DES算法
提供高质量的数据保护，防止数据未经授权的泄露和未被察觉的修改
具有相当高的复杂性，使得破译的开销超过可能获得的利益，同时又要便于理解和掌握
DES密码体制的安全性应该不依赖于算法的保密，其安全性仅以加密密钥的保密为基础
实现经济，运行有效，并且适用于多种完全不同的应用
苹果本身支持DES加密,在项目中引入头文件 CommonCrypto/CommonCryptor.h 即可使用相关函数.
我自己对其进行了封装,支持ARC与非ARC
YXCrypto.h
//
// YXCrypto.h
// 用秘钥给字符串加密或者解密
//
// Created by YouXian on 14-3-18.
// Copyright (c) 2014年 YouXian. All rights reserved.
//
#import <Foundation/Foundation.h>
@interface YXCrypto : NSObject
/*!
* 给字符串加密
*/
+ (NSString *)DesEncryptString:(NSString*)src WithKey:(NSString *)key;
/*!
* 给字符串解密
*/
+ (NSString *)DesDecryptString:(NSString*)src WithKey:(NSString *)key;
@endYXCrypto.m
//
// YXCrypto.m
// 用秘钥给字符串加密或者解密
//
// Created by YouXian on 14-3-18.
// Copyright (c) 2014年 YouXian. All rights reserved.
//
#import "YXCrypto.h"
#import <CommonCrypto/CommonCryptor.h>
#if __has_feature(objc_arc)
// ARC
#define Auto_Release(obj)
#define Safe_Release(obj)
#else
// 非ARC
#define Auto_Release(obj) [obj autorelease]
#define Safe_Release(obj) [obj release]; obj = nil
#endif
static YXCrypto *shareInstance = nil;
@implementation YXCrypto
/*!
* 给字符串加密
*/
+ (NSString *)DesEncryptString:(NSString*)src WithKey:(NSString *)key {
NSString* strRet = @"";
if (shareInstance == nil)
{
shareInstance = [[YXCrypto alloc] init];
}
// encrypt source content
NSData* bytes = [src dataUsingEncoding:NSUTF8StringEncoding];
NSData* data = [shareInstance DesCryptWithOperation:kCCEncrypt
bytes:bytes
key:key];
// format bytes to visible string
char* pBuff = (char*)[data bytes];
for (int i=0; i<data.length; i++) {
strRet = [strRet stringByAppendingFormat:@"%02X", pBuff[i]& 0xFF];
}
return strRet;
}
/*!
* 给字符串解密
*/
+ (NSString *)DesDecryptString:(NSString*)src WithKey:(NSString *)key
{
if (shareInstance == nil)
{
shareInstance = [[YXCrypto alloc] init];
}
static unsigned char _map_ch2hex[] =
{
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
0, 0, 0, 0, 0, 0, 0, // :, ;, <, =, >, ?, @,
0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
};
// decode source content to bytes
unsigned char* bytes = (unsigned char*)malloc((src.length+1)*sizeof(unsigned char));
[[src uppercaseString] getCString:(char*)bytes maxLength:src.length+1 encoding:NSUTF8StringEncoding];
unsigned char *p1 = bytes, *p2 = bytes;
int n = src.length/2;
for (int i=0; i<n; i++) {
*p1 = _map_ch2hex[*p2-'0'] * 0x10 + _map_ch2hex[*(p2+1)-'0'];
p1++;
p2+=2;
}
NSData* data = [NSData dataWithBytes:bytes
length:n];
// decrypt source bytes
NSData* dataOut = [shareInstance DesCryptWithOperation:kCCDecrypt
bytes:data
key:key];
free(bytes);
NSString* strRet = [[NSString alloc] initWithData:dataOut
encoding:NSUTF8StringEncoding];
Auto_Release(strRet);
return strRet;
}
- (NSData *)DesCryptWithOperation:(CCOperation)operation bytes:(NSData*)bytes key:(NSString *)key {
NSUInteger dataLength = [bytes length];
size_t bufferSize = ([bytes length] + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);
unsigned char *buffer = (unsigned char *)malloc(bufferSize*sizeof(unsigned char));
memset((void*)buffer, 0, bufferSize);
size_t numBytesCrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(operation,
kCCAlgorithmDES,
kCCOptionPKCS7Padding | kCCOptionECBMode,
(void const*)[key UTF8String],
kCCKeySizeDES,
NULL,
[bytes bytes], dataLength,
(void*)buffer, bufferSize,
&numBytesCrypted);
NSData* dataRet = nil;
if (cryptStatus == kCCSuccess) {
dataRet = [[NSData alloc] initWithBytes:buffer length:numBytesCrypted];
Auto_Release(dataRet);
}
free(buffer);
return dataRet;
}
@end使用:
附录1：https://github.com/alfaromeodev/Cryptor
//
// Cryptor.h
// test
//
// Created by Da Zhang on 11/5/12.
// Copyright 2012 __MyCompanyName__. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>
@interface Cryptor : NSObject {
}
/*
all the methods below only support utf8 string
*/
+ (NSString *)encodeMD5:(NSString *)str;
+ (NSString *)encodeDES:(NSString *)plainString key:(NSString *)key;
+ (NSString *)decodeDES:(NSString *)decodedString key:(NSString*)key;
+ (NSString *)encodeBase64:(NSString *)plainString;
+ (NSString *)decodeBase64:(NSString *)decodedString;
@end//
// Cryptor.m
// test
//
// Created by Da Zhang on 11/5/12.
// Copyright 2012 __MyCompanyName__. All rights reserved.
//
#import "Cryptor.h"
@interface Cryptor ()
+ (NSString *)encodeBase64WithData:(NSData *)objData;
+ (NSData *)decodeBase64WithUTF8String:(NSString *)strBase64;
+ (NSString *)parseByte2HexString:(Byte *)bytes;
@end
static const char _base64EncodingTable[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const short _base64DecodingTable[256] = {
-2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -1, -1, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2,
-2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -2, -2, -2, -2, -2,
-2, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2
};
@implementation Cryptor
#pragma mark private section
+ (NSData *)decodeBase64WithUTF8String:(NSString *)strBase64 {
const char * objPointer = [strBase64 cStringUsingEncoding:NSUTF8StringEncoding];
int intLength = strlen(objPointer);
int intCurrent;
int i = 0, j = 0, k;
unsigned char * objResult;
objResult = calloc(intLength, sizeof(char));
// Run through the whole string, converting as we go
while ( ((intCurrent = *objPointer++) != '\0') && (intLength-- > 0) ) {
if (intCurrent == '=') {
if (*objPointer != '=' && ((i % 4) == 1)) {// || (intLength > 0)) {
// the padding character is invalid at this point -- so this entire string is invalid
free(objResult);
return nil;
}
continue;
}
intCurrent = _base64DecodingTable[intCurrent];
if (intCurrent == -1) {
// we're at a whitespace -- simply skip over
continue;
} else if (intCurrent == -2) {
// we're at an invalid character
free(objResult);
return nil;
}
switch (i % 4) {
case 0:
objResult[j] = intCurrent << 2;
break;
case 1:
objResult[j++] |= intCurrent >> 4;
objResult[j] = (intCurrent & 0x0f) << 4;
break;
case 2:
objResult[j++] |= intCurrent >>2;
objResult[j] = (intCurrent & 0x03) << 6;
break;
case 3:
objResult[j++] |= intCurrent;
break;
}
i++;
}
// mop things up if we ended on a boundary
k = j;
if (intCurrent == '=') {
switch (i % 4) {
case 1:
// Invalid state
free(objResult);
return nil;
case 2:
k++;
// flow through
case 3:
objResult[k] = 0;
}
}
// Cleanup and setup the return NSData
NSData * objData = [[[NSData alloc] initWithBytes:objResult length:j] autorelease];
free(objResult);
return objData;
}
+ (NSString *)encodeBase64WithData:(NSData *)objData {
const unsigned char * objRawData = [objData bytes];
char * objPointer;
char * strResult;
// Get the Raw Data length and ensure we actually have data
int intLength = [objData length];
if (intLength == 0) return nil;
// Setup the String-based Result placeholder and pointer within that placeholder
strResult = (char *)calloc(((intLength + 2) / 3) * 4, sizeof(char));
objPointer = strResult;
// Iterate through everything
while (intLength > 2) { // keep going until we have less than 24 bits
*objPointer++ = _base64EncodingTable[objRawData[0] >> 2];
*objPointer++ = _base64EncodingTable[((objRawData[0] & 0x03) << 4) + (objRawData[1] >> 4)];
*objPointer++ = _base64EncodingTable[((objRawData[1] & 0x0f) << 2) + (objRawData[2] >> 6)];
*objPointer++ = _base64EncodingTable[objRawData[2] & 0x3f];
// we just handled 3 octets (24 bits) of data
objRawData += 3;
intLength -= 3;
}
// now deal with the tail end of things
if (intLength != 0) {
*objPointer++ = _base64EncodingTable[objRawData[0] >> 2];
if (intLength > 1) {
*objPointer++ = _base64EncodingTable[((objRawData[0] & 0x03) << 4) + (objRawData[1] >> 4)];
*objPointer++ = _base64EncodingTable[(objRawData[1] & 0x0f) << 2];
*objPointer++ = '=';
} else {
*objPointer++ = _base64EncodingTable[(objRawData[0] & 0x03) << 4];
*objPointer++ = '=';
*objPointer++ = '=';
}
}
// Terminate the string-based result
*objPointer = '\0';
// Return the results as an NSString object
return [NSString stringWithCString:strResult encoding:NSUTF8StringEncoding];
}
+ (NSString *)parseByte2HexString:(Byte *)bytes {
NSMutableString *hexStr = [[NSMutableString alloc]init];
int i = 0;
if(bytes) {
while (bytes[i] != '\0') {
NSString *hexByte = [NSString stringWithFormat:@"%x",bytes[i] & 0xff];///16进制数
if([hexByte length]==1) [hexStr appendFormat:@"0%@", hexByte];
else [hexStr appendFormat:@"%@", hexByte];
i++;
}
}
//NSLog(@"bytes 的16进制数为:%@",hexStr);
return hexStr;
}
#pragma mark public section
+ (NSString *)encodeMD5:(NSString *)str {
const char *cStr = [str UTF8String];
unsigned char result[CC_MD5_DIGEST_LENGTH];
CC_MD5( cStr, strlen(cStr), result );
return [NSString
stringWithFormat: @"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
result[0], result[1],
result[2], result[3],
result[4], result[5],
result[6], result[7],
result[8], result[9],
result[10], result[11],
result[12], result[13],
result[14], result[15]
];
}
+ (NSString *)encodeBase64:(NSString *)plainString {
return [Cryptor encodeBase64WithData:[plainString dataUsingEncoding:NSUTF8StringEncoding]];
}
+ (NSString *)decodeBase64:(NSString *)decodedString {
NSData * objData = [Cryptor decodeBase64WithUTF8String:decodedString];
return [[NSString alloc] initWithData:objData encoding:NSUTF8StringEncoding];
}
+ (NSString *)encodeDES:(NSString *)plainString key:(NSString *)key {
NSString *ciphertext = nil;
const char *textBytes = [plainString UTF8String];
NSUInteger dataLength = strlen(textBytes);
unsigned char buffer[1024];
memset(buffer, 0, sizeof(char));
Byte iv[] = {1,2,3,4,5,6,7,8};
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
kCCAlgorithmDES,
kCCOptionPKCS7Padding,
[key UTF8String],
kCCKeySizeDES,
iv,
textBytes,
dataLength,
buffer,
1024,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
NSData *data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesEncrypted];
ciphertext = [[Cryptor encodeBase64WithData:data] autorelease];
}
return ciphertext;
}
+ (NSString *)decodeDES:(NSString*)decodedString key:(NSString*)key {
NSData* cipherData = [Cryptor decodeBase64WithUTF8String:decodedString];
unsigned char buffer[1024];
memset(buffer, 0, sizeof(char));
size_t numBytesDecrypted = 0;
Byte iv[] = {1,2,3,4,5,6,7,8};
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
kCCAlgorithmDES,
kCCOptionPKCS7Padding,
[key UTF8String],
kCCKeySizeDES,
iv,
[cipherData bytes],
[cipherData length],
buffer,
1024,
&numBytesDecrypted);
NSString* plainText = nil;
if (cryptStatus == kCCSuccess) {
NSData* data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesDecrypted];
plainText = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
}
return plainText;
}
@end附录2：AES加密
NSData+AES.h + NSData+AES.m
#import <Foundation/Foundation.h>
/**
* Adds AES encryption and decryption capabilities to NSData.
*/
@interface NSData (AES)
/**
* Encrypt NSData using AES256 with a given symmetric encryption key.
* @param key The symmetric encryption key
*/
- (NSData *)AES256EncryptWithKey:(NSString *)key;
/**
* Decrypt NSData using AES256 with a given symmetric encryption key.
* @param key The symmetric encryption key
*/
- (NSData *)AES256DecryptWithKey:(NSString *)key;
@end#import "NSData+AES.h"
#import <CommonCrypto/CommonCryptor.h>
@implementation NSData (AES)
- (NSData *)AES256EncryptWithKey:(NSString *)key
{
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
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];
//See the doc: For block ciphers, the output size will always be less than or
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES256,
NULL /* initialization vector (optional) */,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
//the returned NSData takes ownership of the buffer and will free it on deallocation
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer); //free the buffer;
return nil;
}
- (NSData *)AES256DecryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
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];
//See the doc: For block ciphers, the output size will always be less than or
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES256,
NULL /* initialization vector (optional) */,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
//the returned NSData takes ownership of the buffer and will free it on deallocation
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer); //free the buffer;
return nil;
}
@end