Add support for generating and verifying digital signatures

CHANGELOG.md

@@ -3,6 +3,8 @@ SwiftyRSA Changelog
 
 # [master]
 
+ - Added digital signature creation & verification support (https://github.com/TakeScoop/SwiftyRSA/pull/7)
+
 # [0.2.1]
 
  - Fixed compiler warnings for Carthage. [#8](https://github.com/TakeScoop/SwiftyRSA/issues/8)
@@ -29,4 +31,4 @@ Initial release.
 [master]: https://github.com/TakeScoop/SwiftyRSA/compare/0.2.0...master
 [0.2.1]: https://github.com/TakeScoop/SwiftyRSA/releases/tag/0.2.1
 [0.2.0]: https://github.com/TakeScoop/SwiftyRSA/releases/tag/0.2.0
-[0.1.0]: https://github.com/TakeScoop/SwiftyRSA/releases/tag/0.1.0
+[0.1.0]: https://github.com/TakeScoop/SwiftyRSA/releases/tag/0.1.0

README.md

@@ -53,6 +53,39 @@ let decryptedString = try! SwiftyRSA.decryptString(str, privateKeyPEM: pemString
 let decryptedData = try! SwiftyRSA.decryptData(data, privateKeyPEM: pemString)
 ```
 
+### Sign
+
+SwiftyRSA can sign data with a private key.  SwiftyRSA will calculate an SHA1 digest
+of the supplied `String`/`NSData` and use this to generate the digital signature.
+
+```
+// String
+let signatureString = try! SwitfyRSA.signString(str, privateKeyPEM: pemString)
+
+// Data
+let signatureData = try! SwiftyRSA.signData(data, privateKeyPEM: pemString)
+```
+
+## Verify
+
+SwiftyRSA can verify digital signatures with a public key.  SwiftyRSA will calculate 
+an SHA1 digest of the supplied `String`/`NSData` and use this to verify the digital 
+signature.
+
+```
+// String
+let verificationResult = try! SwitfyRSA.verifySignatureString(str, signature: sigString, publicKeyPEM: pemString)
+if (verificationResult) {
+    // verification was successful
+}
+
+// Data
+let verificationResult = try! SwitfyRSA.verifySignatureData(data, signature: sigData, publicKeyPEM: String)
+if (verificationResult) {
+    // verification was successful
+}
+```
+
 Advanced Usage
 --------------
 
@@ -105,6 +138,18 @@ let decryptedString = try! rsa.decryptString(str, privateKey: privKey)
 let decryptedData = try! rsa.decryptData(data, privateKey: privKey)
 ```
 
+### Sign or verify an SHA1 digest
+
+```
+let rsa = SwiftyRSA()
+let digestSignature = try! rsa.signSHA1Digest(digest, privateKey: privKey)
+
+let verificationResult = try! rsa.verifySHA1SignatureData(digest, signature: digestSignature, publicKey: pubKey)
+if (verificationResult) {
+    // verification was successful
+}
+```
+
 ### Use with Objective-C
 
 ```
@@ -122,6 +167,13 @@ NSString* privString = [NSString stringWithContentsOfFile:privPath encoding:NSUT
 
 NSString* encrypted = [SwiftyRSA encryptString:str publicKeyPEM:pubString padding:kSecPaddingPKCS1 error:nil];
 NSString* decrypted = [SwiftyRSA decryptString:encrypted privateKeyPEM:privString padding:kSecPaddingPKCS1 error:nil];
+
+NSString* signature = [SwiftyRSA signString:str] privateKeyPEM:privString error:&error];
+VerificationResult* result = [SwiftyRSA verifySignatureString:str signature:signature publicKeyDER:pubData error:&error];
+if (result.boolValue) {
+    // verification was successful
+}    
+
 ```
 
 Under the hood

SwiftyRSA.podspec

@@ -13,7 +13,7 @@ Pod::Spec.new do |s|
   s.author       = { "Scoop" => "ops@takescoop.com" }
 
   s.source       = { :git => "https://github.com/TakeScoop/SwiftyRSA.git", :tag => "0.2.1" }
-  s.source_files = "SwiftyRSA/SwiftyRSA.swift"
+  s.source_files = "SwiftyRSA/*.{swift,m,h}"
   s.framework    = "Security"
 
   s.requires_arc = true

SwiftyRSA.xcodeproj/project.pbxproj

@@ -7,6 +7,8 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		BB8460AE1CC608F6006F802C /* NSData+SHA1.h in Headers */ = {isa = PBXBuildFile; fileRef = BB8460AC1CC608F6006F802C /* NSData+SHA1.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		BB8460AF1CC608F6006F802C /* NSData+SHA1.m in Sources */ = {isa = PBXBuildFile; fileRef = BB8460AD1CC608F6006F802C /* NSData+SHA1.m */; };
 		C01F96141C5AC3E300F232AC /* SwiftyRSAObjcTests.m in Sources */ = {isa = PBXBuildFile; fileRef = C01F96131C5AC3E300F232AC /* SwiftyRSAObjcTests.m */; };
 		C03D827C1B45E649008711CF /* SwiftyRSA.h in Headers */ = {isa = PBXBuildFile; fileRef = C03D827B1B45E649008711CF /* SwiftyRSA.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		C03D82821B45E649008711CF /* SwiftyRSA.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = C03D82761B45E649008711CF /* SwiftyRSA.framework */; };
@@ -31,6 +33,8 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		BB8460AC1CC608F6006F802C /* NSData+SHA1.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "NSData+SHA1.h"; sourceTree = "<group>"; };
+		BB8460AD1CC608F6006F802C /* NSData+SHA1.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSData+SHA1.m"; sourceTree = "<group>"; };
 		C01F96131C5AC3E300F232AC /* SwiftyRSAObjcTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SwiftyRSAObjcTests.m; sourceTree = "<group>"; };
 		C03D82761B45E649008711CF /* SwiftyRSA.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = SwiftyRSA.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		C03D827A1B45E649008711CF /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
@@ -87,6 +91,8 @@
 		C03D82781B45E649008711CF /* SwiftyRSA */ = {
 			isa = PBXGroup;
 			children = (
+				BB8460AC1CC608F6006F802C /* NSData+SHA1.h */,
+				BB8460AD1CC608F6006F802C /* NSData+SHA1.m */,
 				C03D827B1B45E649008711CF /* SwiftyRSA.h */,
 				C03D82921B45E663008711CF /* SwiftyRSA.swift */,
 				C03D82791B45E649008711CF /* Supporting Files */,
@@ -141,6 +147,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				BB8460AE1CC608F6006F802C /* NSData+SHA1.h in Headers */,
 				C03D827C1B45E649008711CF /* SwiftyRSA.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -190,7 +197,7 @@
 		C03D826D1B45E649008711CF /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastSwiftUpdateCheck = 0720;
+				LastSwiftUpdateCheck = 0730;
 				LastUpgradeCheck = 0700;
 				ORGANIZATIONNAME = Scoop;
 				TargetAttributes = {
@@ -247,6 +254,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				BB8460AF1CC608F6006F802C /* NSData+SHA1.m in Sources */,
 				C03D82931B45E663008711CF /* SwiftyRSA.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

SwiftyRSA/NSData+SHA1.h

@@ -0,0 +1,15 @@
+//
+//  NSData_SHA1.h
+//  SwiftyRSA
+//
+//  Created by Paul Wilkinson on 19/04/2016.
+//  Copyright © 2016 Scoop. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface NSData (NSData_SHA1)
+
+- (nonnull NSData*) SHA1;
+
+@end

SwiftyRSA/NSData+SHA1.m

@@ -0,0 +1,22 @@
+//
+//  NSData_SHA1.h
+//  SwiftyRSA
+//
+//  Created by Paul Wilkinson on 19/04/2016.
+//  Copyright © 2016 Scoop. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+#import <CommonCrypto/CommonCrypto.h>
+
+@implementation NSData (NSData_SHA1)
+
+- (nonnull NSData*) SHA1 {
+    unsigned int outputLength = CC_SHA1_DIGEST_LENGTH;
+    unsigned char output[outputLength];
+
+    CC_SHA1(self.bytes, (unsigned int) self.length, output);
+    return [NSData dataWithBytes:output length:outputLength];
+}
+
+@end

SwiftyRSA/SwiftyRSA.h

@@ -16,4 +16,4 @@ FOUNDATION_EXPORT const unsigned char SwiftyRSAVersionString[];
 
 // In this header, you should import all the public headers of your framework using statements like #import <SwiftyRSA/PublicHeader.h>
 
-
+#import "NSData+SHA1.h"