This step is to verify a downloaded firmware binary against a reference checksum to avoid download errors.
Below you will find instructions on
If those strings are not the same, the firmware file was not properly downloaded and if you proceed flashing such a file, you will probably brick the device permanently or requiring annoying procedures to recover.
If checksum mismatches, download the firmware file again and compare it again. If the checksum is still wrong in repeated attempts, ask the OpenWrt forums for help.
Checksums are stored in the folder view of the download server's webpage. Obtain it by following those steps:
/and open the URL in your browser. E.g.
sha256sumis the checksum. E.g.
certutil, but it has no graphical user interface so we will have to use the command line to interact with it.
To use the built-in
certutil -hashfile "%USERPROFILE%\Downloads\openwrt-file-name-here" sha256
SHA256-Hash of file C:\Users\USERNAME\Downloads\openwrt-18.06.1-...-factory.bin: 79 f9 4e fa d3 2c 14 8f f1 95 3f 09 6d 98 c7 41 c0 ff 8f 7e b4 68 8c 9d 5b f9 fb 01 c0 90 fb ab
Mac has an integrated tool to check sha256sums, but it has no graphical user interface so we will have to use the Terminal to interact with it.
shasum -a 256 ./Desktop/file-name-here
Some file managers (dolphin and other more powerful ones used in KDE user interface) offer this functionality in the file property window (right-click on the file, select Properties, click on “Checksums” tab, that tab appears only for binary files, like firmware images). It will offer buttons to calculate the sha256sum and a field where you can paste the SHA256 string from sha256sums file to verify that it is correct.