63 lines
1.8 KiB
Bash
Executable File
63 lines
1.8 KiB
Bash
Executable File
#!/bin/sh
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#
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# This script will extract the necessary certificate from the IMAP server
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# It assumes that an attacker isn't trying to spoof you when you connect
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# to the IMAP server! You're better off downloading the certificate
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# from a trusted source.
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#
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# Copyright (C) 2003 Theodore Ts'o <tytso@alum.mit.edu>
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software Foundation,
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# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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#
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if [ $# != 1 ]; then
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echo "Usage: $0 <host>" >&2
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exit 1
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fi
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HOST=$1
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seed=`date '+%s'`
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try=0
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while :; do
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TMPDIR=/tmp/get-cert.$$.$seed
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mkdir $TMPDIR 2> /dev/null && break
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if [ $try = 1000 ]; then
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echo "Cannot create temporary directory." >&2
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exit 1
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fi
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try=`expr $try + 1`
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seed=`expr \( \( $seed \* 1103515245 \) + 12345 \) % 2147483648`
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done
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TMPFILE=$TMPDIR/get-cert
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ERRFILE=$TMPDIR/get-cert-err
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CERTFILE=$TMPDIR/cert
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echo QUIT | openssl s_client -connect $HOST:993 -showcerts \
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> $TMPFILE 2> $ERRFILE
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sed -e '1,/^-----BEGIN CERTIFICATE-----/d' \
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-e '/^-----END CERTIFICATE-----/,$d' < $TMPFILE > $CERTFILE
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if test -s $CERTFILE ; then
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echo -----BEGIN CERTIFICATE-----
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cat $CERTFILE
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echo -----END CERTIFICATE-----
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else
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echo "Couldn't retrieve certificate. openssl reported the following errors:"
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cat $ERRFILE
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fi
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rm -r $TMPDIR
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