#!/bin/sh

# Like ssh-keygen -lf, but for a file such as authorized_keys, which
# may contain multiple keys.
#
# Usage: sshfprs.sh file [prefix]

set -ue

file="$1"
prefix="${2:-}"

while read pk; do
	# ssh-keygen can't read from STDIN, and ash doesn't have the '<<<'
	# construct, so we save each pubkey in a temporary file
	pkf=$(mktemp)
	echo "$pk" > "$pkf"
	echo "${prefix}$(ssh-keygen -lf $pkf)"
	rm "$pkf"
done < "$file"