//

 //  MYKeychain.m

 //  MYCrypto

 //

 //  Created by Jens Alfke on 3/23/09.

 //  Copyright 2009 Jens Alfke. All rights reserved.

 //

 #import "MYKeychain.h"

 #import "MYCrypto_Private.h"

 #import "MYDigest.h"

 #if !USE_IPHONE_API

 @interface MYKeyEnumerator : NSEnumerator

 {

     MYKeychain *_keychain;

     SecKeychainSearchRef _search;

     SecItemClass _itemClass;

 }

 - (id) initWithKeychain: (MYKeychain*)keychain

               itemClass: (SecItemClass)itemClass

              attributes: (SecKeychainAttribute[])attributes 

                   count: (unsigned)count;

 @end

 @implementation MYKeychain

 - (id) initWithKeychainRef: (SecKeychainRef)keychainRef

 {

     self = [super init];

     if (self != nil) {

         if (keychainRef) {

             CFRetain(keychainRef);

             _keychain = keychainRef;

         }

     }

     return self;

 }

 + (MYKeychain*) _readableKeychainWithRef: (SecKeychainRef)keychainRef fromPath: (NSString*)path {

     if (!keychainRef)

         return nil;

     SecKeychainStatus status;

     BOOL ok = check(SecKeychainGetStatus(keychainRef, &status), @"SecKeychainGetStatus");

     if (ok && !(status & kSecReadPermStatus)) {

         Warn(@"Can't open keychain at %@ : not readable (status=%i)", path,status);

         ok = NO;

     }

     MYKeychain *keychain = nil;

     if (ok)

         keychain = [[[self alloc] initWithKeychainRef: keychainRef] autorelease];

     CFRelease(keychainRef);

     return keychain;

 }

 + (MYKeychain*) openKeychainAtPath: (NSString*)path

 {

     Assert(path);

     SecKeychainRef keychainRef = NULL;

     if (!check(SecKeychainOpen(path.fileSystemRepresentation, &keychainRef), @"SecKeychainOpen"))

         return nil;

     return [self _readableKeychainWithRef: keychainRef fromPath: path];

 }

 + (MYKeychain*) createKeychainAtPath: (NSString*)path

                         withPassword: (NSString*)password

 {

     Assert(path);

     const char *passwordStr = [password UTF8String];

     SecKeychainRef keychainRef = NULL;

     if (!check(SecKeychainCreate(path.fileSystemRepresentation,

                                  passwordStr ?strlen(passwordStr) :0,

                                  passwordStr, 

                                  (password==nil), 

                                  NULL, 

                                  &keychainRef),

                @"SecKeychainCreate"))

         return nil;

     return [self _readableKeychainWithRef: keychainRef fromPath: path];

 }

 - (BOOL) deleteKeychainFile {

     Assert(_keychain);

     return check(SecKeychainDelete(_keychain), @"SecKeychainDelete");

 }

 - (void) dealloc

 {

     if (_keychain) CFRelease(_keychain);

     [super dealloc];

 }

 + (MYKeychain*) allKeychains

 {

     static MYKeychain *sAllKeychains;

     @synchronized(self) {

         if (!sAllKeychains)

             sAllKeychains = [[self alloc] initWithKeychainRef: nil];

     }

     return sAllKeychains;

 }

 + (MYKeychain*) defaultKeychain

 {

     static MYKeychain *sDefaultKeychain;

     @synchronized(self) {

         if (!sDefaultKeychain) {

             SecKeychainRef kc = NULL;

             OSStatus err = SecKeychainCopyDomainDefault(kSecPreferencesDomainUser,&kc);

 #if TARGET_OS_IPHONE

             // In the simulator, an app is run in a sandbox that has no keychain by default.

             // As a convenience, create one if necessary:

             if (err == errSecNoDefaultKeychain) {

                 Log(@"No default keychain in simulator; creating one...");

                 NSString *path = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,

                                                                       NSUserDomainMask, YES) objectAtIndex: 0];

                 path = [path stringByAppendingPathComponent: @"MYCrypto.keychain"];

                 sDefaultKeychain = [[self createKeychainAtPath: path withPassword: nil] retain];

                 Assert(sDefaultKeychain, @"Couldn't create default keychain");

                 SecKeychainSetDomainDefault(kSecPreferencesDomainUser, sDefaultKeychain.keychainRef);

                 Log(@"...created %@", sDefaultKeychain);

                 return sDefaultKeychain;

             }

 #endif

             if (!check(err, @"SecKeychainCopyDefault"))

                 kc = NULL;

             Assert(kc, @"No default keychain");

             sDefaultKeychain = [[self alloc] initWithKeychainRef: kc];

             CFRelease(kc);

         }

     }

     return sDefaultKeychain;

 }

 - (id) copyWithZone: (NSZone*)zone {

     // It's not necessary to make copies of Keychain objects. This makes it more efficient

     // to use instances as NSDictionary keys or store them in NSSets.

     return [self retain];

 }

 - (BOOL) isEqual: (id)obj {

     return (obj == self) || 

             ([obj isKindOfClass: [MYKeychain class]] && CFEqual(_keychain, [obj keychainRef]));

 }

 - (SecKeychainRef) keychainRef {

     return _keychain;

 }

 - (SecKeychainRef) keychainRefOrDefault {

     if (_keychain)

         return _keychain;

     else

         return [[[self class] defaultKeychain] keychainRef];

 }

 - (NSString*) path {

     if (!_keychain)

         return nil;

     char pathBuf[PATH_MAX];

     UInt32 pathLen = sizeof(pathBuf);

     if (!check(SecKeychainGetPath(_keychain, &pathLen, pathBuf), @"SecKeychainGetPath"))

         return nil;

     return [[NSFileManager defaultManager] stringWithFileSystemRepresentation: pathBuf length: pathLen];

 }

 - (NSString*) description {

     if (_keychain)

         return $sprintf(@"%@[%p, %@]", [self class], _keychain, self.path);

     else

         return $sprintf(@"%@[all]", [self class]);

 }

 #pragma mark -

 #pragma mark SEARCHING:

 - (MYKeychainItem*) itemOfClass: (SecItemClass)itemClass 

                      withDigest: (MYSHA1Digest*)pubKeyDigest 

 {

     SecKeychainAttribute attr = {.tag= (itemClass==kSecCertificateItemClass ?kSecPublicKeyHashItemAttr :kSecKeyLabel), 

                                  .length= pubKeyDigest.length, 

                                  .data= (void*) pubKeyDigest.bytes};

     MYKeyEnumerator *e = [[MYKeyEnumerator alloc] initWithKeychain: self

                                                          itemClass: itemClass

                                                         attributes: &attr count: 1];

     MYKeychainItem *item = e.nextObject;

     [e release];

     return item;

 }

 - (MYPublicKey*) publicKeyWithDigest: (MYSHA1Digest*)pubKeyDigest {

     return (MYPublicKey*) [self itemOfClass: kSecPublicKeyItemClass withDigest: pubKeyDigest];

 }   

 - (NSEnumerator*) enumeratePublicKeys {

     return [[[MYKeyEnumerator alloc] initWithKeychain: self

                                             itemClass: kSecPublicKeyItemClass

                                            attributes: NULL count: 0] autorelease];

 }

 - (NSEnumerator*) publicKeysWithAlias: (NSString*)alias {

     NSData *utf8 = [alias dataUsingEncoding: NSUTF8StringEncoding];

     SecKeychainAttribute attr = {.tag=kSecKeyAlias, .length=utf8.length, .data=(void*)utf8.bytes};

     return [[[MYKeyEnumerator alloc] initWithKeychain: self

                                             itemClass: kSecPublicKeyItemClass

                                            attributes: &attr count: 1] autorelease];

 }

 - (MYKeyPair*) keyPairWithDigest: (MYSHA1Digest*)pubKeyDigest {

     return (MYKeyPair*) [self itemOfClass: kSecPrivateKeyItemClass withDigest: pubKeyDigest];

 }

 - (NSEnumerator*) enumerateKeyPairs {

     return [[[MYKeyEnumerator alloc] initWithKeychain: self

                                             itemClass: kSecPrivateKeyItemClass

                                            attributes: NULL count: 0] autorelease];

 }

 - (MYCertificate*) certificateWithDigest: (MYSHA1Digest*)pubKeyDigest {

     return (MYCertificate*) [self itemOfClass: kSecCertificateItemClass withDigest: pubKeyDigest];

 }

 - (NSEnumerator*) enumerateCertificates {

     return [[[MYKeyEnumerator alloc] initWithKeychain: self

                                             itemClass: kSecCertificateItemClass

                                            attributes: NULL count: 0] autorelease];

 }

 - (NSEnumerator*) enumerateSymmetricKeys {

     return [[[MYKeyEnumerator alloc] initWithKeychain: self

                                             itemClass: kSecSymmetricKeyItemClass

                                            attributes: NULL count: 0] autorelease];

 }

 - (NSEnumerator*) symmetricKeysWithAlias: (NSString*)alias {

     NSData *utf8 = [alias dataUsingEncoding: NSUTF8StringEncoding];

     SecKeychainAttribute attr = {.tag=kSecKeyAlias, .length=utf8.length, .data=(void*)utf8.bytes};

     return [[[MYKeyEnumerator alloc] initWithKeychain: self

                                             itemClass: kSecSymmetricKeyItemClass

                                            attributes: &attr count: 1] autorelease];

 }

 #pragma mark -

 #pragma mark IMPORT:

 - (MYPublicKey*) importPublicKey: (NSData*)keyData {

     return [[[MYPublicKey alloc] _initWithKeyData: keyData 

                                       forKeychain: self.keychainRefOrDefault]

             autorelease];

 }

 - (MYKeyPair*) importPublicKey: (NSData*)pubKeyData 

                     privateKey: (NSData*)privKeyData 

                     alertTitle: (NSString*)title

                    alertPrompt: (NSString*)prompt {

     return [[[MYKeyPair alloc] _initWithPublicKeyData: pubKeyData

                                        privateKeyData: privKeyData

                                           forKeychain: self.keychainRefOrDefault

                                            alertTitle: (NSString*)title

                                           alertPrompt: (NSString*)prompt]

             autorelease];

 }

 - (MYKeyPair*) importPublicKey: (NSData*)pubKeyData 

                     privateKey: (NSData*)privKeyData 

 {

     return [self importPublicKey: pubKeyData privateKey: privKeyData

                       alertTitle: @"Import Private Key"

                      alertPrompt: @"To import your saved private key, please re-enter the "

                                    "passphrase you used when you exported it."];

 }

 - (MYCertificate*) importCertificate: (NSData*)data

                                 type: (CSSM_CERT_TYPE) type

                             encoding: (CSSM_CERT_ENCODING) encoding;

 {

     MYCertificate *cert = [[[MYCertificate alloc] initWithCertificateData: data 

                                                                     type: type

                                                                 encoding: encoding]

                            autorelease];

     if (cert) {

         if (!check(SecCertificateAddToKeychain(cert.certificateRef, self.keychainRefOrDefault),

                    @"SecCertificateAddToKeychain"))

             cert = nil;

     }

     return cert;

 }

 - (MYCertificate*) importCertificate: (NSData*)data {

     return [self importCertificate: data 

                               type: CSSM_CERT_X_509v3 

                           encoding: CSSM_CERT_ENCODING_BER];

 }

 - (MYSymmetricKey*) generateSymmetricKeyOfSize: (unsigned)keySizeInBits

                                      algorithm: (CCAlgorithm)algorithm

 {

     return [MYSymmetricKey _generateSymmetricKeyOfSize: keySizeInBits

                                              algorithm: algorithm inKeychain: self];

 }

 - (MYKeyPair*) generateRSAKeyPairOfSize: (unsigned)keySize {

     return [MYKeyPair _generateRSAKeyPairOfSize: keySize inKeychain: self.keychainRefOrDefault];

 }

 - (CSSM_CSP_HANDLE) CSPHandle {

     CSSM_CSP_HANDLE cspHandle = 0;

     Assert(check(SecKeychainGetCSPHandle(self.keychainRefOrDefault, &cspHandle), @"SecKeychainGetCSPHandle"));

     return cspHandle;

 }

 @end

 #pragma mark -

 @implementation MYKeyEnumerator

 - (id) initWithKeychain: (MYKeychain*)keychain

               itemClass: (SecItemClass)itemClass

              attributes: (SecKeychainAttribute[])attributes 

                   count: (unsigned)count {

     self = [super init];

     if (self) {

         _keychain = [keychain retain];

         _itemClass = itemClass;

         SecKeychainAttributeList list = {.count=count, .attr=attributes};

         if (!check(SecKeychainSearchCreateFromAttributes(keychain.keychainRef,

                                                          itemClass,

                                                          &list,

                                                          &_search),

                    @"SecKeychainSearchCreateFromAttributes")) {

             [self release];

             return nil;

         }

     }

     return self;

 }

 - (void) dealloc

 {

     [_keychain release];

     if (_search) CFRelease(_search);

     [super dealloc];

 }

 - (id) nextObject {

     if (!_search)

         return nil;

     MYPublicKey *key = nil;

     do{

         SecKeychainItemRef found = NULL;

         OSStatus err = SecKeychainSearchCopyNext(_search, &found);

         if (err || !found) {

             if (err != errSecItemNotFound)

                 check(err,@"SecKeychainSearchCopyNext");

             CFRelease(_search);

             _search = NULL;

             return nil;

         }

         switch (_itemClass) {

             case kSecPrivateKeyItemClass: {

                 MYSHA1Digest *digest = [MYPublicKey _digestOfKey: (SecKeyRef)found];

                 if (digest) {

                     MYPublicKey *publicKey = [_keychain publicKeyWithDigest: digest];

                     if (publicKey)

                         key = [[[MYKeyPair alloc] initWithPublicKeyRef: publicKey.keyRef

                                                          privateKeyRef: (SecKeyRef)found]

                                autorelease];

                     else {

                         // The matching public key won't turn up if it's embedded in a certificate;

                         // I'd have to search for certs if I wanted to look that up. Skip it for now.

                         //Warn(@"Couldn't find matching public key for private key! digest=%@",digest);

                     }

                 }

                 break;

             }

             case kSecCertificateItemClass:

                 key = [[[MYCertificate alloc] initWithCertificateRef: (SecCertificateRef)found] autorelease];

                 break;

             case kSecPublicKeyItemClass:

                 key = [[[MYPublicKey alloc] initWithKeyRef: (SecKeyRef)found] autorelease];

                 break;

         }

         CFRelease(found);

     } while (key==nil);

     return key;

 }

 @end

 #endif !USE_IPHONE_API

 /*

  Copyright (c) 2009, Jens Alfke <jens@mooseyard.com>. All rights reserved.

  Redistribution and use in source and binary forms, with or without modification, are permitted

  provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice, this list of conditions

  and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright notice, this list of conditions

  and the following disclaimer in the documentation and/or other materials provided with the

  distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR

  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 

  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-

  BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 

   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 

  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 

  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  */