Add more methods to handle RSA keys.

- Check if a RSA key exists
- Get a RSA Key as `SecKeyRef`.

Author: hzalaz

Example/Tests/A0SimpleKeychainSpec.m

@@ -22,7 +22,10 @@
 
 #import "Specta.h"
 #import "A0SimpleKeychain.h"
+#import "A0SimpleKeychain+KeyPair.h"
 
+#define kPublicKeyTag @"public"
+#define kPrivateKeyTag @"private"
 
 SpecBegin(A0SimpleKeychain)
 
@@ -206,6 +209,94 @@
             expect([keychain dataForKey:key]).notTo.beNil();
         });
     });
+
+    describe(@"generate key pair", ^{
+
+        beforeEach(^{
+            keychain = [A0SimpleKeychain keychain];
+        });
+
+        afterEach(^{
+            [keychain deleteRSAKeyWithTag:kPublicKeyTag];
+            [keychain deleteRSAKeyWithTag:kPrivateKeyTag];
+        });
+
+        it(@"should generate a key pair", ^{
+            [keychain generateRSAKeyPairWithLength:A0SimpleKeychainRSAKeySize1024Bits
+                                      publicKeyTag:kPublicKeyTag
+                                     privateKeyTag:kPrivateKeyTag];
+            expect([keychain dataForRSAKeyWithTag:kPublicKeyTag]).notTo.beNil();
+            expect([keychain dataForRSAKeyWithTag:kPrivateKeyTag]).notTo.beNil();
+        });
+
+        sharedExamplesFor(@"failed RSA key generation", ^(NSDictionary *data) {
+
+            it(@"should fail with NSAssert", ^{
+                expect(^{
+                    [keychain generateRSAKeyPairWithLength:A0SimpleKeychainRSAKeySize1024Bits
+                                              publicKeyTag:data[@"publicTag"]
+                                             privateKeyTag:data[@"privateTag"]];
+                }).to.raise(NSInternalInconsistencyException);
+            });
+
+        });
+
+        itShouldBehaveLike(@"failed RSA key generation", @{
+                                                           @"publicTag": kPublicKeyTag,
+                                                           });
+
+        itShouldBehaveLike(@"failed RSA key generation", @{
+                                                           @"privateTag": kPrivateKeyTag,
+                                                           });
+
+        itShouldBehaveLike(@"failed RSA key generation", @{});
+    });
+
+    describe(@"obtain RSA key as NSData", ^{
+
+        beforeEach(^{
+            keychain = [A0SimpleKeychain keychain];
+            [keychain generateRSAKeyPairWithLength:A0SimpleKeychainRSAKeySize1024Bits
+                                      publicKeyTag:kPublicKeyTag
+                                     privateKeyTag:kPrivateKeyTag];
+        });
+
+        afterEach(^{
+            [keychain deleteRSAKeyWithTag:kPublicKeyTag];
+            [keychain deleteRSAKeyWithTag:kPrivateKeyTag];
+        });
+
+        it(@"should obtain keys", ^{
+            expect([keychain dataForRSAKeyWithTag:kPublicKeyTag]).notTo.beNil();
+            expect([keychain dataForRSAKeyWithTag:kPrivateKeyTag]).notTo.beNil();
+        });
+    });
+
+    describe(@"check if RSA key exists", ^{
+
+        beforeEach(^{
+            keychain = [A0SimpleKeychain keychain];
+            [keychain generateRSAKeyPairWithLength:A0SimpleKeychainRSAKeySize1024Bits
+                                      publicKeyTag:kPublicKeyTag
+                                     privateKeyTag:kPrivateKeyTag];
+        });
+
+        afterEach(^{
+            [keychain deleteRSAKeyWithTag:kPublicKeyTag];
+            [keychain deleteRSAKeyWithTag:kPrivateKeyTag];
+        });
+
+        it(@"should check if the key exists", ^{
+            expect([keychain hasRSAKeyWithTag:kPublicKeyTag]).to.beTruthy();
+            expect([keychain hasRSAKeyWithTag:kPrivateKeyTag]).to.beTruthy();
+        });
+
+        it(@"should return NO for nonexisting key", ^{
+            expect([keychain hasRSAKeyWithTag:@"NONEXISTENT"]).to.beFalsy();
+        });
+    });
+
+    
 });
 
 SpecEnd

Pod/Classes/A0SimpleKeychain+KeyPair.h

@@ -65,6 +65,24 @@ typedef NS_ENUM(NSUInteger, A0SimpleKeychainRSAKeySize) {
  */
 - (BOOL)deleteRSAKeyWithTag:(NSString *)keyTag;
 
+/**
+ *  Returns a RSA key as `SecKeyRef`. You must release it when you're done with it
+ *
+ *  @param keyTag tag of the RSA Key
+ *
+ *  @return SecKeyRef of RSA Key
+ */
+- (SecKeyRef)keyRefOfRSAKeyWithTag:(NSString *)keyTag;
+
+/**
+ *  Checks if a RSA key exists with a given tag.
+ *
+ *  @param keyTag tag of RSA Key
+ *
+ *  @return if the key exists or not.
+ */
+- (BOOL)hasRSAKeyWithTag:(NSString *)keyTag;
+
 @end
 
 @interface A0SimpleKeychain (Deprecated)

Pod/Classes/A0SimpleKeychain+KeyPair.m

@@ -79,6 +79,21 @@ - (NSData *)dataForRSAKeyWithTag:(NSString *)keyTag {
     return data;
 }
 
+- (BOOL)hasRSAKeyWithTag:(NSString *)keyTag {
+    NSAssert(keyTag.length > 0, @"key tag should be non-empty!");
+
+    NSDictionary *publicKeyQuery = @{
+                                     (__bridge id)kSecClass: (__bridge id)kSecClassKey,
+                                     (__bridge id)kSecAttrApplicationTag: [keyTag dataUsingEncoding:NSUTF8StringEncoding],
+                                     (__bridge id)kSecAttrType: (__bridge id)kSecAttrKeyTypeRSA,
+                                     (__bridge id)kSecReturnData: @NO,
+                                     };
+
+    OSStatus status = SecItemCopyMatching((__bridge CFDictionaryRef)publicKeyQuery, NULL);
+    return status == errSecSuccess;
+}
+
+
 - (BOOL)deleteRSAKeyWithTag:(NSString *)keyTag {
     NSAssert(keyTag.length > 0, @"key tag should be non-empty!");
     NSDictionary *deleteKeyQuery = @{
@@ -91,6 +106,22 @@ - (BOOL)deleteRSAKeyWithTag:(NSString *)keyTag {
     return status == errSecSuccess;
 }
 
+- (SecKeyRef)keyRefOfRSAKeyWithTag:(NSString *)keyTag {
+    NSAssert(keyTag.length > 0, @"key tag should be non-empty!");
+    NSDictionary *query = @{
+                            (__bridge id)kSecClass: (__bridge id)kSecClassKey,
+                            (__bridge id)kSecAttrKeyType: (__bridge id)kSecAttrKeyTypeRSA,
+                            (__bridge id)kSecReturnRef: @YES,
+                            (__bridge id)kSecAttrApplicationTag: keyTag,
+                            };
+    SecKeyRef privateKeyRef = NULL;
+    OSStatus status = SecItemCopyMatching((__bridge CFDictionaryRef)query, (CFTypeRef *)&privateKeyRef);
+    if (status != errSecSuccess) {
+        return NULL;
+    }
+    return privateKeyRef;
+}
+
 @end
 
 @implementation A0SimpleKeychain (Deprecated)