X-Git-Url: http://www.average.org/gitweb/?p=pam_pcsc_cr.git;a=blobdiff_plain;f=authfile.c;h=bb2d593deefa60a01c331d2adc1557d5e6820e19;hp=abf31fb8f91ff665823e67395fe9eb26043a078c;hb=2b714d273b08b945ef677e0fbbf2c8d3d4437980;hpb=54f191d82623f7bc8468322a0aa044002584827d

diff --git a/authfile.c b/authfile.c
index abf31fb..bb2d593 100644
--- a/authfile.c
+++ b/authfile.c
@@ -1,15 +1,40 @@
+/*
+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>
 #include <unistd.h>
 #include <errno.h>
 #include <alloca.h>
+#include "base64.h"
 #include "authobj.h"
 #include "authfile.h"
 
@@ -26,9 +51,9 @@
  * 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 +61,7 @@ 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 +75,15 @@ 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 +135,9 @@ 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 +157,11 @@ 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)) {
@@ -149,20 +175,10 @@ struct _auth_obj authfile(const char *tokenid,
 	if (ret.err) return ret;
 
 	if (w.hablob) {
-		int hlen = strlen(w.hablob);
-		if (hlen % 32 != 0) {
-			ret.err = "error: auth string has wrong length";
-		} else if (hlen !=
-				strspn(w.hablob, "0123456789abcdefABCDEF")) {
-			ret.err = "error: auth string not hexadecimal";
-		} else {
-			int i;
-
-			blobsize = hlen/2;
-			ablob = alloca(blobsize);
-			for (i = 0; i < blobsize; i++)
-				sscanf(&w.hablob[i*2], "%2hhx", &ablob[i]);
-		}
+		blobsize = strlen(w.hablob)*3/4;
+		ablob = alloca(blobsize);
+		if (b64_decode(w.hablob, ablob, &blobsize))
+			ret.err = "error: undecodeable auth string";
 	}
 	if (ret.err) return ret;
 
@@ -187,17 +203,20 @@ struct _auth_obj authfile(const char *tokenid,
 	}
 
 	oldmask = umask(077);
-	if ((fp = fopen(fn, "w"))) {
-		int i;
+	if ((fp = fopen(nfn, "w"))) {
+		int bsize = ((ao.datasize-1)/3+1)*4+1;
+		char *b64 = alloca(bsize);
 
-		if (fprintf(fp, "%s:%s:%s:", tokenid?tokenid:w.tokenid,
-				userid?userid:w.userid, newnonce) < 0) {
-			ret.err = strerror(errno);
-		} else for (i = 0; i < ao.datasize; i++)
-		    if (fprintf(fp, "%02x", ao.data[i]) < 0) {
+		if (b64_encode(ao.data, ao.datasize, b64, &bsize)) {
+			ret.err = "error: could not encode auth string";
+		} else if (fprintf(fp, "%s:%s:%s:%s\n",
+				tokenid?tokenid:w.tokenid,
+				userid?userid:w.userid, newnonce, b64) < 0) {
 			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 +224,14 @@ 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 +245,9 @@ 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;
 				}
 			}
 		}