CN112286550B - A security signature algorithm for embedded device system upgrade - Google Patents

Abstract

The present invention discloses a security signature algorithm for upgrading an embedded device system, belonging to the field of embedded operating system upgrading and data security encryption technology, the method comprising the following steps: step one, reading a binary data packet to be differentiated; step two, dividing the data packet into blocks; step three, using a predetermined signature algorithm to sign the data blocks respectively, and recording the signature algorithm tag value; step four, checking the signature data of the corresponding block, judging whether there is a conflict in the signature data, if no signature conflict occurs, proceeding to step seven; step five, if there is a conflict in the signature data, adjusting the size of the blocks, repeating steps two to four, until the data block signature is unique, and proceeding to step seven. The method of the present invention completely avoids the hidden danger of upgrade failure caused by data block signature conflict in theory and practice, and improves the security of system upgrade.

Description

A security signature algorithm for embedded device system upgrade

Technical Field

The invention relates to the technical field of embedded operating system upgrade and data security encryption, and in particular to a security signature algorithm for embedded device system upgrade.

Background Art

Embedded operating systems are widely used in various fields. At the same time, in order to adapt to business updates, the terminal system is also a regular iteration. In order to improve the reliability and security of system upgrades and eliminate the hidden dangers of upgrade failure in the case of power failure during upgrades, this invention is based on the company's self-developed invention patents "Differential Upgrade Algorithm for Binary System Files of IOT Devices", "Adaptive Bidirectional Differential Algorithm Based on Block Writeback" and "Hybrid Packaging Compression Technology for Integer Arrays", and has developed a security signature algorithm for embedded device system upgrades.

Summary of the invention

The purpose of the present invention is to provide a security signature algorithm for upgrading an embedded device system to solve the problems raised in the above background technology.

To achieve the above object, the present invention provides the following technical solution: a security signature algorithm for embedded device system upgrade, comprising the following steps:

Step 1, reading the binary data packet to be differentiated;

Step 2: Divide the data packet into blocks;

Step 3: Use the predetermined signature algorithm to sign the data blocks respectively, and record the signature algorithm tag value;

Step 4: Check the signature data of the corresponding block to determine whether there is a conflict in the signature data. If no signature conflict occurs, proceed to step 7;

Step 5: If the signature data conflicts, adjust the size of the block and repeat steps 2 to 4 until the data block signature is unique, and then proceed to step 7;

Step 6: If a signature conflict occurs every time the block size is adjusted using the signature algorithm, the signature algorithm needs to be changed and steps 2 to 5 need to be repeated until the data block signature is unique;

Step 7: Record the size of the block, the signature data, and the tag value of the signature algorithm used;

Step 8: Differentiate and package the successfully divided data;

Step nine, compress the packaged data and write it into a differential package.

Preferably, the signature algorithm replaced in step six is Murmur3, CRC32, xxHash or lookup3, and the order of replacing the signature algorithm is Murmur3, CRC32, xxHash and lookup3.

Preferably, the data obtained by the difference in step eight is used to pack the integer array using a basic storage bit number that is smaller than the integer storage length.

Preferably, the differential in step eight is divided into forward and reverse directions, and the forward and reverse directions are performed simultaneously.

Preferably, the binary data package includes an old version and a new version.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention divides data into blocks and performs signature verification before differentiation, thereby ensuring signature uniqueness and reliability of power-off upgrades; the inventive method completely avoids the hidden danger of upgrade failure caused by data block signature conflicts in theory and practice, and improves the security of system upgrades.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of an algorithm for generating unique signature data according to the present invention;

FIG2 is a diagram illustrating the uniqueness of signatures of the present invention, wherein (a) is a schematic diagram showing a power failure during an upgrade, (b) is a schematic diagram showing a situation where all data block signatures conflict, and (c) is a schematic diagram showing a situation where no data block signatures conflict;

FIG. 3 is a diagram illustrating the signature algorithm tag value of the present invention.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Please refer to FIG1 . The present invention provides a technical solution: a security signature algorithm for upgrading an embedded device system, comprising the following steps:

Step 101, read the binary data packet to be differentiated.

Step 102, dividing the data packets of the new and old versions into blocks respectively.

Step 103, using a predetermined signature algorithm to sign the data blocks respectively, so that if a power failure occurs during the upgrade, the power failure position can be accurately located to continue the upgrade; thus avoiding the failure of the upgrade in the case of a power failure.

Step 104 , verify the signature data, and determine whether the signatures of the corresponding blocks of the new and old versions are the same. If the signature data of the corresponding blocks are different, proceed to step 107 .

Step 105, if the signatures are the same, further determine whether the corresponding data content is the same. If the data content is the same and there is no data signature conflict, proceed to step 107.

Step 106: If the data contents are different, it means that a data signature conflict has occurred in the block, so the size of the data block is adjusted, and steps 102 to 105 are repeated to ensure the uniqueness of the signature data and avoid data signature conflicts.

Step 107, record the block size, the signature data of the new and old versions, and the tag value of the algorithm used, and write them into the differential package.

Step 108, differential the uniquely signed data and package the differential result.

Step 109, compress the packaged data and write it into a differential packet.

In the implementation method, differential data uses a basic storage bit number smaller than the integer storage length to pack the integer array, thereby improving the effective use of integer storage space; and the packed data is then compressed.

When the embedded device system is powered off and upgraded, the data signature of the first block will be verified first, and compared with the new and old version signature data stored in the differential package. If the signature data is the same as the old version, the upgrade will start from this block; if it is different from the old version signature data, the signature of the corresponding new version data block will be compared. If it is the same as the new version data block signature, it means that the block has been upgraded, and the next data block signature will be compared in turn; if it is different from both the old and new version data block signatures, it means that part of the block has been upgraded, indicating that power has been lost in this block, and the backup (the copy of the old version data of this block) should be overwritten to this block, and then the upgrade will start from this block.

If the above process is to proceed normally, the signatures of the corresponding blocks of the new and old versions must be unique; if the signatures of the corresponding blocks conflict, the power failure upgrade may fail. For example, as shown in Figure 2, 2(a) is the case of a power failure during the upgrade. It is necessary to verify the signatures of the data blocks of the new and old versions (A1, A2, B1, B2, C1, C2) to determine which block the power failure occurred.

When data block signatures A1, A2, B1, and B2 all conflict 2(b), not only the corresponding blocks conflict, but also the adjacent blocks conflict. Then the signatures of blocks A1, B1, and C1 are compared in turn, and it is found that the signatures of blocks A1 and A2 are the same, the signatures of blocks B1 and B2 are the same, and the signature of block C1 is judged to be an old version, while the signature of backup is the same as that of A1, A2, B1, and B2. In this case, it is impossible to determine whether A1 or B1 has been upgraded through signatures, and it is also impossible to determine whether the power failure occurred during the upgrade of block A1 or block B1.

When the signatures of data blocks A1 and A2 are unique, and the signatures of data blocks B1 and B2 are unique, the location of the power failure can be determined regardless of whether there is a conflict 2(c) between adjacent blocks A1 and B1; assuming that a power failure occurs in block B1, block A1 has been upgraded to A2, and the signature of block A1 is equal to the signature of block A2. The signature data of the backup is not equal to that of block A1 at this time, and the signature of block B1 is not equal to the signature of block B2. It is uniquely determined that a power failure occurred in block B1, and the backup is overwritten to block B1; assuming that a power failure occurs in block A1, the signature of block A1 is not equal to the signature of block A2, and it is uniquely determined that a power failure occurred in block B1, and the backup is overwritten to block A1. Therefore, the failure of the power failure upgrade can be avoided by only ensuring the uniqueness of the signatures of the data blocks corresponding to the new and old versions.

In this algorithm, the murmur3 hash algorithm is used as the preferred signature algorithm (the investigation found that this signature algorithm has the best quality). If in extreme cases, the signature is performed through adaptive block, and there is a signature conflict in each block size, it is necessary to replace an alternative signature algorithm for signature verification to find a block size that makes the signature unique. We investigated a total of 4 signature algorithms as shown in Figure 3, each corresponding to a 2-bit tag value. The corresponding tag value is written into the header of the differential packet, and the signature algorithm is determined in sequence during the upgrade to completely avoid the failure of the power-off upgrade.

According to one aspect of the present invention, an algorithm for resolving signature conflicts during embedded device system upgrades is provided, and the technical solution is as follows:

Read the old and new versions of the binary data packet to be differentiated. When upgrading the embedded device system, the data packet needs to be divided into blocks first, and then differentiated. The differentiation process is divided into forward and reverse directions respectively;

The data blocks are signed using a predetermined signature algorithm, so that the upgrade process can be judged to be completed during the power-off upgrade to prevent the device from failing to upgrade due to power outage. This requires ensuring the uniqueness of the signature data to ensure the final upgrade success.

Verify the signature data of the corresponding blocks of the new and old versions to determine whether the signature data is unique. If the signature is unique, record the size of the block. If the signature of the corresponding block is the same but the data content is different, the signature data conflicts and the size of the block needs to be adaptively adjusted. Verify the signature data again until the data block signature is unique. Record the signature data of each block in the new and old versions and the signature algorithm used, and write them into the differential package.

The successfully divided data is differentiated, and for the obtained differential data, the integer array is packed using a basic storage bit number smaller than the integer storage length, thereby reducing the storage capacity of small numbers with high-order storage as 0 and improving the effective use of integer storage space.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (4)

1. A security signature algorithm for an embedded device system upgrade, characterized by comprising the following steps: Step 1, reading a binary data packet to be differentiated; Step 2: Divide the data packet into blocks; Step 3: Use the predetermined signature algorithm to sign the data blocks respectively, and record the signature algorithm tag value; Step 4: Check the signature data of the corresponding block to determine whether there is a conflict in the signature data. If no signature conflict occurs, proceed to step 7; Step 5: If the signature data conflicts, adjust the size of the block and repeat steps 2 to 4 until the data block signature is unique, and then proceed to step 7; Step 6: If a signature conflict occurs every time the block size is adjusted using the signature algorithm, the signature algorithm needs to be changed and steps 2 to 5 need to be repeated until the data block signature is unique; Step 7: Record the size of the block, the signature data, and the tag value of the signature algorithm used; Step 8: Differentiate and package the successfully divided data; Step nine, compress the packaged data and write it into a differential package; The signature algorithm replaced in step 6 is Murmur3, CRC32, xxHash or lookup3, and the order of replacing the signature algorithm is Murmur3, CRC32, xxHash and lookup3. 2. According to the security signature algorithm for embedded device system upgrade described in claim 1, it is characterized in that: the data obtained by the difference in step eight uses a basic storage bit number smaller than the integer storage length to pack the integer array. 3. According to the security signature algorithm for embedded device system upgrade described in claim 1, it is characterized in that: the difference in step eight is divided into forward and reverse, and the forward and reverse are performed simultaneously. 4. The security signature algorithm for upgrading an embedded device system according to claim 1, wherein the binary data packet includes an old version and a new version.