IOS加密 AES 256算法(EncryptAndDecrypt.h)

Love The Way You Lie 2023-10-18 13:32 102阅读 0赞

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]);
    }

[http://blog.csdn.net/pjk1129/article/details/8489550][http_blog.csdn.net_pjk1129_article_details_8489550]

[http_blog.csdn.net_pjk1129_article_details_8489550]: http://blog.csdn.net/pjk1129/article/details/8489550