src/misc.c

/* misc.c
 * Copyright (C) 1999, 2001, 2002, 2003, 2007,
 *               2008 Free Software Foundation, Inc.
 *
 * This file is part of Libgcrypt.
 *
 * Libgcrypt is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * Libgcrypt 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>

#include "g10lib.h"
#include "secmem.h"
#include "mpi.h"

static int verbosity_level = 0;

static void (*fatal_error_handler)(void*,int, const char*) = NULL;
static void *fatal_error_handler_value = 0;
static void (*log_handler)(void*,int, const char*, va_list) = NULL;
static void *log_handler_value = 0;

static const char *(*user_gettext_handler)( const char * ) = NULL;

void
_gcry_set_gettext_handler (const char *(*f)(const char*))
{
    user_gettext_handler = f;
}


const char *
_gcry_gettext( const char *key )
{
    if( user_gettext_handler )
	return user_gettext_handler( key );
    /* FIXME: switch the domain to gnupg and restore later */
    return key;
}

void
_gcry_set_fatalerror_handler( void (*fnc)(void*,int, const char*), void *value)
{
    fatal_error_handler_value = value;
    fatal_error_handler = fnc;
}

static void
write2stderr( const char *s )
{
  /* Dummy variable to silence gcc warning.  */
  int res = write( 2, s, strlen(s) );
  (void) res;
}

/*
 * This function is called for fatal errors.  A caller might want to
 * set his own handler because this function simply calls abort().
 */
void
_gcry_fatal_error (int rc, const char *text)
{
  if ( !text ) /* get a default text */
    text = gpg_strerror (rc);

  if (fatal_error_handler && !fips_mode () )
    fatal_error_handler (fatal_error_handler_value, rc, text);

  fips_signal_fatal_error (text);
  write2stderr("\nFatal error: ");
  write2stderr(text);
  write2stderr("\n");
  _gcry_secmem_term ();
  abort ();
}

void
_gcry_set_log_handler (void (*f)(void*,int, const char*, va_list), void *opaque)
{
    log_handler = f;
    log_handler_value = opaque;
}

void
_gcry_set_log_verbosity( int level )
{
    verbosity_level = level;
}

int
_gcry_log_verbosity( int level )
{
    return verbosity_level >= level;
}

/****************
 * This is our log function which prints all log messages to stderr or
 * using the function defined with gcry_set_log_handler().
 */
void
_gcry_logv( int level, const char *fmt, va_list arg_ptr )
{
  if (log_handler)
    log_handler (log_handler_value, level, fmt, arg_ptr);
  else
    {
      switch (level)
        {
        case GCRY_LOG_CONT:  break;
        case GCRY_LOG_INFO:  break;
        case GCRY_LOG_WARN:  break;
        case GCRY_LOG_ERROR: break;
        case GCRY_LOG_FATAL: fputs("Fatal: ",stderr ); break;
        case GCRY_LOG_BUG:   fputs("Ohhhh jeeee: ", stderr); break;
        case GCRY_LOG_DEBUG: fputs("DBG: ", stderr ); break;
        default: fprintf(stderr,"[Unknown log level %d]: ", level ); break;
	}
      vfprintf(stderr,fmt,arg_ptr) ;
    }

  if ( level == GCRY_LOG_FATAL || level == GCRY_LOG_BUG )
    {
      fips_signal_fatal_error ("internal error (fatal or bug)");
      _gcry_secmem_term ();
      abort ();
    }
}


void
_gcry_log( int level, const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    _gcry_logv( level, fmt, arg_ptr );
    va_end(arg_ptr);
}


#if defined(JNLIB_GCC_M_FUNCTION) || __STDC_VERSION__ >= 199901L
void
_gcry_bug( const char *file, int line, const char *func )
{
    _gcry_log( GCRY_LOG_BUG,
	     ("... this is a bug (%s:%d:%s)\n"), file, line, func );
    abort(); /* never called, but it makes the compiler happy */
}
void
_gcry_assert_failed (const char *expr, const char *file, int line,
                     const char *func)
{
  _gcry_log (GCRY_LOG_BUG,
             ("Assertion `%s' failed (%s:%d:%s)\n"), expr, file, line, func );
  abort(); /* Never called, but it makes the compiler happy. */
}
#else
void
_gcry_bug( const char *file, int line )
{
    _gcry_log( GCRY_LOG_BUG,
	     _("you found a bug ... (%s:%d)\n"), file, line);
    abort(); /* never called, but it makes the compiler happy */
}
void
_gcry_assert_failed (const char *expr, const char *file, int line)
{
  _gcry_log (GCRY_LOG_BUG,
             ("Assertion `%s' failed (%s:%d)\n"), expr, file, line);
  abort(); /* Never called, but it makes the compiler happy. */
}
#endif

void
_gcry_log_info( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    _gcry_logv( GCRY_LOG_INFO, fmt, arg_ptr );
    va_end(arg_ptr);
}

int
_gcry_log_info_with_dummy_fp (FILE *fp, const char *fmt, ... )
{
    va_list arg_ptr;

    (void)fp;
    va_start( arg_ptr, fmt ) ;
    _gcry_logv( GCRY_LOG_INFO, fmt, arg_ptr );
    va_end(arg_ptr);
    return 0;
}

void
_gcry_log_error( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    _gcry_logv( GCRY_LOG_ERROR, fmt, arg_ptr );
    va_end(arg_ptr);
}


void
_gcry_log_fatal( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    _gcry_logv( GCRY_LOG_FATAL, fmt, arg_ptr );
    va_end(arg_ptr);
    abort(); /* never called, but it makes the compiler happy */
}

void
_gcry_log_bug( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    _gcry_logv( GCRY_LOG_BUG, fmt, arg_ptr );
    va_end(arg_ptr);
    abort(); /* never called, but it makes the compiler happy */
}

void
_gcry_log_debug( const char *fmt, ... )
{
    va_list arg_ptr ;

    va_start( arg_ptr, fmt ) ;
    _gcry_logv( GCRY_LOG_DEBUG, fmt, arg_ptr );
    va_end(arg_ptr);
}


void
_gcry_log_printf (const char *fmt, ...)
{
  va_list arg_ptr;

  if (fmt)
    {
      va_start( arg_ptr, fmt ) ;
      _gcry_logv (GCRY_LOG_CONT, fmt, arg_ptr);
      va_end(arg_ptr);
    }
}


/* Helper for _gcry_log_printhex and _gcry_log_printmpi.  */
static void
do_printhex (const char *text, const char *text2,
             const void *buffer, size_t length)
{
  int wrap = 0;
  int cnt = 0;

  if (text && *text)
    {
      wrap = 1;
      log_debug ("%s:%s", text, text2);
      if (text2[1] == '[' && length && buffer)
        {
          /* Start with a new line so that we get nice output for
             opaque MPIS:
               "value: [31 bit]"
               "        01020300"  */
          log_printf ("\n");
          text2 = " ";
          log_debug ("%*s  ", (int)strlen(text), "");
        }
    }
  if (length)
    {
      const unsigned char *p = buffer;
      for (; length--; p++)
        {
          log_printf ("%02x", *p);
          if (wrap && ++cnt == 32 && length)
            {
              cnt = 0;
              log_printf (" \\\n");
              log_debug ("%*s %*s",
                         (int)strlen(text), "", (int)strlen(text2), "");
            }
        }
    }
  if (text)
    log_printf ("\n");
}


/* Print a hexdump of BUFFER.  With TEXT of NULL print just the raw
   dump without any wrappping, with TEXT an empty string, print a
   trailing linefeed, otherwise print an entire debug line. */
void
_gcry_log_printhex (const char *text, const void *buffer, size_t length)
{
  do_printhex (text, " ", buffer, length);
}


/* Print MPI in hex notation.  To make clear that the output is an MPI
   a sign is always printed. With TEXT of NULL print just the raw dump
   without any wrapping, with TEXT an empty string, print a trailing
   linefeed, otherwise print an entire debug line. */
void
_gcry_log_printmpi (const char *text, gcry_mpi_t mpi)
{
  unsigned char *rawmpi;
  unsigned int rawmpilen;
  int sign;

  if (!mpi)
    do_printhex (text? text:" ", " (null)", NULL, 0);
  else if (mpi_is_opaque (mpi))
    {
      unsigned int nbits;
      const unsigned char *p;
      char prefix[30];

      p = mpi_get_opaque (mpi, &nbits);
      snprintf (prefix, sizeof prefix, " [%u bit]", nbits);
      do_printhex (text? text:" ", prefix, p, (nbits+7)/8);
    }
  else
    {
      rawmpi = _gcry_mpi_get_buffer (mpi, 0, &rawmpilen, &sign);
      if (!rawmpi)
        do_printhex (text? text:" ", " [out of core]", NULL, 0);
      else
        {
          if (!rawmpilen)
            do_printhex (text, sign? "-":"+", "", 1);
          else
            do_printhex (text, sign? "-":"+", rawmpi, rawmpilen);
          xfree (rawmpi);
        }
    }
}


static int
count_closing_parens (const char *p)
{
  int count = 0;

  for (; *p; p++)
    if (*p == ')')
      count++;
    else if (!strchr ("\n \t", *p))
      return 0;

  return count;
}


/* Print SEXP in human readabale format.  With TEXT of NULL print just the raw
   dump without any wrappping, with TEXT an empty string, print a
   trailing linefeed, otherwise print the full debug output. */
void
_gcry_log_printsxp (const char *text, gcry_sexp_t sexp)
{
  int with_lf = 0;

  if (text && *text)
    {
      if ((with_lf = !!strchr (text, '\n')))
        log_debug ("%s", text);
      else
        log_debug ("%s: ", text);
    }
  if (sexp)
    {
      int any = 0;
      int n_closing;
      char *buf, *pend;
      const char *p;
      size_t size;

      size = sexp_sprint (sexp, GCRYSEXP_FMT_ADVANCED, NULL, 0);
      p = buf = xmalloc (size);
      sexp_sprint (sexp, GCRYSEXP_FMT_ADVANCED, buf, size);

      do
        {
          if (any && !with_lf)
            log_debug ("%*s  ", (int)strlen(text), "");
          else
            any = 1;
          pend = strchr (p, '\n');
          size = pend? (pend - p) : strlen (p);
          if (with_lf)
            log_debug ("%.*s", (int)size, p);
          else
            log_printf ("%.*s", (int)size, p);
          if (pend)
            p = pend + 1;
          else
            p += size;
          n_closing = count_closing_parens (p);
          if (n_closing)
            {
              while (n_closing--)
                log_printf (")");
              p = "";
            }
          log_printf ("\n");
        }
      while (*p);
      xfree (buf);
    }
  else if (text)
    log_printf ("\n");
}


void
__gcry_burn_stack (unsigned int bytes)
{
#ifdef HAVE_VLA
    /* (bytes == 0 ? 1 : bytes) == (!bytes + bytes) */
    unsigned int buflen = ((!bytes + bytes) + 63) & ~63;
    volatile char buf[buflen];

    wipememory (buf, sizeof buf);
#else
    volatile char buf[64];

    wipememory (buf, sizeof buf);

    if (bytes > sizeof buf)
        _gcry_burn_stack (bytes - sizeof buf);
#endif
}

#ifndef HAVE_GCC_ASM_VOLATILE_MEMORY
void
__gcry_burn_stack_dummy (void)
{
}
#endif

void
_gcry_divide_by_zero (void)
{
    gpg_err_set_errno (EDOM);
    _gcry_fatal_error (gpg_err_code_from_errno (errno), "divide by zero");
}