iOS DES，AES加密
最近在準備面試，發現之前項目中用到的加密技術都記得不清楚了，所以總結一下。之前項目用到的加密技術一種是DES加密，用來加密發送請求的字段，保證服務器數據的安全，一種是AES加密，用於加密登錄時發送的賬號密碼數據。
一 . DES加密
DES加密屬於對稱加密算法，即信息的發送者與接受者在進行信息的傳輸與處理上使用的同一秘鑰。
直接上代碼，新建DESEncry文件，.h文件中：
#import <Foundation/Foundation.h>
@interface DESEncry : NSObject
/**
* @brief 對文本進行DES加密
*
* @param data 待加密的文本數據
* @param key 加密所有的公鑰
* @param iv 加密向量
*
* @return 加密好的數據
*/
+ (NSData *)encryptUseDES:(NSString *)string key:(NSString *)key iv:(const void *)iv;
/**
* @brief 對文本進行DES解密
*
* @param data 待解密的數據
* @param key 解密所用的公鑰
*
* @return 解密好的數據
*/
+ (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key;
@end
.m文件：
#import "DESEncry.h"
#import <CommonCrypto/CommonCryptor.h>
@implementation DESEncry
+ (NSData *)encryptUseDES:(NSString *)string key:(NSString *)key iv:(const void *)iv
{
const char *textBytes = [string UTF8String];
NSUInteger dataLength = strlen(textBytes);
NSMutableData *data = [NSMutableData new];
NSUInteger n = dataLength / 1024;
for (int i = 0; i <= n;i++){
unsigned char buffer[1024];
unsigned char temp[1024];
memset(buffer, 0, sizeof(char));
memset(temp, 0, sizeof(char));
strncpy((char*)temp,textBytes, i==n?dataLength-1024*n:1024);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding|kCCOptionECBMode,
[key UTF8String], kCCKeySizeDES,
iv,
temp, i==n?dataLength-1024*n:1024,
buffer, 1024,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
[data appendData:[NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted]];
}
}
return data;
}
+ (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [data length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeDES,
NULL,
[data bytes], dataLength,
buffer, bufferSize,
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer);
return nil;
}
@end
項目中具體調用：
NSString *str=HOST;
_hostUrl = [str stringByAppendingString:@"opt=click&page=Login"];
NSDictionary * resultdic = @{@"pwd":pwd,@"uid":uid};
NSString *strReq = [TypeConversion jsonStringWithDictionary:resultdic];
//加密
Byte iv[] = {1,2,3,4,5,6,7,8};
NSData * data = [DESEncry encryptUseDES:strReq key:@"zywl9876" iv:iv];
NSString *str5 = [[NSString alloc] initWithData:[GTMBase64 encodeData:data] encoding:NSUTF8StringEncoding];
_paramDict = @{@"_json":str5};
二 . AES加密
AES也是屬於對稱加密算法，不過安全級別比DES高。
上代碼，新建MySecurity文件，.h文件中
#import <Foundation/Foundation.h>
@interface MySecurity : NSObject
#pragma mark -根據密匙初始化
-(instancetype) initWithKey:(NSString *) key;
#pragma mark -加密
-(NSString *) AES256EncryptWithString:(NSString *) str;
#pragma mark -解密
-(NSString *) AES256DecryptWithString:(NSString *) str;
#pragma mark -獲取安全密匙
+(NSString*) getSecurityKey;
@end
.m文件：
#import "MySecurity.h"
#import "NSData+AES256.h"
@interface MySecurity ()
@property(strong,nonatomic) NSString *key;
@end
@implementation MySecurity
#pragma mark -獲取安全鑰匙
+(NSString*) getSecurityKey
{
return @"KEY";
}
#pragma mark -更加密碼密匙初始化
-(instancetype) initWithKey:(NSString *) key
{
self = [super init];
if (self)
{
self.key = key;
}
return self;
}
#pragma mark -加密
-(NSString *) AES256EncryptWithString:(NSString *) str
{
NSData *dt1 = [str dataUsingEncoding:NSUTF8StringEncoding];
NSData *dt2 = [dt1 AES256EncryptWithKey:self.key];
NSString *str2 = [dt2 base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
return str2;
}
#pragma mark -解密
-(NSString *) AES256DecryptWithString:(NSString *) str
{
NSData *dt3 = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
NSData *dt4 = [dt3 AES256DecryptWithKey:self.key];
NSString *str4 = [[NSString alloc] initWithData:dt4 encoding:NSUTF8StringEncoding];
return str4;
}
新建一個NSData的類別：
#import <Foundation/Foundation.h>
@interface NSData (AES256)
/*
加密
(NSString*)key 32位秘鑰
返回加密後的 NSData
*/
- (NSData*)AES256EncryptWithKey:(NSString*)key ;
/*
解密
(NSString*)key 32位秘鑰
返回解密後的 NSData
*/
- (NSData*)AES256DecryptWithKey:(NSString*)key ;
@end
.m文件
#import "NSData+AES256.h"
#import <CommonCrypto/CommonCryptor.h>
@implementation NSData (AES256)
- (NSData*)AES256EncryptWithKey:(NSString*)key {
char keyPtr[kCCKeySizeAES256 +1]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
[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 /* initialization vector (optional) */,
[self bytes],
dataLength, /* input */
buffer,
bufferSize, /* output */
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer);
return nil;
}
- (NSData*)AES256DecryptWithKey:(NSString*)key {
char keyPtr[kCCKeySizeAES256+1 ]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
// fetch key data
[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 /* initialization vector (optional) */,
[self bytes],
dataLength, /* input */
buffer,
bufferSize, /* output */
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer); //free the buffer;
return nil;
}
@end
項目中的具體調用：
MySecurity *security = [[MySecurity alloc] initWithKey:[MySecurity getSecurityKey]];
//AES加密
NSMutableDictionary*dic = [[NSMutableDictionary alloc]initWithObjectsAndKeys:self.userTF.text,@"LoginName",self.pswTF.text,@"Password", nil];
NSData*data = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:nil];
NSString*dataStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
NSString * str1 = [security AES256EncryptWithString:dataStr];
iOS DES，AES加密