iOS开发————数据本地化方式之SSKeychain－－基础上进行CBC加解密

 

   if (![SupportUserDefaults
retrieveUUID])

    {

        if ([SupportKeyChain
isExistUUID])

        {

            [SupportKeyChain
getKeyChainUUID];

        }

        else

        {

            //生成一个uuid的方法

            CFUUIDRef uuid =
CFUUIDCreate(NULL);

            NSString *strUuid = (__bridge
NSString*)CFUUIDCreateString(NULL, uuid);

            //将该uuid保存到keychain

            [SupportKeyChain
setKeyChainUUID:strUuid];

            CFRelease(uuid);

        }

    }

+ (NSString*)retrieveUUID {

    NSString *strUuid = (NSString*)[SupportUserDefaults
getObjectForKey:kCreateUUIDKey];

    return strUuid;

}

+ (NSObject *)getObjectForKey:(NSString *)key {

    NSUserDefaults *defaults = [NSUserDefaults
standardUserDefaults];<
15194
/p>

    NSData *encryptedData = [defaults
objectForKey:key];

    NSData *decryptedData = [NSData
getData:encryptedData
setKey:key];

    NSObject *object;

    

    if (decryptedData ==
nil) {

        object = nil;

    }else {

        object = [NSKeyedUnarchiver
unarchiveObjectWithData:decryptedData];

    }

    return object;

}

+ (NSData*)getData:(NSData *)encryptedData setKey:(NSString *)key

{

    NSData *decryptedData = [encryptedData
AES256DecryptWithKey:key];

    return decryptedData;

}

- (NSData *)AES256DecryptWithKey:(NSString *)key {

    char keyPtr[kCCKeySizeAES256+1];

    bzero(keyPtr,
sizeof(keyPtr));

    

    [key getCString:keyPtr
maxLength:sizeof(keyPtr)
encoding:NSUTF8StringEncoding];

    

    NSUInteger dataLength = [self
length];

    

    size_t bufferSize = dataLength +
kCCBlockSizeAES128;

    void *buffer =
malloc(bufferSize);

    

    size_t numBytesDecrypted =
0;

    CCCryptorStatus cryptStatus =
CCCrypt(kCCDecrypt,
kCCAlgorithmAES128,

                                          kCCOptionPKCS7Padding |
kCCOptionECBMode,

                                          keyPtr, kCCKeySizeAES256,

                                          NULL,

                                          [self
bytes], dataLength,

                                          buffer, bufferSize,

                                          &numBytesDecrypted);

    

    if (cryptStatus ==
kCCSuccess) {

        return [NSData
dataWithBytesNoCopy:buffer
length:numBytesDecrypted];

    }

    free(buffer);

    return
nil;

}

#import <Foundation/Foundation.h>

@interface SupportKeyChain :
NSObject

+ (BOOL)isExistUUID;

+ (void)setKeyChainUUID:(NSString*)strUUID;

+ (NSString*)getKeyChainUUID;

@end

#import "SupportKeyChain.h"

#import <Security/Security.h>

#import "SupportUserDefaults.h"

@implementation SupportKeyChain

+ (BOOL)isExistUUID

{

    BOOL isExistUUID =
NO;

    

    NSString* appID = [[[NSBundle
mainBundle] infoDictionary]
objectForKey:@"CFBundleIdentifier"];

    NSMutableDictionary *query = [NSMutableDictionary
dictionary];

    [query setObject:(__bridge
id)kSecClassGenericPassword
forKey:(__bridge
id)kSecClass];

    [query setObject:appID
forKey:(__bridge
id)kSecAttrAccount];

    [query setObject:(__bridge
id)kSecMatchLimitOne
forKey:(__bridge
id)kSecMatchLimit];

    [query setObject:(id)kCFBooleanTrue
forKey:(__bridge
id)kSecReturnAttributes];

    

    CFTypeRef attributesRef =
NULL;

    OSStatus result =
SecItemCopyMatching((__bridge
CFDictionaryRef)query, &attributesRef);

    

    if (result ==
noErr)

    {

        isExistUUID = YES;

    }

    else

    {

        isExistUUID = NO;

    }

    

    return isExistUUID;

}

+ (void)setKeyChainUUID:(NSString*)strUUID

{

    NSString* appID = [[[NSBundle
mainBundle] infoDictionary]
objectForKey:@"CFBundleIdentifier"];

    NSMutableDictionary *item = [NSMutableDictionary
dictionary];

    [item setObject:(__bridge
id)kSecClassGenericPassword
forKey:(__bridge
id)kSecClass];

    [item setObject:appID
forKey:(__bridge
id)kSecAttrAccount];

    [item setObject:[strUUID
dataUsingEncoding:NSUTF8StringEncoding]
forKey:(__bridge
id)kSecValueData];

    

    OSStatus err =
SecItemAdd((__bridge
CFDictionaryRef)item,
nil);

    if (err ==
noErr)

    {

        [SupportUserDefaults
saveUUID:strUUID];

    }

    else

    {

        [self
deleteKeyChainUUID];

    }

}

+ (NSString*)getKeyChainUUID

{

    NSString *strUUID =
@"";

    NSString* appID = [[[NSBundle
mainBundle] infoDictionary]
objectForKey:@"CFBundleIdentifier"];

    NSMutableDictionary *item = [NSMutableDictionary
dictionary];

    [item setObject:(__bridge
id)kSecClassGenericPassword
forKey:(__bridge
id)kSecClass];

    [item setObject:appID
forKey:(__bridge
id)kSecAttrAccount];

    [item setObject:(id)kCFBooleanTrue
forKey:(__bridge
id)kSecReturnData];

    

    CFTypeRef pass =
NULL;

    OSStatus res =
SecItemCopyMatching((__bridge
CFDictionaryRef)item, &pass);

    if(res ==
noErr )

    {

        NSData *data = (__bridge
NSData *)pass;

        

        strUUID = [[NSString
alloc] initWithBytes:[data
bytes] length:[data
length] encoding:NSUTF8StringEncoding];

        [SupportUserDefaults
saveUUID:strUUID];

    }

    

    return strUUID;

}

+ (void)deleteKeyChainUUID

{

    NSString* appID = [[[NSBundle
mainBundle] infoDictionary]
objectForKey:@"CFBundleIdentifier"];

    NSMutableDictionary* query = [NSMutableDictionary
dictionary];

    [query setObject:(__bridge
id)kSecClassGenericPassword
forKey:(__bridge
id)kSecClass];

    [query setObject:appID
forKey:(__bridge
id)kSecAttrAccount];

    [query setObject:(id)kCFBooleanTrue
forKey:(__bridge
id)kSecReturnData];

    

    OSStatus err =
SecItemDelete((__bridge
CFDictionaryRef)query);

    

    if (err ==
noErr)

    {

        

    }

    else

    {

        

    }

}

@end

+ (void)saveUUID:(NSString*)strSetUuid {

    [SupportUserDefaults
setObject:strSetUuid
key:kCreateUUIDKey];

}

+ (void)setObject:(NSObject *)object key:(NSString *)key {

    NSUserDefaults *defaults = [NSUserDefaults
standardUserDefaults];

    NSData *objectData = [NSKeyedArchiver
archivedDataWithRootObject:object];

    NSData *encryptedData = [NSData
setData:objectData
setKey:key];

    [defaults setObject:encryptedData
forKey:key];

    [defaults synchronize];

}

+ (NSData*)setData:(NSData *)data setKey:(NSString *)key

{

    NSData *encryptedData = [data
AES256EncryptWithKey:key];

    return encryptedData;

}

- (NSData *)AES256EncryptWithKey:(NSString *)key {

    char keyPtr[kCCKeySizeAES256+1];

    bzero(keyPtr,
sizeof(keyPtr));

    

    [key getCString:keyPtr
maxLength:sizeof(keyPtr)
encoding:NSUTF8StringEncoding];

    

    NSUInteger dataLength = [self
length];

    

    size_t bufferSize = dataLength +
kCCBlockSizeAES128;

    void *buffer =
malloc(bufferSize);

    

    size_t numBytesEncrypted =
0;

    CCCryptorStatus cryptStatus =
CCCrypt(kCCEncrypt,
kCCAlgorithmAES128,

                                          kCCOptionPKCS7Padding |
kCCOptionECBMode,

                                          keyPtr, kCCKeySizeAES256,

                                          NULL,

                                          [self
bytes], dataLength,

                                          buffer, bufferSize,

                                          &numBytesEncrypted);

    if (cryptStatus ==
kCCSuccess) {

        return [NSData
dataWithBytesNoCopy:buffer
length:numBytesEncrypted];

    }

    free(buffer);

    return
nil;

}