sketch of the identity key stuff

Author: corbett

TextSecureiOS.xcodeproj/project.pbxproj

@@ -2542,11 +2542,8 @@
 				B639AF0D17F5A68100B2244D /* TSNetworkManager.m in Sources */,
 				6FCE040C18D427CE00C33B34 /* TSStartOverSegue.m in Sources */,
 				B63A72161808B8AF00C353F2 /* VerificationCodeViewController.m in Sources */,
-<<<<<<< HEAD
 				A57297DB18E7579F00C8612E /* TSScanIdentityBarcodeViewController.m in Sources */,
-=======
 				FCD30FC918FDBBB7003BD188 /* SignUpStepsViewController.m in Sources */,
->>>>>>> b4cc1284f8f6766b71175818c20063816736fad0
 				8CF7BD9B1870F23D0023A781 /* TSUserKeysDatabase.m in Sources */,
 				8CF7BD951870C8450023A781 /* TSStorageMasterKey.m in Sources */,
 				B6F10B1717EF4A3A00723719 /* NSLocale+phonePrefixes.m in Sources */,
@@ -2799,10 +2796,7 @@
 				LIBRARY_SEARCH_PATHS = "$(inherited)/**";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE = "93C0EB7E-BB96-48CE-9F6A-65CC2BE78DB3";
-<<<<<<< HEAD
-=======
 				TARGETED_DEVICE_FAMILY = "1,2";
->>>>>>> b4cc1284f8f6766b71175818c20063816736fad0
 				USER_HEADER_SEARCH_PATHS = "$(SRCROOT)/Libraries/include/**";
 				WRAPPER_EXTENSION = app;
 			};

TextSecureiOS.xcodeproj/project.pbxproj~

@@ -12,6 +12,7 @@
 @interface Cryptography : NSObject
 +(NSMutableData*) generateRandomBytes:(int)numberBytes;
 #pragma mark SHA and HMAC methods
++(NSData*) computeSHA256:(NSData *)data truncatedToBytes:(int)truncatedBytes;
 +(NSString*)truncatedSHA1Base64EncodedWithoutPadding:(NSString*)string;
 + (NSString*)computeSHA1DigestForString:(NSString*)input;
 

TextSecureiOS/Security/Cryptography.h

@@ -64,7 +64,15 @@ + (NSString*)computeSHA1DigestForString:(NSString*)input {
     return output;
 }
 
-#pragma HMAC/SHA256
+#pragma makr SHA256
++(NSData*) computeSHA256:(NSData *)data truncatedToBytes:(int)truncatedBytes {
+  uint8_t digest[CC_SHA256_DIGEST_LENGTH];
+  CC_SHA256(data.bytes, data.length, digest);
+  return [[NSData dataWithBytes:digest length:CC_SHA256_DIGEST_LENGTH] subdataWithRange:NSMakeRange(0, truncatedBytes)];
+}
+
+
+#pragma mark HMAC/SHA256
 +(NSData*) computeSHA256HMAC:(NSData*)dataToHMAC withHMACKey:(NSData*)HMACKey{
     uint8_t ourHmac[CC_SHA256_DIGEST_LENGTH] = {0};
     CCHmac(kCCHmacAlgSHA256,

TextSecureiOS/Security/Cryptography.m

@@ -42,5 +42,6 @@
 +(void) removeAllKeychainItems;
 +(BOOL) hasVerifiedPhoneNumber;
 
++(NSData*) getFingerprintFromIdentityKey:(NSData*)identityKey;
 
 @end

TextSecureiOS/Security/TSKeyManager.h

@@ -100,4 +100,9 @@ + (NSNumber*) getUserDeviceId{
     return [NSNumber numberWithInt:1];
 }
 
++(NSData*) getFingerprintFromIdentityKey:(NSData*)identityKey {
+  //16-byte truncated sha-256 of public key including version byte
+  return [Cryptography computeSHA256:identityKey truncatedToBytes:16];
+}
+
 @end

TextSecureiOS/Security/TSKeyManager.m

@@ -50,11 +50,11 @@ -(void) setupThread  {
 
 
 -(void)verifyIdentity:(id)sender {
-    [self performSegueWithIdentifier:@"VerifyIdentitySegue" sender:sender];
+    [self performSegueWithIdentifier:@"IdentityVerifySegue" sender:sender];
 }
 
 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
-    if ([[segue identifier] isEqualToString:@"VerifyIdentitySegue"])  {
+    if ([[segue identifier] isEqualToString:@"IdentityVerifySegue"])  {
 
         ((TSVerifyIdentityViewController*)segue.destinationViewController).contact = self.contact;
     }