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Diffstat (limited to 'common/simple-pwquery.c')
| -rw-r--r-- | common/simple-pwquery.c | 690 |
1 files changed, 690 insertions, 0 deletions
diff --git a/common/simple-pwquery.c b/common/simple-pwquery.c new file mode 100644 index 0000000..3598b35 --- /dev/null +++ b/common/simple-pwquery.c @@ -0,0 +1,690 @@ +/* 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 "../jnlib/mischelp.h" +#ifdef HAVE_W32_SYSTEM +#include "../jnlib/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; +} |