Quick snippet to convert public key signatures from an authorized_keys file into their ssh fingerprint

fingerprint_conversion.py

# Quick snippet to convert public key signatures from an authorized_keys file into their ssh fingerprint
# Usage: python fingerprint_conversion.py authorized_keys

import base64,hashlib,sys

line = sys.argv[1]
f = open(line, 'r')

for key in f:
  key = str(key.strip().split()[1])
  k = base64.b64decode(key + '=' * (-len(key) % 4))
  fp_plain = hashlib.md5(k).hexdigest()
  print ':'.join(a+b for a,b in zip(fp_plain[::2], fp_plain[1::2]))