nhyatt/putty-source
1
0
Fork 0
mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 17:38:00 +00:00
Code Issues Projects Releases Wiki Activity
3ad919f9e9
putty-source/sshbpp.h

71 lines
2.5 KiB
C
Raw Normal View History

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
/*
* Abstraction of the binary packet protocols used in SSH.
*/
#ifndef PUTTY_SSHBPP_H
#define PUTTY_SSHBPP_H
typedef struct BinaryPacketProtocol BinaryPacketProtocol;
struct BinaryPacketProtocolVtable {
void (*free)(BinaryPacketProtocol *);
void (*handle_input)(BinaryPacketProtocol *);
PktOut *(*new_pktout)(int type);
void (*format_packet)(BinaryPacketProtocol *, PktOut *);
};
struct BinaryPacketProtocol {
const struct BinaryPacketProtocolVtable *vt;
bufchain *in_raw, *out_raw;
Extend PacketQueue to take PktOut as well. Some upcoming restructuring I've got planned will need to pass output packets back and forth on queues, as well as input ones. So here's a change that arranges that we can have a PktInQueue and a PktOutQueue, sharing most of their implementation via a PacketQueueBase structure which links together the PacketQueueNode fields in the two packet structures. There's a tricksy bit of macro manoeuvring to get all of this type-checked, so that I can't accidentally link a PktOut on to a PktInQueue or vice versa. It works by having the main queue functions wrapped by macros; when receiving a packet structure on input, they type-check it against the queue structure and then automatically look up its qnode field to pass to the underlying PacketQueueBase function; on output, they translate a returned PacketQueueNode back to its containing packet type by calling a 'get' function pointer.
2018-09-19 20:56:11 +00:00
PktInQueue *in_pq;
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
PacketLogSettings *pls;
Make 'LogContext' a typedef visible throughout the code. Same principle again - the more of these structures have globally visible tags (even if the structure contents are still opaque in most places), the fewer of them I can mistake for each other.
2018-09-11 14:17:16 +00:00
LogContext *logctx;
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
int seen_disconnect;
char *error;
};
#define ssh_bpp_free(bpp) ((bpp)->vt->free(bpp))
#define ssh_bpp_handle_input(bpp) ((bpp)->vt->handle_input(bpp))
#define ssh_bpp_new_pktout(bpp, type) ((bpp)->vt->new_pktout(type))
#define ssh_bpp_format_packet(bpp, pkt) ((bpp)->vt->format_packet(bpp, pkt))
BinaryPacketProtocol *ssh1_bpp_new(void);
void ssh1_bpp_new_cipher(BinaryPacketProtocol *bpp,
Turn SSH-1 ciphers into a classoid. The interchangeable system of SSH-1 ciphers previously followed the same pattern as the backends and the public-key algorithms, in that all the clients would maintain two separate pointers, one to the vtable and the other to the individual instance / context. Now I've merged them, just as I did with those other two, so that you only cart around a single pointer, which has a vtable pointer inside it and a type distinguishing it from an instance of any of the other interchangeable sets of algorithms.
2018-09-13 12:29:32 +00:00
const struct ssh1_cipheralg *cipher,
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
const void *session_key);
void ssh1_bpp_start_compression(BinaryPacketProtocol *bpp);
BinaryPacketProtocol *ssh2_bpp_new(void);
void ssh2_bpp_new_outgoing_crypto(
BinaryPacketProtocol *bpp,
Turn SSH-2 ciphers into a classoid. This is more or less the same job as the SSH-1 case, only more extensive, because we have a wider range of ciphers. I'm a bit disappointed about the AES case, in particular, because I feel as if it ought to have been possible to arrange to combine this layer of vtable dispatch with the subsidiary one that selects between hardware and software implementations of the underlying cipher. I may come back later and have another try at that, in fact.
2018-09-13 13:43:04 +00:00
const struct ssh2_cipheralg *cipher, const void *ckey, const void *iv,
Turn SSH-2 MACs into a classoid. This piece of tidying-up has come out particularly well in terms of saving tedious repetition and boilerplate. I've managed to remove three pointless methods from every MAC implementation by means of writing them once centrally in terms of the implementation-specific methods; another method (hmacmd5_sink) vanished because I was able to make the interface type 'ssh2_mac' be directly usable as a BinarySink by way of a new delegation system; and because all the method implementations can now find their own vtable, I was even able to merge a lot of keying and output functions that had previously differed only in length parameters by having them look up the lengths in whatever vtable they were passed.
2018-09-13 15:15:17 +00:00
const struct ssh2_macalg *mac, int etm_mode, const void *mac_key,
Make ssh_compress into a pair of linked classoids. This was mildly fiddly because there's a single vtable structure that implements two distinct interface types, one for compression and one for decompression - and I have actually confused them before now (commit d4304f1b7), so I think it's important to make them actually be separate types!
2018-09-14 08:16:41 +00:00
const struct ssh_compression_alg *compression);
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
void ssh2_bpp_new_incoming_crypto(
BinaryPacketProtocol *bpp,
Turn SSH-2 ciphers into a classoid. This is more or less the same job as the SSH-1 case, only more extensive, because we have a wider range of ciphers. I'm a bit disappointed about the AES case, in particular, because I feel as if it ought to have been possible to arrange to combine this layer of vtable dispatch with the subsidiary one that selects between hardware and software implementations of the underlying cipher. I may come back later and have another try at that, in fact.
2018-09-13 13:43:04 +00:00
const struct ssh2_cipheralg *cipher, const void *ckey, const void *iv,
Turn SSH-2 MACs into a classoid. This piece of tidying-up has come out particularly well in terms of saving tedious repetition and boilerplate. I've managed to remove three pointless methods from every MAC implementation by means of writing them once centrally in terms of the implementation-specific methods; another method (hmacmd5_sink) vanished because I was able to make the interface type 'ssh2_mac' be directly usable as a BinarySink by way of a new delegation system; and because all the method implementations can now find their own vtable, I was even able to merge a lot of keying and output functions that had previously differed only in length parameters by having them look up the lengths in whatever vtable they were passed.
2018-09-13 15:15:17 +00:00
const struct ssh2_macalg *mac, int etm_mode, const void *mac_key,
Make ssh_compress into a pair of linked classoids. This was mildly fiddly because there's a single vtable structure that implements two distinct interface types, one for compression and one for decompression - and I have actually confused them before now (commit d4304f1b7), so I think it's important to make them actually be separate types!
2018-09-14 08:16:41 +00:00
const struct ssh_compression_alg *compression);
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);
Move version string exchange out into a BPP. Getting it out of the overgrown ssh.c is worthwhile in itself! But there are other benefits of this reorganisation too. One is that I get to remove ssh->current_incoming_data_fn, because now _all_ incoming network data is handled by whatever the current BPP is. So now we only indirect through the BPP, not through some other preliminary function pointer _and_ the BPP. Another is that all _outgoing_ network data is now handled centrally, including our outgoing version string - which means that a hex dump of that string now shows up in the raw-data log file, from which it was previously conspicuous by its absence.
2018-09-19 16:37:00 +00:00
/*
* The initial code to handle the SSH version exchange is also
* structured as an implementation of BinaryPacketProtocol, because
* that makes it easy to switch from that to the next BPP once it
* tells us which one we're using.
*/
struct ssh_version_receiver {
void (*got_ssh_version)(struct ssh_version_receiver *rcv,
int major_version);
};
BinaryPacketProtocol *ssh_verstring_new(
Conf *conf, Frontend *frontend, int bare_connection_mode,
const char *protoversion, struct ssh_version_receiver *rcv);
const char *ssh_verstring_get_remote(BinaryPacketProtocol *);
const char *ssh_verstring_get_local(BinaryPacketProtocol *);
int ssh_verstring_get_bugs(BinaryPacketProtocol *);
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
#endif /* PUTTY_SSHBPP_H */
Reference in New Issue Copy Permalink