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Diffstat (limited to 'secmem/util.c')
-rw-r--r-- | secmem/util.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/secmem/util.c b/secmem/util.c new file mode 100644 index 0000000..580fd34 --- /dev/null +++ b/secmem/util.c @@ -0,0 +1,139 @@ +/* Quintuple Agent + * Copyright (C) 1999 Robert Bihlmeyer <robbe@orcus.priv.at> + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#define _GNU_SOURCE 1 + +#include <unistd.h> +#include <errno.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "util.h" + +#ifndef TEMP_FAILURE_RETRY +#define TEMP_FAILURE_RETRY(expression) \ + (__extension__ \ + ({ long int __result; \ + do __result = (long int) (expression); \ + while (__result == -1L && errno == EINTR); \ + __result; })) +#endif + +#ifndef HAVE_DOSISH_SYSTEM +static int uid_set = 0; +static uid_t real_uid, file_uid; +#endif /*!HAVE_DOSISH_SYSTEM*/ + +/* write DATA of size BYTES to FD, until all is written or an error occurs */ +ssize_t xwrite(int fd, const void *data, size_t bytes) +{ + char *ptr; + size_t todo; + ssize_t written = 0; + + for (ptr = (char *)data, todo = bytes; todo; ptr += written, todo -= written) + if ((written = TEMP_FAILURE_RETRY(write(fd, ptr, todo))) < 0) + break; + return written; +} + +#if 0 +extern int debug; + +int debugmsg(const char *fmt, ...) +{ + va_list va; + int ret; + + if (debug) { + va_start(va, fmt); + fprintf(stderr, "\e[4m"); + ret = vfprintf(stderr, fmt, va); + fprintf(stderr, "\e[24m"); + va_end(va); + return ret; + } else + return 0; +} +#endif + +/* initialize uid variables */ +#ifndef HAVE_DOSISH_SYSTEM +static void init_uids(void) +{ + real_uid = getuid(); + file_uid = geteuid(); + uid_set = 1; +} +#endif + + +#if 0 /* Not used. */ +/* lower privileges to the real user's */ +void lower_privs() +{ + if (!uid_set) + init_uids(); + if (real_uid != file_uid) { +#ifdef HAVE_SETEUID + if (seteuid(real_uid) < 0) { + perror("lowering privileges failed"); + exit(EXIT_FAILURE); + } +#else + fprintf(stderr, _("Warning: running q-agent setuid on this system is dangerous\n")); +#endif /* HAVE_SETEUID */ + } +} +#endif /* if 0 */ + +#if 0 /* Not used. */ +/* raise privileges to the effective user's */ +void raise_privs() +{ + assert(real_uid >= 0); /* lower_privs() must be called before this */ +#ifdef HAVE_SETEUID + if (real_uid != file_uid && seteuid(file_uid) < 0) { + perror("Warning: raising privileges failed"); + } +#endif /* HAVE_SETEUID */ +} +#endif /* if 0 */ + +/* drop all additional privileges */ +void drop_privs() +{ +#ifndef HAVE_DOSISH_SYSTEM + if (!uid_set) + init_uids(); + if (real_uid != file_uid) { + if (setuid(real_uid) < 0) { + perror("dropping privileges failed"); + exit(EXIT_FAILURE); + } + file_uid = real_uid; + } +#endif +} |