//

 //  MYKeychainItem.m

 //  MYCrypto

 //

 //  Created by Jens Alfke on 3/26/09.

 //  Copyright 2009 Jens Alfke. All rights reserved.

 //

 #import "MYKeychainItem.h"

 #import "MYCrypto_Private.h"

 #import "MYErrorUtils.h"

 NSString* const MYCSSMErrorDomain = @"CSSMErrorDomain";

 @implementation MYKeychainItem

 - (id) initWithKeychainItemRef: (MYKeychainItemRef)itemRef;

 {

     Assert(itemRef!=NULL);

     self = [super init];

     if (self != nil) {

         _itemRef = itemRef;

         CFRetain(_itemRef);

     }

     return self;

 }

 @synthesize keychainItemRef=_itemRef;

 - (void) dealloc

 {

     if (_itemRef) CFRelease(_itemRef);

     [super dealloc];

 }

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

     // As keys are immutable, it's not necessary to make copies of them. This makes it more efficient

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

     return [self retain];

 }

 - (BOOL) isEqual: (id)obj {

     // Require the objects to be of the same class, so that a MYPublicKey will not be equal to a

     // MYKeyPair with the same public key.

     return (obj == self) || 

            ([obj class] == [self class] && CFEqual(_itemRef, [obj keychainItemRef]));

 }

 - (NSUInteger) hash {

     return CFHash(_itemRef);

 }

 - (NSArray*) _itemList {

     return $array((id)_itemRef);

 }

 #if USE_IPHONE_API

 - (CFDictionaryRef) asQuery {

     return (CFDictionaryRef) $dict( {(id)kSecClass, (id)kSecClassKey},//FIX

                                     {(id)kSecMatchItemList, self._itemList} );

 }

 #endif

 - (MYKeychain*) keychain {

 #if USE_IPHONE_API

     return [MYKeychain defaultKeychain];

 #else

     MYKeychain *keychain = nil;

     SecKeychainRef keychainRef = NULL;

     if (check(SecKeychainItemCopyKeychain((SecKeychainItemRef)_itemRef, &keychainRef), @"SecKeychainItemCopyKeychain")) {

         if (keychainRef) {

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

             CFRelease(keychainRef);

         }

     }

     return keychain;

 #endif

 }

 - (BOOL) removeFromKeychain {

 #if USE_IPHONE_API

     return check(SecItemDelete(self.asQuery), @"SecItemDelete");

 #else

     return check(SecKeychainItemDelete((SecKeychainItemRef)_itemRef), @"SecKeychainItemDelete");

 #endif

 }

 #pragma mark -

 #pragma mark DATA / METADATA ACCESSORS:

 - (NSData*) _getContents: (OSStatus*)outError {

     NSData *contents = nil;

 #if USE_IPHONE_API

 #else

 	UInt32 length = 0;

     void *bytes = NULL;

     *outError = SecKeychainItemCopyAttributesAndData(_itemRef, NULL, NULL, NULL, &length, &bytes);

     if (!*outError && bytes) {

         contents = [NSData dataWithBytes: bytes length: length];

         SecKeychainItemFreeAttributesAndData(NULL, bytes);

     }

 #endif

     return contents;

 }

 + (NSData*) _getAttribute: (SecKeychainAttrType)attr ofItem: (MYKeychainItemRef)item {

     NSData *value = nil;

 #if USE_IPHONE_API

     NSDictionary *info = $dict( {(id)kSecClass, (id)kSecClassKey},

                                 {(id)kSecMatchItemList, $array((id)item)},

                                 {(id)kSecReturnAttributes, $true} );

     CFDictionaryRef attrs;

     if (!check(SecItemCopyMatching((CFDictionaryRef)info, (CFTypeRef*)&attrs), @"SecItemCopyMatching"))

         return nil;

     CFTypeRef rawValue = CFDictionaryGetValue(attrs,attr);

     value = rawValue ?[[(id)CFMakeCollectable(rawValue) retain] autorelease] :nil;

     CFRelease(attrs);

 #else

 	UInt32 format = kSecFormatUnknown;

 	SecKeychainAttributeInfo info = {.count=1, .tag=(UInt32*)&attr, .format=&format};

     SecKeychainAttributeList *list = NULL;

     if (check(SecKeychainItemCopyAttributesAndData((SecKeychainItemRef)item, &info,

                                                    NULL, &list, NULL, NULL),

               @"SecKeychainItemCopyAttributesAndData")) {

         if (list) {

             if (list->count == 1)

                 value = [NSData dataWithBytes: list->attr->data

                                        length: list->attr->length];

             else if (list->count > 1)

                 Warn(@"Multiple values for keychain item attribute");

             SecKeychainItemFreeAttributesAndData(list, NULL);

         }

     }

 #endif

     return value;

 }

 + (NSString*) _getStringAttribute: (SecKeychainAttrType)attr ofItem: (MYKeychainItemRef)item {

     NSData *value = [self _getAttribute: attr ofItem: item];

     if (!value) return nil;

     const char *bytes = value.bytes;

     size_t length = value.length;

     if (length>0 && bytes[length-1] == 0)

         length--;           // Some values are null-terminated!?

     NSString *str = [[NSString alloc] initWithBytes: bytes length: length

                                            encoding: NSUTF8StringEncoding];

     if (!str)

         Warn(@"MYKeychainItem: Couldn't decode attr value as string");

     return [str autorelease];

 }

 - (NSString*) stringValueOfAttribute: (SecKeychainAttrType)attr {

     return [[self class] _getStringAttribute: attr ofItem: _itemRef];

 }

 + (BOOL) _setAttribute: (SecKeychainAttrType)attr ofItem: (MYKeychainItemRef)item

            stringValue: (NSString*)stringValue

 {

 #if USE_IPHONE_API

     id value = stringValue ?(id)stringValue :(id)[NSNull null];

     NSDictionary *query = $dict({(id)kSecClass, (id)kSecClassKey},

                                 {(id)kSecAttrKeyType, (id)attr},

                                 {(id)kSecMatchItemList, $array((id)item)});

     NSDictionary *attrs = $dict({(id)attr, value});

     return check(SecItemUpdate((CFDictionaryRef)query, (CFDictionaryRef)attrs), @"SecItemUpdate");

 #else

     NSData *data = [stringValue dataUsingEncoding: NSUTF8StringEncoding];

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

 	SecKeychainAttributeList list = {.count=1, .attr=&attribute};

     return check(SecKeychainItemModifyAttributesAndData((SecKeychainItemRef)item, &list, 0, NULL),

                  @"SecKeychainItemModifyAttributesAndData");

 #endif

 }

 - (BOOL) setValue: (NSString*)valueStr ofAttribute: (SecKeychainAttrType)attr {

     return [[self class] _setAttribute: attr ofItem: _itemRef stringValue: valueStr];

 }

 @end

 BOOL check(OSStatus err, NSString *what) {

     if (err) {

 #if !USE_IPHONE_API

         if (err < -2000000000)

             return checkcssm(err,what);

 #endif

         Warn(@"MYCrypto error, %@: %@", what, MYErrorName(NSOSStatusErrorDomain,err));

         return NO;

     } else

         return YES;

 }

 #if !USE_IPHONE_API

 BOOL checkcssm(CSSM_RETURN err, NSString *what) {

     if (err != CSSM_OK) {

         Warn(@"MYCrypto error, %@: %@", what, MYErrorName(MYCSSMErrorDomain,err));

         return NO;

     } else

         return YES;

 }

 #endif