.h
#import <Foundation/Foundation.h>
@interface EncryptAndDecrypt3DES : NSObject
/**
* 3DES加密(使用64位转码)
*
* @param plainText 要加密的字符串（如果要加密的是非字符串，要先转为json字符串）
* @param key 密钥
* @param iv 加密时用的偏移字符串
* @return 返回加密之后的字符串
*/
+ (NSString*)encrypt:(NSString*)plainText key:(NSString *)key iv:(NSString *)iv;
/**
* 3DES解密(使用64位转码)
*
* @param encryptText 要解密的字符串（此加密字符串为64位转码之后）
* @param key 密钥
* @param iv 加密时用的偏移字符串
* @return 返回解密之后的字符串（根据情况可为json字符串）
*/
+ (NSString*)decrypt:(NSString*)encryptText key:(NSString *)key iv:(NSString *)iv;
@end
.m
#import "EncryptAndDecrypt3DES.h"
#import <CommonCrypto/CommonCryptor.h>
static const char CRDEncodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
@implementation EncryptAndDecrypt3DES
//加密方法
+ (NSString*)encrypt:(NSString*)plainText key:(NSString *)key iv:(NSString *)iv {
NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
size_t plainTextBufferSize = [data length];
const void *vplainText = (const void *)[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((void *)bufferPtr, 0x0, bufferPtrSize);
const void *vkey = (const void *) [key UTF8String];
const void *vinitVec = (const void *) [iv UTF8String];
ccStatus = CCCrypt(kCCEncrypt,
kCCAlgorithm3DES,
kCCOptionPKCS7Padding,
vkey,
kCCKeySize3DES,
vinitVec,
vplainText,
plainTextBufferSize,
(void *)bufferPtr,
bufferPtrSize,
&movedBytes);
NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];
// NSString *result = [NSString crd_base64EncodedStringFrom:myData];
NSString *result = [self dataToBase64String:myData];
result = [result stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
free(bufferPtr);
return result;
}
// 解密方法
+ (NSString*)decrypt:(NSString*)encryptText key:(NSString *)key iv:(NSString *)iv {
NSData *encryptData = [self base64StringToData:encryptText];
size_t plainTextBufferSize = [encryptData length];
const void *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((void *)bufferPtr, 0x0, bufferPtrSize);
const void *vkey = (const void *) [key UTF8String];
const void *vinitVec = (const void *) [iv UTF8String];
ccStatus = CCCrypt(kCCDecrypt,
kCCAlgorithm3DES,
kCCOptionPKCS7Padding,
vkey,
kCCKeySize3DES,
vinitVec,
vplainText,
plainTextBufferSize,
(void *)bufferPtr,
bufferPtrSize,
&movedBytes);
NSString *result = [[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)bufferPtr
length:(NSUInteger)movedBytes] encoding:NSUTF8StringEncoding] ;
return result;
}
+ (NSString *)dataToBase64String:(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++] = CRDEncodingTable[(buffer[0] & 0xFC) >> 2];
characters[length++] = CRDEncodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
if (bufferLength > 1)
characters[length++] = CRDEncodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
else characters[length++] = '=';
if (bufferLength > 2)
characters[length++] = CRDEncodingTable[buffer[2] & 0x3F];
else characters[length++] = '=';
}
return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
}
+ (NSData *)base64StringToData:(NSString *)string
{
if (string == nil)
return 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)CRDEncodingTable[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];
}
@end
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