ios 加密解密（包括base64，DES）非原创

.h文件

#import <Foundation/Foundation.h>

/******字符串转base64（包括DES加密）******/
#define __BASE64( text )        [Base64codeFunc base64StringFromText:text]

/******base64（通过DES解密）转字符串******/
#define __TEXT( base64 )        [Base64codeFunc textFromBase64String:base64]

@interface Base64codeFunc : NSObject

/************************************************************
 函数名称 : + (NSString *)base64StringFromText:(NSString *)text
 函数描述 : 将文本转换为base64格式字符串
 输入参数 : (NSString *)text    文本
 输出参数 : N/A
 返回参数 : (NSString *)    base64格式字符串
 备注信息 :
 **********************************************************/
+ (NSString *)base64StringFromText:(NSString *)text;

/************************************************************
 函数名称 : + (NSString *)textFromBase64String:(NSString *)base64
 函数描述 : 将base64格式字符串转换为文本
 输入参数 : (NSString *)base64  base64格式字符串
 输出参数 : N/A
 返回参数 : (NSString *)    文本
 备注信息 :
 **********************************************************/
+ (NSString *)textFromBase64String:(NSString *)base64;

@end

.m文件

#import "Base64codeFunc.h"

//引入IOS自带密码库
#import <CommonCrypto/CommonCryptor.h>

//空字符串
#define     LocalStr_None           @""

static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

@implementation Base64codeFunc

+ (NSString *)base64StringFromText:(NSString *)text
{
    if (text && ![text isEqualToString:LocalStr_None]) {
        //取项目的bundleIdentifier作为KEY
        NSString *key = [[NSBundle mainBundle] bundleIdentifier];
        NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];
        //IOS 自带DES加密 Begin
        data = [self DESEncrypt:data WithKey:key];
        //IOS 自带DES加密 End
        return [self base64EncodedStringFrom:data];
    }
    else {
        return LocalStr_None;
    }
}

+ (NSString *)textFromBase64String:(NSString *)base64
{
    if (base64 && ![base64 isEqualToString:LocalStr_None]) {
        //取项目的bundleIdentifier作为KEY
        NSString *key = [[NSBundle mainBundle] bundleIdentifier];
        NSData *data = [self dataWithBase64EncodedString:base64];
        //IOS 自带DES解密 Begin
        data = [self DESDecrypt:data WithKey:key];
        //IOS 自带DES加密 End
        return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    }
    else {
        return LocalStr_None;
    }
}

/************************************************************
 函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
 函数描述 : 文本数据进行DES加密
 输入参数 : (NSData *)data
          (NSString *)key
 输出参数 : N/A
 返回参数 : (NSData *)
 备注信息 : 此函数不可用于过长文本
 **********************************************************/
+ (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
{
    char keyPtr[kCCKeySizeAES256+];
    bzero(keyPtr, sizeof(keyPtr));

    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [data length];

    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesEncrypted = ;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmDES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCBlockSizeDES,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
    }

    free(buffer);
    return nil;
}

/************************************************************
 函数名称 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key
 函数描述 : 文本数据进行DES解密
 输入参数 : (NSData *)data
          (NSString *)key
 输出参数 : N/A
 返回参数 : (NSData *)
 备注信息 : 此函数不可用于过长文本
 **********************************************************/
+ (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key
{
    char keyPtr[kCCKeySizeAES256+];
    bzero(keyPtr, sizeof(keyPtr));

    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [data length];

    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesDecrypted = ;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmDES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCBlockSizeDES,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesDecrypted);

    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
    }

    free(buffer);
    return nil;
}

/************************************************************
 函数名称 : + (NSData *)dataWithBase64EncodedString:(NSString *)string
 函数描述 : base64格式字符串转换为文本数据
 输入参数 : (NSString *)string
 输出参数 : N/A
 返回参数 : (NSData *)
 备注信息 :
 **********************************************************/
+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
    if (string == nil)
        [NSException raise:NSInvalidArgumentException format:nil];
    if ([string length] == )
        return [NSData data];

    static char *decodingTable = NULL;
    if (decodingTable == NULL)
    {
        decodingTable = malloc();
        if (decodingTable == NULL)
            return nil;
        memset(decodingTable, CHAR_MAX, );
        NSUInteger i;
        for (i = ; i < ; 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] + ) / ) * );
    if (bytes == NULL)
        return nil;
    NSUInteger length = ;

    NSUInteger i = ;
    while (YES)
    {
        char buffer[];
        short bufferLength;
        for (bufferLength = ; bufferLength < ; 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 == )
            break;
        if (bufferLength == )      //  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[] << ) | (buffer[] >> );
        if (bufferLength > )
            bytes[length++] = (buffer[] << ) | (buffer[] >> );
        if (bufferLength > )
            bytes[length++] = (buffer[] << ) | buffer[];
    }

    bytes = realloc(bytes, length);
    return [NSData dataWithBytesNoCopy:bytes length:length];
}

/************************************************************
 函数名称 : + (NSString *)base64EncodedStringFrom:(NSData *)data
 函数描述 : 文本数据转换为base64格式字符串
 输入参数 : (NSData *)data
 输出参数 : N/A
 返回参数 : (NSString *)
 备注信息 :
 **********************************************************/
+ (NSString *)base64EncodedStringFrom:(NSData *)data
{
    if ([data length] == )
        return @"";

    char *characters = malloc((([data length] + ) / ) * );
    if (characters == NULL)
        return nil;
    NSUInteger length = ;

    NSUInteger i = ;
    while (i < [data length])
    {
        char buffer[] = {,,};
        short bufferLength = ;
        while (bufferLength <  && 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[] & 0xFC) >> ];
        characters[length++] = encodingTable[((buffer[] & 0x03) << ) | ((buffer[] & 0xF0) >> )];
        if (bufferLength > )
            characters[length++] = encodingTable[((buffer[] & 0x0F) << ) | ((buffer[] & 0xC0) >> )];
        else characters[length++] = '=';
        if (bufferLength > )
            characters[length++] = encodingTable[buffer[] & 0x3F];
        else characters[length++] = '=';
    }

    return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
}

@end

使用方法非常简单

NSString *string = @"需要加密的字符串";
//加密后的字符串
NSString *encodeString = nil;
//解密后的字符串
NSString *decodeString = nil;

- (void)stringToBase64
{
     encodeString  = __BASE64(string);
}

- (void)base64ToString
{
    decodeString = __TEXT(encodeString);
}