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) 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;@end
YXCrypto.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) 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#endifstatic 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 contentNSData* bytes = [src dataUsingEncoding:NSUTF8StringEncoding];NSData* data = [shareInstance DesCryptWithOperation:kCCEncryptbytes:byteskey:key];// format bytes to visible stringchar* 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 bytesunsigned 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:byteslength:n];// decrypt source bytesNSData* dataOut = [shareInstance DesCryptWithOperation:kCCDecryptbytes:datakey:key];free(bytes);NSString* strRet = [[NSString alloc] initWithData:dataOutencoding: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：/alfaromeodev/Cryptor
//// Cryptor.h// test//// Created by Da Zhang on 11/5/12.// Copyright __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 __MyCompanyName__. All rights reserved.//#import "Cryptor.h"@interface Cryptor ()+ (NSString *)encodeBase64WithData:(NSData *)objData;+ (NSData *)decodeBase64WithUTF8String:(NSString *)strBase64;+ (NSString *)parseByte2HexString:(Byte *)bytes;@endstatic 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 gowhile ( ((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 invalidfree(objResult);return nil;}continue;}intCurrent = _base64DecodingTable[intCurrent];if (intCurrent == -1) {// we're at a whitespace -- simply skip overcontinue;} 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 boundaryk = j;if (intCurrent == '=') {switch (i % 4) {case 1:// Invalid statefree(objResult);return nil;case 2:k++;// flow throughcase 3:objResult[k] = 0;}}// Cleanup and setup the return NSDataNSData * 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 dataint intLength = [objData length];if (intLength == 0) return nil;// Setup the String-based Result placeholder and pointer within that placeholderstrResult = (char *)calloc(((intLength + 2) / 3) * 4, sizeof(char));objPointer = strResult;// Iterate through everythingwhile (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 dataobjRawData += 3;intLength -= 3;}// now deal with the tail end of thingsif (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 objectreturn [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 otherwisechar 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 heresize_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 deallocationreturn [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 otherwisechar 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 heresize_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 deallocationreturn [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];}free(buffer); //free the buffer;return nil;}@end
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