Home Home > 2019 > 08 > 07
Sign up | Login

Deprecation notice: openSUSE Lizards user blog platform is deprecated, and will remain read only for the time being. Learn more...

Archive for August 7th, 2019

Tricks with IPFS

August 7th, 2019 by

Since April I am using IPFS

Now I wanted to document some neat tricks and details.

When you have the hex-encoded sha256sum of a small file – for this example let’s use the GPLv3.txt on our media –
sha256sum /ipns/opensuse.zq1.de/tumbleweed/repo/oss/GPLv3.txt

Then you can use the hash to address content directly by prefixing it with /ipfs/f01551220 so it becomes


In theory this also works with SHA1 and the /ipfs/f01551114 prefix, but then you risk experiencing non-unique content like

And dont even think about using MD5.

For this trick to work, the file needs to be added with ipfs add --raw-leaves and it must be a single chunk – by default 256kB or smaller, but if you do the adding, you can also use larger chunks.

Here is a decoding of the different parts of the prefix:
/ipfs/ is the common path for IPFS-addressed content
f is the multibase prefix for hex-encoded data
01 is for the CID version 1
55 is for raw binary
12 is for sha2-256 (the default hash in IPFS)
20 is for 32 byte = 256 bit length of hash

And finally, you can also access this content via the various IPFS-web-gateways:

You can also do the same trick with other multibase encodings of the same data – e.g. base2

Base2 looks pretty geeky, but so far I have not found practical applications.