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-rw-r--r--modules/pam_group/pam_group.c842
1 files changed, 842 insertions, 0 deletions
diff --git a/modules/pam_group/pam_group.c b/modules/pam_group/pam_group.c
new file mode 100644
index 00000000..4a54da14
--- /dev/null
+++ b/modules/pam_group/pam_group.c
@@ -0,0 +1,842 @@
+/* pam_group module */
+
+/*
+ * Written by Andrew Morgan <morgan@linux.kernel.org> 1996/7/6
+ */
+
+#include "config.h"
+
+#include <sys/file.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <time.h>
+#include <syslog.h>
+#include <string.h>
+
+#include <grp.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <netdb.h>
+
+#define PAM_GROUP_BUFLEN 1000
+#define FIELD_SEPARATOR ';' /* this is new as of .02 */
+
+#ifndef TRUE
+# define TRUE 1
+#endif
+#ifndef FALSE
+# define FALSE 0
+#endif
+
+typedef enum { AND, OR } operator;
+
+/*
+ * here, we make definitions for the externally accessible functions
+ * in this file (these definitions are required for static modules
+ * but strongly encouraged generally) they are used to instruct the
+ * modules include file to define their prototypes.
+ */
+
+#define PAM_SM_AUTH
+
+#include <security/pam_modules.h>
+#include <security/_pam_macros.h>
+#include <security/pam_modutil.h>
+#include <security/pam_ext.h>
+
+/* --- static functions for checking whether the user should be let in --- */
+
+static void shift_bytes(char *mem, int from, int by)
+{
+ while (by-- > 0) {
+ *mem = mem[from];
+ ++mem;
+ }
+}
+
+/* This function should initially be called with buf = NULL. If
+ * an error occurs, the file descriptor is closed. Subsequent
+ * calls with a closed descriptor will cause buf to be deallocated.
+ * Therefore, always check buf after calling this to see if an error
+ * occurred.
+ */
+static int
+read_field (const pam_handle_t *pamh, int fd, char **buf, int *from, int *to)
+{
+ /* is buf set ? */
+
+ if (! *buf) {
+ *buf = (char *) malloc(PAM_GROUP_BUFLEN);
+ if (! *buf) {
+ pam_syslog(pamh, LOG_ERR, "out of memory");
+ return -1;
+ }
+ *from = *to = 0;
+ fd = open(PAM_GROUP_CONF, O_RDONLY);
+ }
+
+ /* do we have a file open ? return error */
+
+ if (fd < 0 && *to <= 0) {
+ pam_syslog(pamh, LOG_ERR, "%s not opened", PAM_GROUP_CONF);
+ memset(*buf, 0, PAM_GROUP_BUFLEN);
+ _pam_drop(*buf);
+ return -1;
+ }
+
+ /* check if there was a newline last time */
+
+ if ((*to > *from) && (*to > 0)
+ && ((*buf)[*from] == '\0')) { /* previous line ended */
+ (*from)++;
+ (*buf)[0] = '\0';
+ return fd;
+ }
+
+ /* ready for more data: first shift the buffer's remaining data */
+
+ *to -= *from;
+ shift_bytes(*buf, *from, *to);
+ *from = 0;
+ (*buf)[*to] = '\0';
+
+ while (fd >= 0 && *to < PAM_GROUP_BUFLEN) {
+ int i;
+
+ /* now try to fill the remainder of the buffer */
+
+ i = read(fd, *to + *buf, PAM_GROUP_BUFLEN - *to);
+ if (i < 0) {
+ pam_syslog(pamh, LOG_ERR, "error reading %s: %m", PAM_GROUP_CONF);
+ close(fd);
+ return -1;
+ } else if (!i) {
+ close(fd);
+ fd = -1; /* end of file reached */
+ } else
+ *to += i;
+
+ /*
+ * contract the buffer. Delete any comments, and replace all
+ * multiple spaces with single commas
+ */
+
+ i = 0;
+#ifdef DEBUG_DUMP
+ D(("buffer=<%s>",*buf));
+#endif
+ while (i < *to) {
+ if ((*buf)[i] == ',') {
+ int j;
+
+ for (j=++i; j<*to && (*buf)[j] == ','; ++j);
+ if (j!=i) {
+ shift_bytes(i + (*buf), j-i, (*to) - j);
+ *to -= j-i;
+ }
+ }
+ switch ((*buf)[i]) {
+ int j, c;
+ case '#':
+ c = 0;
+ for (j=i; j < *to && (c = (*buf)[j]) != '\n'; ++j);
+ if (j >= *to) {
+ (*buf)[*to = ++i] = '\0';
+ } else if (c == '\n') {
+ shift_bytes(i + (*buf), j-i, (*to) - j);
+ *to -= j-i;
+ ++i;
+ } else {
+ pam_syslog(pamh, LOG_CRIT,
+ "internal error in file %s at line %d",
+ __FILE__, __LINE__);
+ close(fd);
+ return -1;
+ }
+ break;
+ case '\\':
+ if ((*buf)[i+1] == '\n') {
+ shift_bytes(i + *buf, 2, *to - (i+2));
+ *to -= 2;
+ } else {
+ ++i; /* we don't escape non-newline characters */
+ }
+ break;
+ case '!':
+ case ' ':
+ case '\t':
+ if ((*buf)[i] != '!')
+ (*buf)[i] = ',';
+ /* delete any trailing spaces */
+ for (j=++i; j < *to && ( (c = (*buf)[j]) == ' '
+ || c == '\t' ); ++j);
+ shift_bytes(i + *buf, j-i, (*to)-j );
+ *to -= j-i;
+ break;
+ default:
+ ++i;
+ }
+ }
+ }
+
+ (*buf)[*to] = '\0';
+
+ /* now return the next field (set the from/to markers) */
+ {
+ int i;
+
+ for (i=0; i<*to; ++i) {
+ switch ((*buf)[i]) {
+ case '#':
+ case '\n': /* end of the line/file */
+ (*buf)[i] = '\0';
+ *from = i;
+ return fd;
+ case FIELD_SEPARATOR: /* end of the field */
+ (*buf)[i] = '\0';
+ *from = ++i;
+ return fd;
+ }
+ }
+ *from = i;
+ (*buf)[*from] = '\0';
+ }
+
+ if (*to <= 0) {
+ D(("[end of text]"));
+ *buf = NULL;
+ }
+ return fd;
+}
+
+/* read a member from a field */
+
+static int logic_member(const char *string, int *at)
+{
+ int c,to;
+ int done=0;
+ int token=0;
+
+ to=*at;
+ do {
+ c = string[to++];
+
+ switch (c) {
+
+ case '\0':
+ --to;
+ done = 1;
+ break;
+
+ case '&':
+ case '|':
+ case '!':
+ if (token) {
+ --to;
+ }
+ done = 1;
+ break;
+
+ default:
+ if (isalpha(c) || c == '*' || isdigit(c) || c == '_'
+ || c == '-' || c == '.' || c == '/' || c == ':') {
+ token = 1;
+ } else if (token) {
+ --to;
+ done = 1;
+ } else {
+ ++*at;
+ }
+ }
+ } while (!done);
+
+ return to - *at;
+}
+
+typedef enum { VAL, OP } expect;
+
+static int
+logic_field (const pam_handle_t *pamh, const void *me,
+ const char *x, int rule,
+ int (*agrees)(const pam_handle_t *pamh, const void *,
+ const char *, int, int))
+{
+ int left=FALSE, right, not=FALSE;
+ operator oper=OR;
+ int at=0, l;
+ expect next=VAL;
+
+ while ((l = logic_member(x,&at))) {
+ int c = x[at];
+
+ if (next == VAL) {
+ if (c == '!')
+ not = !not;
+ else if (isalpha(c) || c == '*' || isdigit(c) || c == '_'
+ || c == '-' || c == '.' || c == '/' || c == ':') {
+ right = not ^ agrees(pamh, me, x+at, l, rule);
+ if (oper == AND)
+ left &= right;
+ else
+ left |= right;
+ next = OP;
+ } else {
+ pam_syslog(pamh, LOG_ERR,
+ "garbled syntax; expected name (rule #%d)",
+ rule);
+ return FALSE;
+ }
+ } else { /* OP */
+ switch (c) {
+ case '&':
+ oper = AND;
+ break;
+ case '|':
+ oper = OR;
+ break;
+ default:
+ pam_syslog(pamh, LOG_ERR,
+ "garbled syntax; expected & or | (rule #%d)",
+ rule);
+ D(("%c at %d",c,at));
+ return FALSE;
+ }
+ next = VAL;
+ }
+ at += l;
+ }
+
+ return left;
+}
+
+static int
+is_same (const pam_handle_t *pamh UNUSED,
+ const void *A, const char *b, int len, int rule UNUSED)
+{
+ int i;
+ const char *a;
+
+ a = A;
+ for (i=0; len > 0; ++i, --len) {
+ if (b[i] != a[i]) {
+ if (b[i++] == '*') {
+ return (!--len || !strncmp(b+i,a+strlen(a)-len,len));
+ } else
+ return FALSE;
+ }
+ }
+
+ /* Ok, we know that b is a substring from A and does not contain
+ wildcards, but now the length of both strings must be the same,
+ too. */
+ if (strlen (a) != strlen(b))
+ return FALSE;
+
+ return ( !len );
+}
+
+typedef struct {
+ int day; /* array of 7 bits, one set for today */
+ int minute; /* integer, hour*100+minute for now */
+} TIME;
+
+static struct day {
+ const char *d;
+ int bit;
+} const days[11] = {
+ { "su", 01 },
+ { "mo", 02 },
+ { "tu", 04 },
+ { "we", 010 },
+ { "th", 020 },
+ { "fr", 040 },
+ { "sa", 0100 },
+ { "wk", 076 },
+ { "wd", 0101 },
+ { "al", 0177 },
+ { NULL, 0 }
+};
+
+static TIME time_now(void)
+{
+ struct tm *local;
+ time_t the_time;
+ TIME this;
+
+ the_time = time((time_t *)0); /* get the current time */
+ local = localtime(&the_time);
+ this.day = days[local->tm_wday].bit;
+ this.minute = local->tm_hour*100 + local->tm_min;
+
+ D(("day: 0%o, time: %.4d", this.day, this.minute));
+ return this;
+}
+
+/* take the current date and see if the range "date" passes it */
+static int
+check_time (const pam_handle_t *pamh, const void *AT,
+ const char *times, int len, int rule)
+{
+ int not,pass;
+ int marked_day, time_start, time_end;
+ const TIME *at;
+ int i,j=0;
+
+ at = AT;
+ D(("checking: 0%o/%.4d vs. %s", at->day, at->minute, times));
+
+ if (times == NULL) {
+ /* this should not happen */
+ pam_syslog(pamh, LOG_CRIT, "internal error in file %s at line %d",
+ __FILE__, __LINE__);
+ return FALSE;
+ }
+
+ if (times[j] == '!') {
+ ++j;
+ not = TRUE;
+ } else {
+ not = FALSE;
+ }
+
+ for (marked_day = 0; len > 0 && isalpha(times[j]); --len) {
+ int this_day=-1;
+
+ D(("%c%c ?", times[j], times[j+1]));
+ for (i=0; days[i].d != NULL; ++i) {
+ if (tolower(times[j]) == days[i].d[0]
+ && tolower(times[j+1]) == days[i].d[1] ) {
+ this_day = days[i].bit;
+ break;
+ }
+ }
+ j += 2;
+ if (this_day == -1) {
+ pam_syslog(pamh, LOG_ERR, "bad day specified (rule #%d)", rule);
+ return FALSE;
+ }
+ marked_day ^= this_day;
+ }
+ if (marked_day == 0) {
+ pam_syslog(pamh, LOG_ERR, "no day specified");
+ return FALSE;
+ }
+ D(("day range = 0%o", marked_day));
+
+ time_start = 0;
+ for (i=0; len > 0 && i < 4 && isdigit(times[i+j]); ++i, --len) {
+ time_start *= 10;
+ time_start += times[i+j]-'0'; /* is this portable? */
+ }
+ j += i;
+
+ if (times[j] == '-') {
+ time_end = 0;
+ for (i=1; len > 0 && i < 5 && isdigit(times[i+j]); ++i, --len) {
+ time_end *= 10;
+ time_end += times[i+j]-'0'; /* is this portable? */
+ }
+ j += i;
+ } else
+ time_end = -1;
+
+ D(("i=%d, time_end=%d, times[j]='%c'", i, time_end, times[j]));
+ if (i != 5 || time_end == -1) {
+ pam_syslog(pamh, LOG_ERR, "no/bad times specified (rule #%d)", rule);
+ return TRUE;
+ }
+ D(("times(%d to %d)", time_start,time_end));
+ D(("marked_day = 0%o", marked_day));
+
+ /* compare with the actual time now */
+
+ pass = FALSE;
+ if (time_start < time_end) { /* start < end ? --> same day */
+ if ((at->day & marked_day) && (at->minute >= time_start)
+ && (at->minute < time_end)) {
+ D(("time is listed"));
+ pass = TRUE;
+ }
+ } else { /* spans two days */
+ if ((at->day & marked_day) && (at->minute >= time_start)) {
+ D(("caught on first day"));
+ pass = TRUE;
+ } else {
+ marked_day <<= 1;
+ marked_day |= (marked_day & 0200) ? 1:0;
+ D(("next day = 0%o", marked_day));
+ if ((at->day & marked_day) && (at->minute <= time_end)) {
+ D(("caught on second day"));
+ pass = TRUE;
+ }
+ }
+ }
+
+ return (not ^ pass);
+}
+
+static int find_member(const char *string, int *at)
+{
+ int c,to;
+ int done=0;
+ int token=0;
+
+ to=*at;
+ do {
+ c = string[to++];
+
+ switch (c) {
+
+ case '\0':
+ --to;
+ done = 1;
+ break;
+
+ case '&':
+ case '|':
+ case '!':
+ if (token) {
+ --to;
+ }
+ done = 1;
+ break;
+
+ default:
+ if (isalpha(c) || isdigit(c) || c == '_' || c == '*'
+ || c == '-') {
+ token = 1;
+ } else if (token) {
+ --to;
+ done = 1;
+ } else {
+ ++*at;
+ }
+ }
+ } while (!done);
+
+ return to - *at;
+}
+
+#define GROUP_BLK 10
+#define blk_size(len) (((len-1 + GROUP_BLK)/GROUP_BLK)*GROUP_BLK)
+
+static int mkgrplist(pam_handle_t *pamh, char *buf, gid_t **list, int len)
+{
+ int l,at=0;
+ int blks;
+
+ blks = blk_size(len);
+ D(("cf. blks=%d and len=%d", blks,len));
+
+ while ((l = find_member(buf,&at))) {
+ int edge;
+
+ if (len >= blks) {
+ gid_t *tmp;
+
+ D(("allocating new block"));
+ tmp = (gid_t *) realloc((*list)
+ , sizeof(gid_t) * (blks += GROUP_BLK));
+ if (tmp != NULL) {
+ (*list) = tmp;
+ } else {
+ pam_syslog(pamh, LOG_ERR, "out of memory for group list");
+ free(*list);
+ (*list) = NULL;
+ return -1;
+ }
+ }
+
+ /* '\0' terminate the entry */
+
+ edge = (buf[at+l]) ? 1:0;
+ buf[at+l] = '\0';
+ D(("found group: %s",buf+at));
+
+ /* this is where we convert a group name to a gid_t */
+ {
+ const struct group *grp;
+
+ grp = pam_modutil_getgrnam(pamh, buf+at);
+ if (grp == NULL) {
+ pam_syslog(pamh, LOG_ERR, "bad group: %s", buf+at);
+ } else {
+ D(("group %s exists", buf+at));
+ (*list)[len++] = grp->gr_gid;
+ }
+ }
+
+ /* next entry along */
+
+ at += l + edge;
+ }
+ D(("returning with [%p/len=%d]->%p",list,len,*list));
+ return len;
+}
+
+
+static int check_account(pam_handle_t *pamh, const char *service,
+ const char *tty, const char *user)
+{
+ int from=0,to=0,fd=-1;
+ char *buffer=NULL;
+ int count=0;
+ TIME here_and_now;
+ int retval=PAM_SUCCESS;
+ gid_t *grps;
+ int no_grps;
+
+ /*
+ * first we get the current list of groups - the application
+ * will have previously done an initgroups(), or equivalent.
+ */
+
+ D(("counting supplementary groups"));
+ no_grps = getgroups(0, NULL); /* find the current number of groups */
+ if (no_grps > 0) {
+ grps = calloc( blk_size(no_grps) , sizeof(gid_t) );
+ D(("copying current list into grps [%d big]",blk_size(no_grps)));
+ if (getgroups(no_grps, grps) < 0) {
+ D(("getgroups call failed"));
+ no_grps = 0;
+ grps = NULL;
+ }
+#ifdef DEBUG
+ {
+ int z;
+ for (z=0; z<no_grps; ++z) {
+ D(("gid[%d]=%d", z, grps[z]));
+ }
+ }
+#endif
+ } else {
+ D(("no supplementary groups known"));
+ no_grps = 0;
+ grps = NULL;
+ }
+
+ here_and_now = time_now(); /* find current time */
+
+ /* parse the rules in the configuration file */
+ do {
+ int good=TRUE;
+
+ /* here we get the service name field */
+
+ fd = read_field(pamh,fd,&buffer,&from,&to);
+ if (!buffer || !buffer[0]) {
+ /* empty line .. ? */
+ continue;
+ }
+ ++count;
+ D(("working on rule #%d",count));
+
+ good = logic_field(pamh,service, buffer, count, is_same);
+ D(("with service: %s", good ? "passes":"fails" ));
+
+ /* here we get the terminal name field */
+
+ fd = read_field(pamh,fd,&buffer,&from,&to);
+ if (!buffer || !buffer[0]) {
+ pam_syslog(pamh, LOG_ERR,
+ "%s: no tty entry #%d", PAM_GROUP_CONF, count);
+ continue;
+ }
+ good &= logic_field(pamh,tty, buffer, count, is_same);
+ D(("with tty: %s", good ? "passes":"fails" ));
+
+ /* here we get the username field */
+
+ fd = read_field(pamh,fd,&buffer,&from,&to);
+ if (!buffer || !buffer[0]) {
+ pam_syslog(pamh, LOG_ERR,
+ "%s: no user entry #%d", PAM_GROUP_CONF, count);
+ continue;
+ }
+ /* If buffer starts with @, we are using netgroups */
+ if (buffer[0] == '@')
+ good &= innetgr (&buffer[1], NULL, user, NULL);
+ else
+ good &= logic_field(pamh,user, buffer, count, is_same);
+ D(("with user: %s", good ? "passes":"fails" ));
+
+ /* here we get the time field */
+
+ fd = read_field(pamh,fd,&buffer,&from,&to);
+ if (!buffer || !buffer[0]) {
+ pam_syslog(pamh, LOG_ERR,
+ "%s: no time entry #%d", PAM_GROUP_CONF, count);
+ continue;
+ }
+
+ good &= logic_field(pamh,&here_and_now, buffer, count, check_time);
+ D(("with time: %s", good ? "passes":"fails" ));
+
+ fd = read_field(pamh,fd,&buffer,&from,&to);
+ if (!buffer || !buffer[0]) {
+ pam_syslog(pamh, LOG_ERR,
+ "%s: no listed groups for rule #%d", PAM_GROUP_CONF, count);
+ continue;
+ }
+
+ /*
+ * so we have a list of groups, we need to turn it into
+ * something to send to setgroups(2)
+ */
+
+ if (good) {
+ D(("adding %s to gid list", buffer));
+ good = mkgrplist(pamh, buffer, &grps, no_grps);
+ if (good < 0) {
+ no_grps = 0;
+ } else {
+ no_grps = good;
+ }
+ }
+
+ /* check the line is terminated correctly */
+
+ fd = read_field(pamh,fd,&buffer,&from,&to);
+ if (buffer && buffer[0]) {
+ pam_syslog(pamh, LOG_ERR,
+ "%s: poorly terminated rule #%d", PAM_GROUP_CONF, count);
+ }
+
+ if (good > 0) {
+ D(("rule #%d passed, added %d groups", count, good));
+ } else if (good < 0) {
+ retval = PAM_BUF_ERR;
+ } else {
+ D(("rule #%d failed", count));
+ }
+
+ } while (buffer);
+
+ /* now set the groups for the user */
+
+ if (no_grps > 0) {
+#ifdef DEBUG
+ int err;
+#endif
+ D(("trying to set %d groups", no_grps));
+#ifdef DEBUG
+ for (err=0; err<no_grps; ++err) {
+ D(("gid[%d]=%d", err, grps[err]));
+ }
+#endif
+ if (setgroups(no_grps, grps) != 0) {
+ D(("but couldn't set groups %m"));
+ pam_syslog(pamh, LOG_ERR,
+ "unable to set the group membership for user: %m");
+ retval = PAM_CRED_ERR;
+ }
+ }
+
+ if (grps) { /* tidy up */
+ memset(grps, 0, sizeof(gid_t) * blk_size(no_grps));
+ _pam_drop(grps);
+ no_grps = 0;
+ }
+
+ return retval;
+}
+
+/* --- public authentication management functions --- */
+
+PAM_EXTERN int
+pam_sm_authenticate (pam_handle_t *pamh UNUSED, int flags UNUSED,
+ int argc UNUSED, const char **argv UNUSED)
+{
+ return PAM_IGNORE;
+}
+
+PAM_EXTERN int
+pam_sm_setcred (pam_handle_t *pamh, int flags,
+ int argc UNUSED, const char **argv UNUSED)
+{
+ const void *service=NULL, *void_tty=NULL;
+ const char *user=NULL;
+ const char *tty;
+ int retval;
+ unsigned setting;
+
+ /* only interested in establishing credentials */
+
+ setting = flags;
+ if (!(setting & (PAM_ESTABLISH_CRED | PAM_REINITIALIZE_CRED))) {
+ D(("ignoring call - not for establishing credentials"));
+ return PAM_SUCCESS; /* don't fail because of this */
+ }
+
+ /* set service name */
+
+ if (pam_get_item(pamh, PAM_SERVICE, &service)
+ != PAM_SUCCESS || service == NULL) {
+ pam_syslog(pamh, LOG_ERR, "cannot find the current service name");
+ return PAM_ABORT;
+ }
+
+ /* set username */
+
+ if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL
+ || *user == '\0') {
+ pam_syslog(pamh, LOG_ERR, "cannot determine the user's name");
+ return PAM_USER_UNKNOWN;
+ }
+
+ /* set tty name */
+
+ if (pam_get_item(pamh, PAM_TTY, &void_tty) != PAM_SUCCESS
+ || void_tty == NULL) {
+ D(("PAM_TTY not set, probing stdin"));
+ tty = ttyname(STDIN_FILENO);
+ if (tty == NULL) {
+ tty = "";
+ }
+ if (pam_set_item(pamh, PAM_TTY, tty) != PAM_SUCCESS) {
+ pam_syslog(pamh, LOG_ERR, "couldn't set tty name");
+ return PAM_ABORT;
+ }
+ }
+ else
+ tty = (const char *) void_tty;
+
+ if (tty[0] == '/') { /* full path */
+ const char *t;
+ tty++;
+ if ((t = strchr(tty, '/')) != NULL) {
+ tty = t + 1;
+ }
+ }
+
+ /* good, now we have the service name, the user and the terminal name */
+
+ D(("service=%s", service));
+ D(("user=%s", user));
+ D(("tty=%s", tty));
+
+ retval = check_account(pamh,service,tty,user); /* get groups */
+
+ return retval;
+}
+
+/* end of module definition */
+
+#ifdef PAM_STATIC
+
+/* static module data */
+
+struct pam_module _pam_group_modstruct = {
+ "pam_group",
+ pam_sm_authenticate,
+ pam_sm_setcred,
+ NULL,
+ NULL,
+ NULL,
+ NULL
+};
+#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 21:21:09 +0000