[thirdparty/cups.git] / cups / usersys.c

/*
 * User, system, and password routines for CUPS.
 *
 * Copyright 2007-2017 by Apple Inc.
 * Copyright 1997-2006 by Easy Software Products.
 *
 * These coded instructions, statements, and computer programs are the
 * property of Apple Inc. and are protected by Federal copyright
 * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
 * which should have been included with this file.  If this file is
 * missing or damaged, see the license at "http://www.cups.org/".
 *
 * This file is subject to the Apple OS-Developed Software exception.
 */

/*
 * Include necessary headers...
 */

#include "cups-private.h"
#include <stdlib.h>
#include <sys/stat.h>
#ifdef WIN32
#  include <windows.h>
#else
#  include <pwd.h>
#  include <termios.h>
#  include <sys/utsname.h>
#endif /* WIN32 */


/*
 * Local constants...
 */

#ifdef __APPLE__
#  define kCUPSPrintingPrefs    CFSTR("org.cups.PrintingPrefs")
#  define kAllowAnyRootKey      CFSTR("AllowAnyRoot")
#  define kAllowExpiredCertsKey CFSTR("AllowExpiredCerts")
#  define kEncryptionKey        CFSTR("Encryption")
#  define kGSSServiceNameKey    CFSTR("GSSServiceName")
#  define kSSLOptionsKey        CFSTR("SSLOptions")
#  define kTrustOnFirstUseKey   CFSTR("TrustOnFirstUse")
#  define kValidateCertsKey     CFSTR("ValidateCerts")
#endif /* __APPLE__ */

#define _CUPS_PASSCHAR  '*'             /* Character that is echoed for password */


/*
 * Local types...
 */

typedef struct _cups_client_conf_s      /**** client.conf config data ****/
{
#ifdef HAVE_SSL
  int                   ssl_options;    /* SSLOptions values */
#endif /* HAVE_SSL */
  int                   trust_first,    /* Trust on first use? */
                        any_root,       /* Allow any (e.g., self-signed) root */
                        expired_certs,  /* Allow expired certs */
                        validate_certs; /* Validate certificates */
  http_encryption_t     encryption;     /* Encryption setting */
  char                  user[65],       /* User name */
                        server_name[256];
                                        /* Server hostname */
#ifdef HAVE_GSSAPI
  char                  gss_service_name[32];
                                        /* Kerberos service name */
#endif /* HAVE_GSSAPI */
} _cups_client_conf_t;


/*
 * Local functions...
 */

#ifdef __APPLE__
static int      cups_apple_get_boolean(CFStringRef key, int *value);
static int      cups_apple_get_string(CFStringRef key, char *value, size_t valsize);
#endif /* __APPLE__ */
static int      cups_boolean_value(const char *value);
static void     cups_finalize_client_conf(_cups_client_conf_t *cc);
static void     cups_init_client_conf(_cups_client_conf_t *cc);
static void     cups_read_client_conf(cups_file_t *fp, _cups_client_conf_t *cc);
static void     cups_set_default_ipp_port(_cups_globals_t *cg);
static void     cups_set_encryption(_cups_client_conf_t *cc, const char *value);
#ifdef HAVE_GSSAPI
static void     cups_set_gss_service_name(_cups_client_conf_t *cc, const char *value);
#endif /* HAVE_GSSAPI */
static void     cups_set_server_name(_cups_client_conf_t *cc, const char *value);
#ifdef HAVE_SSL
static void     cups_set_ssl_options(_cups_client_conf_t *cc, const char *value);
#endif /* HAVE_SSL */
static void     cups_set_user(_cups_client_conf_t *cc, const char *value);


/*
 * 'cupsEncryption()' - Get the current encryption settings.
 *
 * The default encryption setting comes from the CUPS_ENCRYPTION
 * environment variable, then the ~/.cups/client.conf file, and finally the
 * /etc/cups/client.conf file. If not set, the default is
 * @code HTTP_ENCRYPTION_IF_REQUESTED@.
 *
 * Note: The current encryption setting is tracked separately for each thread
 * in a program. Multi-threaded programs that override the setting via the
 * @link cupsSetEncryption@ function need to do so in each thread for the same
 * setting to be used.
 */

http_encryption_t                       /* O - Encryption settings */
cupsEncryption(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (cg->encryption == (http_encryption_t)-1)
    _cupsSetDefaults();

  return (cg->encryption);
}


/*
 * 'cupsGetPassword()' - Get a password from the user.
 *
 * Uses the current password callback function. Returns @code NULL@ if the
 * user does not provide a password.
 *
 * Note: The current password callback function is tracked separately for each
 * thread in a program. Multi-threaded programs that override the setting via
 * the @link cupsSetPasswordCB@ or @link cupsSetPasswordCB2@ functions need to
 * do so in each thread for the same function to be used.
 *
 * @exclude all@
 */

const char *                            /* O - Password */
cupsGetPassword(const char *prompt)     /* I - Prompt string */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  return ((cg->password_cb)(prompt, NULL, NULL, NULL, cg->password_data));
}


/*
 * 'cupsGetPassword2()' - Get a password from the user using the advanced
 *                        password callback.
 *
 * Uses the current password callback function. Returns @code NULL@ if the
 * user does not provide a password.
 *
 * Note: The current password callback function is tracked separately for each
 * thread in a program. Multi-threaded programs that override the setting via
 * the @link cupsSetPasswordCB@ or @link cupsSetPasswordCB2@ functions need to
 * do so in each thread for the same function to be used.
 *
 * @since CUPS 1.4/macOS 10.6@
 */

const char *                            /* O - Password */
cupsGetPassword2(const char *prompt,    /* I - Prompt string */
                 http_t     *http,      /* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
                 const char *method,    /* I - Request method ("GET", "POST", "PUT") */
                 const char *resource)  /* I - Resource path */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (!http)
    http = _cupsConnect();

  return ((cg->password_cb)(prompt, http, method, resource, cg->password_data));
}


/*
 * 'cupsServer()' - Return the hostname/address of the current server.
 *
 * The default server comes from the CUPS_SERVER environment variable, then the
 * ~/.cups/client.conf file, and finally the /etc/cups/client.conf file. If not
 * set, the default is the local system - either "localhost" or a domain socket
 * path.
 *
 * The returned value can be a fully-qualified hostname, a numeric IPv4 or IPv6
 * address, or a domain socket pathname.
 *
 * Note: The current server is tracked separately for each thread in a program.
 * Multi-threaded programs that override the server via the
 * @link cupsSetServer@ function need to do so in each thread for the same
 * server to be used.
 */

const char *                            /* O - Server name */
cupsServer(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (!cg->server[0])
    _cupsSetDefaults();

  return (cg->server);
}


/*
 * 'cupsSetClientCertCB()' - Set the client certificate callback.
 *
 * Pass @code NULL@ to restore the default callback.
 *
 * Note: The current certificate callback is tracked separately for each thread
 * in a program. Multi-threaded programs that override the callback need to do
 * so in each thread for the same callback to be used.
 *
 * @since CUPS 1.5/macOS 10.7@
 */

void
cupsSetClientCertCB(
    cups_client_cert_cb_t cb,           /* I - Callback function */
    void                  *user_data)   /* I - User data pointer */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  cg->client_cert_cb    = cb;
  cg->client_cert_data  = user_data;
}


/*
 * 'cupsSetCredentials()' - Set the default credentials to be used for SSL/TLS
 *                          connections.
 *
 * Note: The default credentials are tracked separately for each thread in a
 * program. Multi-threaded programs that override the setting need to do so in
 * each thread for the same setting to be used.
 *
 * @since CUPS 1.5/macOS 10.7@
 */

int                                     /* O - Status of call (0 = success) */
cupsSetCredentials(
    cups_array_t *credentials)          /* I - Array of credentials */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (cupsArrayCount(credentials) < 1)
    return (-1);

#ifdef HAVE_SSL
  _httpFreeCredentials(cg->tls_credentials);
  cg->tls_credentials = _httpCreateCredentials(credentials);
#endif /* HAVE_SSL */

  return (cg->tls_credentials ? 0 : -1);
}


/*
 * 'cupsSetEncryption()' - Set the encryption preference.
 *
 * The default encryption setting comes from the CUPS_ENCRYPTION
 * environment variable, then the ~/.cups/client.conf file, and finally the
 * /etc/cups/client.conf file. If not set, the default is
 * @code HTTP_ENCRYPTION_IF_REQUESTED@.
 *
 * Note: The current encryption setting is tracked separately for each thread
 * in a program. Multi-threaded programs that override the setting need to do
 * so in each thread for the same setting to be used.
 */

void
cupsSetEncryption(http_encryption_t e)  /* I - New encryption preference */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  cg->encryption = e;

  if (cg->http)
    httpEncryption(cg->http, e);
}


/*
 * 'cupsSetPasswordCB()' - Set the password callback for CUPS.
 *
 * Pass @code NULL@ to restore the default (console) password callback, which
 * reads the password from the console. Programs should call either this
 * function or @link cupsSetPasswordCB2@, as only one callback can be registered
 * by a program per thread.
 *
 * Note: The current password callback is tracked separately for each thread
 * in a program. Multi-threaded programs that override the callback need to do
 * so in each thread for the same callback to be used.
 *
 * @exclude all@
 */

void
cupsSetPasswordCB(cups_password_cb_t cb)/* I - Callback function */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (cb == (cups_password_cb_t)0)
    cg->password_cb = (cups_password_cb2_t)_cupsGetPassword;
  else
    cg->password_cb = (cups_password_cb2_t)cb;

  cg->password_data = NULL;
}


/*
 * 'cupsSetPasswordCB2()' - Set the advanced password callback for CUPS.
 *
 * Pass @code NULL@ to restore the default (console) password callback, which
 * reads the password from the console. Programs should call either this
 * function or @link cupsSetPasswordCB2@, as only one callback can be registered
 * by a program per thread.
 *
 * Note: The current password callback is tracked separately for each thread
 * in a program. Multi-threaded programs that override the callback need to do
 * so in each thread for the same callback to be used.
 *
 * @since CUPS 1.4/macOS 10.6@
 */

void
cupsSetPasswordCB2(
    cups_password_cb2_t cb,             /* I - Callback function */
    void                *user_data)     /* I - User data pointer */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (cb == (cups_password_cb2_t)0)
    cg->password_cb = (cups_password_cb2_t)_cupsGetPassword;
  else
    cg->password_cb = cb;

  cg->password_data = user_data;
}


/*
 * 'cupsSetServer()' - Set the default server name and port.
 *
 * The "server" string can be a fully-qualified hostname, a numeric
 * IPv4 or IPv6 address, or a domain socket pathname. Hostnames and numeric IP
 * addresses can be optionally followed by a colon and port number to override
 * the default port 631, e.g. "hostname:8631". Pass @code NULL@ to restore the
 * default server name and port.
 *
 * Note: The current server is tracked separately for each thread in a program.
 * Multi-threaded programs that override the server need to do so in each
 * thread for the same server to be used.
 */

void
cupsSetServer(const char *server)       /* I - Server name */
{
  char          *options,               /* Options */
                *port;                  /* Pointer to port */
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (server)
  {
    strlcpy(cg->server, server, sizeof(cg->server));

    if (cg->server[0] != '/' && (options = strrchr(cg->server, '/')) != NULL)
    {
      *options++ = '\0';

      if (!strcmp(options, "version=1.0"))
        cg->server_version = 10;
      else if (!strcmp(options, "version=1.1"))
        cg->server_version = 11;
      else if (!strcmp(options, "version=2.0"))
        cg->server_version = 20;
      else if (!strcmp(options, "version=2.1"))
        cg->server_version = 21;
      else if (!strcmp(options, "version=2.2"))
        cg->server_version = 22;
    }
    else
      cg->server_version = 20;

    if (cg->server[0] != '/' && (port = strrchr(cg->server, ':')) != NULL &&
        !strchr(port, ']') && isdigit(port[1] & 255))
    {
      *port++ = '\0';

      cg->ipp_port = atoi(port);
    }

    if (!cg->ipp_port)
      cups_set_default_ipp_port(cg);

    if (cg->server[0] == '/')
      strlcpy(cg->servername, "localhost", sizeof(cg->servername));
    else
      strlcpy(cg->servername, cg->server, sizeof(cg->servername));
  }
  else
  {
    cg->server[0]      = '\0';
    cg->servername[0]  = '\0';
    cg->server_version = 20;
    cg->ipp_port       = 0;
  }

  if (cg->http)
  {
    httpClose(cg->http);
    cg->http = NULL;
  }
}


/*
 * 'cupsSetServerCertCB()' - Set the server certificate callback.
 *
 * Pass @code NULL@ to restore the default callback.
 *
 * Note: The current credentials callback is tracked separately for each thread
 * in a program. Multi-threaded programs that override the callback need to do
 * so in each thread for the same callback to be used.
 *
 * @since CUPS 1.5/macOS 10.7@
 */

void
cupsSetServerCertCB(
    cups_server_cert_cb_t cb,           /* I - Callback function */
    void                  *user_data)   /* I - User data pointer */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  cg->server_cert_cb    = cb;
  cg->server_cert_data  = user_data;
}


/*
 * 'cupsSetUser()' - Set the default user name.
 *
 * Pass @code NULL@ to restore the default user name.
 *
 * Note: The current user name is tracked separately for each thread in a
 * program. Multi-threaded programs that override the user name need to do so
 * in each thread for the same user name to be used.
 */

void
cupsSetUser(const char *user)           /* I - User name */
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (user)
    strlcpy(cg->user, user, sizeof(cg->user));
  else
    cg->user[0] = '\0';
}


/*
 * 'cupsSetUserAgent()' - Set the default HTTP User-Agent string.
 *
 * Setting the string to NULL forces the default value containing the CUPS
 * version, IPP version, and operating system version and architecture.
 *
 * @since CUPS 1.7/macOS 10.9@
 */

void
cupsSetUserAgent(const char *user_agent)/* I - User-Agent string or @code NULL@ */
{
  _cups_globals_t       *cg = _cupsGlobals();
                                        /* Thread globals */
#ifdef WIN32
  SYSTEM_INFO           sysinfo;        /* System information */
  OSVERSIONINFO         version;        /* OS version info */
#else
  struct utsname        name;           /* uname info */
#endif /* WIN32 */


  if (user_agent)
  {
    strlcpy(cg->user_agent, user_agent, sizeof(cg->user_agent));
    return;
  }

#ifdef WIN32
  version.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
  GetVersionEx(&version);
  GetNativeSystemInfo(&sysinfo);

  snprintf(cg->user_agent, sizeof(cg->user_agent),
           CUPS_MINIMAL " (Windows %d.%d; %s) IPP/2.0",
           version.dwMajorVersion, version.dwMinorVersion,
           sysinfo.wProcessorArchitecture
               == PROCESSOR_ARCHITECTURE_AMD64 ? "amd64" :
               sysinfo.wProcessorArchitecture
                   == PROCESSOR_ARCHITECTURE_ARM ? "arm" :
               sysinfo.wProcessorArchitecture
                   == PROCESSOR_ARCHITECTURE_IA64 ? "ia64" :
               sysinfo.wProcessorArchitecture
                   == PROCESSOR_ARCHITECTURE_INTEL ? "intel" :
               "unknown");

#else
  uname(&name);

  snprintf(cg->user_agent, sizeof(cg->user_agent),
           CUPS_MINIMAL " (%s %s; %s) IPP/2.0",
           name.sysname, name.release, name.machine);
#endif /* WIN32 */
}


/*
 * 'cupsUser()' - Return the current user's name.
 *
 * Note: The current user name is tracked separately for each thread in a
 * program. Multi-threaded programs that override the user name with the
 * @link cupsSetUser@ function need to do so in each thread for the same user
 * name to be used.
 */

const char *                            /* O - User name */
cupsUser(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  if (!cg->user[0])
    _cupsSetDefaults();

  return (cg->user);
}


/*
 * 'cupsUserAgent()' - Return the default HTTP User-Agent string.
 *
 * @since CUPS 1.7/macOS 10.9@
 */

const char *                            /* O - User-Agent string */
cupsUserAgent(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Thread globals */


  if (!cg->user_agent[0])
    cupsSetUserAgent(NULL);

  return (cg->user_agent);
}


/*
 * '_cupsGetPassword()' - Get a password from the user.
 */

const char *                            /* O - Password or @code NULL@ if none */
_cupsGetPassword(const char *prompt)    /* I - Prompt string */
{
#ifdef WIN32
  HANDLE                tty;            /* Console handle */
  DWORD                 mode;           /* Console mode */
  char                  passch,         /* Current key press */
                        *passptr,       /* Pointer into password string */
                        *passend;       /* End of password string */
  DWORD                 passbytes;      /* Bytes read */
  _cups_globals_t       *cg = _cupsGlobals();
                                        /* Thread globals */


 /*
  * Disable input echo and set raw input...
  */

  if ((tty = GetStdHandle(STD_INPUT_HANDLE)) == INVALID_HANDLE_VALUE)
    return (NULL);

  if (!GetConsoleMode(tty, &mode))
    return (NULL);

  if (!SetConsoleMode(tty, 0))
    return (NULL);

 /*
  * Display the prompt...
  */

  printf("%s ", prompt);
  fflush(stdout);

 /*
  * Read the password string from /dev/tty until we get interrupted or get a
  * carriage return or newline...
  */

  passptr = cg->password;
  passend = cg->password + sizeof(cg->password) - 1;

  while (ReadFile(tty, &passch, 1, &passbytes, NULL))
  {
    if (passch == 0x0A || passch == 0x0D)
    {
     /*
      * Enter/return...
      */

      break;
    }
    else if (passch == 0x08 || passch == 0x7F)
    {
     /*
      * Backspace/delete (erase character)...
      */

      if (passptr > cg->password)
      {
        passptr --;
        fputs("\010 \010", stdout);
      }
      else
        putchar(0x07);
    }
    else if (passch == 0x15)
    {
     /*
      * CTRL+U (erase line)
      */

      if (passptr > cg->password)
      {
        while (passptr > cg->password)
        {
          passptr --;
          fputs("\010 \010", stdout);
        }
      }
      else
        putchar(0x07);
    }
    else if (passch == 0x03)
    {
     /*
      * CTRL+C...
      */

      passptr = cg->password;
      break;
    }
    else if ((passch & 255) < 0x20 || passptr >= passend)
      putchar(0x07);
    else
    {
      *passptr++ = passch;
      putchar(_CUPS_PASSCHAR);
    }

    fflush(stdout);
  }

  putchar('\n');
  fflush(stdout);

 /*
  * Cleanup...
  */

  SetConsoleMode(tty, mode);

 /*
  * Return the proper value...
  */

  if (passbytes == 1 && passptr > cg->password)
  {
    *passptr = '\0';
    return (cg->password);
  }
  else
  {
    memset(cg->password, 0, sizeof(cg->password));
    return (NULL);
  }

#else
  int                   tty;            /* /dev/tty - never read from stdin */
  struct termios        original,       /* Original input mode */
                        noecho;         /* No echo input mode */
  char                  passch,         /* Current key press */
                        *passptr,       /* Pointer into password string */
                        *passend;       /* End of password string */
  ssize_t               passbytes;      /* Bytes read */
  _cups_globals_t       *cg = _cupsGlobals();
                                        /* Thread globals */


 /*
  * Disable input echo and set raw input...
  */

  if ((tty = open("/dev/tty", O_RDONLY)) < 0)
    return (NULL);

  if (tcgetattr(tty, &original))
  {
    close(tty);
    return (NULL);
  }

  noecho = original;
  noecho.c_lflag &= (tcflag_t)~(ICANON | ECHO | ECHOE | ISIG);
  noecho.c_cc[VMIN]  = 1;
  noecho.c_cc[VTIME] = 0;

  if (tcsetattr(tty, TCSAFLUSH, &noecho))
  {
    close(tty);
    return (NULL);
  }

 /*
  * Display the prompt...
  */

  printf("%s ", prompt);
  fflush(stdout);

 /*
  * Read the password string from /dev/tty until we get interrupted or get a
  * carriage return or newline...
  */

  passptr = cg->password;
  passend = cg->password + sizeof(cg->password) - 1;

  while ((passbytes = read(tty, &passch, 1)) == 1)
  {
    if (passch == noecho.c_cc[VEOL] ||
#  ifdef VEOL2
        passch == noecho.c_cc[VEOL2] ||
#  endif /* VEOL2 */
        passch == 0x0A || passch == 0x0D)
    {
     /*
      * Enter/return...
      */

      break;
    }
    else if (passch == noecho.c_cc[VERASE] ||
             passch == 0x08 || passch == 0x7F)
    {
     /*
      * Backspace/delete (erase character)...
      */

      if (passptr > cg->password)
      {
        passptr --;
        fputs("\010 \010", stdout);
      }
      else
        putchar(0x07);
    }
    else if (passch == noecho.c_cc[VKILL])
    {
     /*
      * CTRL+U (erase line)
      */

      if (passptr > cg->password)
      {
        while (passptr > cg->password)
        {
          passptr --;
          fputs("\010 \010", stdout);
        }
      }
      else
        putchar(0x07);
    }
    else if (passch == noecho.c_cc[VINTR] || passch == noecho.c_cc[VQUIT] ||
             passch == noecho.c_cc[VEOF])
    {
     /*
      * CTRL+C, CTRL+D, or CTRL+Z...
      */

      passptr = cg->password;
      break;
    }
    else if ((passch & 255) < 0x20 || passptr >= passend)
      putchar(0x07);
    else
    {
      *passptr++ = passch;
      putchar(_CUPS_PASSCHAR);
    }

    fflush(stdout);
  }

  putchar('\n');
  fflush(stdout);

 /*
  * Cleanup...
  */

  tcsetattr(tty, TCSAFLUSH, &original);
  close(tty);

 /*
  * Return the proper value...
  */

  if (passbytes == 1 && passptr > cg->password)
  {
    *passptr = '\0';
    return (cg->password);
  }
  else
  {
    memset(cg->password, 0, sizeof(cg->password));
    return (NULL);
  }
#endif /* WIN32 */
}


#ifdef HAVE_GSSAPI
/*
 * '_cupsGSSServiceName()' - Get the GSS (Kerberos) service name.
 */

const char *
_cupsGSSServiceName(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Thread globals */


  if (!cg->gss_service_name[0])
    _cupsSetDefaults();

  return (cg->gss_service_name);
}
#endif /* HAVE_GSSAPI */


/*
 * '_cupsSetDefaults()' - Set the default server, port, and encryption.
 */

void
_cupsSetDefaults(void)
{
  cups_file_t   *fp;                    /* File */
  const char    *home;                  /* Home directory of user */
  char          filename[1024];         /* Filename */
  _cups_client_conf_t cc;               /* client.conf values */
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals */


  DEBUG_puts("_cupsSetDefaults()");

 /*
  * Load initial client.conf values...
  */

  cups_init_client_conf(&cc);

 /*
  * Read the /etc/cups/client.conf and ~/.cups/client.conf files, if
  * present.
  */

  snprintf(filename, sizeof(filename), "%s/client.conf", cg->cups_serverroot);
  if ((fp = cupsFileOpen(filename, "r")) != NULL)
  {
    cups_read_client_conf(fp, &cc);
    cupsFileClose(fp);
  }

#  ifdef HAVE_GETEUID
  if ((geteuid() == getuid() || !getuid()) && getegid() == getgid() && (home = getenv("HOME")) != NULL)
#  elif !defined(WIN32)
  if (getuid() && (home = getenv("HOME")) != NULL)
#  else
  if ((home = getenv("HOME")) != NULL)
#  endif /* HAVE_GETEUID */
  {
   /*
    * Look for ~/.cups/client.conf...
    */

    snprintf(filename, sizeof(filename), "%s/.cups/client.conf", home);
    if ((fp = cupsFileOpen(filename, "r")) != NULL)
    {
      cups_read_client_conf(fp, &cc);
      cupsFileClose(fp);
    }
  }

 /*
  * Finalize things so every client.conf value is set...
  */

  cups_finalize_client_conf(&cc);

  if (cg->encryption == (http_encryption_t)-1)
    cg->encryption = cc.encryption;

  if (!cg->server[0] || !cg->ipp_port)
    cupsSetServer(cc.server_name);

  if (!cg->ipp_port)
    cups_set_default_ipp_port(cg);

  if (!cg->user[0])
    strlcpy(cg->user, cc.user, sizeof(cg->user));

#ifdef HAVE_GSSAPI
  if (!cg->gss_service_name[0])
    strlcpy(cg->gss_service_name, cc.gss_service_name, sizeof(cg->gss_service_name));
#endif /* HAVE_GSSAPI */

  if (cg->trust_first < 0)
    cg->trust_first = cc.trust_first;

  if (cg->any_root < 0)
    cg->any_root = cc.any_root;

  if (cg->expired_certs < 0)
    cg->expired_certs = cc.expired_certs;

  if (cg->validate_certs < 0)
    cg->validate_certs = cc.validate_certs;

#ifdef HAVE_SSL
  _httpTLSSetOptions(cc.ssl_options);
#endif /* HAVE_SSL */
}


#ifdef __APPLE__
/*
 * 'cups_apple_get_boolean()' - Get a boolean setting from the CUPS preferences.
 */

static int                              /* O - 1 if set, 0 otherwise */
cups_apple_get_boolean(
    CFStringRef key,                    /* I - Key (name) */
    int         *value)                 /* O - Boolean value */
{
  Boolean       bval,                   /* Preference value */
                bval_set;               /* Value is set? */


  bval = CFPreferencesGetAppBooleanValue(key, kCUPSPrintingPrefs, &bval_set);

  if (bval_set)
    *value = (int)bval;

  return ((int)bval_set);
}


/*
 * 'cups_apple_get_string()' - Get a string setting from the CUPS preferences.
 */

static int                              /* O - 1 if set, 0 otherwise */
cups_apple_get_string(
    CFStringRef key,                    /* I - Key (name) */
    char        *value,                 /* O - String value */
    size_t      valsize)                /* I - Size of value buffer */
{
  CFStringRef   sval;                   /* String value */


  if ((sval = CFPreferencesCopyAppValue(key, kCUPSPrintingPrefs)) != NULL)
  {
    Boolean result = CFStringGetCString(sval, value, (CFIndex)valsize, kCFStringEncodingUTF8);

    CFRelease(sval);

    if (result)
      return (1);
  }

  return (0);
}
#endif /* __APPLE__ */


/*
 * 'cups_boolean_value()' - Convert a string to a boolean value.
 */

static int                              /* O - Boolean value */
cups_boolean_value(const char *value)   /* I - String value */
{
  return (!_cups_strcasecmp(value, "yes") || !_cups_strcasecmp(value, "on") || !_cups_strcasecmp(value, "true"));
}


/*
 * 'cups_finalize_client_conf()' - Finalize client.conf values.
 */

static void
cups_finalize_client_conf(
    _cups_client_conf_t *cc)            /* I - client.conf values */
{
  const char    *value;                 /* Environment variable */


  if ((value = getenv("CUPS_TRUSTFIRST")) != NULL)
    cc->trust_first = cups_boolean_value(value);

  if ((value = getenv("CUPS_ANYROOT")) != NULL)
    cc->any_root = cups_boolean_value(value);

  if ((value = getenv("CUPS_ENCRYPTION")) != NULL)
    cups_set_encryption(cc, value);

  if ((value = getenv("CUPS_EXPIREDCERTS")) != NULL)
    cc->expired_certs = cups_boolean_value(value);

#ifdef HAVE_GSSAPI
  if ((value = getenv("CUPS_GSSSERVICENAME")) != NULL)
    cups_set_gss_service_name(cc, value);
#endif /* HAVE_GSSAPI */

  if ((value = getenv("CUPS_SERVER")) != NULL)
    cups_set_server_name(cc, value);

  if ((value = getenv("CUPS_USER")) != NULL)
    cups_set_user(cc, value);

  if ((value = getenv("CUPS_VALIDATECERTS")) != NULL)
    cc->validate_certs = cups_boolean_value(value);

 /*
  * Then apply defaults for those values that haven't been set...
  */

  if (cc->trust_first < 0)
    cc->trust_first = 1;

  if (cc->any_root < 0)
    cc->any_root = 1;

  if (cc->encryption == (http_encryption_t)-1)
    cc->encryption = HTTP_ENCRYPTION_IF_REQUESTED;

  if (cc->expired_certs < 0)
    cc->expired_certs = 0;

#ifdef HAVE_GSSAPI
  if (!cc->gss_service_name[0])
    cups_set_gss_service_name(cc, CUPS_DEFAULT_GSSSERVICENAME);
#endif /* HAVE_GSSAPI */

  if (!cc->server_name[0])
  {
#ifdef CUPS_DEFAULT_DOMAINSOCKET
   /*
    * If we are compiled with domain socket support, only use the
    * domain socket if it exists and has the right permissions...
    */

    if (!access(CUPS_DEFAULT_DOMAINSOCKET, R_OK))
      cups_set_server_name(cc, CUPS_DEFAULT_DOMAINSOCKET);
    else
#endif /* CUPS_DEFAULT_DOMAINSOCKET */
      cups_set_server_name(cc, "localhost");
  }

  if (!cc->user[0])
  {
#ifdef WIN32
   /*
    * Get the current user name from the OS...
    */

    DWORD       size;                   /* Size of string */

    size = sizeof(cc->user);
    if (!GetUserName(cc->user, &size))
#else
   /*
    * Try the USER environment variable as the default username...
    */

    const char *envuser = getenv("USER");
                                        /* Default username */
    struct passwd *pw = NULL;           /* Account information */

    if (envuser)
    {
     /*
      * Validate USER matches the current UID, otherwise don't allow it to
      * override things...  This makes sure that printing after doing su
      * or sudo records the correct username.
      */

      if ((pw = getpwnam(envuser)) != NULL && pw->pw_uid != getuid())
        pw = NULL;
    }

    if (!pw)
      pw = getpwuid(getuid());

    if (pw)
      strlcpy(cc->user, pw->pw_name, sizeof(cc->user));
    else
#endif /* WIN32 */
    {
     /*
      * Use the default "unknown" user name...
      */

      strlcpy(cc->user, "unknown", sizeof(cc->user));
    }
  }

  if (cc->validate_certs < 0)
    cc->validate_certs = 0;
}


/*
 * 'cups_init_client_conf()' - Initialize client.conf values.
 */

static void
cups_init_client_conf(
    _cups_client_conf_t *cc)            /* I - client.conf values */
{
 /*
  * Clear all values to "not set"...
  */

  memset(cc, 0, sizeof(_cups_client_conf_t));

  cc->encryption     = (http_encryption_t)-1;
  cc->trust_first    = -1;
  cc->any_root       = -1;
  cc->expired_certs  = -1;
  cc->validate_certs = -1;

 /*
  * Load settings from the org.cups.PrintingPrefs plist (which trump
  * everything...)
  */

#ifdef __APPLE__
  char  sval[1024];                     /* String value */
  int   bval;                           /* Boolean value */

  if (cups_apple_get_boolean(kAllowAnyRootKey, &bval))
    cc->any_root = bval;

  if (cups_apple_get_boolean(kAllowExpiredCertsKey, &bval))
    cc->expired_certs = bval;

  if (cups_apple_get_string(kEncryptionKey, sval, sizeof(sval)))
    cups_set_encryption(cc, sval);

  if (cups_apple_get_string(kSSLOptionsKey, sval, sizeof(sval)))
    cups_set_ssl_options(cc, sval);

  if (cups_apple_get_boolean(kTrustOnFirstUseKey, &bval))
    cc->trust_first = bval;

  if (cups_apple_get_boolean(kValidateCertsKey, &bval))
    cc->validate_certs = bval;
#endif /* __APPLE__ */
}


/*
 * 'cups_read_client_conf()' - Read a client.conf file.
 */

static void
cups_read_client_conf(
    cups_file_t         *fp,            /* I - File to read */
    _cups_client_conf_t *cc)            /* I - client.conf values */
{
  int   linenum;                        /* Current line number */
  char  line[1024],                     /* Line from file */
        *value;                         /* Pointer into line */


 /*
  * Read from the file...
  */

  linenum = 0;
  while (cupsFileGetConf(fp, line, sizeof(line), &value, &linenum))
  {
    if (!_cups_strcasecmp(line, "Encryption") && value)
      cups_set_encryption(cc, value);
#ifndef __APPLE__
   /*
    * The ServerName directive is not supported on macOS due to app
    * sandboxing restrictions, i.e. not all apps request network access.
    */
    else if (!_cups_strcasecmp(line, "ServerName") && value)
      cups_set_server_name(cc, value);
#endif /* !__APPLE__ */
    else if (!_cups_strcasecmp(line, "User") && value)
      cups_set_user(cc, value);
    else if (!_cups_strcasecmp(line, "TrustOnFirstUse") && value)
      cc->trust_first = cups_boolean_value(value);
    else if (!_cups_strcasecmp(line, "AllowAnyRoot") && value)
      cc->any_root = cups_boolean_value(value);
    else if (!_cups_strcasecmp(line, "AllowExpiredCerts") &&
             value)
      cc->expired_certs = cups_boolean_value(value);
    else if (!_cups_strcasecmp(line, "ValidateCerts") && value)
      cc->validate_certs = cups_boolean_value(value);
#ifdef HAVE_GSSAPI
    else if (!_cups_strcasecmp(line, "GSSServiceName") && value)
      cups_set_gss_service_name(cc, value);
#endif /* HAVE_GSSAPI */
#ifdef HAVE_SSL
    else if (!_cups_strcasecmp(line, "SSLOptions") && value)
      cups_set_ssl_options(cc, value);
#endif /* HAVE_SSL */
  }
}


/*
 * 'cups_set_default_ipp_port()' - Set the default IPP port value.
 */

static void
cups_set_default_ipp_port(
    _cups_globals_t *cg)                /* I - Global data */
{
  const char    *ipp_port;              /* IPP_PORT environment variable */


  if ((ipp_port = getenv("IPP_PORT")) != NULL)
  {
    if ((cg->ipp_port = atoi(ipp_port)) <= 0)
      cg->ipp_port = CUPS_DEFAULT_IPP_PORT;
  }
  else
    cg->ipp_port = CUPS_DEFAULT_IPP_PORT;
}

/*
 * 'cups_set_encryption()' - Set the Encryption value.
 */

static void
cups_set_encryption(
    _cups_client_conf_t *cc,            /* I - client.conf values */
    const char          *value)         /* I - Value */
{
  if (!_cups_strcasecmp(value, "never"))
    cc->encryption = HTTP_ENCRYPTION_NEVER;
  else if (!_cups_strcasecmp(value, "always"))
    cc->encryption = HTTP_ENCRYPTION_ALWAYS;
  else if (!_cups_strcasecmp(value, "required"))
    cc->encryption = HTTP_ENCRYPTION_REQUIRED;
  else
    cc->encryption = HTTP_ENCRYPTION_IF_REQUESTED;
}


/*
 * 'cups_set_gss_service_name()' - Set the GSSServiceName value.
 */

#ifdef HAVE_GSSAPI
static void
cups_set_gss_service_name(
    _cups_client_conf_t *cc,            /* I - client.conf values */
    const char          *value)         /* I - Value */
{
  strlcpy(cc->gss_service_name, value, sizeof(cc->gss_service_name));
}
#endif /* HAVE_GSSAPI */


/*
 * 'cups_set_server_name()' - Set the ServerName value.
 */

static void
cups_set_server_name(
    _cups_client_conf_t *cc,            /* I - client.conf values */
    const char          *value)         /* I - Value */
{
  strlcpy(cc->server_name, value, sizeof(cc->server_name));
}


/*
 * 'cups_set_ssl_options()' - Set the SSLOptions value.
 */

#ifdef HAVE_SSL
static void
cups_set_ssl_options(
    _cups_client_conf_t *cc,            /* I - client.conf values */
    const char          *value)         /* I - Value */
{
 /*
  * SSLOptions [AllowRC4] [AllowSSL3] [AllowDH] [DenyTLS1.0] [None]
  */

  int   options = _HTTP_TLS_NONE;       /* SSL/TLS options */
  char  temp[256],                      /* Copy of value */
        *start,                         /* Start of option */
        *end;                           /* End of option */


  strlcpy(temp, value, sizeof(temp));

  for (start = temp; *start; start = end)
  {
   /*
    * Find end of keyword...
    */

    end = start;
    while (*end && !_cups_isspace(*end))
      end ++;

    if (*end)
      *end++ = '\0';

   /*
    * Compare...
    */

    if (!_cups_strcasecmp(start, "AllowRC4"))
      options |= _HTTP_TLS_ALLOW_RC4;
    else if (!_cups_strcasecmp(start, "AllowSSL3"))
      options |= _HTTP_TLS_ALLOW_SSL3;
    else if (!_cups_strcasecmp(start, "AllowDH"))
      options |= _HTTP_TLS_ALLOW_DH;
    else if (!_cups_strcasecmp(start, "DenyTLS1.0"))
      options |= _HTTP_TLS_DENY_TLS10;
    else if (!_cups_strcasecmp(start, "None"))
      options = _HTTP_TLS_NONE;
  }

  cc->ssl_options = options;

  DEBUG_printf(("4cups_set_ssl_options(cc=%p, value=\"%s\") options=%x", (void *)cc, value, options));
}
#endif /* HAVE_SSL */


/*
 * 'cups_set_user()' - Set the User value.
 */

static void
cups_set_user(
    _cups_client_conf_t *cc,            /* I - client.conf values */
    const char          *value)         /* I - Value */
{
  strlcpy(cc->user, value, sizeof(cc->user));
}