usr/src/lib/gss_mechs/mech_krb5/krb5/os/prompter.c

   1 #include "k5-int.h"
   2 #if !defined(_WIN32) || (defined(_WIN32) && defined(__CYGWIN32__))
   3 #include <stdio.h>
   4 #include <errno.h>
   5 #include <signal.h>
   6 #include <limits.h>
   7 /* Is vxworks broken w.r.t. termios? --tlyu */
   8 #ifdef __vxworks
   9 #define ECHO_PASSWORD
  10 #endif
  11
  12 #include <termios.h>
  13
  14 #ifdef POSIX_SIGNALS
  15 typedef struct sigaction osiginfo;
  16 #else
  17 typedef struct krb5_sigtype (*osiginfo)();
  18 #endif
  19
  20 static void     catch_signals(osiginfo *);
  21 static void     restore_signals(osiginfo *);
  22 static krb5_sigtype     intrfunc(int sig);
  23
  24 static krb5_error_code  setup_tty(FILE*, int, struct termios *, osiginfo *);
  25 static krb5_error_code  restore_tty(FILE*, struct termios *, osiginfo *);
  26
  27 static volatile int got_int;    /* should be sig_atomic_t */
  28
  29 krb5_error_code KRB5_CALLCONV
  30 krb5_prompter_posix(
  31     krb5_context        context,
  32     void                *data,
  33     const char          *name,
  34     const char          *banner,
  35     int                 num_prompts,
  36     krb5_prompt         prompts[])
  37 {
  38     int         fd, i, scratchchar;
  39     FILE        *fp;
  40     char        *retp;
  41     krb5_error_code     errcode;
  42     struct termios saveparm;
  43     osiginfo osigint;
  44
  45     errcode = KRB5_LIBOS_CANTREADPWD;
  46
  47     if (name) {
  48         fputs(name, stdout);
  49         fputs("\n", stdout);
  50     }
  51     if (banner) {
  52        fputs(banner, stdout);
  53        fputs("\n", stdout);
  54     }
  55
  56     /*
  57      * Get a non-buffered stream on stdin.
  58      */
  59     fp = NULL;
  60     fd = dup(STDIN_FILENO);
  61     if (fd < 0)
  62         return KRB5_LIBOS_CANTREADPWD;
  63     fp = fdopen(fd, "r");
  64     if (fp == NULL)
  65         goto cleanup;
  66     if (setvbuf(fp, NULL, _IONBF, 0))
  67         goto cleanup;
  68
  69     for (i = 0; i < num_prompts; i++) {
  70         errcode = KRB5_LIBOS_CANTREADPWD;
  71         /* fgets() takes int, but krb5_data.length is unsigned. */
  72         if (prompts[i].reply->length > INT_MAX)
  73             goto cleanup;
  74
  75         errcode = setup_tty(fp, prompts[i].hidden, &saveparm, &osigint);
  76         if (errcode)
  77             break;
  78
  79         /* put out the prompt */
  80         (void)fputs(prompts[i].prompt, stdout);
  81         (void)fputs(": ", stdout);
  82         (void)fflush(stdout);
  83         (void)memset(prompts[i].reply->data, 0, prompts[i].reply->length);
  84
  85         got_int = 0;
  86         retp = fgets(prompts[i].reply->data, (int)prompts[i].reply->length,
  87                      fp);
  88         if (prompts[i].hidden)
  89             putchar('\n');
  90         if (retp == NULL) {
  91             if (got_int)
  92                 errcode = KRB5_LIBOS_PWDINTR;
  93             else
  94                 errcode = KRB5_LIBOS_CANTREADPWD;
  95             restore_tty(fp, &saveparm, &osigint);
  96             break;
  97         }
  98
  99         /* replace newline with null */
 100         retp = strchr(prompts[i].reply->data, '\n');
 101         if (retp != NULL)
 102             *retp = '\0';
 103         else {
 104             /* flush rest of input line */
 105             do {
 106                 scratchchar = getc(fp);
 107             } while (scratchchar != EOF && scratchchar != '\n');
 108         }
 109
 110         errcode = restore_tty(fp, &saveparm, &osigint);
 111         if (errcode)
 112             break;
 113         prompts[i].reply->length = strlen(prompts[i].reply->data);
 114     }
 115 cleanup:
 116     if (fp != NULL)
 117         fclose(fp);
 118     else if (fd >= 0)
 119         close(fd);
 120
 121     return errcode;
 122 }
 123
 124 static krb5_sigtype intrfunc(int sig)
 125 {
 126     got_int = 1;
 127 }
 128
 129 static void
 130 catch_signals(osiginfo *osigint)
 131 {
 132 #ifdef POSIX_SIGNALS
 133     struct sigaction sa;
 134
 135     sigemptyset(&sa.sa_mask);
 136     sa.sa_flags = 0;
 137     sa.sa_handler = intrfunc;
 138     sigaction(SIGINT, &sa, osigint);
 139 #else
 140     *osigint = signal(SIGINT, intrfunc);
 141 #endif
 142 }
 143
 144 static void
 145 restore_signals(osiginfo *osigint)
 146 {
 147 #ifdef POSIX_SIGNALS
 148     sigaction(SIGINT, osigint, NULL);
 149 #else
 150     signal(SIGINT, *osigint);
 151 #endif
 152 }
 153
 154 static krb5_error_code
 155 setup_tty(FILE *fp, int hidden, struct termios *saveparm, osiginfo *osigint)
 156 {
 157     krb5_error_code     ret;
 158     int                 fd;
 159     struct termios      tparm;
 160
 161     ret = KRB5_LIBOS_CANTREADPWD;
 162     catch_signals(osigint);
 163     fd = fileno(fp);
 164     do {
 165         if (!isatty(fd)) {
 166             ret = 0;
 167             break;
 168         }
 169         if (tcgetattr(fd, &tparm) < 0)
 170             break;
 171         *saveparm = tparm;
 172 #ifndef ECHO_PASSWORD
 173         if (hidden)
 174             tparm.c_lflag &= ~(ECHO|ECHONL);
 175 #endif
 176         tparm.c_lflag |= ISIG|ICANON;
 177         if (tcsetattr(STDIN_FILENO, TCSANOW, &tparm) < 0)
 178             break;
 179         ret = 0;
 180     } while (0);
 181     /* If we're losing, restore signal handlers. */
 182     if (ret)
 183         restore_signals(osigint);
 184     return ret;
 185 }
 186
 187 static krb5_error_code
 188 restore_tty(FILE* fp, struct termios *saveparm, osiginfo *osigint)
 189 {
 190     int ret, fd;
 191
 192     ret = 0;
 193     fd = fileno(fp);
 194     if (isatty(fd)) {
 195         ret = tcsetattr(fd, TCSANOW, saveparm);
 196         if (ret < 0)
 197             ret = KRB5_LIBOS_CANTREADPWD;
 198         else
 199             ret = 0;
 200     }
 201     restore_signals(osigint);
 202     return ret;
 203 }
 204
 205 #else /* non-Cygwin Windows, or Mac */
 206
 207 #if defined(_WIN32)
 208
 209 #include <io.h>
 210
 211 krb5_error_code KRB5_CALLCONV
 212 krb5_prompter_posix(krb5_context context,
 213                     void *data,
 214                     const char *name,
 215                     const char *banner,
 216                     int num_prompts,
 217                     krb5_prompt prompts[])
 218 {
 219     HANDLE              handle;
 220     DWORD               old_mode, new_mode;
 221     char                *ptr;
 222     int                 scratchchar;
 223     krb5_error_code     errcode = 0;
 224     int                 i;
 225
 226     handle = GetStdHandle(STD_INPUT_HANDLE);
 227     if (handle == INVALID_HANDLE_VALUE)
 228         return ENOTTY;
 229     if (!GetConsoleMode(handle, &old_mode))
 230         return ENOTTY;
 231
 232     new_mode = old_mode;
 233     new_mode |=  ( ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT );
 234     new_mode &= ~( ENABLE_ECHO_INPUT );
 235
 236     if (!SetConsoleMode(handle, new_mode))
 237         return ENOTTY;
 238
 239     if (!SetConsoleMode(handle, old_mode))
 240         return ENOTTY;
 241
 242     if (name) {
 243         fputs(name, stdout);
 244         fputs("\n", stdout);
 245     }
 246
 247     if (banner) {
 248        fputs(banner, stdout);
 249        fputs("\n", stdout);
 250     }
 251
 252     for (i = 0; i < num_prompts; i++) {
 253         if (prompts[i].hidden) {
 254             if (!SetConsoleMode(handle, new_mode)) {
 255                 errcode = ENOTTY;
 256                 goto cleanup;
 257             }
 258         }
 259
 260         fputs(prompts[i].prompt,stdout);
 261         fputs(": ", stdout);
 262         fflush(stdout);
 263         memset(prompts[i].reply->data, 0, prompts[i].reply->length);
 264
 265         if (fgets(prompts[i].reply->data, prompts[i].reply->length, stdin)
 266             == NULL) {
 267             if (prompts[i].hidden)
 268                 putchar('\n');
 269             errcode = KRB5_LIBOS_CANTREADPWD;
 270             goto cleanup;
 271         }
 272         if (prompts[i].hidden)
 273             putchar('\n');
 274         /* fgets always null-terminates the returned string */
 275
 276         /* replace newline with null */
 277         if ((ptr = strchr(prompts[i].reply->data, '\n')))
 278             *ptr = '\0';
 279         else /* flush rest of input line */
 280             do {
 281                 scratchchar = getchar();
 282             } while (scratchchar != EOF && scratchchar != '\n');
 283
 284         prompts[i].reply->length = strlen(prompts[i].reply->data);
 285
 286         if (!SetConsoleMode(handle, old_mode)) {
 287             errcode = ENOTTY;
 288             goto cleanup;
 289         }
 290     }
 291
 292  cleanup:
 293     if (errcode) {
 294         for (i = 0; i < num_prompts; i++) {
 295             memset(prompts[i].reply->data, 0, prompts[i].reply->length);
 296         }
 297     }
 298     return errcode;
 299 }
 300
 301 #else /* !_WIN32 */
 302
 303 krb5_error_code KRB5_CALLCONV
 304 krb5_prompter_posix(krb5_context context,
 305                     void *data,
 306                     const char *name,
 307                     const char *banner,
 308                     int num_prompts,
 309                     krb5_prompt prompts[])
 310 {
 311     return(EINVAL);
 312 }
 313 #endif /* !_WIN32 */
 314 #endif /* Windows or Mac */
 315
 316 void
 317 krb5int_set_prompt_types(krb5_context context, krb5_prompt_type *types)
 318 {
 319     context->prompt_types = types;
 320 }
 321
 322 krb5_prompt_type*
 323 KRB5_CALLCONV
 324 krb5_get_prompt_types(krb5_context context)
 325 {
 326     return context->prompt_types;
 327 }