include base64 encoder

[pam_pcsc_cr.git] / authfile.c

diff --git a/authfile.c b/authfile.c
index abf31fb8f91ff665823e67395fe9eb26043a078c..c43b2d655b0a6f2ee1d7640b648b0cc0cf9f35c7 100644 (file)
--- a/authfile.c
+++ b/authfile.c
@@ -1,9 +1,33 @@
+/*
+Copyright (c) 2013 Eugene Crosser
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must
+    not claim that you wrote the original software. If you use this
+    software in a product, an acknowledgment in the product documentation
+    would be appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must
+    not be misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.
+*/
+
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <pwd.h>
+#include <time.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -26,9 +50,9 @@
  * string.
  */
 
-static char *template = "~/.pam_cr/auth";
+static const char *template = "~/.pam_cr/auth";
 
-void authfile_template(char *str)
+void authfile_template(const char *str)
 {
        template = str;
 }
@@ -36,7 +60,7 @@ void authfile_template(char *str)
 static int path_size(const char *tokenid, const char *userid)
 {
        const char *usub;
-       char *p, *q;
+       const char *p, *q;
        struct passwd *pw;
 
        if ((p = strchr(template, '~')) != strrchr(template, '~')) return 0;
@@ -50,14 +74,15 @@ static int path_size(const char *tokenid, const char *userid)
        } else {
                usub = userid;
        }
-       return strlen(template) + p?strlen(usub):0 + q?strlen(tokenid):0 + 1;
+       return strlen(template)+(p?strlen(usub):0)+(q?strlen(tokenid):0)+1;
 }
 
 static void
 make_path(char * const path, const char *tokenid, const char *userid)
 {
        const char *usub;
-       char *p, *q;
+       const char *p;
+       char *q;
        struct passwd *pw;
 
        path[0] = '\0';
@@ -109,8 +134,9 @@ struct _auth_obj authfile(const char *tokenid,
        struct _auth_obj ret = {0};
        mode_t oldmask;
        FILE *fp = NULL;
-       char *fn;
+       char *fn, *nfn;
        int fnl;
+       struct stat st = {0};
        char *buf = NULL;
        struct {
                const char *tokenid;
@@ -130,12 +156,11 @@ struct _auth_obj authfile(const char *tokenid,
        }
        fn = alloca(fnl);
        make_path(fn, tokenid, userid);
+       nfn = alloca(fnl+32);
+       snprintf(nfn, fnl+32, "%s.%d.%ld", fn, (int)getpid(), (long)time(NULL));
        fp = fopen(fn, "r");
        if (fp) {
-               struct stat st;
-               int fd = fileno(fp);
-
-               if (fstat(fd, &st)) st.st_size = 2047;
+               if (fstat(fileno(fp), &st)) st.st_size = 2047;
                if (st.st_size > 2047) st.st_size = 2047;
                buf = alloca(st.st_size + 1);
                if (!fgets(buf, st.st_size + 1, fp)) {
@@ -187,7 +212,7 @@ struct _auth_obj authfile(const char *tokenid,
        }
 
        oldmask = umask(077);
-       if ((fp = fopen(fn, "w"))) {
+       if ((fp = fopen(nfn, "w"))) {
                int i;
 
                if (fprintf(fp, "%s:%s:%s:", tokenid?tokenid:w.tokenid,
@@ -198,6 +223,9 @@ struct _auth_obj authfile(const char *tokenid,
                        ret.err = strerror(errno);
                }
                fprintf(fp, "\n");
+               if (st.st_uid || st.st_gid) {
+                       if (fchown(fileno(fp), st.st_uid, st.st_gid)) /*ign*/;
+               }
                if (fclose(fp) < 0) {
                        ret.err = strerror(errno);
                }
@@ -205,9 +233,14 @@ struct _auth_obj authfile(const char *tokenid,
                ret.err = strerror(errno);
        }
        (void)umask(oldmask);
+       if (ret.err) {
+               unlink(nfn); /* may not exist but no matter */
+       } else if (rename(nfn, fn)) {
+               ret.err = strerror(errno);
+       }
 
        if (!ret.err) {
-               int bufsize = (w.userid?strlen(w.userid)+1:0) + ao.paylsize;
+               int bufsize = (w.userid?strlen(w.userid)+1:0) + ao.paylsize + 1;
                if (bufsize) {
                        if ((ret.buffer = malloc(bufsize)) == NULL) {
                                ret.err = "authfile malloc failed";
@@ -221,8 +254,9 @@ struct _auth_obj authfile(const char *tokenid,
                                }
                                if (ao.payload) {
                                        memcpy(p, ao.payload, ao.paylsize);
+                                       p[ao.paylsize] = '\0';
                                        ret.payload = p;
-                                       ret.paylsize = ao.paylsize;
+                                       ret.paylsize = ao.paylsize+1;
                                }
                        }
                }