最近項(xiàng)目里需要對URL的參數(shù)進(jìn)行DES加密,研究了一下,現(xiàn)分享一下.
#封裝好的DES加密邏輯,具體調(diào)用如下:
//加密的密匙(也是解密的密匙)
NSString *str = @"abcdefghigklmnopqrstuvwxyz";
//加密
NSString *eStr = [DesEncrypt base64StringFromText:str];
NSLog(@"--%@",eStr);
//解密
NSLog(@"--%@",[DesEncrypt textFromBase64String:eStr]);
注:偏移量在內(nèi)部已經(jīng)給出(可修改),如有任何疑問歡迎留言交流!
具體實(shí)現(xiàn)參考以下代碼,也可以進(jìn)入github直接下載
DesEncrypt.h
#import <Foundation/Foundation.h>
/******字符串轉(zhuǎn)base64（包括DES加密）******/
#define __BASE64( text ) [Base64codeFunc base64StringFromText:text]
/******base64（通過DES解密）轉(zhuǎn)字符串******/
#define __TEXT( base64 ) [Base64codeFunc textFromBase64String:base64]
@interface DesEncrypt : NSObject
/************************************************************
函數(shù)名稱 : + (NSString *)base64StringFromText:(NSString *)text
函數(shù)描述 : 將文本轉(zhuǎn)換為base64格式字符串
輸入?yún)?shù) : (NSString *)text 文本
輸出參數(shù) : N/A
返回參數(shù) : (NSString *) base64格式字符串
備注信息 :
**********************************************************/
+ (NSString *)base64StringFromText:(NSString *)text;
/************************************************************
函數(shù)名稱 : + (NSString *)textFromBase64String:(NSString *)base64
函數(shù)描述 : 將base64格式字符串轉(zhuǎn)換為文本
輸入?yún)?shù) : (NSString *)base64 base64格式字符串
輸出參數(shù) : N/A
返回參數(shù) : (NSString *) 文本
備注信息 :
**********************************************************/
+ (NSString *)textFromBase64String:(NSString *)base64;
DesEncrypt.m
#import "DesEncrypt.h"
//引入IOS自帶密碼庫
#import <CommonCrypto/CommonCryptor.h>
//空字符串
#define LocalStr_None @""
static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
#define ENCRYPTKEY @"123456789"
#define ENCRYPTIV @"CCCrypr"
@implementation DesEncrypt
+ (NSString *)base64StringFromText:(NSString *)text
{
if (text && ![text isEqualToString:LocalStr_None]) {
//取項(xiàng)目的bundleIdentifier作為KEY
NSString *key = ENCRYPTKEY;//[[NSBundle mainBundle] bundleIdentifier];
NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];
//IOS 自帶DES加密 Begin
data = [self DESEncrypt:data WithKey:key];
//IOS 自帶DES加密 End
return [self base64EncodedStringFrom:data];
}
else {
return LocalStr_None;
}
}
+ (NSString *)textFromBase64String:(NSString *)base64
{
if (base64 && ![base64 isEqualToString:LocalStr_None]) {
//取項(xiàng)目的bundleIdentifier作為KEY
NSString *key = ENCRYPTKEY;//[[NSBundle mainBundle] bundleIdentifier];
NSData *data = [self dataWithBase64EncodedString:base64];
//IOS 自帶DES解密 Begin
data = [self DESDecrypt:data WithKey:key];
//IOS 自帶DES加密 End
return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
}
else {
return LocalStr_None;
}
}
/************************************************************
函數(shù)名稱 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
函數(shù)描述 : 文本數(shù)據(jù)進(jìn)行DES加密
輸入?yún)?shù) : (NSData *)data
(NSString *)key
輸出參數(shù) : N/A
返回參數(shù) : (NSData *)
備注信息 : 此函數(shù)不可用于過長文本
**********************************************************/
+ (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
char ivPtr[kCCKeySizeAES256+1];
bzero(ivPtr, sizeof(ivPtr));
[ENCRYPTIV getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [data length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(0, kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeDES,
ivPtr,
[data bytes], dataLength,
buffer, bufferSize,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer);
return nil;
}
/************************************************************
函數(shù)名稱 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
函數(shù)描述 : 文本數(shù)據(jù)進(jìn)行DES解密
輸入?yún)?shù) : (NSData *)data
(NSString *)key
輸出參數(shù) : N/A
返回參數(shù) : (NSData *)
備注信息 : 此函數(shù)不可用于過長文本
**********************************************************/
+ (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
char ivPtr[kCCKeySizeAES256+1];
bzero(ivPtr, sizeof(ivPtr));
[ENCRYPTIV getCString:ivPtr maxLength:sizeof(ivPtr) 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,
ivPtr,
[data bytes], dataLength,
buffer, bufferSize,
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer);
return nil;
}
/************************************************************
函數(shù)名稱 : + (NSData *)dataWithBase64EncodedString:(NSString *)string
函數(shù)描述 : base64格式字符串轉(zhuǎn)換為文本數(shù)據(jù)
輸入?yún)?shù) : (NSString *)string
輸出參數(shù) : N/A
返回參數(shù) : (NSData *)
備注信息 :
**********************************************************/
+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
if (string == nil)
[NSException raise:NSInvalidArgumentException format:nil];
if ([string length] == 0)
return [NSData data];
static char *decodingTable = NULL;
if (decodingTable == NULL)
{
decodingTable = malloc(256);
if (decodingTable == NULL)
return nil;
memset(decodingTable, CHAR_MAX, 256);
NSUInteger i;
for (i = 0; i < 64; i++)
decodingTable[(short)encodingTable[i]] = i;
}
const char *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];
if (characters == NULL) // Not an ASCII string!
return nil;
char *bytes = malloc((([string length] + 3) / 4) * 3);
if (bytes == NULL)
return nil;
NSUInteger length = 0;
NSUInteger i = 0;
while (YES)
{
char buffer[4];
short bufferLength;
for (bufferLength = 0; bufferLength < 4; i++)
{
if (characters[i] == '\0')
break;
if (isspace(characters[i]) || characters[i] == '=')
continue;
buffer[bufferLength] = decodingTable[(short)characters[i]];
if (buffer[bufferLength++] == CHAR_MAX) // Illegal character!
{
free(bytes);
return nil;
}
}
if (bufferLength == 0)
break;
if (bufferLength == 1) // At least two characters are needed to produce one byte!
{
free(bytes);
return nil;
}
// Decode the characters in the buffer to bytes.
bytes[length++] = (buffer[0] << 2) | (buffer[1] >> 4);
if (bufferLength > 2)
bytes[length++] = (buffer[1] << 4) | (buffer[2] >> 2);
if (bufferLength > 3)
bytes[length++] = (buffer[2] << 6) | buffer[3];
}
bytes = realloc(bytes, length);
return [NSData dataWithBytesNoCopy:bytes length:length];
}
/************************************************************
函數(shù)名稱 : + (NSString *)base64EncodedStringFrom:(NSData *)data
函數(shù)描述 : 文本數(shù)據(jù)轉(zhuǎn)換為base64格式字符串
輸入?yún)?shù) : (NSData *)data
輸出參數(shù) : N/A
返回參數(shù) : (NSString *)
備注信息 :
**********************************************************/
+ (NSString *)base64EncodedStringFrom:(NSData *)data
{
if ([data length] == 0)
return @"";
char *characters = malloc((([data length] + 2) / 3) * 4);
if (characters == NULL)
return nil;
NSUInteger length = 0;
NSUInteger i = 0;
while (i < [data length])
{
char buffer[3] = {0,0,0};
short bufferLength = 0;
while (bufferLength < 3 && i < [data length])
buffer[bufferLength++] = ((char *)[data bytes])[i++];
// Encode the bytes in the buffer to four characters, including padding "=" characters if necessary.
characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];
characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
if (bufferLength > 1)
characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
else characters[length++] = '=';
if (bufferLength > 2)
characters[length++] = encodingTable[buffer[2] & 0x3F];
else characters[length++] = '=';
}
return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
}
@end
如果想詳細(xì)了解DES算法原理,請參考http://www.cocoachina.com/bbs/read.php?tid=105524
