-possibly-go-wrong
L A S T S L I D E
@vixentael
Odessa Innovation Week, WebCamp 2015
Anastasi, iOS dev @ Stanfy