mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-01-09 01:18:00 +00:00
2ec2b796ed
Most of them are now _mandatory_ P3 scripts, because I'm tired of maintaining everything to be compatible with both versions. The current exceptions are gdb.py (which has to live with whatever gdb gives it), and kh2reg.py (which is actually designed for other people to use, and some of them might still be stuck on P2 for the moment).
95 lines
5.0 KiB
Python
Executable File
95 lines
5.0 KiB
Python
Executable File
#!/usr/bin/env python3
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# Example Python script to synthesise the server end of an SSH key exchange.
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# This script expects to be run with its standard input and output
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# channels both connected to PuTTY. Run it by means of a command such
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# as
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#
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# rm -f test.log && ./plink -sshrawlog test.log -v -proxycmd './contrib/samplekex.py' dummy
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#
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# It will conduct the whole of an SSH connection setup, up to the
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# point where it ought to present a valid host key signature and
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# switch over to the encrypted protocol; but because this is a simple
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# script (and also because at that point PuTTY would annoyingly give a
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# host key prompt), it doesn't actually bother to do either, and will
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# instead present a nonsense signature and terminate. The above sample
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# command will log the whole of the exchange from PuTTY's point of
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# view in 'test.log'.
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#
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# The intention is that this forms example code that can be easily
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# adapted to demonstrate bugs in our SSH connection setup. With more
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# effort it could be expanded into some kind of a regression-testing
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# suite, although in order to reliably test particular corner cases
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# that would probably also need PuTTY-side modifications to make the
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# random numbers deterministic.
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import sys, random
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from encodelib import *
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assert sys.version_info[:2] >= (3,0), "This is Python 3 code"
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# A random Diffie-Hellman group, taken from an SSH server I made a
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# test connection to.
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groupgen = 5
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group = 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# An RSA key, generated specially for this script.
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rsaexp = 0x10001
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rsamod = 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# 16 bytes of random data for the start of KEXINIT.
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cookie = bytes(random.randint(0,255) for i in range(16))
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def expect(var, expr):
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expected_val = eval(expr)
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if var != expected_val:
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sys.stderr.write("Expected %s (%s), got %s\n" % (
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expr, repr(expected_val), repr(var)))
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sys.exit(1)
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sys.stdout.buffer.write(greeting("SSH-2.0-Example KEX synthesis"))
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greeting = sys.stdin.buffer.readline()
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expect(greeting[:8].decode("ASCII"), '"SSH-2.0-"')
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sys.stdout.buffer.write(
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clearpkt(SSH2_MSG_KEXINIT,
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cookie,
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name_list(("diffie-hellman-group-exchange-sha256",)), # kex
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name_list(("ssh-rsa",)), # host keys
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name_list(("aes128-ctr",)), # client->server ciphers
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name_list(("aes128-ctr",)), # server->client ciphers
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name_list(("hmac-sha2-256",)), # client->server MACs
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name_list(("hmac-sha2-256",)), # server->client MACs
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name_list(("none",)), # client->server compression
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name_list(("none",)), # server->client compression
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name_list(()), # client->server languages
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name_list(()), # server->client languages
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boolean(False), # first kex packet does not follow
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uint32(0)))
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sys.stdout.buffer.flush()
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intype, inpkt = read_clearpkt(sys.stdin.buffer)
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expect(intype, "SSH2_MSG_KEXINIT")
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intype, inpkt = read_clearpkt(sys.stdin.buffer)
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expect(intype, "SSH2_MSG_KEX_DH_GEX_REQUEST")
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expect(inpkt, "uint32(0x400) + uint32(0x400) + uint32(0x2000)")
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sys.stdout.buffer.write(
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clearpkt(SSH2_MSG_KEX_DH_GEX_GROUP,
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mpint(group),
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mpint(groupgen)))
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sys.stdout.buffer.flush()
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intype, inpkt = read_clearpkt(sys.stdin.buffer)
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expect(intype, "SSH2_MSG_KEX_DH_GEX_INIT")
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sys.stdout.buffer.write(
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clearpkt(SSH2_MSG_KEX_DH_GEX_REPLY,
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ssh_rsa_key_blob(rsaexp, rsamod),
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mpint(random.randint(2, group-2)),
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ssh_rsa_signature_blob(random.randint(2, rsamod-2))))
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sys.stdout.buffer.flush()
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