//
//  LPSecureData.m
//  zhimi
//
//  Created by 张灿 on 2019/1/22.
//  Copyright © 2019年 caiPro. All rights reserved.
//

#import "LPSecureData.h"
#import  <CommonCrypto/CommonCryptor.h>

#define LocalStr_None @""
//#define AESKEYVALUE @"!IQ31NeGcV&*n6w="
#define AESKEYVALUE @"JANp_XpXL^&1c47l"

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


@implementation LPSecureData
+ (NSString*)getRadomStr:(int)count{
    NSString *string = [[NSString alloc]init];
    for (int i = 0; i < count; i++) {
        int number = arc4random() % 36;
        if (number < 10) {
            int figure = arc4random() % 10;
            NSString *tempString = [NSString stringWithFormat:@"%d", figure];
            string = [string stringByAppendingString:tempString];
        }else {
            int figure = (arc4random() % 26) + 97;
            char character = figure;
            NSString *tempString = [NSString stringWithFormat:@"%c", character];
            string = [string stringByAppendingString:tempString];
        }
    }
    NSLog(@"%@", string);
    return string;
}
//将字典进行AES128加密
+ (NSString*)setSecureWithDict:(NSDictionary*)dict{
    NSString* jsonStr = [dict mj_JSONString];
//    NSString* newStr = [jsonStr stringByAppendingString:[self getRadomStr:4]];
    NSData *data = [jsonStr dataUsingEncoding:NSUTF8StringEncoding];
    NSData* aesdata = [self AES128operation:kCCEncrypt data:data key:AESKEYVALUE iv:AESKEYVALUE];
    NSLog(@"加密后的字符串为%@",[self base64EncodedStringFrom:aesdata]);
    return [self base64EncodedStringFrom:aesdata];
}
//将字符串解密为字典
+ (NSDictionary*)getDictWithSecureString:(NSString*)str{
    NSData *data = [self dataWithBase64EncodedString:str];
    NSData *aesData = [self AES128operation:kCCDecrypt
                                           data:data
                                            key:AESKEYVALUE
                                             iv:AESKEYVALUE];
    NSDictionary* dict = [aesData mj_JSONObject];
    return dict;
}
+ (NSData *)AES128operation:(CCOperation)operation data:(NSData *)data key:(NSString *)key iv:(NSString *)iv {
    
    char keyPtr[kCCKeySizeAES128 + 1];  //kCCKeySizeAES128是加密位数 可以替换成256位的
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    // IV
    char ivPtr[kCCBlockSizeAES128 + 1];
    bzero(ivPtr, sizeof(ivPtr));
    [iv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
    
    size_t bufferSize = [data length] + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;

    CCCryptorStatus cryptorStatus = CCCrypt(operation, kCCAlgorithmAES128, kCCOptionPKCS7Padding|kCCOptionECBMode,
                                            keyPtr, kCCKeySizeAES128,
                                            ivPtr,
                                            [data bytes], [data length],
                                            buffer, bufferSize,
                                            &numBytesEncrypted);
    
    if(cryptorStatus == kCCSuccess) {
        NSLog(@"Success");
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
        
    } else {
        NSLog(@"Error");
    }
    
    free(buffer);
    return nil;
}

//base64字符串转二进制
+ (NSData *)dataWithBase64EncodedString:(NSString *)string{
    if (string == nil)
        return [NSData data];
    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];
}
//NSData转base64字符串
+ (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];
}
//普通字符串转base64
+ (NSString *)base64StringFromText:(NSString *)text {
    NSData *data = [text dataUsingEncoding:NSUTF8StringEncoding];
    NSString *base64String = [data base64EncodedStringWithOptions:0];
    return base64String;
}
//base64转普通字符串
+ (NSString *)textFromBase64String:(NSString *)base64 {
    if (!base64) { return @""; }
    NSData *data = [[NSData alloc] initWithBase64EncodedString:base64 options:0];
    NSString *text = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    return text;
    
}

//将字符串解密为字符串
+ (NSString*)getStrWithSecureString:(NSString*)str {
    NSData *data = [self dataWithBase64EncodedString:str];
    NSData *aesData = [self AES128operation:kCCDecrypt
                                           data:data
                                            key:AESKEYVALUE
                                             iv:AESKEYVALUE];//AES解密
    NSString *base64 = [[NSString alloc] initWithData:aesData encoding:NSUTF8StringEncoding];
    if (!base64) {
        NSLog(@"AES加密解析失败");
        return @"";
    }
    NSData *base64Data = [[NSData alloc] initWithBase64EncodedString:base64 options:0];//base64解密
    
    NSString *text = [[NSString alloc] initWithData:base64Data encoding:NSUTF8StringEncoding];

    return text;
}



@end