NSString *str = [NSString stringWithFormat:@"YWE="];   NSString *str1 = [NSString stringWithFormat:@"aa"];   NSLog(@"resultStr========%@",[CommonFunc textFromBase64String:str]);  //使用類名進行調用   NSLog(@"resultStr=========%@",[CommonFunc base64StringFromText:str1]); //使用類名進行調用 

#define __BASE64( text )    [CommonFunc base64StringFromText:text] #define __TEXT( base64 )    [CommonFunc textFromBase64String:base64] #import <Foundation/Foundation.h> @interface JKCommonFunc : NSObject /******************************************************************************  函數名稱 : + (NSString *)base64StringFromText:(NSString *)text  函數描述 : 將文本轉換為base64格式字符串  輸入參數 : (NSString *)text  文本  輸出參數 : N/A  返回參數 : (NSString *)  base64格式字符串  備注信息 :  ******************************************************************************/ + (NSString *)base64StringFromText:(NSString *)text; /******************************************************************************  函數名稱 : + (NSString *)textFromBase64String:(NSString *)base64  函數描述 : 將base64格式字符串轉換為文本  輸入參數 : (NSString *)base64 base64格式字符串  輸出參數 : N/A  返回參數 : (NSString *)  文本  備注信息 :  ******************************************************************************/ + (NSString *)textFromBase64String:(NSString *)base64; @end 

#import "CommonFunc.h"    //引入IOS自帶密碼庫  #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]) {      //取項目的bundleIdentifier作為KEY 改動了此處     //NSString *key = [[NSBundle mainBundle] bundleIdentifier];      NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];      //IOS 自帶DES加密 Begin 改動了此處     //data = [self DESEncrypt:data WithKey:key];      //IOS 自帶DES加密 End      return [self base64EncodedStringFrom:data];    }    else {      return LocalStr_None;    }  }  + (NSString *)textFromBase64String:(NSString *)base64  {    if (base64 && ![base64 isEqualToString:LocalStr_None]) {      //取項目的bundleIdentifier作為KEY  改動了此處     //NSString *key = [[NSBundle mainBundle] bundleIdentifier];      NSData *data = [self dataWithBase64EncodedString:base64];      //IOS 自帶DES解密 Begin  改動了此處     //data = [self DESDecrypt:data WithKey:key];       //IOS 自帶DES加密 End      return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];    }    else {      return LocalStr_None;    }  }  /******************************************************************************  函數名稱 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key  函數描述 : 文本數據進行DES加密  輸入參數 : (NSData *)data        (NSString *)key  輸出參數 : N/A  返回參數 : (NSData *)  備注信息 : 此函數不可用于過長文本  ******************************************************************************/  + (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;    voidvoid *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;  }  /******************************************************************************  函數名稱 : + (NSData *)DESEncrypt:(NSData *)data WithKey:(NSString *)key  函數描述 : 文本數據進行DES解密  輸入參數 : (NSData *)data      (NSString *)key  輸出參數 : N/A  返回參數 : (NSData *)  備注信息 : 此函數不可用于過長文本  ******************************************************************************/  + (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;    voidvoid *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;  }  /******************************************************************************  函數名稱 : + (NSData *)dataWithBase64EncodedString:(NSString *)string  函數描述 : base64格式字符串轉換為文本數據  輸入參數 : (NSString *)string  輸出參數 : N/A  返回參數 : (NSData *)  備注信息 :  ******************************************************************************/  + (NSData *)dataWithBase64EncodedString:(NSString *)string  {    if (string == nil)      [NSException raise:NSInvalidArgumentException format:nil];    if ([string length] == 0)      return [NSData data];    static charchar *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 charchar *characters = [string cStringUsingEncoding:NSASCIIStringEncoding];    if (characters == NULL)   // Not an ASCII string!      return nil;    charchar *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];  }  /******************************************************************************  函數名稱 : + (NSString *)base64EncodedStringFrom:(NSData *)data  函數描述 : 文本數據轉換為base64格式字符串  輸入參數 : (NSData *)data  輸出參數 : N/A  返回參數 : (NSString *)  備注信息 :   ******************************************************************************/  + (NSString *)base64EncodedStringFrom:(NSData *)data  {    if ([data length] == 0)      return @"";    charchar *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++] = ((charchar *)[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