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364 lines
8.1 KiB
364 lines
8.1 KiB
--- a/modules/pam_rhosts/pam_rhosts.c
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+++ b/modules/pam_rhosts/pam_rhosts.c
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@@ -43,6 +43,361 @@
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#include <security/pam_modutil.h>
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#include <security/pam_ext.h>
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+#ifdef __UCLIBC__
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+
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+#include <stdio.h>
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+#include <sys/stat.h>
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+
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+
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+int __check_rhosts_file = 1;
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+
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+/* Extremely paranoid file open function. */
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+static FILE *
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+iruserfopen (const char *file, uid_t okuser)
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+{
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+ struct stat st;
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+ char *cp = NULL;
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+ FILE *res = NULL;
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+
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+ /* If not a regular file, if owned by someone other than user or
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+ root, if writeable by anyone but the owner, or if hardlinked
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+ anywhere, quit. */
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+ if (lstat (file, &st))
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+ cp = "lstat failed";
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+ else if (!S_ISREG (st.st_mode))
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+ cp = "not regular file";
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+ else
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+ {
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+ res = fopen (file, "r");
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+ if (!res)
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+ cp = "cannot open";
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+ else if (fstat (fileno (res), &st) < 0)
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+ cp = "fstat failed";
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+ else if (st.st_uid && st.st_uid != okuser)
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+ cp = "bad owner";
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+ else if (st.st_mode & (S_IWGRP|S_IWOTH))
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+ cp = "writeable by other than owner";
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+ else if (st.st_nlink > 1)
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+ cp = "hard linked somewhere";
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+ }
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+
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+ /* If there were any problems, quit. */
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+ if (cp != NULL)
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+ {
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+ if (res)
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+ fclose (res);
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+ return NULL;
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+ }
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+
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+ return res;
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+}
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+
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+/*
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+ * Returns 1 for blank lines (or only comment lines) and 0 otherwise
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+ */
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+static int
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+__isempty(char *p)
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+{
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+ while (*p && isspace (*p)) {
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+ ++p;
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+ }
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+
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+ return (*p == '\0' || *p == '#') ? 1 : 0 ;
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+}
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+
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+/* Returns 1 on positive match, 0 on no match, -1 on negative match. */
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+static int
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+__icheckhost (u_int32_t raddr, char *lhost, const char *rhost)
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+{
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+ struct hostent *hp;
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+ u_int32_t laddr;
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+ int negate=1; /* Multiply return with this to get -1 instead of 1 */
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+ char **pp;
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+
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+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
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+ int save_errno;
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+ size_t buflen;
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+ char *buffer;
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+ struct hostent hostbuf;
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+ int herr;
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+#endif
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+
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+#ifdef HAVE_NETGROUP
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+ /* Check nis netgroup. */
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+ if (strncmp ("+@", lhost, 2) == 0)
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+ return innetgr (&lhost[2], rhost, NULL, NULL);
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+
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+ if (strncmp ("-@", lhost, 2) == 0)
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+ return -innetgr (&lhost[2], rhost, NULL, NULL);
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+#endif /* HAVE_NETGROUP */
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+
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+ /* -host */
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+ if (strncmp ("-", lhost,1) == 0) {
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+ negate = -1;
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+ lhost++;
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+ } else if (strcmp ("+",lhost) == 0) {
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+ return 1; /* asking for trouble, but ok.. */
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+ }
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+
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+ /* Try for raw ip address first. */
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+ if (isdigit (*lhost) && (laddr = inet_addr (lhost)) != INADDR_NONE)
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+ return negate * (! (raddr ^ laddr));
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+
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+ /* Better be a hostname. */
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+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
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+ buflen = 1024;
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+ buffer = malloc(buflen);
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+ save_errno = errno;
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+
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+ while (gethostbyname_r (lhost, &hostbuf, buffer, buflen, &hp, &herr)
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+ != 0) {
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+ free(buffer);
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+ return (0);
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+ }
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+ free(buffer);
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+ __set_errno (save_errno);
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+#else
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+ hp = gethostbyname(lhost);
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+#endif /* __UCLIBC_HAS_REENTRANT_RPC__ */
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+
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+ if (hp == NULL)
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+ return 0;
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+
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+ /* Spin through ip addresses. */
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+ for (pp = hp->h_addr_list; *pp; ++pp)
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+ if (!memcmp (&raddr, *pp, sizeof (u_int32_t)))
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+ return negate;
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+
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+ /* No match. */
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+ return (0);
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+}
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+
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+/* Returns 1 on positive match, 0 on no match, -1 on negative match. */
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+static int
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+__icheckuser (const char *luser, const char *ruser)
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+{
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+
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+ /*
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+ luser is user entry from .rhosts/hosts.equiv file
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+ ruser is user id on remote host
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+ */
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+
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+#ifdef HAVE_NETGROUP
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+ /* [-+]@netgroup */
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+ if (strncmp ("+@", luser, 2) == 0)
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+ return innetgr (&luser[2], NULL, ruser, NULL);
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+
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+ if (strncmp ("-@", luser,2) == 0)
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+ return -innetgr (&luser[2], NULL, ruser, NULL);
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+#endif /* HAVE_NETGROUP */
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+
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+ /* -user */
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+ if (strncmp ("-", luser, 1) == 0)
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+ return -(strcmp (&luser[1], ruser) == 0);
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+
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+ /* + */
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+ if (strcmp ("+", luser) == 0)
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+ return 1;
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+
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+ /* simple string match */
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+ return strcmp (ruser, luser) == 0;
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+}
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+
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+/*
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+ * Returns 0 if positive match, -1 if _not_ ok.
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+ */
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+static int
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+__ivaliduser2(FILE *hostf, u_int32_t raddr, const char *luser,
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+ const char *ruser, const char *rhost)
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+{
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+ register const char *user;
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+ register char *p;
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+ int hcheck, ucheck;
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+ char *buf = NULL;
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+ size_t bufsize = 0;
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+ int retval = -1;
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+
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+ while (getline (&buf, &bufsize, hostf) > 0) {
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+ buf[bufsize - 1] = '\0'; /* Make sure it's terminated. */
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+ p = buf;
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+
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+ /* Skip empty or comment lines */
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+ if (__isempty (p)) {
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+ continue;
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+ }
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+
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+ /* Skip lines that are too long. */
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+ if (strchr (p, '\n') == NULL) {
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+ int ch = getc_unlocked (hostf);
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+
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+ while (ch != '\n' && ch != EOF)
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+ ch = getc_unlocked (hostf);
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+ continue;
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+ }
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+
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+ for (;*p && !isspace(*p); ++p) {
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+ *p = tolower (*p);
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+ }
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+
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+ /* Next we want to find the permitted name for the remote user. */
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+ if (*p == ' ' || *p == '\t') {
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+ /* <nul> terminate hostname and skip spaces */
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+ for (*p++='\0'; *p && isspace (*p); ++p);
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+
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+ user = p; /* this is the user's name */
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+ while (*p && !isspace (*p))
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+ ++p; /* find end of user's name */
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+ } else
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+ user = p;
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+
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+ *p = '\0'; /* <nul> terminate username (+host?) */
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+
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+ /* buf -> host(?) ; user -> username(?) */
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+
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+ /* First check host part */
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+ hcheck = __icheckhost (raddr, buf, rhost);
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+
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+ if (hcheck < 0)
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+ break;
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+
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+ if (hcheck) {
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+ /* Then check user part */
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+ if (! (*user))
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+ user = luser;
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+
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+ ucheck = __icheckuser (user, ruser);
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+
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+ /* Positive 'host user' match? */
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+ if (ucheck > 0) {
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+ retval = 0;
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+ break;
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+ }
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+
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+ /* Negative 'host -user' match? */
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+ if (ucheck < 0)
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+ break;
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+
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+ /* Neither, go on looking for match */
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+ }
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+ }
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+
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+ free (buf);
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+
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+ return retval;
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+}
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+
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+static int
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+iruserok2 (u_int32_t raddr, int superuser, const char *ruser, const char *luser,
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+ const char *rhost)
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+{
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+ FILE *hostf = NULL;
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+ int isbad = -1;
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+
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+ if (!superuser)
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+ hostf = iruserfopen (_PATH_HEQUIV, 0);
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+
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+ if (hostf) {
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+ isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
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+ fclose (hostf);
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+
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+ if (!isbad)
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+ return 0;
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+ }
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+
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+ if (__check_rhosts_file || superuser) {
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+ char *pbuf;
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+ struct passwd *pwd;
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+ size_t dirlen;
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+ uid_t uid;
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+
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+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
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+ size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX);
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+ struct passwd pwdbuf;
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+ char *buffer = stack_heap_alloc(buflen);
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+
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+ if (getpwnam_r (luser, &pwdbuf, buffer,
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+ buflen, &pwd) != 0 || pwd == NULL)
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+ {
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+ stack_heap_free(buffer);
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+ return -1;
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+ }
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+ stack_heap_free(buffer);
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+#else
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+ if ((pwd = getpwnam(luser)) == NULL)
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+ return -1;
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+#endif
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+
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+ dirlen = strlen (pwd->pw_dir);
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+ pbuf = malloc (dirlen + sizeof "/.rhosts");
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+ strcpy (pbuf, pwd->pw_dir);
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+ strcat (pbuf, "/.rhosts");
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+
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+ /* Change effective uid while reading .rhosts. If root and
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+ reading an NFS mounted file system, can't read files that
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+ are protected read/write owner only. */
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+ uid = geteuid ();
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+ seteuid (pwd->pw_uid);
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+ hostf = iruserfopen (pbuf, pwd->pw_uid);
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+ free(pbuf);
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+
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+ if (hostf != NULL) {
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+ isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
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+ fclose (hostf);
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+ }
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+
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+ seteuid (uid);
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+ return isbad;
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+ }
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+ return -1;
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+}
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+
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+int ruserok(const char *rhost, int superuser, const char *ruser,
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+ const char *luser)
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+{
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+ struct hostent *hp;
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+ u_int32_t addr;
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+ char **ap;
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+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
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+ size_t buflen;
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+ char *buffer;
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+ int herr;
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+ struct hostent hostbuf;
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+#endif
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+
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+#ifdef __UCLIBC_HAS_REENTRANT_RPC__
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+ buflen = 1024;
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+ buffer = stack_heap_alloc(buflen);
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+
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+ while (gethostbyname_r (rhost, &hostbuf, buffer,
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+ buflen, &hp, &herr) != 0 || hp == NULL)
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+ {
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+ if (herr != NETDB_INTERNAL || errno != ERANGE) {
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+ stack_heap_free(buffer);
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+ return -1;
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+ } else
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+ {
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+ /* Enlarge the buffer. */
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+ buflen *= 2;
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+ stack_heap_free(buffer);
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+ buffer = stack_heap_alloc(buflen);
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+ }
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+ }
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+ stack_heap_free(buffer);
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+#else
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+ if ((hp = gethostbyname(rhost)) == NULL) {
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+ return -1;
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+ }
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+#endif
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+ for (ap = hp->h_addr_list; *ap; ++ap) {
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+ memmove(&addr, *ap, sizeof(addr));
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+ if (iruserok2(addr, superuser, ruser, luser, rhost) == 0)
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+ return 0;
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+ }
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+ return -1;
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+}
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+
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+#endif /* __UCLIBC__ */
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+
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PAM_EXTERN
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int pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc,
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const char **argv)
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