mirror of https://git.code.sf.net/p/isync/isync
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
50 lines
1.2 KiB
50 lines
1.2 KiB
#!/bin/sh |
|
# |
|
# SPDX-FileCopyrightText: 2003 Theodore Ts'o <tytso@alum.mit.edu> |
|
# SPDX-License-Identifier: GPL-2.0-or-later |
|
# |
|
# This script will extract the necessary certificate from the IMAP server |
|
# It assumes that an attacker isn't trying to spoof you when you connect |
|
# to the IMAP server! You're better off downloading the certificate |
|
# from a trusted source. |
|
# |
|
|
|
if [ $# != 1 ]; then |
|
echo "Usage: $0 <host>" >&2 |
|
exit 1 |
|
fi |
|
|
|
HOST=$1 |
|
|
|
seed=`date '+%s'` |
|
try=0 |
|
while :; do |
|
TMPDIR=/tmp/get-cert.$$.$seed |
|
mkdir $TMPDIR 2> /dev/null && break |
|
if [ $try = 1000 ]; then |
|
echo "Cannot create temporary directory." >&2 |
|
exit 1 |
|
fi |
|
try=`expr $try + 1` |
|
seed=`expr \( \( $seed \* 1103515245 \) + 12345 \) % 2147483648` |
|
done |
|
|
|
TMPFILE=$TMPDIR/get-cert |
|
ERRFILE=$TMPDIR/get-cert-err |
|
CERTFILE=$TMPDIR/cert |
|
|
|
echo QUIT | openssl s_client -connect $HOST:993 -showcerts \ |
|
> $TMPFILE 2> $ERRFILE |
|
sed -e '1,/^-----BEGIN CERTIFICATE-----/d' \ |
|
-e '/^-----END CERTIFICATE-----/,$d' < $TMPFILE > $CERTFILE |
|
|
|
if test -s $CERTFILE ; then |
|
echo -----BEGIN CERTIFICATE----- |
|
cat $CERTFILE |
|
echo -----END CERTIFICATE----- |
|
else |
|
echo "Couldn't retrieve certificate. openssl reported the following errors:" |
|
cat $ERRFILE |
|
fi |
|
|
|
rm -r $TMPDIR
|
|
|