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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 17:38:00 +00:00
putty-source/misc.c
Simon Tatham 76d8d363be Seat method to set the current trust status.
In terminal-based GUI applications, this is passed through to
term_set_trust_status, to toggle whether lines are prefixed with the
new trust sigil. In console applications, the function returns false,
indicating to the backend that it should employ some other technique
for spoofing protection.
2019-03-16 12:25:23 +00:00

362 lines
11 KiB
C

/*
* Platform-independent routines shared between all PuTTY programs.
*
* This file contains functions that use the kind of infrastructure
* like conf.c that tends to only live in the main applications, or
* that do things that only something like a main PuTTY application
* would need. So standalone test programs should generally be able to
* avoid linking against it.
*
* More standalone functions that depend on nothing but the C library
* live in utils.c.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <limits.h>
#include <ctype.h>
#include <assert.h>
#include "defs.h"
#include "putty.h"
#include "misc.h"
void seat_connection_fatal(Seat *seat, const char *fmt, ...)
{
va_list ap;
char *msg;
va_start(ap, fmt);
msg = dupvprintf(fmt, ap);
va_end(ap);
seat->vt->connection_fatal(seat, msg);
sfree(msg); /* if we return */
}
prompts_t *new_prompts(void)
{
prompts_t *p = snew(prompts_t);
p->prompts = NULL;
p->n_prompts = p->prompts_size = 0;
p->data = NULL;
p->to_server = true; /* to be on the safe side */
p->name = p->instruction = NULL;
p->name_reqd = p->instr_reqd = false;
return p;
}
void add_prompt(prompts_t *p, char *promptstr, bool echo)
{
prompt_t *pr = snew(prompt_t);
pr->prompt = promptstr;
pr->echo = echo;
pr->result = NULL;
pr->resultsize = 0;
sgrowarray(p->prompts, p->prompts_size, p->n_prompts);
p->prompts[p->n_prompts++] = pr;
}
void prompt_ensure_result_size(prompt_t *pr, int newlen)
{
if ((int)pr->resultsize < newlen) {
char *newbuf;
newlen = newlen * 5 / 4 + 512; /* avoid too many small allocs */
/*
* We don't use sresize / realloc here, because we will be
* storing sensitive stuff like passwords in here, and we want
* to make sure that the data doesn't get copied around in
* memory without the old copy being destroyed.
*/
newbuf = snewn(newlen, char);
memcpy(newbuf, pr->result, pr->resultsize);
smemclr(pr->result, pr->resultsize);
sfree(pr->result);
pr->result = newbuf;
pr->resultsize = newlen;
}
}
void prompt_set_result(prompt_t *pr, const char *newstr)
{
prompt_ensure_result_size(pr, strlen(newstr) + 1);
strcpy(pr->result, newstr);
}
void free_prompts(prompts_t *p)
{
size_t i;
for (i=0; i < p->n_prompts; i++) {
prompt_t *pr = p->prompts[i];
smemclr(pr->result, pr->resultsize); /* burn the evidence */
sfree(pr->result);
sfree(pr->prompt);
sfree(pr);
}
sfree(p->prompts);
sfree(p->name);
sfree(p->instruction);
sfree(p);
}
/*
* Determine whether or not a Conf represents a session which can
* sensibly be launched right now.
*/
bool conf_launchable(Conf *conf)
{
if (conf_get_int(conf, CONF_protocol) == PROT_SERIAL)
return conf_get_str(conf, CONF_serline)[0] != 0;
else
return conf_get_str(conf, CONF_host)[0] != 0;
}
char const *conf_dest(Conf *conf)
{
if (conf_get_int(conf, CONF_protocol) == PROT_SERIAL)
return conf_get_str(conf, CONF_serline);
else
return conf_get_str(conf, CONF_host);
}
/*
* Validate a manual host key specification (either entered in the
* GUI, or via -hostkey). If valid, we return true, and update 'key'
* to contain a canonicalised version of the key string in 'key'
* (which is guaranteed to take up at most as much space as the
* original version), suitable for putting into the Conf. If not
* valid, we return false.
*/
bool validate_manual_hostkey(char *key)
{
char *p, *q, *r, *s;
/*
* Step through the string word by word, looking for a word that's
* in one of the formats we like.
*/
p = key;
while ((p += strspn(p, " \t"))[0]) {
q = p;
p += strcspn(p, " \t");
if (*p) *p++ = '\0';
/*
* Now q is our word.
*/
if (strlen(q) == 16*3 - 1 &&
q[strspn(q, "0123456789abcdefABCDEF:")] == 0) {
/*
* Might be a key fingerprint. Check the colons are in the
* right places, and if so, return the same fingerprint
* canonicalised into lowercase.
*/
int i;
for (i = 0; i < 16; i++)
if (q[3*i] == ':' || q[3*i+1] == ':')
goto not_fingerprint; /* sorry */
for (i = 0; i < 15; i++)
if (q[3*i+2] != ':')
goto not_fingerprint; /* sorry */
for (i = 0; i < 16*3 - 1; i++)
key[i] = tolower(q[i]);
key[16*3 - 1] = '\0';
return true;
}
not_fingerprint:;
/*
* Before we check for a public-key blob, trim newlines out of
* the middle of the word, in case someone's managed to paste
* in a public-key blob _with_ them.
*/
for (r = s = q; *r; r++)
if (*r != '\n' && *r != '\r')
*s++ = *r;
*s = '\0';
if (strlen(q) % 4 == 0 && strlen(q) > 2*4 &&
q[strspn(q, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz+/=")] == 0) {
/*
* Might be a base64-encoded SSH-2 public key blob. Check
* that it starts with a sensible algorithm string. No
* canonicalisation is necessary for this string type.
*
* The algorithm string must be at most 64 characters long
* (RFC 4251 section 6).
*/
unsigned char decoded[6];
unsigned alglen;
int minlen;
int len = 0;
len += base64_decode_atom(q, decoded+len);
if (len < 3)
goto not_ssh2_blob; /* sorry */
len += base64_decode_atom(q+4, decoded+len);
if (len < 4)
goto not_ssh2_blob; /* sorry */
alglen = GET_32BIT_MSB_FIRST(decoded);
if (alglen > 64)
goto not_ssh2_blob; /* sorry */
minlen = ((alglen + 4) + 2) / 3;
if (strlen(q) < minlen)
goto not_ssh2_blob; /* sorry */
strcpy(key, q);
return true;
}
not_ssh2_blob:;
}
return false;
}
char *buildinfo(const char *newline)
{
strbuf *buf = strbuf_new();
strbuf_catf(buf, "Build platform: %d-bit %s",
(int)(CHAR_BIT * sizeof(void *)),
BUILDINFO_PLATFORM);
#ifdef __clang_version__
#define FOUND_COMPILER
strbuf_catf(buf, "%sCompiler: clang %s", newline, __clang_version__);
#elif defined __GNUC__ && defined __VERSION__
#define FOUND_COMPILER
strbuf_catf(buf, "%sCompiler: gcc %s", newline, __VERSION__);
#endif
#if defined _MSC_VER
#ifndef FOUND_COMPILER
#define FOUND_COMPILER
strbuf_catf(buf, "%sCompiler: ", newline);
#else
strbuf_catf(buf, ", emulating ");
#endif
strbuf_catf(buf, "Visual Studio", newline);
#if _MSC_VER == 1900
strbuf_catf(buf, " 2015 / MSVC++ 14.0");
#elif _MSC_VER == 1912
strbuf_catf(buf, " 2017 / MSVC++ 14.12");
#elif _MSC_VER == 1800
strbuf_catf(buf, " 2013 / MSVC++ 12.0");
#elif _MSC_VER == 1700
strbuf_catf(buf, " 2012 / MSVC++ 11.0");
#elif _MSC_VER == 1600
strbuf_catf(buf, " 2010 / MSVC++ 10.0");
#elif _MSC_VER == 1500
strbuf_catf(buf, " 2008 / MSVC++ 9.0");
#elif _MSC_VER == 1400
strbuf_catf(buf, " 2005 / MSVC++ 8.0");
#elif _MSC_VER == 1310
strbuf_catf(buf, " 2003 / MSVC++ 7.1");
#elif _MSC_VER == 1300
strbuf_catf(buf, " 2003 / MSVC++ 7.0");
#else
strbuf_catf(buf, ", unrecognised version");
#endif
strbuf_catf(buf, " (_MSC_VER=%d)", (int)_MSC_VER);
#endif
#ifdef BUILDINFO_GTK
{
char *gtk_buildinfo = buildinfo_gtk_version();
if (gtk_buildinfo) {
strbuf_catf(buf, "%sCompiled against GTK version %s",
newline, gtk_buildinfo);
sfree(gtk_buildinfo);
}
}
#endif
#if defined _WINDOWS
{
int echm = has_embedded_chm();
if (echm >= 0)
strbuf_catf(buf, "%sEmbedded HTML Help file: %s", newline,
echm ? "yes" : "no");
}
#endif
#if defined _WINDOWS && defined MINEFIELD
strbuf_catf(buf, "%sBuild option: MINEFIELD", newline);
#endif
#ifdef NO_SECURITY
strbuf_catf(buf, "%sBuild option: NO_SECURITY", newline);
#endif
#ifdef NO_SECUREZEROMEMORY
strbuf_catf(buf, "%sBuild option: NO_SECUREZEROMEMORY", newline);
#endif
#ifdef NO_IPV6
strbuf_catf(buf, "%sBuild option: NO_IPV6", newline);
#endif
#ifdef NO_GSSAPI
strbuf_catf(buf, "%sBuild option: NO_GSSAPI", newline);
#endif
#ifdef STATIC_GSSAPI
strbuf_catf(buf, "%sBuild option: STATIC_GSSAPI", newline);
#endif
#ifdef UNPROTECT
strbuf_catf(buf, "%sBuild option: UNPROTECT", newline);
#endif
#ifdef FUZZING
strbuf_catf(buf, "%sBuild option: FUZZING", newline);
#endif
#ifdef DEBUG
strbuf_catf(buf, "%sBuild option: DEBUG", newline);
#endif
strbuf_catf(buf, "%sSource commit: %s", newline, commitid);
return strbuf_to_str(buf);
}
size_t nullseat_output(
Seat *seat, bool is_stderr, const void *data, size_t len) { return 0; }
bool nullseat_eof(Seat *seat) { return true; }
int nullseat_get_userpass_input(
Seat *seat, prompts_t *p, bufchain *input) { return 0; }
void nullseat_notify_remote_exit(Seat *seat) {}
void nullseat_connection_fatal(Seat *seat, const char *message) {}
void nullseat_update_specials_menu(Seat *seat) {}
char *nullseat_get_ttymode(Seat *seat, const char *mode) { return NULL; }
void nullseat_set_busy_status(Seat *seat, BusyStatus status) {}
int nullseat_verify_ssh_host_key(
Seat *seat, const char *host, int port,
const char *keytype, char *keystr, char *key_fingerprint,
void (*callback)(void *ctx, int result), void *ctx) { return 0; }
int nullseat_confirm_weak_crypto_primitive(
Seat *seat, const char *algtype, const char *algname,
void (*callback)(void *ctx, int result), void *ctx) { return 0; }
int nullseat_confirm_weak_cached_hostkey(
Seat *seat, const char *algname, const char *betteralgs,
void (*callback)(void *ctx, int result), void *ctx) { return 0; }
bool nullseat_is_never_utf8(Seat *seat) { return false; }
bool nullseat_is_always_utf8(Seat *seat) { return true; }
void nullseat_echoedit_update(Seat *seat, bool echoing, bool editing) {}
const char *nullseat_get_x_display(Seat *seat) { return NULL; }
bool nullseat_get_windowid(Seat *seat, long *id_out) { return false; }
bool nullseat_get_window_pixel_size(
Seat *seat, int *width, int *height) { return false; }
StripCtrlChars *nullseat_stripctrl_new(
Seat *seat, BinarySink *bs_out, SeatInteractionContext sic) {return NULL;}
bool nullseat_set_trust_status(Seat *seat, bool tr) { return false; }
bool nullseat_set_trust_status_vacuously(Seat *seat, bool tr) { return true; }
void sk_free_peer_info(SocketPeerInfo *pi)
{
if (pi) {
sfree((char *)pi->addr_text);
sfree((char *)pi->log_text);
sfree(pi);
}
}
void out_of_memory(void)
{
modalfatalbox("Out of memory");
}