sslutil: calculate host fingerprints from additional algorithms Currently, we only support defining host fingerprints with SHA-1. A future patch will introduce support for defining fingerprints using other hashing algorithms. In preparation for that, we rewrite the fingerprint verification code to support multiple fingerprints, namely SHA-256 and SHA-512 fingerprints. We still only display the SHA-1 fingerprint. We'll have to revisit this code once we support defining fingerprints with other hash functions. As part of this, I snuck in a change to use range() instead of xrange() because xrange() isn't necessary for such small values.