What is a certificate signature?

1. What is a signature?

The third version of S60 has made major improvements in security, and has stricter regulations on third-party software installed and run in the system. Certain operations related to mobile phone software and hardware security/personal information security and other aspects have been specially restricted (for example, automatic startup when the phone is turned on is one of the restricted functions). Applications must obtain a "signature" to implement these "specially restricted" functions. In other words, someone must be responsible for the safety of this operation! Programs without any signature cannot be installed and run.

Signature (sign): writing specific tag information in specific fields of the application, indicating that the software has passed the review of the signer. The signer is responsible for the security of this software. There are roughly three types of signatures:

1. Symbian signature.

That is the official signature of Symbian (Saipan) mobile operating system. Only software that has passed the Symbian security certification will be signed by Symbian. This type of software has the highest security level. It can be installed/run normally on the mobile phone and all functions provided by the software can be realized. Obtaining a Symbian signature requires software authors to deal directly with Symbian officials. Due to various reasons, not all software authors are able to obtain this certification.

2. Author’s signature.

The software author signs the software when it is released. This type of software can be installed and run on your mobile phone (you may encounter a security warning, which can be skipped). However, those "specially restricted" functions cannot be implemented. If a piece of software does not involve such functions at all, then the software author may just sign it himself. Another possibility is that although some functions of the software fall into the "specially restricted" range, they are not the main functions. The software author may also release an "author-signed version", which can use most functions normally, but will lose some specific functions. For example, the "Laitengtong" software has such a version, almost all functions can be used, but it cannot start automatically when the computer is turned on.

3. User signature.

Strictly speaking, this should be a "developer signature". Because Symbian provides a "development certificate" for software developers, the original intention was to allow software developers to conduct software testing. This "development certificate" is linked to the IMEI code of the machine used for testing. Software signed with this certificate can only be used on the machine corresponding to the IMEI code and cannot be used on other machines. What we call "self-signing" actually makes use of this method. To put it bluntly, you say you are developing software, you provide the IMEI code of your test machine, and Symbian issues you a "development certificate". You use this certificate to sign your "test software". You are solely responsible for your own "development behavior"! That's all. In addition, the development certificate is valid for three years from the date of issuance. However, there is no time limit for the use of programs signed within the validity period of the certificate.

2. What is a certificate?

1. The certificate is the "permission to install the software". When you install a certain software, the Nokia mobile phone S60 third version system will analyze whether the software you want to install has the installation permission (certificate). If not, the system will not let you install it. Certificates have restrictions on levels and permissions. The lowest certificates can only be used to install ordinary games, themes, and general application software. This type of certificate can be turned off by setting the certificate check option (operation steps: Menu key--Application--Program In Management - Options - Settings, select "All" for software installation and "Off" for online certificate checking) to avoid certificate checking and obtain installation. Since the default setting is to turn off checking, this means that many ordinary software do not require certificates. That’s why it can be installed. A slightly higher certificate can allow software information to enter the system folder of the mobile phone's C drive, allow the software to run automatically at boot, modify system parameters, and other high-level permissions. Currently, all certificates that require our self-signing are of this type. The highest authority certificate can modify the system, but you need to pay Nokia to purchase it.

2. What is the function of the certificate?

It is to improve system security. As we all know, viruses occur because they can secretly install into your system without authorization, automatically run, call programs, modify system files, and run automatically every time you turn on the computer. Then they replicate themselves exponentially and are transferred between different computers. They cannot get rid of. And all of this becomes impossible under the third version of S60, because it is this certificate verification mechanism that makes you love and hate it.

Even if the virus creator uses the lowest-end certificate, you can install it, but because he does not have permission, he cannot start automatically, cannot call system files and programs, and cannot spread to other mobile phones, so it is equal to waste. .

To obtain high authority, unless the software asks you to sign it, you must first pass it yourself. If you really sign a virus, the harm of the virus will be minimal, because the certificate is unique to your phone. Corresponding to the IMEI code (serial number), if it cannot be diffused, it loses the possibility of transmission. How meaningful is it for a virus creator to create such a virus? The only possibility now is that the virus maker obtains the highest authority certificate to achieve his evil purpose. But how can Nokia grant the certificate to a virus maker? Unless the highest authority certificate is cracked by hackers. Such a thing has not happened yet, so the anti-virus software of the third version of S60 is currently useless.

Use the signing tool

Step one: Import the certificate. [Right-click on your own certificate → ◤Import Certificate (Replace)]

Step 2: Right-click to sign.

Now you can right-click the sis(x) program that needs to be signed anywhere to execute the signature!

SIS right-click instructions: ◤Sign this file (SymbianOSv9) → Sign only this file

◤Sign all files (SymbianOSv9) → Sign all sis(x in this folder) ) file

◤Check the validity period (SymbianOSv9) → Check the validity period of the sis(x) program

Let me tell you, you don’t have to go to the Symbian forum to find out. Now, just download a signature software. The best signature software at present is "Loader". Not only does it sign with your mobile phone, you can also sign it when you download games that need to be signed in the future. It is very convenient. If you download It doesn’t work, or the software is installed and you can’t sign. Tell me your QQ email address and I’ll send you the software, including every step of the operation. I’ve answered a lot of questions like yours, so don’t worry