started implementing password checking logic

diff --git a/Makefile b/Makefile
index eebb6c62bb2ec629f998b4038419b86546feecb9..54d572056c19dc3186372e6f570a5aefbd42c799 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -7,15 +7,15 @@ CC = cc
 # flags
 LIBS     =
 INCS     = -Iinclude
-CPPFLAGS =
-CFLAGS   = -O2 $(INCS) $(CPPFLAGS)
+CPPFLAGS = $(INCS)
+CFLAGS   = -O2 $(CPPFLAGS)
 LDFLAGS  = $(LIBS)
 BUILD    = $(CC) $(CFLAGS) -o $@ $<
 
 #------------------------------------------------------------------------------
 # Build-Specific Macros
 #------------------------------------------------------------------------------
-BINS = init getty
+BINS = init getty login
 
 # load user-specific settings
 -include config.mk
@@ -33,6 +33,9 @@ init: source/init.c
 getty: source/getty.c
        $(BUILD)
 
+login: source/login.c
+       $(BUILD)
+
 clean:
        $(RM) $(BINS)
 

diff --git a/source/login.c b/source/login.c
index ec9b80089383a61519e816f602e328aa5b62cb87..cce61fec9f8164fd248433881f38e7e250011a05 100644 (file)
--- a/source/login.c
+++ b/source/login.c
@@ -1,130 +1,302 @@
-/* See LICENSE file for copyright and license details. */
-#include <sys/ioctl.h>
-#include <sys/types.h>
-
-#include <errno.h>
-#include <grp.h>
-#include <pwd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
+/**
+  @brief
+  @author Michael D. Lowis
+  @license BSD 2-clause License
+*/
+#include "util.h"
 #include <unistd.h>
-#include <utmp.h>
+#include <pwd.h>
+#include <shadow.h>
 
-#include "config.h"
-#include "passwd.h"
-#include "util.h"
+//#include <sys/ioctl.h>
+//#include <sys/types.h>
+//#include <errno.h>
+//#include <grp.h>
+//#include <pwd.h>
+//#include <stdio.h>
+//#include <stdlib.h>
+//#include <string.h>
+//#include <time.h>
+//#include <unistd.h>
+//#include <utmp.h>
 
-/* Write utmp entry */
-static void
-writeutmp(const char *user, const char *tty)
-{
-    struct utmp usr;
-    FILE *fp;
-
-    memset(&usr, 0, sizeof(usr));
-
-    usr.ut_type = USER_PROCESS;
-    usr.ut_pid = getpid();
-    strlcpy(usr.ut_user, user, sizeof(usr.ut_user));
-    strlcpy(usr.ut_line, tty, sizeof(usr.ut_line));
-    usr.ut_tv.tv_sec = time(NULL);
-
-    fp = fopen(UTMP_PATH, "a");
-    if (fp) {
-        if (fwrite(&usr, sizeof(usr), 1, fp) != 1)
-            if (ferror(fp))
-                weprintf("%s: write error:", UTMP_PATH);
-        fclose(fp);
+//#include "config.h"
+//#include "passwd.h"
+//#include "util.h"
+
+char* ARGV0;
+static char* Hostname = NULL;
+static char* Username = NULL;
+static char* Password = NULL;
+static bool  PreserveEnv = false;
+
+static char* get_host(void) {
+    static char hostname[256] = { 0 };
+    if (Hostname == NULL) {
+        gethostname(hostname, sizeof(hostname)-1);
+        return hostname;
     } else {
-        weprintf("fopen %s:", UTMP_PATH);
+        return Hostname;
     }
 }
 
-static int
-dologin(struct passwd *pw, int preserve)
-{
-    char *shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
-
-    if (preserve == 0)
-        clearenv();
-    setenv("HOME", pw->pw_dir, 1);
-    setenv("SHELL", shell, 1);
-    setenv("USER", pw->pw_name, 1);
-    setenv("LOGNAME", pw->pw_name, 1);
-    setenv("PATH", ENV_PATH, 1);
-    if (chdir(pw->pw_dir) < 0)
-        eprintf("chdir %s:", pw->pw_dir);
-    execlp(shell, shell, "-l", NULL);
-    weprintf("execlp %s:", shell);
-    return (errno == ENOENT) ? 127 : 126;
+static char* get_user(void) {
+    static char username[256] = { 0 };
+    if (Username == NULL) {
+        printf("login: ");
+        fflush(stdout);
+        fgets(username, sizeof(username)-1, stdin);
+        username[strlen(username)-1] = '\0';
+        return username;
+    } else {
+        return Username;
+    }
 }
 
-static void
-usage(void)
-{
-    eprintf("usage: %s [-p] username\n", argv0);
+static char* get_pass(void) {
+    return getpass("password: ");
 }
 
-int
-main(int argc, char *argv[])
-{
-    struct passwd *pw;
-    char *pass, *user;
-    char *tty;
-    uid_t uid;
-    gid_t gid;
-    int pflag = 0;
-
-    ARGBEGIN {
-    case 'p':
-        pflag = 1;
-        break;
-    default:
-        usage();
-    } ARGEND;
-
-    if (argc < 1)
-        usage();
+static bool check_pass(const char* user, char* pass) {
+    struct spwd* spw;
+    struct passwd* pwentry = getpwnam(user);
+    if (!pwentry || errno)
+        die("Could not find entry for user: %s", user);
+    /* Handle disabled accounts */
+    if (pwentry->pw_passwd[0] == '!' || pwentry->pw_passwd[0] == '*') {
+        warn("access denied");
+        return false;
+    }
+    /* Handle blank pass or blank pass entry */
+    if ((pwentry->pw_passwd[0] == '\0') || (pass[0] == '\0')) {
+        warn("incorrect password\n");
+        return false;
+    }
+    /* Handle shadow passwd entries */
+    if (pwentry->pw_passwd[0] == 'x' && pwentry->pw_passwd[1] == '\0') {
+        errno = 0;
+        spw = getspnam(pwentry->pw_name);
+        if (!spw || errno)
+            die("could not retrieve shadow entry for %s", user);
 
-    if (isatty(0) == 0 || isatty(1) == 0 || isatty(2) == 0)
-        eprintf("no tty");
-
-    user = argv[0];
-    errno = 0;
-    pw = getpwnam(user);
-    if (!pw) {
-        if (errno)
-            eprintf("getpwnam %s:", user);
-        else
-            eprintf("who are you?\n");
+        if (spw->sp_pwdp[0] == '!' || spw->sp_pwdp[0] == '*') {
+            warn("access denied\n");
+            return false;
+        }
+    }
+    /* Check the password */
+    char* cryptpass = crypt(pass, spw->sp_pwdp);
+    if (strcmp(cryptpass, spw->sp_pwdp) != 0) {
+        warn("incorrect password");
+        return false;
     }
+    return true;
+}
 
-    uid = pw->pw_uid;
-    gid = pw->pw_gid;
+int pw_check(const struct passwd *pw, const char *pass)
+{
+    char *cryptpass, *p;
+    struct spwd *spw;
 
-    /* Flush pending input */
-    ioctl(0, TCFLSH, (void *)0);
+    p = pw->pw_passwd;
+    if (p[0] == '!' || p[0] == '*') {
+    weprintf("denied\n");
+    return -1;
+    }
 
-    pass = getpass("Password: ");
-    if (!pass)
-        eprintf("getpass:");
-    if (pw_check(pw, pass) <= 0)
-        exit(1);
+    if (pw->pw_passwd[0] == '\0') {
+        if (pass[0] == '\0')
+            return 1;
+        weprintf("incorrect password\n");
+        return 0;
+    }
 
-    tty = ttyname(0);
-    if (!tty)
-        eprintf("ttyname:");
+    if (pw->pw_passwd[0] == 'x' && pw->pw_passwd[1] == '\0') {
+        errno = 0;
+        spw = getspnam(pw->pw_name);
+        if (!spw) {
+            if (errno)
+                weprintf("getspnam: %s:", pw->pw_name);
+            else
+                weprintf("who are you?\n");
+            return -1;
+        }
+        p = spw->sp_pwdp;
+        if (p[0] == '!' || p[0] == '*') {
+            weprintf("denied\n");
+            return -1;
+        }
+    }
 
-    writeutmp(user, tty);
+    cryptpass = crypt(pass, p);
+    if (!cryptpass) {
+    weprintf("crypt:");
+    return -1;
+    }
+    if (strcmp(cryptpass, p) != 0) {
+    weprintf("incorrect password\n");
+    return 0;
+    }
+    return 1;
+}
+
+int main(int argc, char** argv) {
+    /* Parse command line options */
+    OPTBEGIN {
+        case 'p':
+            PreserveEnv = true;
+            break;
+        case 'h':
+            Hostname = EOPTARG(die("no hostname provided"));
+            break;
+        case 'u':
+            Username = EOPTARG(die("no username provided"));
+            break;
+        default:
+            die("Usage: %s [-p] [-h host] [-u user]", ARGV0);
+    } OPTEND;
+    /*  */
+    if (isatty(0) == 0 || isatty(1) == 0 || isatty(2) == 0)
+        die("no tty");
+    printf("%s\n", get_host());
 
-    if (initgroups(user, gid) < 0)
-        eprintf("initgroups:");
-    if (setgid(gid) < 0)
-        eprintf("setgid:");
-    if (setuid(uid) < 0)
-        eprintf("setuid:");
+    char* user = get_user();
+    char* pass = get_pass();
+    if (check_pass(user, pass)) {
 
-    return dologin(pw, pflag);
+    } else {
+        return EXIT_FAILURE;
+    }
+    return EXIT_SUCCESS;
 }
+
+//* See LICENSE file for copyright and license details. */
+//#include <sys/ioctl.h>
+//#include <sys/types.h>
+//
+//#include <errno.h>
+//#include <grp.h>
+//#include <pwd.h>
+//#include <stdio.h>
+//#include <stdlib.h>
+//#include <string.h>
+//#include <time.h>
+//#include <unistd.h>
+//#include <utmp.h>
+//
+//#include "config.h"
+//#include "passwd.h"
+//#include "util.h"
+//
+///* Write utmp entry */
+//static void
+//writeutmp(const char *user, const char *tty)
+//{
+//    struct utmp usr;
+//    FILE *fp;
+//
+//    memset(&usr, 0, sizeof(usr));
+//
+//    usr.ut_type = USER_PROCESS;
+//    usr.ut_pid = getpid();
+//    strlcpy(usr.ut_user, user, sizeof(usr.ut_user));
+//    strlcpy(usr.ut_line, tty, sizeof(usr.ut_line));
+//    usr.ut_tv.tv_sec = time(NULL);
+//
+//    fp = fopen(UTMP_PATH, "a");
+//    if (fp) {
+//        if (fwrite(&usr, sizeof(usr), 1, fp) != 1)
+//            if (ferror(fp))
+//                weprintf("%s: write error:", UTMP_PATH);
+//        fclose(fp);
+//    } else {
+//        weprintf("fopen %s:", UTMP_PATH);
+//    }
+//}
+//
+//static int
+//dologin(struct passwd *pw, int preserve)
+//{
+//    char *shell = pw->pw_shell[0] == '\0' ? "/bin/sh" : pw->pw_shell;
+//
+//    if (preserve == 0)
+//        clearenv();
+//    setenv("HOME", pw->pw_dir, 1);
+//    setenv("SHELL", shell, 1);
+//    setenv("USER", pw->pw_name, 1);
+//    setenv("LOGNAME", pw->pw_name, 1);
+//    setenv("PATH", ENV_PATH, 1);
+//    if (chdir(pw->pw_dir) < 0)
+//        eprintf("chdir %s:", pw->pw_dir);
+//    execlp(shell, shell, "-l", NULL);
+//    weprintf("execlp %s:", shell);
+//    return (errno == ENOENT) ? 127 : 126;
+//}
+//
+//static void
+//usage(void)
+//{
+//    eprintf("usage: %s [-p] username\n", argv0);
+//}
+//
+//int
+//main(int argc, char *argv[])
+//{
+//    struct passwd *pw;
+//    char *pass, *user;
+//    char *tty;
+//    uid_t uid;
+//    gid_t gid;
+//    int pflag = 0;
+//
+//    ARGBEGIN {
+//    case 'p':
+//        pflag = 1;
+//        break;
+//    default:
+//        usage();
+//    } ARGEND;
+//
+//    if (argc < 1)
+//        usage();
+//
+//    if (isatty(0) == 0 || isatty(1) == 0 || isatty(2) == 0)
+//        eprintf("no tty");
+//
+//    user = argv[0];
+//    errno = 0;
+//    pw = getpwnam(user);
+//    if (!pw) {
+//        if (errno)
+//            eprintf("getpwnam %s:", user);
+//        else
+//            eprintf("who are you?\n");
+//    }
+//
+//    uid = pw->pw_uid;
+//    gid = pw->pw_gid;
+//
+//    /* Flush pending input */
+//    ioctl(0, TCFLSH, (void *)0);
+//
+//    pass = getpass("Password: ");
+//    if (!pass)
+//        eprintf("getpass:");
+//    if (pw_check(pw, pass) <= 0)
+//        exit(1);
+//
+//    tty = ttyname(0);
+//    if (!tty)
+//        eprintf("ttyname:");
+//
+//    writeutmp(user, tty);
+//
+//    if (initgroups(user, gid) < 0)
+//        eprintf("initgroups:");
+//    if (setgid(gid) < 0)
+//        eprintf("setgid:");
+//    if (setuid(uid) < 0)
+//        eprintf("setuid:");
+//
+//    return dologin(pw, pflag);
+//}