102 lines
2.2 KiB
Bash
Executable File
102 lines
2.2 KiB
Bash
Executable File
#! /bin/bash
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# source: socks4echo.sh
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# Copyright Gerhard Rieger 2004-2006
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# Published under the GNU General Public License V.2, see file COPYING
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# perform primitive simulation of a socks4 server with echo function via stdio.
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# accepts and answers correct SOCKS4 requests, but then just echoes data.
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# it is required for test.sh
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# for TCP, use this script as:
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# socat tcp-l:1080,reuseaddr,crlf system:"socks4echo.sh"
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# older bash and ksh do not have -n option to read command; we try dd then
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if echo a |read -n 1 null >/dev/null 2>&1; then
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HAVE_READ_N=1
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else
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HAVE_READ_N=
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fi
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if type socat >/dev/null 2>&1; then
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SOCAT=socat
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else
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SOCAT=./socat
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fi
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case `uname` in
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HP-UX|OSF1)
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CAT="$SOCAT -u stdin stdout"
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;;
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*)
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CAT=cat
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;;
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esac
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if [ $(echo "x\c") = "x" ]; then E=""
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elif [ $(echo -e "x\c") = "x" ]; then E="-e"
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else
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echo "cannot suppress trailing newline on echo" >&2
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exit 1
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fi
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ECHO="echo $E"
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if [ $($ECHO "\0101") = "A" ]; then
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SOCKSREPLY_FAILED="\0\0133\0\0\0\0\0\0\c"
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SOCKSREPLY_OK="\0\0132\0\0\0\0\0\0\c"
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else
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SOCKSREPLY_FAILED="\0\133\0\0\0\0\0\0\c"
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SOCKSREPLY_OK="\0\132\0\0\0\0\0\0\c"
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fi
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# read and parse SOCKS4 header
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if [ "$HAVE_READ_N" ]; then
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read -r -n 1 vn # bash 2.0.3 does not support -n
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else
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vn=$(dd bs=1 count=1 2>/dev/null)
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fi
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if [ "$vn" != $($ECHO "\04") ]; then
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$ECHO "$SOCKSREPLY_FAILED"
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echo "invalid socks version requested" >&2
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exit
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fi
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if [ "$HAVE_READ_N" ]; then
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read -r -n 1 cd
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else
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cd=$(dd bs=1 count=1 2>/dev/null)
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fi
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if [ "$cd" != $($ECHO "\01") ]; then
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$ECHO "$SOCKSREPLY_FAILED"
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echo "invalid socks operation requested" >&2
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exit
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fi
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if [ "$HAVE_READ_N" ]; then
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read -r -n 6 a
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else
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a=$(dd bs=1 count=6 2>/dev/null)
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fi
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if [ "$a" != "$($ECHO "}m bL6")" ]; then
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$ECHO "$SOCKSREPLY_FAILED"
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echo "$0: wrong socks address or port requested" >&2
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echo "$0: expected $($ECHO "}m bL6"|od -t x1), received $($ECHO "$a"|od -t x1)" >&2
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exit
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fi
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if [ "$HAVE_READ_N" ]; then
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read -r -n 7 u
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else
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u=$(dd bs=1 count=7 2>/dev/null)
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fi
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if [ "$u" != "nobody" ]; then
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$ECHO "$SOCKSREPLY_FAILED"
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echo "wrong socks user requested" >&2
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exit
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fi
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# send ok status
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$ECHO "$SOCKSREPLY_OK"
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# perform echo function
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$CAT
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