+/*
+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"
-#include "pcsc_cr.h"
-#define OBJSIZE 256
+/*
+ * 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. 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 const char *template = "~/.pam_cr/auth";
+
+void authfile_template(const char *str)
+{
+ template = str;
+}
+
+/*
+ I know using these two functions and alloca() in between it ugly, but
+ I like the alternatives even less. =ec
+*/
-int update_authfile(const char *fn, const char *tokenid, const char *id,
- const char *password, const char *nonce,
- const unsigned char *secret, const int secsize,
- const unsigned char *payload, const int paysize)
+static int path_size(const struct passwd *pw)
{
- FILE *fp;
- int rc;
+ const char *p;
+
+ if ((p = strchr(template, '~')) != strrchr(template, '~')) return 0;
+ 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 int
+make_path(char * const path, const struct passwd *pw)
+{
+ const char *p;
+ char *q;
+
+ path[0] = '\0';
+ q = path;
+ for (p = template; *p; p++) switch (*p) {
+ case '~':
+ if (!pw) return 1;
+ if (p == template) strcpy(q, pw->pw_dir);
+ else strcpy(q, pw->pw_name);
+ while (*q) q++;
+ break;
+ default:
+ *q++ = *p;
+ break;
+ }
+ *q = '\0';
+ return 0;
+}
+
+int parse(char * const buf, const int argc, const char *argv[const])
+{
+ char *p, *q;
int i;
- unsigned char key[20];
- int keysize = sizeof(key);
- unsigned char mysecret[20];
- int mysecsize = sizeof(mysecret);
- unsigned char myload[256];
- int myloadsize = sizeof(myload);
- unsigned char *authobj = alloca(OBJSIZE);
- int authsize = OBJSIZE;
- char buf[512];
- char *oldtokenid = NULL, *oldid = NULL, *oldnonce = NULL,
- *hauthobj = NULL;
- unsigned char *oldauthobj = NULL;
- int oldauthsize;
-
- if ((fp = fopen(fn, "r"))) {
- if (fgets(buf, sizeof(buf), fp)) {
- oldtokenid = strtok(buf, ":\r\n");
- oldid = strtok(NULL, ":\r\n");
- oldnonce = strtok(NULL, ":\r\n");
- hauthobj = strtok(NULL, ":\r\n");
- } else {
- eprint("error reading from %s: %s",
- fn, strerror(errno));
+
+ for (i = 0, p = buf; *p; p = q+1, i++) {
+ for (q = p; *q && *q != ':' && *q != '\r' && *q != '\n'; q++) ;
+ *q = '\0';
+ if (*p && i < argc) argv[i] = p;
+ }
+ return i != argc;
+}
+
+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,
+ struct _auth_chunk (*fetch_key)(const unsigned char *chal,
+ 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 *userid;
+ const char *nonce;
+ const char *hablob;
+ } w = {NULL, NULL, NULL};
+ unsigned char *ablob = NULL;
+ int blobsize = 0;
+ char *newnonce;
+ int nonsize;
+ struct _auth_obj ao;
+
+ if (userid) pw = getpwnam(userid);
+ if ((fnl = path_size(pw)) == 0) {
+ ret.err = "authfile path_size failed";
+ return ret;
+ }
+ fn = alloca(fnl);
+ 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) {
+ 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)) {
+ ret.err = strerror(errno);
+ } else if (parse(buf, sizeof(w)/sizeof(char*),
+ (const char ** const)&w)){
+ ret.err = "error: unparseable auth file";
}
fclose(fp);
}
- if (hauthobj) {
- int hlen;
-
- hlen = strlen(hauthobj);
- if (hlen % 32 != 0) {
- eprint("error: auth string has wrong length");
- } else if (hlen !=
- strspn(hauthobj, "0123456789abcdefABCDEF")) {
- eprint("error: auth string not hexadecimal");
- } else {
- oldauthsize = hlen/2;
- oldauthobj = alloca(oldauthsize);
- for (i = 0; i < oldauthsize; i++)
- sscanf(&hauthobj[i*2], "%2hhx", &oldauthobj[i]);
- }
+ if (ret.err) return ret;
+
+ if (w.hablob) {
+ 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;
- if (oldauthobj && password && !secret) {
- unsigned char chal[64];
- int csize = sizeof(chal);
- long rc;
+ nonsize = w.nonce ? strlen(w.nonce)*2 : 32;
+ if (nonsize < 32) nonsize = 32;
+ newnonce = alloca(nonsize);
+ if (w.nonce) strcpy(newnonce, w.nonce);
+ else memset(newnonce, 0, nonsize);
+ update_nonce(newnonce, nonsize);
- rc = make_challenge(id, password, nonce, chal, &csize);
- if (rc) {
- eprint("cannot make challenge");
- return -1;
+ ao = authobj(userid?userid:w.userid, password,
+ w.nonce, newnonce, secret, secsize,
+ payload, paylsize, ablob, blobsize,
+ fetch_key);
+
+ if (ao.err) {
+ ret.err = ao.err;
+ if (ao.data) memset(ao.data, 0, ao.datasize);
+ if (ao.payload) memset(ao.payload, 0, ao.paylsize);
+ if (ao.buffer) free(ao.buffer);
+ return ret;
+ }
+
+ oldmask = umask(077);
+ if ((fp = fopen(nfn, "w"))) {
+ int bsize = ((ao.datasize-1)/3+1)*4+1;
+ char *b64 = alloca(bsize);
+
+ 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);
}
- rc = pcsc_cr(chal, csize, key, &keysize);
- if (rc) {
- eprint("error querying token: %s", pcsc_errstr(rc));
- return -1;
+ if (st.st_uid || st.st_gid) {
+ if (fchown(fileno(fp), st.st_uid, st.st_gid)) /*ign*/;
}
- rc = parse_authobj(key, keysize, oldauthobj, oldauthsize,
- mysecret, &mysecsize, myload, &myloadsize);
- if (rc) {
- eprint("cannot parse old authobj: %d", rc);
- return -1;
+ if (fclose(fp) < 0) {
+ ret.err = strerror(errno);
}
+ } else {
+ ret.err = strerror(errno);
}
-
- rc = make_authobj(id, password, nonce, mysecret, mysecsize,
- payload, paysize, authobj, &authsize);
- if (rc) {
- eprint("make_authobj error %d", rc);
- return -1;
- }
- fp = fopen(fn, "w");
- if (!fp) {
- eprint("cannot open \"%s\": %s",
- fn, strerror(errno));
- return -1;
- }
- if (fprintf(fp, "%s:%s:%s:", tokenid, id, nonce) < 0) {
- eprint("cannot write to \"%s\": %s",
- fn, strerror(errno));
- return -1;
+ (void)umask(oldmask);
+ if (ret.err) {
+ unlink(nfn); /* may not exist but no matter */
+ } else if (rename(nfn, fn)) {
+ ret.err = strerror(errno);
}
- for (i = 0; i < authsize; i++)
- if (fprintf(fp, "%02x", authobj[i]) < 0) {
- eprint("cannot write to \"%s\": %s",
- fn, strerror(errno));
- return -1;
- }
- fprintf(fp, "\n");
- if (fclose(fp) < 0) {
- eprint("cannot close \"%s\": %s",
- fn, strerror(errno));
- return -1;
+
+ if (!ret.err) {
+ 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";
+ } else {
+ unsigned char *p = ret.buffer;
+ if (w.userid) {
+ strcpy((char*)p, w.userid);
+ ret.data = p;
+ ret.datasize = strlen(w.userid)+1;
+ p += strlen(w.userid)+1;
+ }
+ if (ao.payload) {
+ memcpy(p, ao.payload, ao.paylsize);
+ p[ao.paylsize] = '\0';
+ ret.payload = p;
+ ret.paylsize = ao.paylsize+1;
+ }
+ }
+ }
}
- return 0;
+
+ if (ao.data) memset(ao.data, 0, ao.datasize);
+ if (ao.payload) memset(ao.payload, 0, ao.paylsize);
+ if (ao.buffer) free(ao.buffer);
+ return ret;
}
projects / pam_pcsc_cr.git / blobdiff