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mirror of git://git.gnupg.org/gnupg.git synced 2024-12-22 10:19:57 +01:00
gnupg/common/simple-pwquery.c
Werner Koch b008274afd Nuked almost all trailing white space.
We better do this once and for all instead of cluttering all future
commits with diffs of trailing white spaces.  In the majority of cases
blank or single lines are affected and thus this change won't disturb
a git blame too much.  For future commits the pre-commit scripts
checks that this won't happen again.
2011-02-04 12:57:53 +01:00

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/* simple-pwquery.c - A simple password query client for gpg-agent
* Copyright (C) 2002, 2004, 2007 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/* This module is intended as a standalone client implementation to
gpg-agent's GET_PASSPHRASE command. In particular it does not use
the Assuan library and can only cope with an already running
gpg-agent. Some stuff is configurable in the header file. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#ifdef HAVE_W32_SYSTEM
#include <winsock2.h>
#else
#include <sys/socket.h>
#include <sys/un.h>
#endif
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#define JNLIB_NEED_AFLOCAL
#include "../common/mischelp.h"
#ifdef HAVE_W32_SYSTEM
#include "../common/w32-afunix.h"
#endif
#define SIMPLE_PWQUERY_IMPLEMENTATION 1
#include "simple-pwquery.h"
#if defined(SPWQ_USE_LOGGING) && !defined(HAVE_JNLIB_LOGGING)
# undef SPWQ_USE_LOGGING
#endif
#ifndef _
#define _(a) (a)
#endif
#if !defined (hexdigitp) && !defined (xtoi_2)
#define digitp(p) (*(p) >= '0' && *(p) <= '9')
#define hexdigitp(a) (digitp (a) \
|| (*(a) >= 'A' && *(a) <= 'F') \
|| (*(a) >= 'a' && *(a) <= 'f'))
#define xtoi_1(p) (*(p) <= '9'? (*(p)- '0'): \
*(p) <= 'F'? (*(p)-'A'+10):(*(p)-'a'+10))
#define xtoi_2(p) ((xtoi_1(p) * 16) + xtoi_1((p)+1))
#endif
/* Name of the socket to be used if GPG_AGENT_INFO has not been
set. No default socket is used if this is NULL. */
static char *default_gpg_agent_info;
#ifndef HAVE_STPCPY
static char *
my_stpcpy(char *a,const char *b)
{
while( *b )
*a++ = *b++;
*a = 0;
return (char*)a;
}
#define stpcpy(a,b) my_stpcpy((a), (b))
#endif
/* Write NBYTES of BUF to file descriptor FD. */
static int
writen (int fd, const void *buf, size_t nbytes)
{
size_t nleft = nbytes;
int nwritten;
while (nleft > 0)
{
#ifdef HAVE_W32_SYSTEM
nwritten = send (fd, buf, nleft, 0);
#else
nwritten = write (fd, buf, nleft);
#endif
if (nwritten < 0)
{
if (errno == EINTR)
nwritten = 0;
else {
#ifdef SPWQ_USE_LOGGING
log_error ("write failed: %s\n", strerror (errno));
#endif
return SPWQ_IO_ERROR;
}
}
nleft -= nwritten;
buf = (const char*)buf + nwritten;
}
return 0;
}
/* Read an entire line and return number of bytes read. */
static int
readline (int fd, char *buf, size_t buflen)
{
size_t nleft = buflen;
char *p;
int nread = 0;
while (nleft > 0)
{
#ifdef HAVE_W32_SYSTEM
int n = recv (fd, buf, nleft, 0);
#else
int n = read (fd, buf, nleft);
#endif
if (n < 0)
{
if (errno == EINTR)
continue;
return -(SPWQ_IO_ERROR);
}
else if (!n)
{
return -(SPWQ_PROTOCOL_ERROR); /* incomplete line */
}
p = buf;
nleft -= n;
buf += n;
nread += n;
for (; n && *p != '\n'; n--, p++)
;
if (n)
{
break; /* At least one full line available - that's enough.
This function is just a simple implementation, so
it is okay to forget about pending bytes. */
}
}
return nread;
}
/* Send an option to the agent */
static int
agent_send_option (int fd, const char *name, const char *value)
{
char buf[200];
int nread;
char *line;
int i;
line = spwq_malloc (7 + strlen (name) + 1 + strlen (value) + 2);
if (!line)
return SPWQ_OUT_OF_CORE;
strcpy (stpcpy (stpcpy (stpcpy (
stpcpy (line, "OPTION "), name), "="), value), "\n");
i = writen (fd, line, strlen (line));
spwq_free (line);
if (i)
return i;
/* get response */
nread = readline (fd, buf, DIM(buf)-1);
if (nread < 0)
return -nread;
if (nread < 3)
return SPWQ_PROTOCOL_ERROR;
if (buf[0] == 'O' && buf[1] == 'K' && (buf[2] == ' ' || buf[2] == '\n'))
return 0; /* okay */
return SPWQ_ERR_RESPONSE;
}
/* Send all available options to the agent. */
static int
agent_send_all_options (int fd)
{
char *dft_display = NULL;
char *dft_ttyname = NULL;
char *dft_ttytype = NULL;
char *dft_xauthority = NULL;
char *dft_pinentry_user_data = NULL;
int rc = 0;
dft_display = getenv ("DISPLAY");
if (dft_display)
{
if ((rc = agent_send_option (fd, "display", dft_display)))
return rc;
}
dft_ttyname = getenv ("GPG_TTY");
#ifndef HAVE_W32_SYSTEM
if ((!dft_ttyname || !*dft_ttyname) && ttyname (0))
dft_ttyname = ttyname (0);
#endif
if (dft_ttyname && *dft_ttyname)
{
if ((rc=agent_send_option (fd, "ttyname", dft_ttyname)))
return rc;
}
dft_ttytype = getenv ("TERM");
if (dft_ttyname && dft_ttytype)
{
if ((rc = agent_send_option (fd, "ttytype", dft_ttytype)))
return rc;
}
#if defined(HAVE_SETLOCALE)
{
char *old_lc = NULL;
char *dft_lc = NULL;
#if defined(LC_CTYPE)
old_lc = setlocale (LC_CTYPE, NULL);
if (old_lc)
{
char *p = spwq_malloc (strlen (old_lc)+1);
if (!p)
return SPWQ_OUT_OF_CORE;
strcpy (p, old_lc);
old_lc = p;
}
dft_lc = setlocale (LC_CTYPE, "");
if (dft_ttyname && dft_lc)
rc = agent_send_option (fd, "lc-ctype", dft_lc);
if (old_lc)
{
setlocale (LC_CTYPE, old_lc);
spwq_free (old_lc);
}
if (rc)
return rc;
#endif
#if defined(LC_MESSAGES)
old_lc = setlocale (LC_MESSAGES, NULL);
if (old_lc)
{
char *p = spwq_malloc (strlen (old_lc)+1);
if (!p)
return SPWQ_OUT_OF_CORE;
strcpy (p, old_lc);
old_lc = p;
}
dft_lc = setlocale (LC_MESSAGES, "");
if (dft_ttyname && dft_lc)
rc = agent_send_option (fd, "lc-messages", dft_lc);
if (old_lc)
{
setlocale (LC_MESSAGES, old_lc);
spwq_free (old_lc);
}
if (rc)
return rc;
#endif
}
#endif /*HAVE_SETLOCALE*/
/* Send the XAUTHORITY variable. */
dft_xauthority = getenv ("XAUTHORITY");
if (dft_xauthority)
{
/* We ignore errors here because older gpg-agents don't support
this option. */
agent_send_option (fd, "xauthority", dft_xauthority);
}
/* Send the PINENTRY_USER_DATA variable. */
dft_pinentry_user_data = getenv ("PINENTRY_USER_DATA");
if (dft_pinentry_user_data)
{
/* We ignore errors here because older gpg-agents don't support
this option. */
agent_send_option (fd, "pinentry-user-data", dft_pinentry_user_data);
}
return 0;
}
/* Try to open a connection to the agent, send all options and return
the file descriptor for the connection. Return -1 in case of
error. */
static int
agent_open (int *rfd)
{
int rc;
int fd;
char *infostr, *p;
struct sockaddr_un client_addr;
size_t len;
int prot;
char line[200];
int nread;
*rfd = -1;
infostr = getenv ( "GPG_AGENT_INFO" );
if ( !infostr || !*infostr )
infostr = default_gpg_agent_info;
if ( !infostr || !*infostr )
{
#ifdef SPWQ_USE_LOGGING
log_error (_("gpg-agent is not available in this session\n"));
#endif
return SPWQ_NO_AGENT;
}
p = spwq_malloc (strlen (infostr)+1);
if (!p)
return SPWQ_OUT_OF_CORE;
strcpy (p, infostr);
infostr = p;
if ( !(p = strchr ( infostr, PATHSEP_C)) || p == infostr
|| (p-infostr)+1 >= sizeof client_addr.sun_path )
{
#ifdef SPWQ_USE_LOGGING
log_error ( _("malformed GPG_AGENT_INFO environment variable\n"));
#endif
return SPWQ_NO_AGENT;
}
*p++ = 0;
while (*p && *p != PATHSEP_C)
p++;
prot = *p? atoi (p+1) : 0;
if ( prot != 1)
{
#ifdef SPWQ_USE_LOGGING
log_error (_("gpg-agent protocol version %d is not supported\n"),prot);
#endif
return SPWQ_PROTOCOL_ERROR;
}
#ifdef HAVE_W32_SYSTEM
fd = _w32_sock_new (AF_UNIX, SOCK_STREAM, 0);
#else
fd = socket (AF_UNIX, SOCK_STREAM, 0);
#endif
if (fd == -1)
{
#ifdef SPWQ_USE_LOGGING
log_error ("can't create socket: %s\n", strerror(errno) );
#endif
return SPWQ_SYS_ERROR;
}
memset (&client_addr, 0, sizeof client_addr);
client_addr.sun_family = AF_UNIX;
strcpy (client_addr.sun_path, infostr);
len = SUN_LEN (&client_addr);
#ifdef HAVE_W32_SYSTEM
rc = _w32_sock_connect (fd, (struct sockaddr*)&client_addr, len );
#else
rc = connect (fd, (struct sockaddr*)&client_addr, len );
#endif
if (rc == -1)
{
#ifdef SPWQ_USE_LOGGING
log_error ( _("can't connect to `%s': %s\n"), infostr, strerror (errno));
#endif
close (fd );
return SPWQ_IO_ERROR;
}
nread = readline (fd, line, DIM(line));
if (nread < 3 || !(line[0] == 'O' && line[1] == 'K'
&& (line[2] == '\n' || line[2] == ' ')) )
{
#ifdef SPWQ_USE_LOGGING
log_error ( _("communication problem with gpg-agent\n"));
#endif
close (fd );
return SPWQ_PROTOCOL_ERROR;
}
rc = agent_send_all_options (fd);
if (rc)
{
#ifdef SPWQ_USE_LOGGING
log_error (_("problem setting the gpg-agent options\n"));
#endif
close (fd);
return rc;
}
*rfd = fd;
return 0;
}
/* Copy text to BUFFER and escape as required. Return a pointer to
the end of the new buffer. Note that BUFFER must be large enough
to keep the entire text; allocataing it 3 times the size of TEXT
is sufficient. */
static char *
copy_and_escape (char *buffer, const char *text)
{
int i;
const unsigned char *s = (unsigned char *)text;
char *p = buffer;
for (i=0; s[i]; i++)
{
if (s[i] < ' ' || s[i] == '+')
{
sprintf (p, "%%%02X", s[i]);
p += 3;
}
else if (s[i] == ' ')
*p++ = '+';
else
*p++ = s[i];
}
return p;
}
/* Set the name of the default socket to NAME. */
int
simple_pw_set_socket (const char *name)
{
spwq_free (default_gpg_agent_info);
if (name)
{
default_gpg_agent_info = spwq_malloc (strlen (name) + 4 + 1);
if (!default_gpg_agent_info)
return SPWQ_OUT_OF_CORE;
/* We don't know the PID thus we use 0. */
strcpy (stpcpy (default_gpg_agent_info, name),
PATHSEP_S "0" PATHSEP_S "1");
}
else
default_gpg_agent_info = NULL;
return 0;
}
/* Ask the gpg-agent for a passphrase and present the user with a
DESCRIPTION, a PROMPT and optionally with a TRYAGAIN extra text.
If a CACHEID is not NULL it is used to locate the passphrase in in
the cache and store it under this ID. If OPT_CHECK is true
gpg-agent is asked to apply some checks on the passphrase security.
If ERRORCODE is not NULL it should point a variable receiving an
errorcode; this error code might be 0 if the user canceled the
operation. The function returns NULL to indicate an error. */
char *
simple_pwquery (const char *cacheid,
const char *tryagain,
const char *prompt,
const char *description,
int opt_check,
int *errorcode)
{
int fd = -1;
int nread;
char *result = NULL;
char *pw = NULL;
char *p;
int rc, i;
rc = agent_open (&fd);
if (rc)
goto leave;
if (!cacheid)
cacheid = "X";
if (!tryagain)
tryagain = "X";
if (!prompt)
prompt = "X";
if (!description)
description = "X";
{
char *line;
/* We allocate 3 times the needed space so that there is enough
space for escaping. */
line = spwq_malloc (15 + 10
+ 3*strlen (cacheid) + 1
+ 3*strlen (tryagain) + 1
+ 3*strlen (prompt) + 1
+ 3*strlen (description) + 1
+ 2);
if (!line)
{
rc = SPWQ_OUT_OF_CORE;
goto leave;
}
strcpy (line, "GET_PASSPHRASE ");
p = line+15;
if (opt_check)
p = stpcpy (p, "--check ");
p = copy_and_escape (p, cacheid);
*p++ = ' ';
p = copy_and_escape (p, tryagain);
*p++ = ' ';
p = copy_and_escape (p, prompt);
*p++ = ' ';
p = copy_and_escape (p, description);
*p++ = '\n';
rc = writen (fd, line, p - line);
spwq_free (line);
if (rc)
goto leave;
}
/* get response */
pw = spwq_secure_malloc (500);
nread = readline (fd, pw, 499);
if (nread < 0)
{
rc = -nread;
goto leave;
}
if (nread < 3)
{
rc = SPWQ_PROTOCOL_ERROR;
goto leave;
}
if (pw[0] == 'O' && pw[1] == 'K' && pw[2] == ' ')
{ /* we got a passphrase - convert it back from hex */
size_t pwlen = 0;
for (i=3; i < nread && hexdigitp (pw+i); i+=2)
pw[pwlen++] = xtoi_2 (pw+i);
pw[pwlen] = 0; /* make a C String */
result = pw;
pw = NULL;
}
else if ((nread > 7 && !memcmp (pw, "ERR 111", 7)
&& (pw[7] == ' ' || pw[7] == '\n') )
|| ((nread > 4 && !memcmp (pw, "ERR ", 4)
&& (strtoul (pw+4, NULL, 0) & 0xffff) == 99)) )
{
/* 111 is the old Assuan code for canceled which might still
be in use by old installations. 99 is GPG_ERR_CANCELED as
used by modern gpg-agents; 0xffff is used to mask out the
error source. */
#ifdef SPWQ_USE_LOGGING
log_info (_("canceled by user\n") );
#endif
*errorcode = 0; /* Special error code to indicate Cancel. */
}
else if (nread > 4 && !memcmp (pw, "ERR ", 4))
{
switch ( (strtoul (pw+4, NULL, 0) & 0xffff) )
{
case 85: rc = SPWQ_NO_PIN_ENTRY; break;
default: rc = SPWQ_GENERAL_ERROR; break;
}
}
else
{
#ifdef SPWQ_USE_LOGGING
log_error (_("problem with the agent\n"));
#endif
rc = SPWQ_ERR_RESPONSE;
}
leave:
if (errorcode)
*errorcode = rc;
if (fd != -1)
close (fd);
if (pw)
spwq_secure_free (pw);
return result;
}
/* Ask the gpg-agent to clear the passphrase for the cache ID CACHEID. */
int
simple_pwclear (const char *cacheid)
{
char line[500];
char *p;
/* We need not more than 50 characters for the command and the
terminating nul. */
if (strlen (cacheid) * 3 > sizeof (line) - 50)
return SPWQ_PROTOCOL_ERROR;
strcpy (line, "CLEAR_PASSPHRASE ");
p = line + 17;
p = copy_and_escape (p, cacheid);
*p++ = '\n';
*p++ = '\0';
return simple_query (line);
}
/* Perform the simple query QUERY (which must be new-line and 0
terminated) and return the error code. */
int
simple_query (const char *query)
{
int fd = -1;
int nread;
char response[500];
int rc;
rc = agent_open (&fd);
if (rc)
goto leave;
rc = writen (fd, query, strlen (query));
if (rc)
goto leave;
/* get response */
nread = readline (fd, response, 499);
if (nread < 0)
{
rc = -nread;
goto leave;
}
if (nread < 3)
{
rc = SPWQ_PROTOCOL_ERROR;
goto leave;
}
if (response[0] == 'O' && response[1] == 'K')
/* OK, do nothing. */;
else if ((nread > 7 && !memcmp (response, "ERR 111", 7)
&& (response[7] == ' ' || response[7] == '\n') )
|| ((nread > 4 && !memcmp (response, "ERR ", 4)
&& (strtoul (response+4, NULL, 0) & 0xffff) == 99)) )
{
/* 111 is the old Assuan code for canceled which might still
be in use by old installations. 99 is GPG_ERR_CANCELED as
used by modern gpg-agents; 0xffff is used to mask out the
error source. */
#ifdef SPWQ_USE_LOGGING
log_info (_("canceled by user\n") );
#endif
}
else
{
#ifdef SPWQ_USE_LOGGING
log_error (_("problem with the agent\n"));
#endif
rc = SPWQ_ERR_RESPONSE;
}
leave:
if (fd != -1)
close (fd);
return rc;
}