AESUtil.m 6.11 KB
//
//  AESUtil.m
//  CocoaSecurity
//
//  Created by jhsonzhi on 16/2/18.
//
//

#import "AESUtil.h"
#import <CommonCrypto/CommonCryptor.h>



@implementation AESUtil

+(NSString *)AES128Encrypt:(NSString *)plainText key:(NSString *)key
{
    char keyPtr[kCCKeySizeAES128+1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    memset(buffer, 0, bufferSize);
    size_t numBytesCrypted = 0;
    
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          kCCAlgorithmAES128,
                                          kCCOptionECBMode | kCCOptionPKCS7Padding,  //服务器使用ECB,这里对应
                                          keyPtr,
                                          kCCKeySizeAES128,
                                          NULL,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        return [GTMBase64 stringByEncodingData:resultData];
    }
    free(buffer);
    return nil;
}

+(NSString *)AES128Decrypt:(NSString *)encryptText key:(NSString *)key
{
    char keyPtr[kCCKeySizeAES128 + 1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSData *data = [GTMBase64 decodeData:[encryptText dataUsingEncoding:NSUTF8StringEncoding]];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    
    size_t numBytesCrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          kCCAlgorithmAES128,
                                          kCCOptionECBMode | kCCOptionPKCS7Padding,
                                          keyPtr,
                                          kCCBlockSizeAES128,
                                          NULL,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        return [[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
    }
    free(buffer);
    return nil;
}

+(NSString *)AES128Encrypt:(NSString *)plainText key:(NSString *)key iv:(NSString *)iv
{
    char keyPtr[kCCKeySizeAES128+1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    
    char cIv[kCCBlockSizeAES128+1];
    if (iv) {
        memset(cIv, 0, sizeof(cIv));
        [iv getCString:cIv maxLength:sizeof(cIv) encoding:NSUTF8StringEncoding];
    }
    
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    memset(buffer, 0, bufferSize);
    size_t numBytesCrypted = 0;
    
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          kCCAlgorithmAES128,
                                          iv ? kCCOptionPKCS7Padding : (kCCOptionECBMode | kCCOptionPKCS7Padding),
                                          keyPtr,
                                          kCCKeySizeAES128,
                                          iv ? cIv: NULL,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        return [GTMBase64 stringByEncodingData:resultData];
    }
    free(buffer);
    return nil;
}

+(NSString *)AES128Decrypt:(NSString *)encryptText key:(NSString *)key iv:(NSString *)iv
{
    char keyPtr[kCCKeySizeAES128 + 1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    char cIv[kCCBlockSizeAES128+1];
    if (iv) {
        memset(cIv, 0, sizeof(cIv));
        [iv getCString:cIv maxLength:sizeof(cIv) encoding:NSUTF8StringEncoding];
    }
    
    NSData *data = [GTMBase64 decodeData:[encryptText dataUsingEncoding:NSUTF8StringEncoding]];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    
    size_t numBytesCrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          kCCAlgorithmAES128,
                                          iv ? kCCOptionPKCS7Padding : (kCCOptionECBMode | kCCOptionPKCS7Padding),
                                          keyPtr,
                                          kCCBlockSizeAES128,
                                          iv ? cIv: NULL,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        return [[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
    }
    free(buffer);
    return nil;
}

@end