How to use [crypto.hash]

The reference page of crypto.hash has its arguments, constraints and declaration.

The [crypto.hash] slot can be used to generate hash values. When you invoke it, you can choose between having the hash returned as raw a byte[], as a “fingerprint” or as its bit encoded hex version. Below is an example of all three of these formats.

.data:Some data to hash

crypto.hash:x:@.data
   format:fingerprint

crypto.hash:x:@.data
   format:text

crypto.hash:x:@.data
   format:raw

To override the hashing algorithm used when creating hash values, apply an [algorithm] argument, and set its value to the hashing algorithm you want to use. You can choose between the following hashing algorithms as you consume the above slot.

• sha1
• md5
• sha256
• sha384
• sha512

Notice - sha1 and md5 is supported only for legacy reasons, and should not be used unless you have a legacy system depending upon it. Sha1 and md5 are considered weak today due to the statistical probability of that they can result in what’s commonly referred to as “hash collision”. This project also contains convenience overloads with the hashing algorithm being a part of the name of the invocation, such as illustrated below.

• [crypto.hash.sha1]
• [crypto.hash.md5]
• [crypto.hash.sha256]
• [crypto.hash.sha384]
• [crypto.hash.sha512]

In addition you can hash a file directly, without having to load it first, by providing a [filename] argument to it, such as illustrated below.

crypto.hash.sha256
   filename:/README.md

About cryptography fingerprints

The fingerprint format resulting from a hash invocation is useful due to being much more easily read by humans, and in such a regard better suited for being stored as a key reference into for instance a database, and/or transmitted as a key reference over the network to other machines.

A fingerprint is actually just a cryptographic hash of your data, such as for instance your public key, payload, etc.