80 lines
2.4 KiB
Bash
80 lines
2.4 KiB
Bash
# $OpenBSD: keys-command.sh,v 1.8 2021/09/30 04:22:50 dtucker Exp $
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# Placed in the Public Domain.
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tid="authorized keys from command"
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if [ -z "$SUDO" -a ! -w /var/run ]; then
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skip "need SUDO to create file in /var/run, test won't work without"
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fi
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rm -f $OBJ/keys-command-args
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touch $OBJ/keys-command-args
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chmod a+rw $OBJ/keys-command-args
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expected_key_text=`awk '{ print $2 }' < $OBJ/ssh-ed25519.pub`
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expected_key_fp=`$SSHKEYGEN -lf $OBJ/ssh-ed25519.pub | awk '{ print $2 }'`
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# Establish a AuthorizedKeysCommand in /var/run where it will have
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# acceptable directory permissions.
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KEY_COMMAND="/var/run/keycommand_${LOGNAME}.$$"
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trap "${SUDO} rm -f ${KEY_COMMAND}" 0
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cat << _EOF | $SUDO sh -c "rm -f '$KEY_COMMAND' ; cat > '$KEY_COMMAND'"
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#!/bin/sh
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echo args: "\$@" >> $OBJ/keys-command-args
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echo "$PATH" | grep -q mekmitasdigoat && exit 7
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test "x\$1" != "x${LOGNAME}" && exit 1
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if test $# -eq 6 ; then
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test "x\$2" != "xblah" && exit 2
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test "x\$3" != "x${expected_key_text}" && exit 3
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test "x\$4" != "xssh-rsa" && exit 4
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test "x\$5" != "x${expected_key_fp}" && exit 5
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test "x\$6" != "xblah" && exit 6
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fi
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exec cat "$OBJ/authorized_keys_${LOGNAME}"
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_EOF
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$SUDO chmod 0755 "$KEY_COMMAND"
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if ! $OBJ/check-perm -m keys-command $KEY_COMMAND ; then
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echo "skipping: $KEY_COMMAND is unsuitable as AuthorizedKeysCommand"
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$SUDO rm -f $KEY_COMMAND
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exit 0
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fi
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if [ -x $KEY_COMMAND ]; then
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cp $OBJ/sshd_proxy $OBJ/sshd_proxy.bak
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verbose "AuthorizedKeysCommand with arguments"
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(
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grep -vi AuthorizedKeysFile $OBJ/sshd_proxy.bak
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echo AuthorizedKeysFile none
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echo AuthorizedKeysCommand $KEY_COMMAND %u blah %k %t %f blah
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echo AuthorizedKeysCommandUser ${LOGNAME}
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) > $OBJ/sshd_proxy
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# Ensure that $PATH is sanitised in sshd
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env PATH=$PATH:/sbin/mekmitasdigoat \
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${SSH} -F $OBJ/ssh_proxy somehost true
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if [ $? -ne 0 ]; then
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fail "connect failed"
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fi
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verbose "AuthorizedKeysCommand without arguments"
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# Check legacy behavior of no-args resulting in username being passed.
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(
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grep -vi AuthorizedKeysFile $OBJ/sshd_proxy.bak
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echo AuthorizedKeysFile none
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echo AuthorizedKeysCommand $KEY_COMMAND
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echo AuthorizedKeysCommandUser ${LOGNAME}
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) > $OBJ/sshd_proxy
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# Ensure that $PATH is sanitised in sshd
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env PATH=$PATH:/sbin/mekmitasdigoat \
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${SSH} -F $OBJ/ssh_proxy somehost true
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if [ $? -ne 0 ]; then
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fail "connect failed"
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fi
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else
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skip "$KEY_COMMAND not executable (/var/run mounted noexec?)"
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fi
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