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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 17:38:00 +00:00
putty-source/sshserver.h
Simon Tatham 3214563d8e Convert a lot of 'int' variables to 'bool'.
My normal habit these days, in new code, is to treat int and bool as
_almost_ completely separate types. I'm still willing to use C's
implicit test for zero on an integer (e.g. 'if (!blob.len)' is fine,
no need to spell it out as blob.len != 0), but generally, if a
variable is going to be conceptually a boolean, I like to declare it
bool and assign to it using 'true' or 'false' rather than 0 or 1.

PuTTY is an exception, because it predates the C99 bool, and I've
stuck to its existing coding style even when adding new code to it.
But it's been annoying me more and more, so now that I've decided C99
bool is an acceptable thing to require from our toolchain in the first
place, here's a quite thorough trawl through the source doing
'boolification'. Many variables and function parameters are now typed
as bool rather than int; many assignments of 0 or 1 to those variables
are now spelled 'true' or 'false'.

I managed this thorough conversion with the help of a custom clang
plugin that I wrote to trawl the AST and apply heuristics to point out
where things might want changing. So I've even managed to do a decent
job on parts of the code I haven't looked at in years!

To make the plugin's work easier, I pushed platform front ends
generally in the direction of using standard 'bool' in preference to
platform-specific boolean types like Windows BOOL or GTK's gboolean;
I've left the platform booleans in places they _have_ to be for the
platform APIs to work right, but variables only used by my own code
have been converted wherever I found them.

In a few places there are int values that look very like booleans in
_most_ of the places they're used, but have a rarely-used third value,
or a distinction between different nonzero values that most users
don't care about. In these cases, I've _removed_ uses of 'true' and
'false' for the return values, to emphasise that there's something
more subtle going on than a simple boolean answer:
 - the 'multisel' field in dialog.h's list box structure, for which
   the GTK front end in particular recognises a difference between 1
   and 2 but nearly everything else treats as boolean
 - the 'urgent' parameter to plug_receive, where 1 vs 2 tells you
   something about the specific location of the urgent pointer, but
   most clients only care about 0 vs 'something nonzero'
 - the return value of wc_match, where -1 indicates a syntax error in
   the wildcard.
 - the return values from SSH-1 RSA-key loading functions, which use
   -1 for 'wrong passphrase' and 0 for all other failures (so any
   caller which already knows it's not loading an _encrypted private_
   key can treat them as boolean)
 - term->esc_query, and the 'query' parameter in toggle_mode in
   terminal.c, which _usually_ hold 0 for ESC[123h or 1 for ESC[?123h,
   but can also hold -1 for some other intervening character that we
   don't support.

In a few places there's an integer that I haven't turned into a bool
even though it really _can_ only take values 0 or 1 (and, as above,
tried to make the call sites consistent in not calling those values
true and false), on the grounds that I thought it would make it more
confusing to imply that the 0 value was in some sense 'negative' or
bad and the 1 positive or good:
 - the return value of plug_accepting uses the POSIXish convention of
   0=success and nonzero=error; I think if I made it bool then I'd
   also want to reverse its sense, and that's a job for a separate
   piece of work.
 - the 'screen' parameter to lineptr() in terminal.c, where 0 and 1
   represent the default and alternate screens. There's no obvious
   reason why one of those should be considered 'true' or 'positive'
   or 'success' - they're just indices - so I've left it as int.

ssh_scp_recv had particularly confusing semantics for its previous int
return value: its call sites used '<= 0' to check for error, but it
never actually returned a negative number, just 0 or 1. Now the
function and its call sites agree that it's a bool.

In a couple of places I've renamed variables called 'ret', because I
don't like that name any more - it's unclear whether it means the
return value (in preparation) for the _containing_ function or the
return value received from a subroutine call, and occasionally I've
accidentally used the same variable for both and introduced a bug. So
where one of those got in my way, I've renamed it to 'toret' or 'retd'
(the latter short for 'returned') in line with my usual modern
practice, but I haven't done a thorough job of finding all of them.

Finally, one amusing side effect of doing this is that I've had to
separate quite a few chained assignments. It used to be perfectly fine
to write 'a = b = c = TRUE' when a,b,c were int and TRUE was just a
the 'true' defined by stdbool.h, that idiom provokes a warning from
gcc: 'suggest parentheses around assignment used as truth value'!
2018-11-03 13:45:00 +00:00

104 lines
4.3 KiB
C

typedef struct AuthPolicy AuthPolicy;
Plug *ssh_server_plug(
Conf *conf, ssh_key *const *hostkeys, int nhostkeys,
struct RSAKey *hostkey1, AuthPolicy *authpolicy, LogPolicy *logpolicy,
const SftpServerVtable *sftpserver_vt);
void ssh_server_start(Plug *plug, Socket *socket);
void server_instance_terminated(void);
void platform_logevent(const char *msg);
#define AUTHMETHODS(X) \
X(NONE) \
X(PASSWORD) \
X(PUBLICKEY) \
X(KBDINT) \
X(TIS) \
X(CRYPTOCARD) \
/* end of list */
#define AUTHMETHOD_BIT_INDEX(name) AUTHMETHOD_BIT_INDEX_##name,
enum { AUTHMETHODS(AUTHMETHOD_BIT_INDEX) AUTHMETHOD_BIT_INDEX_dummy };
#define AUTHMETHOD_BIT_VALUE(name) \
AUTHMETHOD_##name = 1 << AUTHMETHOD_BIT_INDEX_##name,
enum { AUTHMETHODS(AUTHMETHOD_BIT_VALUE) AUTHMETHOD_BIT_VALUE_dummy };
typedef struct AuthKbdInt AuthKbdInt;
typedef struct AuthKbdIntPrompt AuthKbdIntPrompt;
struct AuthKbdInt {
char *title, *instruction; /* both need freeing */
int nprompts;
AuthKbdIntPrompt *prompts; /* the array itself needs freeing */
};
struct AuthKbdIntPrompt {
char *prompt; /* needs freeing */
bool echo;
};
unsigned auth_methods(AuthPolicy *);
bool auth_none(AuthPolicy *, ptrlen username);
int auth_password(AuthPolicy *, ptrlen username, ptrlen password,
ptrlen *opt_new_password);
/* auth_password returns 1 for 'accepted', 0 for 'rejected', and 2 for
* 'ok but now you need to change your password' */
bool auth_publickey(AuthPolicy *, ptrlen username, ptrlen public_blob);
/* auth_publickey_ssh1 must return the whole public key given the modulus,
* because the SSH-1 client never transmits the exponent over the wire.
* The key remains owned by the AuthPolicy. */
AuthKbdInt *auth_kbdint_prompts(AuthPolicy *, ptrlen username);
/* auth_kbdint_prompts returns NULL to trigger auth failure */
int auth_kbdint_responses(AuthPolicy *, const ptrlen *responses);
/* auth_kbdint_responses returns >0 for success, <0 for failure, and 0
* to indicate that we haven't decided yet and further prompts are
* coming */
/* The very similar SSH-1 TIS and CryptoCard methods are combined into
* a single API for AuthPolicy, which takes a method argument */
char *auth_ssh1int_challenge(AuthPolicy *, unsigned method, ptrlen username);
bool auth_ssh1int_response(AuthPolicy *, ptrlen response);
struct RSAKey *auth_publickey_ssh1(
AuthPolicy *ap, ptrlen username, Bignum rsa_modulus);
/* auth_successful returns false if further authentication is needed */
bool auth_successful(AuthPolicy *, ptrlen username, unsigned method);
PacketProtocolLayer *ssh2_userauth_server_new(
PacketProtocolLayer *successor_layer, AuthPolicy *authpolicy);
void ssh2_userauth_server_set_transport_layer(
PacketProtocolLayer *userauth, PacketProtocolLayer *transport);
void ssh2connection_server_configure(
PacketProtocolLayer *ppl, const SftpServerVtable *sftpserver_vt);
PacketProtocolLayer *ssh1_login_server_new(
PacketProtocolLayer *successor_layer, struct RSAKey *hostkey,
AuthPolicy *authpolicy);
Channel *sesschan_new(SshChannel *c, LogContext *logctx,
const SftpServerVtable *sftpserver_vt);
Backend *pty_backend_create(
Seat *seat, LogContext *logctx, Conf *conf, char **argv, const char *cmd,
struct ssh_ttymodes ttymodes, bool pipes_instead_of_pty);
ptrlen pty_backend_exit_signame(Backend *be, char **aux_msg);
/*
* Establish a listening X server. Return value is the _number_ of
* Sockets that it established pointing at the given Plug. (0
* indicates complete failure.) The socket pointers themselves are
* written into sockets[], up to a possible total of MAX_X11_SOCKETS.
*
* The supplied Conf has necessary environment variables written into
* it. (And is also used to open the port listeners, though that
* shouldn't affect anything.)
*/
#define MAX_X11_SOCKETS 2
int platform_make_x11_server(Plug *plug, const char *progname, int mindisp,
const char *screen_number_suffix,
ptrlen authproto, ptrlen authdata,
Socket **sockets, Conf *conf);