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putty-source/ssh2bpp-bare.c

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Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
/*
* Trivial binary packet protocol for the 'bare' ssh-connection
* protocol used in PuTTY's SSH-2 connection sharing system.
*/
#include <assert.h>
#include "putty.h"
#include "ssh.h"
#include "sshbpp.h"
#include "sshcr.h"
struct ssh2_bare_bpp_state {
int crState;
long packetlen, maxlen;
unsigned char *data;
unsigned long incoming_sequence, outgoing_sequence;
PktIn *pktin;
BinaryPacketProtocol bpp;
};
static void ssh2_bare_bpp_free(BinaryPacketProtocol *bpp);
static void ssh2_bare_bpp_handle_input(BinaryPacketProtocol *bpp);
static void ssh2_bare_bpp_handle_output(BinaryPacketProtocol *bpp);
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
static PktOut *ssh2_bare_bpp_new_pktout(int type);
static const struct BinaryPacketProtocolVtable ssh2_bare_bpp_vtable = {
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
ssh2_bare_bpp_free,
ssh2_bare_bpp_handle_input,
ssh2_bare_bpp_handle_output,
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
ssh2_bare_bpp_new_pktout,
ssh2_bpp_queue_disconnect, /* in sshcommon.c */
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
};
BinaryPacketProtocol *ssh2_bare_bpp_new(void)
{
struct ssh2_bare_bpp_state *s = snew(struct ssh2_bare_bpp_state);
memset(s, 0, sizeof(*s));
s->bpp.vt = &ssh2_bare_bpp_vtable;
ssh_bpp_common_setup(&s->bpp);
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
return &s->bpp;
}
static void ssh2_bare_bpp_free(BinaryPacketProtocol *bpp)
{
struct ssh2_bare_bpp_state *s =
FROMFIELD(bpp, struct ssh2_bare_bpp_state, bpp);
sfree(s->pktin);
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
sfree(s);
}
#define BPP_READ(ptr, len) do \
{ \
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 17:28:16 +00:00
crMaybeWaitUntilV(s->bpp.input_eof || \
bufchain_try_fetch_consume( \
s->bpp.in_raw, ptr, len)); \
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 17:28:16 +00:00
if (s->bpp.input_eof) \
goto eof; \
} while (0)
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
static void ssh2_bare_bpp_handle_input(BinaryPacketProtocol *bpp)
{
struct ssh2_bare_bpp_state *s =
FROMFIELD(bpp, struct ssh2_bare_bpp_state, bpp);
crBegin(s->crState);
while (1) {
/* Read the length field. */
{
unsigned char lenbuf[4];
BPP_READ(lenbuf, 4);
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
s->packetlen = toint(GET_32BIT_MSB_FIRST(lenbuf));
}
if (s->packetlen <= 0 || s->packetlen >= (long)OUR_V2_PACKETLIMIT) {
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 17:28:16 +00:00
ssh_sw_abort(s->bpp.ssh, "Invalid packet length received");
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
crStopV;
}
/*
* Allocate the packet to return, now we know its length.
*/
s->pktin = snew_plus(PktIn, s->packetlen);
s->pktin->qnode.prev = s->pktin->qnode.next = NULL;
s->pktin->qnode.on_free_queue = FALSE;
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
s->maxlen = 0;
s->data = snew_plus_get_aux(s->pktin);
s->pktin->sequence = s->incoming_sequence++;
/*
* Read the remainder of the packet.
*/
BPP_READ(s->data, s->packetlen);
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
/*
* The data we just read is precisely the initial type byte
* followed by the packet payload.
*/
s->pktin->type = s->data[0];
s->data++;
s->packetlen--;
BinarySource_INIT(s->pktin, s->data, s->packetlen);
/*
* Log incoming packet, possibly omitting sensitive fields.
*/
if (s->bpp.logctx) {
logblank_t blanks[MAX_BLANKS];
int nblanks = ssh2_censor_packet(
s->bpp.pls, s->pktin->type, FALSE,
make_ptrlen(s->data, s->packetlen), blanks);
log_packet(s->bpp.logctx, PKT_INCOMING, s->pktin->type,
ssh2_pkt_type(s->bpp.pls->kctx, s->bpp.pls->actx,
s->pktin->type),
get_ptr(s->pktin), get_avail(s->pktin), nblanks, blanks,
&s->pktin->sequence, 0, NULL);
}
if (ssh2_bpp_check_unimplemented(&s->bpp, s->pktin)) {
sfree(s->pktin);
s->pktin = NULL;
continue;
}
pq_push(&s->bpp.in_pq, s->pktin);
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 17:28:16 +00:00
s->pktin = NULL;
}
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 17:28:16 +00:00
eof:
if (!s->bpp.expect_close) {
ssh_remote_error(s->bpp.ssh,
"Server unexpectedly closed network connection");
} else {
ssh_remote_eof(s->bpp.ssh, "Server closed network connection");
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
}
return; /* avoid touching s now it's been freed */
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 17:28:16 +00:00
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
crFinishV;
}
static PktOut *ssh2_bare_bpp_new_pktout(int pkt_type)
{
PktOut *pkt = ssh_new_packet();
pkt->length = 4; /* space for packet length */
pkt->type = pkt_type;
put_byte(pkt, pkt_type);
return pkt;
}
static void ssh2_bare_bpp_format_packet(struct ssh2_bare_bpp_state *s,
PktOut *pkt)
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
{
if (s->bpp.logctx) {
ptrlen pktdata = make_ptrlen(pkt->data + 5, pkt->length - 5);
logblank_t blanks[MAX_BLANKS];
int nblanks = ssh2_censor_packet(
s->bpp.pls, pkt->type, TRUE, pktdata, blanks);
log_packet(s->bpp.logctx, PKT_OUTGOING, pkt->type,
ssh2_pkt_type(s->bpp.pls->kctx, s->bpp.pls->actx,
pkt->type),
pktdata.ptr, pktdata.len, nblanks, blanks,
&s->outgoing_sequence,
pkt->downstream_id, pkt->additional_log_text);
}
s->outgoing_sequence++; /* only for diagnostics, really */
PUT_32BIT(pkt->data, pkt->length - 4);
bufchain_add(s->bpp.out_raw, pkt->data, pkt->length);
}
static void ssh2_bare_bpp_handle_output(BinaryPacketProtocol *bpp)
{
struct ssh2_bare_bpp_state *s =
FROMFIELD(bpp, struct ssh2_bare_bpp_state, bpp);
PktOut *pkt;
while ((pkt = pq_pop(&s->bpp.out_pq)) != NULL) {
ssh2_bare_bpp_format_packet(s, pkt);
ssh_free_pktout(pkt);
}
Move binary packet protocols and censoring out of ssh.c. sshbpp.h now defines a classoid that encapsulates both directions of an SSH binary packet protocol - that is, a system for reading a bufchain of incoming data and turning it into a stream of PktIn, and another system for taking a PktOut and turning it into data on an outgoing bufchain. The state structure in each of those files contains everything that used to be in the 'rdpkt2_state' structure and its friends, and also quite a lot of bits and pieces like cipher and MAC states that used to live in the main Ssh structure. One minor effect of this layer separation is that I've had to extend the packet dispatch table by one, because the BPP layer can no longer directly trigger sending of SSH_MSG_UNIMPLEMENTED for a message too short to have a type byte. Instead, I extend the PktIn type field to use an out-of-range value to encode that, and the easiest way to make that trigger an UNIMPLEMENTED message is to have the dispatch table contain an entry for it. (That's a system that may come in useful again - I was also wondering about inventing a fake type code to indicate network EOF, so that that could be propagated through the layers and be handled by whichever one currently knew best how to respond.) I've also moved the packet-censoring code into its own pair of files, partly because I was going to want to do that anyway sooner or later, and mostly because it's called from the BPP code, and the SSH-2 version in particular has to be called from both the main SSH-2 BPP and the bare unencrypted protocol used for connection sharing. While I was at it, I took the opportunity to merge the outgoing and incoming censor functions, so that the parts that were common between them (e.g. CHANNEL_DATA messages look the same in both directions) didn't need to be repeated.
2018-06-09 08:09:10 +00:00
}