HMAC-SHA1 in bash

Question

Is there a bash script available to generate a HMAC-SHA1 hash?

The equivalent of the following PHP code:

hash_hmac("sha1", "value", "key", TRUE);

Parameters

true : When set to TRUE, outputs raw binary data. FALSE outputs lowercase hexits. 

Thanks.

see HMAC-SHA1 in bash

Answer 1

In bash itself, no, it can do a lot of stuff but it also knows when to rely on external tools.

For example, the Wikipedia page provides a Python implementation which bash can call to do the grunt work for HMAC_MD5, repeated below to make this answer self-contained:

#!/usr/bin/env python
from hashlib import md5 
trans_5C = "".join(chr(x ^ 0x5c) for x in xrange(256))
trans_36 = "".join(chr(x ^ 0x36) for x in xrange(256))
blocksize = md5().block_size

def hmac_md5(key, msg):
    if len(key) > blocksize:
        key = md5(key).digest()
    key += chr(0) * (blocksize - len(key))
    o_key_pad = key.translate(trans_5C)
    i_key_pad = key.translate(trans_36)
    return md5(o_key_pad + md5(i_key_pad + msg).digest())

if __name__ == "__main__":
    h = hmac_md5("key", "The quick brown fox jumps over the lazy dog")
    print h.hexdigest()  # 80070713463e7749b90c2dc24911e275

(keeping in mind that Python also contains SHA1 stuff as well, see here for details on how to use HMAC with the hashlib.sha1() constructor).

Or, if you want to run the exact same code as PHP does, you could try running it with phpsh, as detailed here.