IOS加密 AES 256算法(EncryptAndDecrypt.h)

      EncryptAndDecrypt.h
      #import <Foundation/Foundation.h>
      @class NSString;
      @interface NSData (Encryption)
      - (NSData *)AES256EncryptWithKey:(NSData *)key;   //加密
      - (NSData *)AES256DecryptWithKey:(NSData *)key;   //解密
      - (NSString *)newStringInBase64FromData;            //追加64编码
      + (NSString*)base64encode:(NSString*)str;           //同上64编码
      +(NSData*)stringToByte:(NSString*)string;
      +(NSString*)byteToString:(NSData*)data;
      @end
  
 

  
 
 

      ///EncryptAndDecrypt.m
      #import "EncryptAndDecrypt.h"
      #import <CommonCrypto/CommonCrypto.h>
      static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
      @implementation NSData (Encryption)
      - (NSData *)AES256EncryptWithKey:(NSData *)key //加密
      {
         //AES256加密，密钥应该是32位的
         const void * keyPtr2 = [key bytes];
         char (*keyPtr)[32] = keyPtr2;
         //对于块加密算法，输出大小总是等于或小于输入大小加上一个块的大小
         //所以在下边需要再加上一个块的大小
          NSUInteger dataLength = [self length];
         size_t bufferSize = dataLength + kCCBlockSizeAES128;
         void *buffer = malloc(bufferSize);
         size_t numBytesEncrypted = 0;
          CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
                                                kCCOptionPKCS7Padding/*这里就是刚才说到的PKCS7Padding填充了*/| kCCOptionECBMode,
                                                [key bytes], kCCKeySizeAES256,
                                               NULL,/* 初始化向量(可选) */
                                                [self bytes], dataLength,/*输入*/
                                                buffer, bufferSize,/* 输出 */
                                                &numBytesEncrypted);
         if (cryptStatus == kCCSuccess) {
             return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
          }
         free(buffer);//释放buffer
         return nil;
      }
      - (NSData *)AES256DecryptWithKey:(NSData *)key   //解密
      {
         //同理，解密中，密钥也是32位的
         const void * keyPtr2 = [key bytes];
         char (*keyPtr)[32] = keyPtr2;
         //对于块加密算法，输出大小总是等于或小于输入大小加上一个块的大小
         //所以在下边需要再加上一个块的大小
          NSUInteger dataLength = [self length];
         size_t bufferSize = dataLength + kCCBlockSizeAES128;
         void *buffer = malloc(bufferSize);
         size_t numBytesDecrypted = 0;
          CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
                                                kCCOptionPKCS7Padding/*这里就是刚才说到的PKCS7Padding填充了*/| kCCOptionECBMode,
                                                keyPtr, kCCKeySizeAES256,
                                               NULL,/* 初始化向量(可选) */
                                                [self bytes], dataLength,/* 输入 */
                                                buffer, bufferSize,/* 输出 */
                                                &numBytesDecrypted);
         if (cryptStatus == kCCSuccess) {
             return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
          }
         free(buffer);
         return nil;
      }
      - (NSString *)newStringInBase64FromData            //追加64编码
      {
          NSMutableString *dest = [[NSMutableString alloc] initWithString:@""];
         unsigned char * working = (unsigned char *)[self bytes];
         int srcLen = [self length];
         for (int i=0; i<srcLen; i += 3) {
             for (int nib=0; nib<4; nib++) {
                 int byt = (nib == 0)?0:nib-1;
                 int ix = (nib+1)*2;
                 if (i+byt >= srcLen) break;
                 unsigned char curr = ((working[i+byt] << (8-ix)) & 0x3F);
                 if (i+nib < srcLen) curr |= ((working[i+nib] >> ix) & 0x3F);
                  [dest appendFormat:@"%c", base64[curr]];
              }
          }
         return dest;
      }
      + (NSString*)base64encode:(NSString*)str
      {
         if ([str length] == 0)
             return @"";
         const char *source = [str UTF8String];
         int strlength  = strlen(source);
         char *characters = malloc(((strlength + 2) / 3) * 4);
         if (characters == NULL)
             return nil;
          NSUInteger length = 0;
          NSUInteger i = 0;
         while (i < strlength) {
             char buffer[3] = {0,0,0};
             short bufferLength = 0;
             while (bufferLength < 3 && i < strlength)
                  buffer[bufferLength++] = source[i++];
              characters[length++] = base64[(buffer[0] & 0xFC) >> 2];
              characters[length++] = base64[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
             if (bufferLength > 1)
                  characters[length++] = base64[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
             else characters[length++] = '=';
             if (bufferLength > 2)
                  characters[length++] = base64[buffer[2] & 0x3F];
             else characters[length++] = '=';
          }
          NSString *g = [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
         return g;
      }
      +(NSData*)stringToByte:(NSString*)string
      {
          NSString *hexString=[[string uppercaseString] stringByReplacingOccurrencesOfString:@" " withString:@""];
         if ([hexString length]%2!=0) {
             return nil;
          }
          Byte tempbyt[1]={0};
          NSMutableData* bytes=[NSMutableData data];
         for(int i=0;i<[hexString length];i++)
          {
              unichar hex_char1 = [hexString characterAtIndex:i]; 两位16进制数中的第一位(高位*16)
             int int_ch1;
             if(hex_char1 >= '0' && hex_char1 <='9')
                  int_ch1 = (hex_char1-48)*16;    0 的Ascll - 48
             else if(hex_char1 >= 'A' && hex_char1 <='F')
                  int_ch1 = (hex_char1-55)*16;  A 的Ascll - 65
             else
                 return nil;
              i++;
              unichar hex_char2 = [hexString characterAtIndex:i]; ///两位16进制数中的第二位(低位)
             int int_ch2;
             if(hex_char2 >= '0' && hex_char2 <='9')
                  int_ch2 = (hex_char2-48);  0 的Ascll - 48
             else if(hex_char2 >= 'A' && hex_char2 <='F')
                  int_ch2 = hex_char2-55;  A 的Ascll - 65
             else
                 return nil;
              tempbyt[0] = int_ch1+int_ch2;  ///将转化后的数放入Byte数组里
              [bytes appendBytes:tempbyt length:1];
          }
         return bytes;
      }
      +(NSString*)byteToString:(NSData*)data
      {
          Byte *plainTextByte = (Byte *)[data bytes];
          NSString *hexStr=@"";
         for(int i=0;i<[data length];i++)
          {
              NSString *newHexStr = [NSString stringWithFormat:@"%x",plainTextByte[i]&0xff];///16进制数
             if([newHexStr length]==1)
                  hexStr = [NSString stringWithFormat:@"%@0%@",hexStr,newHexStr];
             else
                  hexStr = [NSString stringWithFormat:@"%@%@",hexStr,newHexStr];
          }
         return hexStr;
      }
      @end
  
 

  
 
 

使用

      -(void)Jiami
      {
          NSString *plainText = @"AES中国";//明文
          NSData *plainTextData = [plainText dataUsingEncoding:NSUTF8StringEncoding];
          NSString *keyStr = @"12345678901234567890123456789012";
          NSData *keyDataStr = [keyStr dataUsingEncoding:NSUTF8StringEncoding];
          NSData *cipherTextData = [plainTextData AES256EncryptWithKey:keyDataStr];
          NSString *hexStr = [NSData byteToString:cipherTextData];
         NSLog(@"密文:%@",hexStr);
          [self Jiemi:hexStr];
      }
      -(void)Jiemi:(NSString *)hexString
      {
          NSString *keyStr = @"12345678901234567890123456789012";
          NSData *keyDataStr = [keyStr dataUsingEncoding:NSUTF8StringEncoding];
          NSData *data = [NSData stringToByte:hexString];
          /
          NSData *datas = [data AES256DecryptWithKey:keyDataStr];
         NSLog([[NSString alloc]initWithData:datas encoding:NSUTF8StringEncoding]);
      }
  
 

  
 
 

文章来源: zzzili.blog.csdn.net，作者：清雨小竹，版权归原作者所有，如需转载，请联系作者。

原文链接：zzzili.blog.csdn.net/article/details/8610060