iOS开发学习中用到的3DES密码算法-优快云博客

本文介绍了一种使用ThreeDES算法进行加密和解密的方法。通过SHA1生成密钥，并利用Objective-C编程语言实现了字符串的加密与解密过程。文章详细展示了如何利用CommonCrypto库进行操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

NSString+ThreeDES.m
// 3DE
//
// Created by Brandon Zhu on 31/10/2012.
//
#import "NSString+ThreeDES.h"
#import <CommonCrypto/CommonCryptor.h>
#import <CommonCrypto/CommonDigest.h>
#import "GTMBase64.h"
// 前端与后台商量KEY
#define gkey @""
#define gIv @""
#define kSecrectKeyLength 24
@implementation NSString (ThreeDES)
+ (NSString*)encrypt:(NSString*)plainText withKey:(NSString*)key{
const charchar *cstr = [key cStringUsingEncoding:NSUTF8StringEncoding];
NSData *keyData = [NSData dataWithBytes:cstr length:key.length];
uint8_t digest[CC_SHA1_DIGEST_LENGTH];
CC_SHA1(keyData.bytes, (CC_LONG)keyData.length, digest);
uint8_t keyByte[kSecrectKeyLength];
for (int i=0; i<16; i++) {
keyByte[i] = digest[i];
}
for (int i=0; i<8; i++) {
keyByte[16+i] = digest[i];
}
NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
size_t plainTextBufferSize = [data length];
const voidvoid *vplainText = (const voidvoid *)[data bytes];
CCCryptorStatus ccStatus;
uint8_t *bufferPtr = NULL;
size_t bufferPtrSize = 0;
size_t movedBytes = 0;
bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
memset((voidvoid *)bufferPtr, 0x0, bufferPtrSize);
const voidvoid *vkey = (const voidvoid *) keyByte;
const voidvoid *vinitVec = (const voidvoid *) [gIv UTF8String];
ccStatus = CCCrypt(kCCEncrypt,
kCCAlgorithm3DES,
kCCOptionPKCS7Padding,
vkey,
kCCKeySize3DES,
vinitVec,
vplainText,
plainTextBufferSize,
(voidvoid *)bufferPtr,
bufferPtrSize,
&movedBytes);
NSData *myData = [NSData dataWithBytes:(const voidvoid *)bufferPtr length:(NSUInteger)movedBytes];
NSString *result = [GTMBase64 stringByEncodingData:myData];
return result;
}
+ (NSString*)decrypt:(NSString*)encryptText withKey:(NSString*)key{
const charchar *cstr = [key cStringUsingEncoding:NSUTF8StringEncoding];
NSData *data = [NSData dataWithBytes:cstr length:key.length];
uint8_t digest[CC_SHA1_DIGEST_LENGTH];
CC_SHA1(data.bytes, (CC_LONG)data.length, digest);
uint8_t keyByte[kSecrectKeyLength];
for (int i=0; i<16; i++) {
keyByte[i] = digest[i];
}
for (int i=0; i<8; i++) {
keyByte[16+i] = digest[i];
}
NSData *encryptData = [GTMBase64 decodeData:[encryptText dataUsingEncoding:NSUTF8StringEncoding]];
size_t plainTextBufferSize = [encryptData length];
const voidvoid *vplainText = [encryptData bytes];
CCCryptorStatus ccStatus;
uint8_t *bufferPtr = NULL;
size_t bufferPtrSize = 0;
size_t movedBytes = 0;
bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
memset((voidvoid *)bufferPtr, 0x0, bufferPtrSize);
const voidvoid *vkey = (const voidvoid *) keyByte;
const voidvoid *vinitVec = (const voidvoid *) [gIv UTF8String];
ccStatus = CCCrypt(kCCDecrypt,
kCCAlgorithm3DES,
kCCOptionPKCS7Padding,
vkey,
kCCKeySize3DES,
vinitVec,
vplainText,
plainTextBufferSize,
(voidvoid *)bufferPtr,
bufferPtrSize,
&movedBytes);
NSString *result = [[[NSString alloc] initWithData:[NSData dataWithBytes:(const voidvoid *)bufferPtr
length:(NSUInteger)movedBytes] encoding:NSUTF8StringEncoding] autorelease];
return result;
}
- (NSString*) sha1
{
const charchar *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
NSData *data = [NSData dataWithBytes:cstr length:self.length];
uint8_t digest[CC_SHA1_DIGEST_LENGTH];
CC_SHA1(data.bytes, data.length, digest);
NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
for(int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)
[output appendFormat:@"%02x", digest[i]];
return output;
}
@end