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-rw-r--r--lib/lib.h5
-rw-r--r--lib/password.c172
-rw-r--r--toys/lsb/passwd.c113
3 files changed, 172 insertions, 118 deletions
diff --git a/lib/lib.h b/lib/lib.h
index fe494e72..ef688a32 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -187,6 +187,11 @@ mode_t string_to_mode(char *mode_str, mode_t base);
void mode_to_string(mode_t mode, char *buf);
// password helper functions
+#define MAX_SALT_LEN 20 //3 for id, 16 for key, 1 for '\0'
+#define SYS_FIRST_ID 100
+#define SYS_LAST_ID 999
+int get_salt(char *salt, char * algo);
+void is_valid_username(const char *name);
int read_password(char * buff, int buflen, char* mesg);
int update_password(char *filename, char* username, char* encrypted);
diff --git a/lib/password.c b/lib/password.c
index d1489eb3..b340ef48 100644
--- a/lib/password.c
+++ b/lib/password.c
@@ -1,19 +1,87 @@
-/* pwdutils.c - password read/update helper functions.
+/* password.c - password read/update helper functions.
*
* Copyright 2012 Ashwini Kumar <ak.ashwini@gmail.com>
*/
#include "toys.h"
+#include "xregcomp.h"
#include <time.h>
+static unsigned int random_number_generator(int fd)
+{
+ unsigned int randnum;
+
+ xreadall(fd, &randnum, sizeof(randnum));
+ return randnum;
+}
+
+static char inttoc(int i)
+{
+ // salt value uses 64 chracters in "./0-9a-zA-Z"
+ const char character_set[]="./0123456789abcdefghijklmnopqrstuvwxyz"
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+ i &= 0x3f; // masking for using 10 bits only
+ return character_set[i];
+}
+
+int get_salt(char *salt, char *algo)
+{
+ int i, randfd, salt_length = 0, offset;
+
+ if (!strcmp(algo,"des")){
+ // 2 bytes salt value is used in des
+ salt_length = 2;
+ offset = 0;
+ } else {
+ *salt++ = '$';
+ if (!strcmp(algo,"md5")){
+ *salt++ = '1';
+ // 8 bytes salt value is used in md5
+ salt_length = 8;
+ } else if (!strcmp(algo,"sha256")){
+ *salt++ = '5';
+ // 16 bytes salt value is used in sha256
+ salt_length = 16;
+ } else if (!strcmp(algo,"sha512")){
+ *salt++ = '6';
+ // 16 bytes salt value is used in sha512
+ salt_length = 16;
+ } else return -1;
+
+ *salt++ = '$';
+ offset = 3;
+ }
+
+ randfd = xopen("/dev/urandom", O_RDONLY);
+ for (i=0; i<salt_length; i++)
+ salt[i] = inttoc(random_number_generator(randfd));
+ salt[salt_length+1] = '\0';
+ xclose(randfd);
+
+ return offset;
+}
+
+static void handle(int signo)
+{
+ //Dummy.. so that read breaks on the signal,
+ //instead of the applocation exit
+}
+
int read_password(char * buff, int buflen, char* mesg)
{
int i = 0;
struct termios termio, oldtermio;
+ struct sigaction sa, oldsa;
+
tcgetattr(0, &oldtermio);
tcflush(0, TCIFLUSH);
termio = oldtermio;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = handle;
+ sigaction(SIGINT, &sa, &oldsa);
+
termio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
termio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
tcsetattr(0, TCSANOW, &termio);
@@ -25,7 +93,10 @@ int read_password(char * buff, int buflen, char* mesg)
int ret = read(0, &buff[i], 1);
if ( ret < 0 ) {
buff[0] = 0;
+ sigaction(SIGINT, &oldsa, NULL);
tcsetattr(0, TCSANOW, &oldtermio);
+ xputc('\n');
+ fflush(stdout);
return 1;
} else if (ret == 0 || buff[i] == '\n' || buff[i] == '\r' || buflen == i+1)
{
@@ -34,35 +105,45 @@ int read_password(char * buff, int buflen, char* mesg)
}
i++;
}
-
+ sigaction(SIGINT, &oldsa, NULL);
tcsetattr(0, TCSANOW, &oldtermio);
puts("");
fflush(stdout);
return 0;
}
-static char *get_nextcolon(const char *line, char delim)
+static char *get_nextcolon(char *line, int cnt)
{
- char *current_ptr = NULL;
- if((current_ptr = strchr(line, ':')) == NULL) error_exit("Invalid Entry\n");
- return current_ptr;
+ while (cnt--) {
+ if (!(line = strchr(line, ':'))) error_exit("Invalid Entry\n");
+ line++; //jump past the colon
+ }
+ return line;
}
-int update_password(char *filename, char* username, char* encrypted)
+/*update_password is used by multiple utilities to update /etc/passwd,
+ * /etc/shadow, /etc/group and /etc/gshadow files,
+ * which are used as user, group databeses
+ * entry can be
+ * 1. encrypted password, when updating user password.
+ * 2. complete entry for user details, when creating new user
+ * 3. group members comma',' separated list, when adding user to group
+ * 4. complete entry for group details, when creating new group
+ */
+int update_password(char *filename, char* username, char* entry)
{
- char *filenamesfx = NULL, *namesfx = NULL;
- char *shadow = NULL, *sfx = NULL;
+ char *filenamesfx = NULL, *namesfx = NULL, *shadow = NULL,
+ *sfx = NULL, *line = NULL;
FILE *exfp, *newfp;
- int ret = -1; //fail
+ int ret = -1, found = 0;
struct flock lock;
- char *line = NULL;
shadow = strstr(filename, "shadow");
filenamesfx = xmsprintf("%s+", filename);
sfx = strchr(filenamesfx, '+');
exfp = fopen(filename, "r+");
- if(!exfp) {
+ if (!exfp) {
perror_msg("Couldn't open file %s",filename);
goto free_storage;
}
@@ -70,7 +151,7 @@ int update_password(char *filename, char* username, char* encrypted)
*sfx = '-';
ret = unlink(filenamesfx);
ret = link(filename, filenamesfx);
- if(ret < 0) error_msg("can't create backup file");
+ if (ret < 0) error_msg("can't create backup file");
*sfx = '+';
lock.l_type = F_WRLCK;
@@ -79,12 +160,12 @@ int update_password(char *filename, char* username, char* encrypted)
lock.l_len = 0;
ret = fcntl(fileno(exfp), F_SETLK, &lock);
- if(ret < 0) perror_msg("Couldn't lock file %s",filename);
+ if (ret < 0) perror_msg("Couldn't lock file %s",filename);
lock.l_type = F_UNLCK; //unlocking at a later stage
newfp = fopen(filenamesfx, "w+");
- if(!newfp) {
+ if (!newfp) {
error_msg("couldn't open file for writing");
ret = -1;
fclose(exfp);
@@ -93,29 +174,34 @@ int update_password(char *filename, char* username, char* encrypted)
ret = 0;
namesfx = xmsprintf("%s:",username);
- while((line = get_line(fileno(exfp))) != NULL)
+ while ((line = get_line(fileno(exfp))) != NULL)
{
- if(strncmp(line, namesfx, strlen(namesfx)) != 0)
+ if (strncmp(line, namesfx, strlen(namesfx)))
fprintf(newfp, "%s\n", line);
else {
char *current_ptr = NULL;
- fprintf(newfp, "%s%s:",namesfx,encrypted);
- current_ptr = get_nextcolon(line, ':'); //past username
- current_ptr++; //past colon ':' after username
- current_ptr = get_nextcolon(current_ptr, ':'); //past passwd
- current_ptr++; //past colon ':' after passwd
- if(shadow) {
- fprintf(newfp, "%u:",(unsigned)(time(NULL))/(24*60*60));
- current_ptr = get_nextcolon(current_ptr, ':');
- current_ptr++; //past time stamp colon.
- fprintf(newfp, "%s\n",current_ptr);
+
+ found = 1;
+ if (!strcmp(toys.which->name, "passwd")) {
+ fprintf(newfp, "%s%s:",namesfx, entry);
+ current_ptr = get_nextcolon(line, 2); //past passwd
+ if (shadow) {
+ fprintf(newfp, "%u:",(unsigned)(time(NULL))/(24*60*60));
+ current_ptr = get_nextcolon(current_ptr, 1);
+ fprintf(newfp, "%s\n",current_ptr);
+ } else fprintf(newfp, "%s\n",current_ptr);
+ } else if (!strcmp(toys.which->name, "groupadd") ||
+ !strcmp(toys.which->name, "addgroup")){
+ current_ptr = get_nextcolon(line, 3); //past gid/admin list
+ *current_ptr = '\0';
+ fprintf(newfp, "%s", line);
+ fprintf(newfp, "%s\n", entry);
}
- else fprintf(newfp, "%s\n",current_ptr);
}
-
free(line);
}
free(namesfx);
+ if (!found) fprintf(newfp, "%s\n", entry);
fcntl(fileno(exfp), F_SETLK, &lock);
fclose(exfp);
@@ -124,7 +210,7 @@ int update_password(char *filename, char* username, char* encrypted)
fsync(fileno(newfp));
fclose(newfp);
rename(filenamesfx, filename);
- if(errno) {
+ if (errno) {
perror_msg("File Writing/Saving failed: ");
unlink(filenamesfx);
ret = -1;
@@ -134,3 +220,29 @@ free_storage:
free(filenamesfx);
return ret;
}
+
+void is_valid_username(const char *name)
+{
+ regex_t rp;
+ regmatch_t rm[1];
+ int eval;
+ char *regex = "^[_.A-Za-z0-9][-_.A-Za-z0-9]*"; //User name REGEX
+
+ xregcomp(&rp, regex, REG_NEWLINE);
+
+ /* compare string against pattern -- remember that patterns
+ are anchored to the beginning of the line */
+ eval = regexec(&rp, name, 1, rm, 0);
+ regfree(&rp);
+ if (!eval && !rm[0].rm_so) {
+ int len = strlen(name);
+ if ((rm[0].rm_eo == len) ||
+ (rm[0].rm_eo == len - 1 && name[len - 1] == '$')) {
+ if (len >= LOGIN_NAME_MAX) error_exit("name is too long");
+ else return;
+ }
+ }
+ error_exit("'%s', not valid %sname",name,
+ (((toys.which->name[3] == 'g') ||
+ (toys.which->name[0] == 'g'))? "group" : "user"));
+}
diff --git a/toys/lsb/passwd.c b/toys/lsb/passwd.c
index 167d5730..1784c049 100644
--- a/toys/lsb/passwd.c
+++ b/toys/lsb/passwd.c
@@ -11,9 +11,9 @@ config PASSWD
bool "passwd"
default y
help
- usage: passwd [-a ALGO] [-d] [-l] [-u] <account name>
+ usage: passwd [-a ALGO] [-dlu] <account name>
- update user’s authentication tokens. Default : current user
+ update user's authentication tokens. Default : current user
-a ALGO Encryption method (des, md5, sha256, sha512) default: des
-d Set password to ''
@@ -23,81 +23,25 @@ config PASSWD
#define FOR_passwd
#include "toys.h"
-#include <time.h>
GLOBALS(
char *algo;
)
-#define MAX_SALT_LEN 20 //3 for id, 16 for key, 1 for '\0'
-#define URANDOM_PATH "/dev/urandom"
-
#ifndef _GNU_SOURCE
char *strcasestr(const char *haystack, const char *needle);
#endif
-unsigned int random_number_generator(int fd)
-{
- unsigned int randnum;
-
- xreadall(fd, &randnum, sizeof(randnum));
- return randnum;
-}
-
-char inttoc(int i)
-{
- // salt value uses 64 chracters in "./0-9a-zA-Z"
- const char character_set[]="./0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
-
- i &= 0x3f; // masking for using 10 bits only
- return character_set[i];
-}
-
-int get_salt(char *salt)
-{
- int i, salt_length = 0;
- int randfd;
-
- if (!strncmp(TT.algo,"des",3)) {
- // 2 bytes salt value is used in des
- salt_length = 2;
- } else {
- *salt++ = '$';
- if (!strncmp(TT.algo,"md5",3)) {
- *salt++ = '1';
- // 8 bytes salt value is used in md5
- salt_length = 8;
- } else if (!strncmp(TT.algo,"sha256",6)) {
- *salt++ = '5';
- // 16 bytes salt value is used in sha256
- salt_length = 16;
- } else if (!strncmp(TT.algo,"sha512",6)) {
- *salt++ = '6';
- // 16 bytes salt value is used in sha512
- salt_length = 16;
- } else return 1;
-
- *salt++ = '$';
- }
-
- randfd = xopen(URANDOM_PATH, O_RDONLY);
- for (i=0; i<salt_length; i++)
- salt[i] = inttoc(random_number_generator(randfd));
- salt[salt_length+1] = '\0';
- xclose(randfd);
-
- return 0;
-}
-
static int str_check(char *s, char *p)
{
- if ((strcasestr(s, p) != NULL) || (strcasestr(p, s) != NULL)) return 1;
+ if (strcasestr(s, p) || strcasestr(p, s)) return 1;
return 0;
}
static void strength_check(char *newp, char *oldp, char *user)
{
char *msg = NULL;
+
if (strlen(newp) < 6) { //Min passwd len
msg = "too short";
xprintf("BAD PASSWORD: %s\n",msg);
@@ -123,7 +67,7 @@ static int verify_passwd(char * pwd)
if (pwd[0] == '!' || pwd[0] == '*') return 1;
pass = crypt(toybuf, pwd);
- if (pass != NULL && strcmp(pass, pwd)==0) return 0;
+ if (pass && !strcmp(pass, pwd)) return 0;
return 1;
}
@@ -142,32 +86,27 @@ static char *new_password(char *oldp, char *user)
return NULL; //may be due to Ctrl-C
}
- if (strcmp(newp, toybuf) == 0) return newp;
+ if (!strcmp(newp, toybuf)) return newp;
else error_msg("Passwords do not match.\n");
- /*Failure Case */
+ // Failure Case
free(newp);
-
return NULL;
}
-
void passwd_main(void)
{
uid_t myuid;
struct passwd *pw;
struct spwd *sp;
- char *name = NULL;
- char *pass = NULL, *encrypted = NULL, *newp = NULL;
- char *orig = (char *)"";
- char salt[MAX_SALT_LEN];
+ char *name = NULL, *pass = NULL, *encrypted = NULL, *newp = NULL,
+ *orig = (char *)"", salt[MAX_SALT_LEN];
int ret = -1;
myuid = getuid();
- if ((myuid != 0) && (toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
+ if ((myuid) && (toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
error_exit("You need to be root to do these actions\n");
pw = getpwuid(myuid);
-
if (!pw) error_exit("Unknown uid '%u'",myuid);
if (toys.optargs[0]) name = toys.optargs[0];
@@ -176,23 +115,28 @@ void passwd_main(void)
pw = getpwnam(name);
if (!pw) error_exit("Unknown user '%s'",name);
- if (myuid != 0 && (myuid != pw->pw_uid))
+ if (myuid && (myuid != pw->pw_uid))
error_exit("You need to be root to change '%s' password\n", name);
pass = pw->pw_passwd;
if (pw->pw_passwd[0] == 'x') {
- /*get shadow passwd */
+ //get shadow passwd
sp = getspnam(name);
if (sp) pass = sp->sp_pwdp;
}
if (!(toys.optflags & (FLAG_l | FLAG_u | FLAG_d))) {
+
+ if (!(toys.optflags & FLAG_a)) TT.algo = "des";
+ if (get_salt(salt, TT.algo) == -1)
+ error_exit("Error: Unkown encryption algorithm\n");
+
printf("Changing password for %s\n",name);
- if (pass[0] == '!')
+ if (myuid && pass[0] == '!')
error_exit("Can't change, password is locked for %s",name);
- if (myuid != 0) {
- /*Validate user */
+ if (myuid) {
+ //Validate user
if (read_password(toybuf, sizeof(toybuf), "Origial password:")) {
if (!toys.optargs[0]) free(name);
@@ -204,7 +148,7 @@ void passwd_main(void)
orig = xstrdup(orig);
- /*Get new password */
+ // Get new password
newp = new_password(orig, name);
if (!newp) {
free(orig);
@@ -212,31 +156,24 @@ void passwd_main(void)
return; //new password is not set well.
}
- /*Encrypt the passwd */
- if (!(toys.optflags & FLAG_a)) TT.algo = "des";
-
- if (get_salt(salt)) error_exit("Error: Unkown encryption algorithm\n");
-
encrypted = crypt(newp, salt);
free(newp);
free(orig);
} else if (toys.optflags & FLAG_l) {
- if (pass[0] == '!')
- error_exit("password is already locked for %s",name);
+ if (pass[0] == '!') error_exit("password is already locked for %s",name);
printf("Locking password for %s\n",name);
encrypted = xmsprintf("!%s",pass);
} else if (toys.optflags & FLAG_u) {
- if (pass[0] != '!')
- error_exit("password is already unlocked for %s",name);
+ if (pass[0] != '!') error_exit("password is already unlocked for %s",name);
printf("Unlocking password for %s\n",name);
encrypted = xstrdup(&pass[1]);
} else if (toys.optflags & FLAG_d) {
printf("Deleting password for %s\n",name);
- encrypted = (char*)xzalloc(sizeof(char)*2); //1 = "", 2 = '\0'
+ encrypted = xstrdup(""); //1 = "", 2 = '\0'
}
- /*Update the passwd */
+ // Update the passwd
if (pw->pw_passwd[0] == 'x')
ret = update_password("/etc/shadow", name, encrypted);
else ret = update_password("/etc/passwd", name, encrypted);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 06:03:28 +0000