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ipa包完整性验证

ipa包完整性验证

作者: revivefsd | 来源:发表于2021-01-28 18:36 被阅读0次

    这个是一个比较快速简单的实现方式,原理大概是通过python脚本计算出需要检查文件的hash值,写入一个本地文件中。同样在oc代码中读取需要检查的文件,用同样的方式计算出hash值,对比本地文件的hash值与计算的是否一致,如果一致则说明没有被修改,否则就是被修改了可以上报或者退出程序。

    readme

    
    ### checkipa.py
    #### 用于安全审核检查ipa的完整性,防止越狱手机动态修改plist或者其他文件
    
    使用说明:
    1.cd到workspace.app文件夹
    2.执行命令  $ python checkipa.py
    3.会自动生成appinfo.json 文件,里面为需要检查的文件名和md5
    4.appinfo.json 作为资源文件到工程中,或者直接在.app文件中加上此文件后打包
    ****
    
    已知问题:不能知道二进制文件的md5值打包后因为签名会改变,只能判断资源文件
    方案:如果需要判断二进制文件的值可以通过server下发的方式,server获取到ipa文件之后运行checkipa.py脚本,将生成的json作为网络请求返回给客户端,客户端通过服务端返回的hash值,再计算出对应的hash值,再对比。
    
    checkipa.py说明
    需要添加检查的脚本直接修改py即可
    #需要检查的文件名-目前只支持.app目录下的文件,在数组中放入需要检查的文件名即可
    checklist = ['Info.plist','embedded.mobileprovision']
    #md5规则自己定义 修改脚本和oc中对应的规则一致即可
    md5 = (文件修改时间+文件md5)的字符串md5值
    
    以下为appinfo.json 示例
    {"Info.plist": "C61813D910C9A419758E53C33636D2A7", "embedded.mobileprovision": "239A9565E650216E2AEFCC4E29E376E0"}
    
    

    checkipa.py

    # coding: utf-8
    # checkipa.py
    
    import os
    import shutil
    import sys
    import os.path
    import time
    import json
    import hashlib
    
    def file_exist(path):
            if not os.path.isfile(path):
                return False
            if not os.access(path, os.R_OK):
                return False
            return True
    
    def checkFileExist(checklist):
        file_dir = os.getcwd()
        print('currentPath:' +  file_dir)
        for checkFile in checklist: 
            allPath = file_dir + '/' + checkFile
            print(allPath)
            fileExist = file_exist(allPath)
            if not fileExist:
                print('文件不存在' + allPath)
                return False
        return True
    
    def getStrMD5(string):
        stringEncode = string.encode('utf8')
        md5hash = hashlib.md5(stringEncode)
        md5 = md5hash.hexdigest()
        return str(md5).upper()
    
    def getFileMD5(checkFilePath):
        f = open(checkFilePath,'rb')
        md5obj = hashlib.md5()
        md5obj.update(f.read())
        hash = md5obj.hexdigest()
        f.close()
        return str(hash).upper()
    
    def getFileDic(checkFilePath):
        fileJsonDic = {}
        fileJsonDic['filePath'] = checkFilePath
        fileCreatTime = os.path.getctime(checkFilePath)
        fileJsonDic['fileCreateTime'] = fileCreatTime
        fileModifyTime = int(os.path.getmtime(checkFilePath))
        fileJsonDic['fileModifyTime'] = fileModifyTime
        fileJsonDic['fileMd5'] = getFileMD5(checkFilePath)
        fileEncap = str(fileModifyTime) + getFileMD5(checkFilePath)
        fileJsonDic['fileEncap'] = fileEncap
        fileJsonDic['fileEncapMd5'] = getStrMD5(fileEncap)
        return fileJsonDic
    
    def writeAppParams(checklist):   
        file_dir = os.getcwd()
        #输出所有需要的参数,用于调试
        json_dir = file_dir + '/' + "app.json"
        with open(json_dir, 'w') as f:
            jsonDic = {}
            for checkFileName in checklist: 
                checkFilePath = file_dir + '/' + checkFileName
                checkFileDic = getFileDic(checkFilePath)
                jsonDic[checkFileName] = checkFileDic
            jsonStr = json.dumps(jsonDic)
            f.write(jsonStr)
        #生成检查文件
        check_json_dir = file_dir + '/' + "appinfo.json"
        with open(check_json_dir, 'w') as f:
            check_jsonDic = {}
            for checkFileName in checklist: 
                checkFilePath = file_dir + '/' + checkFileName
                checkFileDic = getFileDic(checkFilePath)
                jsonDic[checkFileName] = checkFileDic['fileEncapMd5']
            jsonStr = json.dumps(jsonDic)
            f.write(jsonStr)
        #删除调试文件   
        os.remove(json_dir)
    
    
    if __name__ == '__main__':
    
        #需要检查的文件
        checklist = ['Info.plist','embedded.mobileprovision']
    
        #1.判断文件是否都存在
        exist = checkFileExist(checklist)
        if not exist:
            print('检查文件缺少,可能被移除')
            sys.exit(-1)
        print('继续检查')
    
        #2.生成一个json记录文件的creatTime和md5
        writeAppParams(checklist)
        print('检查结束')
    
    

    OC方法

    .h

    /**
     检查ipa文件是否被修改
     */
    + (void)checkIpaFile
    
    

    .m

    #import "CheckIPA.h"
    #import <CommonCrypto/CommonDigest.h>
    #import <CommonCrypto/CommonCrypto.h>
    #define FileHashDefaultChunkSizeForReadingData 1024*8
    
    @implementation CheckIPA
    
    /**
     检查ipa文件是否被修改
     */
    + (void)checkIpaFile{
        NSString *checkFilePath = [[NSBundle mainBundle] pathForResource:@"appinfo.json" ofType:@""];
        if (!(checkFilePath && checkFilePath.length > 0)) {
            exit(0);
        }
        NSDictionary * dic;
        if ([[NSFileManager defaultManager] fileExistsAtPath:checkFilePath]) {
            NSString *checkFile = [NSString stringWithContentsOfFile:checkFilePath encoding:NSASCIIStringEncoding error:nil];
            dic = [self getDicWithJsonString:checkFile];
        }
        //   checklist--需要检查的文件列表,需要与python脚本中的一致
        //   NSArray * arr = @[@"info.plist",@"embedded.mobileprovision"];
        NSArray * arr = @[@"Info.plist"];
        //读取检查文件中的md5值
        for (NSString * fileName in arr) {
            BOOL isMod = [self checkSameMD5:fileName dic:dic];
            if (!isMod) {
                exit(0);
            }
        }
    }
    
    + (BOOL)checkSameMD5:(NSString*)fileName dic:(NSDictionary*)dic{
        NSString * encapMd5 = dic[fileName];
        if ([self stringIsNil:encapMd5]) {
            return NO;
        }
        //读取本地文件真实的md5
        NSString *checkPath = [[NSBundle mainBundle] pathForResource:fileName ofType:@""];
        if ([[NSFileManager defaultManager] fileExistsAtPath:checkPath]) {
            NSString * md5 = [self getFileMD5WithPath:checkPath];
            md5 = [md5 uppercaseString];
            NSString * modTime = [self getFileModifyTime:checkPath];
            if (![self stringIsNil:md5] && ![self stringIsNil:modTime]) {
                NSString * encapStr = [NSString stringWithFormat:@"%@%@",modTime,md5];
                NSString * encapStrMd5 = [[self stringToMD5:encapStr] uppercaseString];
                NSLog(@"encapMd5,%@\n encapStrMd5:%@",encapMd5,encapStrMd5);
                if ([encapStrMd5 isEqualToString:encapMd5]) {
                    return YES;
                }
            }
        }
        return NO;
    }
    
    + (NSString *)getFileModifyTime:(NSString*)path{
        NSFileManager *fileManager = [NSFileManager defaultManager];
        NSError *error = nil;
        NSDictionary *fileAttributes = [fileManager attributesOfItemAtPath:path error:&error];
        if (fileAttributes != nil) {
            NSDate *fileModDate = [fileAttributes objectForKey:NSFileModificationDate];
            if (fileModDate) {
                NSLog(@"Modification date: %@\n", fileModDate);
                NSString *timestamp = [NSString stringWithFormat:@"%.f", [fileModDate timeIntervalSince1970]];
                return timestamp;
            }
            NSDate *fileCreateDate = [fileAttributes objectForKey:NSFileCreationDate];
            if (fileCreateDate) {
                NSLog(@"create date:%@\n", fileModDate);
            }
            NSNumber *fileSize = [fileAttributes objectForKey:NSFileSize];
            if (fileSize) {
                NSLog(@"File size: %qi\n", [fileSize unsignedLongLongValue]);
            }
            NSString *fileOwner = [fileAttributes objectForKey:NSFileOwnerAccountName];
            if (fileOwner) {
                NSLog(@"Owner: %@\n", fileOwner);
            }
        }
        else {
            NSLog(@"Path (%@) is invalid.", path);
            return nil;
            
        }
        return nil;
    }
    
    + (NSDictionary *)getDicWithJsonString:(NSString*)string{
        NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
        if (!data) {
            return nil;
        }
        NSError *error;
        NSDictionary *jsonDic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
        if (jsonDic == nil || error != nil) {
            NSLog(@"getArrWithJsonString  fail:%@", error);
            return nil;
        }
        return jsonDic;
    }
    
    + (BOOL)stringIsNil:(NSString *)string {
        if (string == nil || string == NULL || [string isKindOfClass:[NSNull class]] || [string isEqualToString:@""]) {
            return YES;
        }
        return NO;
    }
    
    /**
     获取文件的MD5值
     @param path 源文件路径
     @return MD5值字符串
     */
    + (NSString*)getFileMD5WithPath:(NSString*)path {
        return (__bridge_transfer NSString *)FileMD5HashCreateWithPath((__bridge CFStringRef)path, FileHashDefaultChunkSizeForReadingData);
    }
    
    /**
     获取文件的MD5值,来源:http://www.cnblogs.com/visen-0/p/3160907.html
     @Caller self
     @param filePath 源文件路径
     @param chunkSizeForReadingData
     @return MD5值字符串
     */
    CFStringRef FileMD5HashCreateWithPath(CFStringRef filePath,size_t chunkSizeForReadingData) {
        CFStringRef result = NULL;
        CFReadStreamRef readStream = NULL;
        CFURLRef fileURL =
        CFURLCreateWithFileSystemPath(kCFAllocatorDefault,
                                      (CFStringRef)filePath,
                                      kCFURLPOSIXPathStyle,
                                      (Boolean)false);
        if (!fileURL) goto done;
        readStream = CFReadStreamCreateWithFile(kCFAllocatorDefault,
                                                (CFURLRef)fileURL);
        if (!readStream) goto done;
        bool didSucceed = (bool)CFReadStreamOpen(readStream);
        if (!didSucceed) goto done;
        CC_MD5_CTX hashObject;
        CC_MD5_Init(&hashObject);
        if (!chunkSizeForReadingData) {
            chunkSizeForReadingData = FileHashDefaultChunkSizeForReadingData;
        }
        bool hasMoreData = true;
        while (hasMoreData) {
            uint8_t buffer[chunkSizeForReadingData];
            CFIndex readBytesCount = CFReadStreamRead(readStream,(UInt8 *)buffer,(CFIndex)sizeof(buffer));
            if (readBytesCount == -1) break;
            if (readBytesCount == 0) {
                hasMoreData = false;
                continue;
            }
            CC_MD5_Update(&hashObject,(const void *)buffer,(CC_LONG)readBytesCount);
        }
        didSucceed = !hasMoreData;
        unsigned char digest[CC_MD5_DIGEST_LENGTH];
        CC_MD5_Final(digest, &hashObject);
        if (!didSucceed) goto done;
        char hash[2 *sizeof(digest) + 1];
        for (size_t i = 0; i < sizeof(digest); ++i) {
            snprintf(hash + (2 *i), 3, "%02x", (int)(digest[i]));
        }
        result = CFStringCreateWithCString(kCFAllocatorDefault,(const char *)hash,kCFStringEncodingUTF8);
    done:
        if (readStream) {
            CFReadStreamClose(readStream);
            CFRelease(readStream);
        }
        if (fileURL) {
            CFRelease(fileURL);
        }
        return result;
    }
    
    /**
     字符串转md5字符串
    
     @param string 原始字符串
     @return md5后的字符串
     */
    + (NSString *)stringToMD5:(NSString *)string
    {
        const char *cStr = [string UTF8String];
        unsigned char digest[16];
        CC_MD5( cStr, (CC_LONG)[string length], digest ); // This is the md5 call
        NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
        for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
            [output appendFormat:@"%02x", digest[i]];
        }
        return  output;
    }
    
    
    
    @end
    
    
    

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