iOSAES加密的实现

+(NSData *)AES256ParmEncryptWithKey:(NSString *)key Encrypttext:(NSData *)text  //加密

{

char keyPtr[kCCKeySizeAES256+1];

bzero(keyPtr, sizeof(keyPtr));

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

NSUInteger dataLength = [text length];

size_t bufferSize = dataLength + kCCBlockSizeAES128;

void *buffer = malloc(bufferSize);

size_t numBytesEncrypted = 0;

CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,

kCCOptionPKCS7Padding | kCCOptionECBMode,

keyPtr, kCCBlockSizeAES128,

NULL,

[text bytes], dataLength,

buffer, bufferSize,

&numBytesEncrypted);

if (cryptStatus == kCCSuccess) {

return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];

}

free(buffer);

return nil;

}

+ (NSData *)AES256ParmDecryptWithKey:(NSString *)key Decrypttext:(NSData *)text  //解密

{

char keyPtr[kCCKeySizeAES256+1];

bzero(keyPtr, sizeof(keyPtr));

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

NSUInteger dataLength = [text length];

size_t bufferSize = dataLength + kCCBlockSizeAES128;

void *buffer = malloc(bufferSize);

size_t numBytesDecrypted = 0;

CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,

kCCOptionPKCS7Padding | kCCOptionECBMode,

keyPtr, kCCBlockSizeAES128,

NULL,

[text bytes], dataLength,

buffer, bufferSize,

&numBytesDecrypted);

if (cryptStatus == kCCSuccess) {

return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];

}

free(buffer);

return nil;

}

+(NSString *) aes256_encrypt:(NSString *)key Encrypttext:(NSString *)text

{

const char *cstr = [text cStringUsingEncoding:NSUTF8StringEncoding];

NSData *data = [NSData dataWithBytes:cstr length:text.length];

//对数据进行加密

NSData *result = [LanAES AES256ParmEncryptWithKey:key Encrypttext:data];

//转换为2进制字符串

if (result && result.length > 0) {

Byte *datas = (Byte*)[result bytes];

NSMutableString *output = [NSMutableString stringWithCapacity:result.length * 2];

for(int i = 0; i < result.length; i++){

[output appendFormat:@"%02x", datas[i]];

}

return output;

}

return nil;

}

+(NSString *) aes256_decrypt:(NSString *)key Decrypttext:(NSString *)text

{

//转换为2进制Data

NSMutableData *data = [NSMutableData dataWithCapacity:text.length / 2];

unsigned char whole_byte;

char byte_chars[3] = {'\0','\0','\0'};

int i;

for (i=0; i < [text length] / 2; i++) {

byte_chars[0] = [text characterAtIndex:i*2];

byte_chars[1] = [text characterAtIndex:i*2+1];

whole_byte = strtol(byte_chars, NULL, 16);

[data appendBytes:&whole_byte length:1];

}

//对数据进行解密

NSData* result = [LanAES  AES256ParmDecryptWithKey:key Decrypttext:data];

if (result && result.length > 0) {

return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];

}

return nil;

}