X-Git-Url: http://www.average.org/gitweb/?p=pam_pcsc_cr.git;a=blobdiff_plain;f=authfile.c;h=93157a4e1a9a8460c46a6fc609e1b18a62fd5885;hp=8c023d1e8e3a8a0ddd422082d96c5288e69dabec;hb=eaaae6374b2e8949fd2d13b45e3b9cbdb95f5299;hpb=d428f25cb05d2def10d08cd0e34fe5fe4d4b45fc

diff --git a/authfile.c b/authfile.c
index 8c023d1..93157a4 100644
--- a/authfile.c
+++ b/authfile.c
@@ -1,3 +1,26 @@
+/*
+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
@@ -11,6 +34,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <alloca.h>
+#include "base64.h"
 #include "authobj.h"
 #include "authfile.h"
 
@@ -18,65 +42,48 @@
  * Template string may contain zero or one '~' and zero or one '?'.
  * '~' at the beginning of the template string is substituted with
  * the home directory of the userid. In any other position it is
- * substituted with the userid itself. '?' is substituted with the
- * tokenid. There is no way to make the resulting path contain '~'
- * or '?'. If there is more than one '~' or '?', or if the '~' is
- * at the beginning but userid does not resolve via getpwnam, or
- * the character to substitute is present but the argument is NULL,
- * NULL is returned. Otherwise, malloc()'ed area containg the path
- * string.
+ * substituted with the userid itself. There is no way to make the
+ * resulting path contain '~'. If there is more than one '~', or if
+ * the '~' is at the beginning but userid does not resolve via
+ * getpwnam, or '~' is present but the argument is NULL, path_size
+ * returns 0, and make_path returns 1.
  */
 
-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;
 }
 
-static int path_size(const char *tokenid, const char *userid)
+/*
+  I know using these two functions and alloca() in between it ugly, but
+  I like the alternatives even less. =ec
+*/
+
+static int path_size(const struct passwd *pw)
 {
-	const char *usub;
-	char *p, *q;
-	struct passwd *pw;
+	const char *p;
 
 	if ((p = strchr(template, '~')) != strrchr(template, '~')) return 0;
-	if ((q = strchr(template, '?')) != strrchr(template, '?')) return 0;
-	if (p && !userid) return 0;
-	if (q && !tokenid) return 0;
-	if (p == template) {
-		pw = getpwnam(userid);
-		if (!pw) return 0;
-		usub = pw->pw_dir;
-	} else {
-		usub = userid;
-	}
-	return strlen(template) + p?strlen(usub):0 + q?strlen(tokenid):0 + 1;
+	if (p && !pw) return 0;
+	if (p == template) return strlen(template)+strlen(pw->pw_dir)+1;
+	else return strlen(template)+strlen(pw->pw_name)+1;
 }
 
-static void
-make_path(char * const path, const char *tokenid, const char *userid)
+static int
+make_path(char * const path, const struct passwd *pw)
 {
-	const char *usub;
-	char *p, *q;
-	struct passwd *pw;
+	const char *p;
+	char *q;
 
 	path[0] = '\0';
-	if (template[0] == '~') {
-		pw = getpwnam(userid);
-		if (!pw) return;
-		usub = pw->pw_dir;
-	} else {
-		usub = userid;
-	}
 	q = path;
 	for (p = template; *p; p++) switch (*p) {
 	case '~':
-		strcpy(q, usub);
-		while (*q) q++;
-		break;
-	case '?':
-		strcpy(q, tokenid);
+		if (!pw) return 1;
+		if (p == template) strcpy(q, pw->pw_dir);
+		else strcpy(q, pw->pw_name);
 		while (*q) q++;
 		break;
 	default:
@@ -84,6 +91,7 @@ make_path(char * const path, const char *tokenid, const char *userid)
 		break;
 	}
 	*q = '\0';
+	return 0;
 }
 
 int parse(char * const buf, const int argc, const char *argv[const])
@@ -99,8 +107,7 @@ int parse(char * const buf, const int argc, const char *argv[const])
 	return i != argc;
 }
 
-struct _auth_obj authfile(const char *tokenid,
-		const char *userid, const char *password,
+struct _auth_obj authfile(const char *userid, const char *password,
 		void (*update_nonce)(char *nonce, const int nonsize),
 		const unsigned char *secret, const int secsize,
 		const unsigned char *payload, const int paylsize,
@@ -108,37 +115,39 @@ struct _auth_obj authfile(const char *tokenid,
 						const int csize))
 {
 	struct _auth_obj ret = {0};
+	const struct passwd *pw = NULL;
 	mode_t oldmask;
 	FILE *fp = NULL;
 	char *fn, *nfn;
 	int fnl;
+	struct stat st = {0};
 	char *buf = NULL;
 	struct {
-		const char *tokenid;
 		const char *userid;
 		const char *nonce;
 		const char *hablob;
-	} w = {"", NULL, NULL, NULL};
+	} w = {NULL, NULL, NULL};
 	unsigned char *ablob = NULL;
 	int blobsize = 0;
 	char *newnonce;
 	int nonsize;
 	struct _auth_obj ao;
 
-	if ((fnl = path_size(tokenid, userid)) == 0) {
-		ret.err = "authfile path impossible to build";
+	if (userid) pw = getpwnam(userid);
+	if ((fnl = path_size(pw)) == 0) {
+		ret.err = "authfile path_size failed";
 		return ret;
 	}
 	fn = alloca(fnl);
-	make_path(fn, tokenid, userid);
+	if (make_path(fn, pw)) {
+		ret.err = "authfile make_path failed";
+		return ret;
+	}
 	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)) {
@@ -152,20 +161,10 @@ 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;
 
@@ -191,16 +190,18 @@ struct _auth_obj authfile(const char *tokenid,
 
 	oldmask = umask(077);
 	if ((fp = fopen(nfn, "w"))) {
-		int i;
+		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\n",
+				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);
 		}
@@ -215,7 +216,7 @@ struct _auth_obj authfile(const char *tokenid,
 	}
 
 	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";
@@ -229,8 +230,9 @@ 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;
 				}
 			}
 		}