CN100462995C - A method for verifying and using an image file - Google Patents

Abstract

The invention provides an image file using and verifying method, compressing image file into a file packet to be stored at client end, and the file packet includes a list of HASH values of all files in the image file; when verifying the image file, reading in the list of HASH values; drawing a record from the list; calculating the HASH value of an image file in the client end corresponding to the record; comparing whether the HASH value of the record is equal to the calculated HASH value of the current file. Thus, it can prevent image files being modified at will.

Description

A method for verifying and using an image file

technical field

The invention relates to image data processing technology, in particular to a method for verifying and using image files to prevent the image files from being changed arbitrarily.

Background technique

With the development of society and technology, image processing technology has been more and more applied in the computer field, making people's work, study and daily life more and more colorful.

In the prior art, Flash animation is usually used to express some required actions, such as a virtual pet game running on a user's computer desktop. Specifically, it can be implemented in the form of a computer program. The program realizes the description of the entire life of the pet by controlling the playback of each Flash animation, and gives the user a virtual pet experience with vitality. After the pet's Flash animation is transparentized, it can be displayed anywhere on the user's desktop.

In addition, in order to increase the personalization effect of the virtual pet game, players can purchase corresponding image files (props), such as toys, bubble backgrounds, etc. for pets to play with and decorate pets to increase the fun of adopting pets. In the prior art, first the user needs to use virtual currency to download the image file, the image file is stored in the client in the form of a GIF picture or other files, and the user clicks on the corresponding item to start the image file on the client, making the pet play with a ball Or display a more beautiful background, etc.

All image files need to be downloaded to the client before they can be used, so that users can change pictures or other files at will on the client, resulting in poor personalized display of pets, and can enjoy without using virtual currency to purchase A variety of personalized services will also harm the interests of virtual pet developers.

Contents of the invention

The main purpose of the present invention is to solve the above-mentioned problem in the prior art that image files can be changed at will, and provide a method for using image files.

In order to achieve the above-mentioned main purpose, the present invention compresses it into a file package and stores it in the client when downloading the image file. The feature value list of all files in the image file is included in the file package. The steps used include the following: The terminal detects whether the image file has been downloaded; if it has been downloaded, the image file needs to be verified, and the image file is verified through the list of feature values; the image file can be used if the image file is verified; if the verification is not passed, the image file is re-downloaded .

Another main object of the present invention is to provide a method of authenticating an image file when using the image file.

In order to achieve the above-mentioned another main purpose, the image file of the present invention is compressed into a file package and stored on the client, and the file package contains a list of feature values of all files in the image file; the verification method includes the following steps: Each feature value list; take out a record in turn from the above feature value list; calculate the feature value of the file corresponding to the record in the current client image file; compare the feature value recorded in the record with the corresponding file Whether the calculated eigenvalues are the same.

Preferably, the feature value is a HASH value calculated through the MD5 encryption algorithm. Before reading in the characteristic value list, a step of setting a verification directory is also included, and then the characteristic value list must be decrypted. The verification directory is a temporary directory of the client system, and the decompression directory of image files is stored in the temporary directory.

Preferably, before calculating the characteristic value of the file corresponding to the record in the client, the method further includes: judging whether the corresponding image file exists in the verification directory.

Preferably, the characteristic value is a HASH value, and the characteristic value list includes a file name and a HASH value, and there is a one-to-one correspondence between the file name and the HASH value.

To sum up, in the present invention, when the client downloads an image file, the feature value list of the image file is compressed together in the file package, and each time before using the local image file, the HASH value list and all current file contents are always used Comparing them one by one, once a difference is found, it means that the file may be changed or replaced, and the local image file will no longer be used. Thereby effectively preventing the image file from being changed arbitrarily.

Description of drawings

FIG. 1 is a schematic diagram of the use of image files in the present invention.

Fig. 2 is a flow chart of using image files in the present invention.

Fig. 3 is a flow chart of verifying image files in the present invention.

FIG. 4 is a schematic diagram of a list of feature values according to one embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

In order to increase the personalization effect of the virtual pet, the player can purchase corresponding image files (props), such as toys, bubble backgrounds, etc. for the virtual pet to play and decorate the pet. As shown in Figure 1, the image file generally includes multiple files, such as image file 1, image file 2, etc. First, the multiple files need to be compressed into a file package and downloaded to the pet resource directory of the client. The file package includes a list of feature values of each file in the image file, and then decompress it on the client, and store the decompressed directory of each image file in the temporary directory of the client system, and self-decompress when using the image file Read related data from the directory.

The specific process when the client of the present invention uses the image file will be described below in conjunction with Fig. 2:

The client first detects whether the image file has been downloaded (step 10);

If downloaded, the image file needs to be verified (step 20);

If the verification is passed, the image file can be used (step 50);

If verification is not passed, then step 30 is reached, and the image file is re-downloaded;

If it is detected that the image file is not downloaded, then the image file is compressed into a file package and downloaded in the pet resource directory of the client, and the file package includes a feature value list (step 30) of each file in the image file;

Then decompress the image file, and store the decompression directory of the image file in the temporary directory of the client system (step 40);

Finally, the relevant data can be read from the self-extracting directory to use the image file (step 50).

In a preferred embodiment of the present invention, the characteristic value list is a HASH value list, and each record in the HASH value list is equivalent to taking a "snapshot" for a corresponding file under the image file, which can record the The raw content of the image file file. The HASH list includes file names and HASH values, and there is a one-to-one correspondence between file names and HASH values. The HASH values are calculated using the MD5 encryption algorithm. The MD5 encryption algorithm can convert data calculations of any length into a fixed-length Data string, once the content of the file changes slightly, the calculated data string will change greatly.

How to implement step 20 will be described below in conjunction with what is shown in Figure 3, and the image file is verified (as shown in Figure 3):

At first setting verification directory is the temporary directory (step 201) of client system, because the temporary directory of client system is stored with the decompression directory of image file, namely setting needs to verify the decompression directory of image file;

Decrypt the HASH list (step 202);

If the decryption is successful, read in the HASH value list (step 203);

Then take out a record (step 204) from the HASH list;

Judging whether there is a file corresponding to the record under the verification directory (step 205);

If exist, then utilize MD5 algorithm to calculate the current HASH value of this file, this MD5 encryption algorithm algorithm can convert the data calculation of any length into a fixed-length data string (step 205);

Judging whether the HASH value in the record is equal to the current HASH value calculated for the file (step 207);

If equal, then judge whether the record in the HASH list has been verified (step 208);

If complete, then the verification is passed, reaching step 50, and the image file can be used;

If the verification is not completed, return to step 204 and continue to read the next record.

During the above steps, if the decryption of the HASH list fails, or there is no file corresponding to the verified record in the verification directory, or the two HASH values are not equal, the verification will fail and go directly to step 30 to start re-downloading The image file instead of using the image file in the current client.

In order to describe the verification method of the image file of the present invention more clearly, the following will take the "personalized bubble background image file" in the virtual pet as an example for a more detailed description.

A bubble background generally includes three files: "background GIF file", "button BMP file" and "configuration file". For the convenience of downloading, compress the above three files into a ZIP file package and download it to the pet resource directory of the client, then decompress the three files, and store the decompressed directory in the temporary directory of the client system. And also comprise a HASH list in this ZIP file package, as shown in Figure 4, include three records in this HASH list, are respectively background, button and configuration file, correspond to a 16-byte information string (HASH value) in each record ).

Before the client uses the image file, first set the verification directory as the temporary directory of the client system; decrypt the HASH list; then take out the corresponding record in the background column from the list; verify the decompression directory in the client system Whether there is a file corresponding to the record, that is, "background GIF file"; if so, use the MD5 algorithm to calculate the HASH value of the current "background GIF file"; then judge whether the HASH value in the list is the same as the currently calculated The HASH values are the same; and so on, until the HASH values of all records in the HASH list are the same as the currently calculated HASH values, then the verification is passed. If one of the records fails to pass the verification, the bubble background that has been downloaded on this client can no longer be used, and the image file needs to be downloaded again.

To sum up, before each use of an image file, the client must use the encrypted HASH value to compare all file contents under the current image file. Once a difference is found, it means that the image file has been replaced or changed, and the The current file is no longer used and the image file is re-downloaded. Thereby effectively preventing the image file from being changed arbitrarily.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (14)

1. the verification method of an image file, be used for when client is used image file, image file being verified, this image file is compressed into a literature kit and is stored in client when downloading, it is characterized in that: include the eigenwert tabulation of All Files in this image file in this document bag, All Files in this image file is verified, if the checking to one of them file in this image file is not passed through, then the checking of this image file is not passed through; The method that All Files is verified comprises the steps:

Read in each eigenwert tabulation;

From above-mentioned eigenwert tabulation, take out a record;

Calculate in the active client image file eigenwert with the corresponding file of this record;

Relatively whether this eigenwert of being put down in writing of record is identical with the eigenwert that is calculated by corresponding file.

2. a kind of verification method of image file according to claim 1, it is characterized in that: described eigenwert is the HASH value.

3. as the verification method of a kind of image file as described in the claim 2, it is characterized in that: described eigenwert tabulation comprises filename and HASH value, and is corresponding one by one between filename and the HASH value.

4. as the verification method of a kind of image file as described in the claim 2, it is characterized in that: described HASH value utilizes the md5 encryption algorithm computation to come out, and needs the HASH value list is decrypted before reading in HASH value list step.

5. as the verification method of a kind of image file as described in the claim 4, it is characterized in that: before the HASH value list is decrypted, also comprise the step that the checking catalogue is set.

6. as the verification method of a kind of image file as described in the claim 5, it is characterized in that: described checking catalogue is the temp directory of client.

7. as the verification method of a kind of image file as described in the claim 5, it is characterized in that: in calculating client with before the step of the corresponding file characteristic value of this record, also comprise:

Judge under the checking catalogue and whether have this corresponding image file.

8. the using method of an image file, this image file is compressed into a literature kit and is stored in client when downloading, it is characterized in that: include the eigenwert tabulation of All Files in this image file in this document bag, and this using method comprises the steps:

Whether client detected image file is downloaded;

Then need this image file is verified if downloaded, the All Files of image file is verified,, then the checking of this image file is not passed through if the checking of one of them file in this image file is not passed through by the eigenwert tabulation;

The image file checking is by then using this image file;

If download images file is not again passed through then in checking;

Described image file is verified comprises the steps:

Read in each eigenwert tabulation;

From above-mentioned eigenwert tabulation, take out a record;

Calculate in the active client image file eigenwert with the corresponding file of this record;

Relatively whether this eigenwert of being put down in writing of record is identical with the eigenwert that calculates.

9. as the using method of a kind of image file as described in the claim 8, it is characterized in that: described eigenwert is the HASH value.

10. as the using method of a kind of image file as described in the claim 9, it is characterized in that: described eigenwert tabulation comprises filename and HASH value, and is corresponding one by one between filename and the HASH value.

11. as the using method of a kind of image file as described in the claim 9, it is characterized in that: described HASH value utilizes the md5 encryption algorithm computation to come out, and needs the HASH value list is decrypted before reading in HASH value list step.

12. the using method as a kind of image file as described in the claim 11 is characterized in that: before the HASH value list is decrypted, also comprise the step that the checking catalogue is set.

13. as the using method of a kind of image file as described in the claim 12, it is characterized in that: described checking catalogue is the temp directory of client.

14. the using method as a kind of image file as described in the claim 12 is characterized in that: in calculating client with before the step of the corresponding file characteristic value of this record, also comprise:

Judge under the checking catalogue and whether have this corresponding image file.

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