iOS base64 加密解密

在使用过程中，直接将被类引入到项目中即可，不需要其它辅助类。

使用示例：  将此通用类的头文件引入到目标类后，直接使用类名进行调用即可。

NSString *str = [NSString stringWithFormat:@"YWE="];    NSString *str1 = [NSString stringWithFormat:@"aa"];    NSLog(@"resultStr========%@",[CommonFunc textFromBase64String:str]);   //使用类名进行调用    NSLog(@"resultStr=========%@",[CommonFunc base64StringFromText:str1]);  //使用类名进行调用

在项目中遇到字符串的base64编解码，分享一下工具类：

//  //  CommonFunc.h  //  PRJ_base64  //  //  Created by wangzhipeng on 12-11-29.  //  Copyright (c) 2012年 com.comsoft. All rights reserved.  //    #import <Foundation/Foundation.h>    #define __BASE64( text )        [CommonFunc base64StringFromText:text]  #define __TEXT( base64 )        [CommonFunc textFromBase64String:base64]    @interface CommonFunc : 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

//  //  CommonFunc.m  //  PRJ_base64  //  //  Created by wangzhipeng on 12-11-29.  //  Copyright (c) 2012年 com.comsoft. All rights reserved.  //    #import "CommonFunc.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 CommonFunc    + (NSString *)base64StringFromText:(NSString *)text  {      if (text && ![text isEqualToString:LocalStr_None]) {          //取项目的bundleIdentifier作为KEY  改动了此处        //NSString *key = [[NSBundle mainBundle] bundleIdentifier];          NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];          //IOS 自带DES加密 Begin  改动了此处        //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   改动了此处        //NSString *key = [[NSBundle mainBundle] bundleIdentifier];          NSData *data = [self dataWithBase64EncodedString:base64];          //IOS 自带DES解密 Begin    改动了此处        //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+1];      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 = 0;      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+1];      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 = 0;      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] == 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)encodingTable[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];  }    /******************************************************************************  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] == 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++] = encodingTable[(buffer[0] & 0xFC) >> 2];          characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];          if (bufferLength > 1)              characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];          else characters[length++] = '=';          if (bufferLength > 2)              characters[length++] = encodingTable[buffer[2] & 0x3F];          else characters[length++] = '=';      }            return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];  }    @end