/* * Copyright (c) 2000-2005, 2007-2011 * Todd C. Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Sponsored in part by the Defense Advanced Research Projects * Agency (DARPA) and Air Force Research Laboratory, Air Force * Materiel Command, USAF, under agreement number F39502-99-1-0512. */ #include #include #include #include #include #ifdef STDC_HEADERS # include # include #else # ifdef HAVE_STDLIB_H # include # endif #endif /* STDC_HEADERS */ #ifdef HAVE_STRING_H # include #endif /* HAVE_STRING_H */ #ifdef HAVE_STRINGS_H # include #endif /* HAVE_STRINGS_H */ #ifdef HAVE_UNISTD_H # include #endif /* HAVE_UNISTD_H */ #include #include #include #include "sudoers.h" /* * Flags used in rebuild_env() */ #undef DID_TERM #define DID_TERM 0x0001 #undef DID_PATH #define DID_PATH 0x0002 #undef DID_HOME #define DID_HOME 0x0004 #undef DID_SHELL #define DID_SHELL 0x0008 #undef DID_LOGNAME #define DID_LOGNAME 0x0010 #undef DID_USER #define DID_USER 0x0020 #undef DID_USERNAME #define DID_USERNAME 0x0040 #undef DID_MAIL #define DID_MAIL 0x0080 #undef DID_MAX #define DID_MAX 0x00ff #undef KEPT_TERM #define KEPT_TERM 0x0100 #undef KEPT_PATH #define KEPT_PATH 0x0200 #undef KEPT_HOME #define KEPT_HOME 0x0400 #undef KEPT_SHELL #define KEPT_SHELL 0x0800 #undef KEPT_LOGNAME #define KEPT_LOGNAME 0x1000 #undef KEPT_USER #define KEPT_USER 0x2000 #undef KEPT_USERNAME #define KEPT_USERNAME 0x4000 #undef KEPT_MAIL #define KEPT_MAIL 0x8000 #undef KEPT_MAX #define KEPT_MAX 0xff00 struct environment { char **envp; /* pointer to the new environment */ size_t env_size; /* size of new_environ in char **'s */ size_t env_len; /* number of slots used, not counting NULL */ }; /* * Prototypes */ static void sudo_setenv(const char *, const char *, int); static void sudo_putenv(char *, int, int); /* * Copy of the sudo-managed environment. */ static struct environment env; /* * Default table of "bad" variables to remove from the environment. * XXX - how to omit TERMCAP if it starts with '/'? */ static const char *initial_badenv_table[] = { "IFS", "CDPATH", "LOCALDOMAIN", "RES_OPTIONS", "HOSTALIASES", "NLSPATH", "PATH_LOCALE", "LD_*", "_RLD*", #ifdef __hpux "SHLIB_PATH", #endif /* __hpux */ #ifdef _AIX "LDR_*", "LIBPATH", "AUTHSTATE", #endif #ifdef __APPLE__ "DYLD_*", #endif #ifdef HAVE_KERB4 "KRB_CONF*", "KRBCONFDIR", "KRBTKFILE", #endif /* HAVE_KERB4 */ #ifdef HAVE_KERB5 "KRB5_CONFIG*", "KRB5_KTNAME", #endif /* HAVE_KERB5 */ #ifdef HAVE_SECURID "VAR_ACE", "USR_ACE", "DLC_ACE", #endif /* HAVE_SECURID */ "TERMINFO", /* terminfo, exclusive path to terminfo files */ "TERMINFO_DIRS", /* terminfo, path(s) to terminfo files */ "TERMPATH", /* termcap, path(s) to termcap files */ "TERMCAP", /* XXX - only if it starts with '/' */ "ENV", /* ksh, file to source before script runs */ "BASH_ENV", /* bash, file to source before script runs */ "PS4", /* bash, prefix for lines in xtrace mode */ "GLOBIGNORE", /* bash, globbing patterns to ignore */ "SHELLOPTS", /* bash, extra command line options */ "JAVA_TOOL_OPTIONS", /* java, extra command line options */ "PERLIO_DEBUG ", /* perl, debugging output file */ "PERLLIB", /* perl, search path for modules/includes */ "PERL5LIB", /* perl 5, search path for modules/includes */ "PERL5OPT", /* perl 5, extra command line options */ "PERL5DB", /* perl 5, command used to load debugger */ "FPATH", /* ksh, search path for functions */ "NULLCMD", /* zsh, command for null file redirection */ "READNULLCMD", /* zsh, command for null file redirection */ "ZDOTDIR", /* zsh, search path for dot files */ "TMPPREFIX", /* zsh, prefix for temporary files */ "PYTHONHOME", /* python, module search path */ "PYTHONPATH", /* python, search path */ "PYTHONINSPECT", /* python, allow inspection */ "PYTHONUSERBASE", /* python, per user site-packages directory */ "RUBYLIB", /* ruby, library load path */ "RUBYOPT", /* ruby, extra command line options */ NULL }; /* * Default table of variables to check for '%' and '/' characters. */ static const char *initial_checkenv_table[] = { "COLORTERM", "LANG", "LANGUAGE", "LC_*", "LINGUAS", "TERM", NULL }; /* * Default table of variables to preserve in the environment. */ static const char *initial_keepenv_table[] = { "COLORS", "DISPLAY", "HOSTNAME", "KRB5CCNAME", "LS_COLORS", "PATH", "PS1", "PS2", "TZ", "XAUTHORITY", "XAUTHORIZATION", #ifdef _AIX "ODMDIR", #endif NULL }; /* * Initialize env based on envp. */ void env_init(char * const envp[]) { char * const *ep; size_t len; for (ep = envp; *ep != NULL; ep++) continue; len = (size_t)(ep - envp); env.env_len = len; env.env_size = len + 1 + 128; env.envp = emalloc2(env.env_size, sizeof(char *)); #ifdef ENV_DEBUG memset(env.envp, 0, env.env_size * sizeof(char *)); #endif memcpy(env.envp, envp, len * sizeof(char *)); env.envp[len] = '\0'; } char ** env_get(void) { return env.envp; } /* * Similar to setenv(3) but operates on sudo's private copy of the environment * (not environ) and it always overwrites. The dupcheck param determines * whether we need to verify that the variable is not already set. */ static void sudo_setenv(const char *var, const char *val, int dupcheck) { char *estring; size_t esize; esize = strlen(var) + 1 + strlen(val) + 1; estring = emalloc(esize); /* Build environment string and insert it. */ if (strlcpy(estring, var, esize) >= esize || strlcat(estring, "=", esize) >= esize || strlcat(estring, val, esize) >= esize) { errorx(1, _("internal error, sudo_setenv() overflow")); } sudo_putenv(estring, dupcheck, TRUE); } /* * Similar to putenv(3) but operates on sudo's private copy of the * environment (not environ) and it always overwrites. The dupcheck param * determines whether we need to verify that the variable is not already set. * Will only overwrite an existing variable if overwrite is set. */ static void sudo_putenv(char *str, int dupcheck, int overwrite) { char **ep; size_t len; int found = FALSE; /* Make sure there is room for the new entry plus a NULL. */ if (env.env_len + 2 > env.env_size) { env.env_size += 128; env.envp = erealloc3(env.envp, env.env_size, sizeof(char *)); #ifdef ENV_DEBUG memset(env.envp + env.env_len, 0, (env.env_size - env.env_len) * sizeof(char *)); #endif } #ifdef ENV_DEBUG if (env.envp[env.env_len] != NULL) errorx(1, _("sudo_putenv: corrupted envp, length mismatch")); #endif if (dupcheck) { len = (strchr(str, '=') - str) + 1; for (ep = env.envp; !found && *ep != NULL; ep++) { if (strncmp(str, *ep, len) == 0) { if (overwrite) *ep = str; found = TRUE; } } /* Prune out duplicate variables. */ if (found && overwrite) { while (*ep != NULL) { if (strncmp(str, *ep, len) == 0) { char **cur = ep; while ((*cur = *(cur + 1)) != NULL) cur++; } else { ep++; } } env.env_len = ep - env.envp; } } if (!found) { ep = env.envp + env.env_len; env.env_len++; *ep++ = str; *ep = NULL; } } /* * Check the env_delete blacklist. * Returns TRUE if the variable was found, else false. */ static int matches_env_delete(const char *var) { struct list_member *cur; size_t len; int iswild, match = FALSE; /* Skip anything listed in env_delete. */ for (cur = def_env_delete; cur; cur = cur->next) { len = strlen(cur->value); /* Deal with '*' wildcard */ if (cur->value[len - 1] == '*') { len--; iswild = TRUE; } else iswild = FALSE; if (strncmp(cur->value, var, len) == 0 && (iswild || var[len] == '=')) { match = TRUE; break; } } return match; } /* * Apply the env_check list. * Returns TRUE if the variable is allowed, FALSE if denied * or -1 if no match. */ static int matches_env_check(const char *var) { struct list_member *cur; size_t len; int iswild, keepit = -1; for (cur = def_env_check; cur; cur = cur->next) { len = strlen(cur->value); /* Deal with '*' wildcard */ if (cur->value[len - 1] == '*') { len--; iswild = TRUE; } else iswild = FALSE; if (strncmp(cur->value, var, len) == 0 && (iswild || var[len] == '=')) { keepit = !strpbrk(var, "/%"); break; } } return keepit; } /* * Check the env_keep list. * Returns TRUE if the variable is allowed else FALSE. */ static int matches_env_keep(const char *var) { struct list_member *cur; size_t len; int iswild, keepit = FALSE; /* Preserve SHELL variable for "sudo -s". */ if (ISSET(sudo_mode, MODE_SHELL) && strncmp(var, "SHELL=", 6) == 0) return TRUE; for (cur = def_env_keep; cur; cur = cur->next) { len = strlen(cur->value); /* Deal with '*' wildcard */ if (cur->value[len - 1] == '*') { len--; iswild = TRUE; } else iswild = FALSE; if (strncmp(cur->value, var, len) == 0 && (iswild || var[len] == '=')) { keepit = TRUE; break; } } return keepit; } /* * Build a new environment and ether clear potentially dangerous * variables from the old one or start with a clean slate. * Also adds sudo-specific variables (SUDO_*). */ void rebuild_env(void) { char **old_envp, **ep, *cp, *ps1; char idbuf[MAX_UID_T_LEN]; unsigned int didvar; int reset_home = FALSE; /* * Either clean out the environment or reset to a safe default. */ ps1 = NULL; didvar = 0; env.env_len = 0; env.env_size = 128; old_envp = env.envp; env.envp = emalloc2(env.env_size, sizeof(char *)); #ifdef ENV_DEBUG memset(env.envp, 0, env.env_size * sizeof(char *)); #endif /* Reset HOME based on target user if configured to. */ if (ISSET(sudo_mode, MODE_RUN)) { if (def_always_set_home || ISSET(sudo_mode, MODE_RESET_HOME | MODE_LOGIN_SHELL) || (ISSET(sudo_mode, MODE_SHELL) && def_set_home)) reset_home = TRUE; } if (def_env_reset || ISSET(sudo_mode, MODE_LOGIN_SHELL)) { /* Pull in vars we want to keep from the old environment. */ for (ep = old_envp; *ep; ep++) { int keepit; /* Skip variables with values beginning with () (bash functions) */ if ((cp = strchr(*ep, '=')) != NULL) { if (strncmp(cp, "=() ", 3) == 0) continue; } /* * First check certain variables for '%' and '/' characters. * If no match there, check the keep list. * If nothing matched, we remove it from the environment. */ keepit = matches_env_check(*ep); if (keepit == -1) keepit = matches_env_keep(*ep); /* For SUDO_PS1 -> PS1 conversion. */ if (strncmp(*ep, "SUDO_PS1=", 8) == 0) ps1 = *ep + 5; if (keepit) { /* Preserve variable. */ switch (**ep) { case 'H': if (strncmp(*ep, "HOME=", 5) == 0) SET(didvar, DID_HOME); break; case 'L': if (strncmp(*ep, "LOGNAME=", 8) == 0) SET(didvar, DID_LOGNAME); break; case 'M': if (strncmp(*ep, "MAIL=", 5) == 0) SET(didvar, DID_MAIL); break; case 'P': if (strncmp(*ep, "PATH=", 5) == 0) SET(didvar, DID_PATH); break; case 'S': if (strncmp(*ep, "SHELL=", 6) == 0) SET(didvar, DID_SHELL); break; case 'T': if (strncmp(*ep, "TERM=", 5) == 0) SET(didvar, DID_TERM); break; case 'U': if (strncmp(*ep, "USER=", 5) == 0) SET(didvar, DID_USER); if (strncmp(*ep, "USERNAME=", 5) == 0) SET(didvar, DID_USERNAME); break; } sudo_putenv(*ep, FALSE, FALSE); } } didvar |= didvar << 8; /* convert DID_* to KEPT_* */ /* * Add in defaults. In -i mode these come from the runas user, * otherwise they may be from the user's environment (depends * on sudoers options). */ if (ISSET(sudo_mode, MODE_LOGIN_SHELL)) { sudo_setenv("SHELL", runas_pw->pw_shell, ISSET(didvar, DID_SHELL)); sudo_setenv("LOGNAME", runas_pw->pw_name, ISSET(didvar, DID_LOGNAME)); sudo_setenv("USER", runas_pw->pw_name, ISSET(didvar, DID_USER)); sudo_setenv("USERNAME", runas_pw->pw_name, ISSET(didvar, DID_USERNAME)); } else { if (!ISSET(didvar, DID_SHELL)) sudo_setenv("SHELL", sudo_user.pw->pw_shell, FALSE); if (!ISSET(didvar, DID_LOGNAME)) sudo_setenv("LOGNAME", user_name, FALSE); if (!ISSET(didvar, DID_USER)) sudo_setenv("USER", user_name, FALSE); if (!ISSET(didvar, DID_USERNAME)) sudo_setenv("USERNAME", user_name, FALSE); } /* If we didn't keep HOME, reset it based on target user. */ if (!ISSET(didvar, KEPT_HOME)) reset_home = TRUE; /* * Set MAIL to target user in -i mode or if MAIL is not preserved * from user's environment. */ if (ISSET(sudo_mode, MODE_LOGIN_SHELL) || !ISSET(didvar, KEPT_MAIL)) { cp = _PATH_MAILDIR; if (cp[sizeof(_PATH_MAILDIR) - 2] == '/') easprintf(&cp, "MAIL=%s%s", _PATH_MAILDIR, runas_pw->pw_name); else easprintf(&cp, "MAIL=%s/%s", _PATH_MAILDIR, runas_pw->pw_name); sudo_putenv(cp, ISSET(didvar, DID_MAIL), TRUE); } } else { /* * Copy environ entries as long as they don't match env_delete or * env_check. */ for (ep = old_envp; *ep; ep++) { int okvar; /* Skip variables with values beginning with () (bash functions) */ if ((cp = strchr(*ep, '=')) != NULL) { if (strncmp(cp, "=() ", 3) == 0) continue; } /* * First check variables against the blacklist in env_delete. * If no match there check for '%' and '/' characters. */ okvar = matches_env_delete(*ep) != TRUE; if (okvar) okvar = matches_env_check(*ep) != FALSE; if (okvar) { if (strncmp(*ep, "SUDO_PS1=", 9) == 0) ps1 = *ep + 5; else if (strncmp(*ep, "PATH=", 5) == 0) SET(didvar, DID_PATH); else if (strncmp(*ep, "TERM=", 5) == 0) SET(didvar, DID_TERM); sudo_putenv(*ep, FALSE, FALSE); } } } /* Replace the PATH envariable with a secure one? */ if (def_secure_path && !user_is_exempt()) { sudo_setenv("PATH", def_secure_path, TRUE); SET(didvar, DID_PATH); } /* * Set $USER, $LOGNAME and $USERNAME to target if "set_logname" is not * disabled. We skip this if we are running a login shell (because * they have already been set them) or sudoedit (because we want the * editor to find the user's startup files). */ if (def_set_logname && !ISSET(sudo_mode, MODE_LOGIN_SHELL|MODE_EDIT)) { if (!ISSET(didvar, KEPT_LOGNAME)) sudo_setenv("LOGNAME", runas_pw->pw_name, TRUE); if (!ISSET(didvar, KEPT_USER)) sudo_setenv("USER", runas_pw->pw_name, TRUE); if (!ISSET(didvar, KEPT_USERNAME)) sudo_setenv("USERNAME", runas_pw->pw_name, TRUE); } /* Set $HOME to target user if not preserving user's value. */ if (reset_home) sudo_setenv("HOME", runas_pw->pw_dir, TRUE); /* Provide default values for $TERM and $PATH if they are not set. */ if (!ISSET(didvar, DID_TERM)) sudo_putenv("TERM=unknown", FALSE, FALSE); if (!ISSET(didvar, DID_PATH)) sudo_setenv("PATH", _PATH_STDPATH, FALSE); /* Set PS1 if SUDO_PS1 is set. */ if (ps1 != NULL) sudo_putenv(ps1, TRUE, TRUE); /* Add the SUDO_COMMAND envariable (cmnd + args). */ if (user_args) { easprintf(&cp, "%s %s", user_cmnd, user_args); sudo_setenv("SUDO_COMMAND", cp, TRUE); efree(cp); } else { sudo_setenv("SUDO_COMMAND", user_cmnd, TRUE); } /* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */ sudo_setenv("SUDO_USER", user_name, TRUE); snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) user_uid); sudo_setenv("SUDO_UID", idbuf, TRUE); snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) user_gid); sudo_setenv("SUDO_GID", idbuf, TRUE); /* Free old environment. */ efree(old_envp); } void insert_env_vars(char * const envp[]) { char * const *ep; if (envp == NULL) return; /* Add user-specified environment variables. */ for (ep = envp; *ep != NULL; ep++) sudo_putenv(*ep, TRUE, TRUE); } /* * Validate the list of environment variables passed in on the command * line against env_delete, env_check, and env_keep. * Calls log_error() if any specified variables are not allowed. */ void validate_env_vars(char * const env_vars[]) { char * const *ep; char *eq, *bad = NULL; size_t len, blen = 0, bsize = 0; int okvar; if (env_vars == NULL) return; /* Add user-specified environment variables. */ for (ep = env_vars; *ep != NULL; ep++) { if (def_secure_path && !user_is_exempt() && strncmp(*ep, "PATH=", 5) == 0) { okvar = FALSE; } else if (def_env_reset) { okvar = matches_env_check(*ep); if (okvar == -1) okvar = matches_env_keep(*ep); } else { okvar = matches_env_delete(*ep) == FALSE; if (okvar == FALSE) okvar = matches_env_check(*ep) != FALSE; } if (okvar == FALSE) { /* Not allowed, add to error string, allocating as needed. */ if ((eq = strchr(*ep, '=')) != NULL) *eq = '\0'; len = strlen(*ep) + 2; if (blen + len >= bsize) { do { bsize += 1024; } while (blen + len >= bsize); bad = erealloc(bad, bsize); bad[blen] = '\0'; } strlcat(bad, *ep, bsize); strlcat(bad, ", ", bsize); blen += len; if (eq != NULL) *eq = '='; } } if (bad != NULL) { bad[blen - 2] = '\0'; /* remove trailing ", " */ log_error(NO_MAIL, _("sorry, you are not allowed to set the following environment variables: %s"), bad); /* NOTREACHED */ efree(bad); } } /* * Read in /etc/environment ala AIX and Linux. * Lines may be in either of three formats: * NAME=VALUE * NAME="VALUE" * NAME='VALUE' * with an optional "export" prefix so the shell can source the file. * Invalid lines, blank lines, or lines consisting solely of a comment * character are skipped. */ void read_env_file(const char *path, int overwrite) { FILE *fp; char *cp, *var, *val; size_t var_len, val_len; if ((fp = fopen(path, "r")) == NULL) return; while ((var = sudo_parseln(fp)) != NULL) { /* Skip blank or comment lines */ if (*var == '\0') continue; /* Skip optional "export " */ if (strncmp(var, "export", 6) == 0 && isspace((unsigned char) var[6])) { var += 7; while (isspace((unsigned char) *var)) { var++; } } /* Must be of the form name=["']value['"] */ for (val = var; *val != '\0' && *val != '='; val++) ; if (var == val || *val != '=') continue; var_len = (size_t)(val - var); val_len = strlen(++val); /* Strip leading and trailing single/double quotes */ if ((val[0] == '\'' || val[0] == '\"') && val[0] == val[val_len - 1]) { val[val_len - 1] = '\0'; val++; val_len -= 2; } cp = emalloc(var_len + 1 + val_len + 1); memcpy(cp, var, var_len + 1); /* includes '=' */ memcpy(cp + var_len + 1, val, val_len + 1); /* includes NUL */ sudo_putenv(cp, TRUE, overwrite); } fclose(fp); } void init_envtables(void) { struct list_member *cur; const char **p; /* Fill in the "env_delete" list. */ for (p = initial_badenv_table; *p; p++) { cur = emalloc(sizeof(struct list_member)); cur->value = estrdup(*p); cur->next = def_env_delete; def_env_delete = cur; } /* Fill in the "env_check" list. */ for (p = initial_checkenv_table; *p; p++) { cur = emalloc(sizeof(struct list_member)); cur->value = estrdup(*p); cur->next = def_env_check; def_env_check = cur; } /* Fill in the "env_keep" list. */ for (p = initial_keepenv_table; *p; p++) { cur = emalloc(sizeof(struct list_member)); cur->value = estrdup(*p); cur->next = def_env_keep; def_env_keep = cur; } }