最近在弄ndk,需要做一个用纯C校验签名的功能,也看了一些帖子,主要是参考下面两个:
主要思路是参考这个帖子,java代码和c代码都是,但是这个帖子里有几个小错误
http://blog.csdn.net/lgl1170860350/article/details/46348965
有的地方看了下这个帖:
http://blog.csdn.net/leifengpeng/article/details/52681196
因为同时用的是unity3D,没法传context参数给我,还顺便研究了下怎么获取context,参考贴:
http://blog.csdn.net/xiaogazhang/article/details/46891139
我的代码:
bool soulgameCheckMD5InPureC(jobject context,JNIEnv *env){ SGLOGD("soulgameCheckMD5InPureC() begin!"); // jclass tem_class; jmethodID tem_method; jclass class_context = env->GetObjectClass(context); //PackageInfo localPackageInfo = context.getPackageManager() tem_method = env->GetMethodID(class_context, "getPackageManager", "()Landroid/content/pm/PackageManager;"); jobject obj_package_manager = env->CallObjectMethod(context, tem_method); if(obj_package_manager == NULL){ SGLOGD("soulgameCheckMD5InPureC() getPackageManager failed!"); return false; } // getPackageName tem_method = env->GetMethodID(class_context, "getPackageName", "()Ljava/lang/String;"); jobject obj_package_name = env->CallObjectMethod(context, tem_method); env->DeleteLocalRef(class_context); env->DeleteLocalRef(context); if(obj_package_name == NULL){ SGLOGD("soulgameCheckMD5InPureC() getPackageName failed!"); return false; } // getPackageInfo tem_class = env->GetObjectClass(obj_package_manager); tem_method = env->GetMethodID(tem_class, "getPackageInfo", "(Ljava/lang/String;I)Landroid/content/pm/PackageInfo;"); jobject obj_package_info = env->CallObjectMethod(obj_package_manager, tem_method, obj_package_name, 64); env->DeleteLocalRef(obj_package_name); env->DeleteLocalRef(obj_package_manager); if(obj_package_info == NULL){ SGLOGD("soulgameCheckMD5InPureC() getPackageInfo failed!"); return false; } // Signature[] arrayOfSignature = localPackageInfo.signatures; tem_class = env->GetObjectClass(obj_package_info); jfieldID fieldID_signatures = env->GetFieldID(tem_class, "signatures", "[Landroid/content/pm/Signature;"); // Signature localSignature = arrayOfSignature[0]; jobject signatur = env->GetObjectField(obj_package_info, fieldID_signatures); jobjectArray signatures = (jobjectArray)(signatur); jobject signature = env->GetObjectArrayElement(signatures, 0); env->DeleteLocalRef(signatures); env->DeleteLocalRef(obj_package_info); if(signatur == NULL){ SGLOGD("soulgameCheckMD5InPureC() signatures failed!"); return false; } // localSignature.toByteArray() tem_class = env->GetObjectClass(signature); tem_method = env->GetMethodID(tem_class, "toByteArray", "()[B"); jobject obj_sign_byte_array = env->CallObjectMethod(signature, tem_method);// 这个就是拿到的签名byte数组 env->DeleteLocalRef(signature); env->DeleteLocalRef(tem_class); if(obj_sign_byte_array == NULL){ SGLOGD("soulgameCheckMD5InPureC() toByteArray failed!"); return false; } // MessageDigest localMessageDigest = MessageDigest.getInstance("MD5"); jclass class_MessageDigest = env->FindClass( "java/security/MessageDigest"); tem_method = env->GetStaticMethodID( class_MessageDigest, "getInstance", "(Ljava/lang/String;)Ljava/security/MessageDigest;"); jobject obj_md5 = env->CallStaticObjectMethod( class_MessageDigest, tem_method, env->NewStringUTF("md5")); if(obj_md5 == NULL){ SGLOGD("soulgameCheckMD5InPureC() getInstance failed!"); return false; } // localMessageDigest.update(localSignature.toByteArray()); tem_method = env->GetMethodID(class_MessageDigest, "update", "([B)V");// 这个函数的返回值是void,写V env->CallVoidMethod(obj_md5, tem_method, obj_sign_byte_array); env->DeleteLocalRef(obj_sign_byte_array); // localMessageDigest.digest() tem_method = env->GetMethodID(class_MessageDigest, "digest", "()[B"); // 这个是md5以后的byte数组,现在只要将它转换成16进制字符串,就可以和之前的比较了 jbyteArray obj_array_sign = (jbyteArray)env->CallObjectMethod(obj_md5, tem_method);// jni中有强转类型的概念吗 env->DeleteLocalRef(obj_md5); env->DeleteLocalRef(class_MessageDigest); if(obj_array_sign == NULL){ SGLOGD("soulgameCheckMD5InPureC() digest failed!"); return false; } // 尝试用c写一下:http://blog.csdn.net/pingd/article/details/41945417 jsize int_array_length = env->GetArrayLength(obj_array_sign); jbyte* byte_array_elements = env->GetByteArrayElements(obj_array_sign, NULL); char* char_result = (char*) malloc(int_array_length*2+1);// 开始没有+1,在有的情况下会越界产生问题,还是在后面补上\0比较好 // 将byte数组转换成16进制字符串,发现这里不用强转,jbyte和unsigned char应该字节数是一样的 ByteToHexStr((unsigned char*)byte_array_elements, char_result, int_array_length); *(char_result+int_array_length*2) = '\0';// 在末尾补\0 // jstring string_result = env->NewStringUTF(char_result); // env->DeleteLocalRef(string_result); // release env->ReleaseByteArrayElements( obj_array_sign, byte_array_elements, JNI_ABORT); env->DeleteLocalRef(obj_array_sign); //校验 const char* pWhiteObject; bool bIsMD5Right; int nIndex = 0; int nLen = sizeof(pMD5WhiteList)/4; for(nIndex = 0;nIndex<nLen;nIndex++){ pWhiteObject = pMD5WhiteList[nIndex]; if( strcmp(char_result,pWhiteObject) == 0 ){ break; } } if(nIndex<nLen){ bIsMD5Right = true; }else{ bIsMD5Right = false; } // 释放指针使用free free(char_result); SGLOGD("soulgameCheckMD5InPureC() finish!"); if(bIsMD5Right){ return true; }else{ return false; } }