/* password.c - password read/update helper functions.
*
* Copyright 2012 Ashwini Kumar <ak.ashwini@gmail.com>
+ *
+ * TODO: cleanup
*/
#include "toys.h"
-#include "xregcomp.h"
#include <time.h>
+// generate appropriate random salt string for given encryption algorithm.
int get_salt(char *salt, char *algo)
-{
- int i, len = 0, offset = 0;
- char buf[12];
-
- if (!strcmp(algo,"des")) len = 2;
- else {
- *salt++ = '$';
- if (!strcmp(algo,"md5")) {
- *salt++ = '1';
- len = 8;
- } else if (!strcmp(algo,"sha256")) {
- *salt++ = '5';
- len = 16;
- } else if (!strcmp(algo,"sha512")) {
- *salt++ = '6';
- len = 16;
- } else return -1;
-
- *salt++ = '$';
- offset = 3;
- }
-
- // Read appropriate number of random bytes for salt
- i = xopen("/dev/urandom", O_RDONLY);
- xreadall(i, buf, ((len*6)+7)/8);
- close(i);
-
- // Grab 6 bit chunks and convert to characters in ./0-9a-zA-Z
- for (i=0; i<len; i++) {
- int bitpos = i*6, bits = bitpos/8;
-
- bits = ((buf[i]+(buf[i+1]<<8)) >> (bitpos&7)) & 0x3f;
- bits += 46;
- if (bits > 57) bits += 7;
- if (bits > 90) bits += 6;
-
- salt[i] = bits;
- }
- salt[i] = 0;
+{
+ struct {
+ char *type, id, len;
+ } al[] = {{"des", 0, 2}, {"md5", 1, 8}, {"sha256", 5, 16}, {"sha512", 6, 16}};
+ int i;
- return offset;
-}
+ for (i = 0; i < ARRAY_LEN(al); i++) {
+ if (!strcmp(algo, al[i].type)) {
+ int len = al[i].len;
+ char *s = salt;
-static void handle(int signo)
-{
- //Dummy.. so that read breaks on the signal,
- //instead of the applocation exit
+ if (al[i].id) s += sprintf(s, "$%c$", '0'+al[i].id);
+
+ // Read appropriate number of random bytes for salt
+ i = xopenro("/dev/urandom");
+ xreadall(i, libbuf, ((len*6)+7)/8);
+ close(i);
+
+ // Grab 6 bit chunks and convert to characters in ./0-9a-zA-Z
+ for (i=0; i<len; i++) {
+ int bitpos = i*6, bits = bitpos/8;
+
+ bits = ((libbuf[i]+(libbuf[i+1]<<8)) >> (bitpos&7)) & 0x3f;
+ bits += 46;
+ if (bits > 57) bits += 7;
+ if (bits > 90) bits += 6;
+
+ s[i] = bits;
+ }
+ salt[len] = 0;
+
+ return s-salt;
+ }
+ }
+
+ return -1;
}
-int read_password(char * buff, int buflen, char* mesg)
+// Prompt with mesg, read password into buf, return 0 for success 1 for fail
+int read_password(char *buf, int buflen, char *mesg)
{
- int i = 0;
- struct termios termio, oldtermio;
+ struct termios oldtermio;
struct sigaction sa, oldsa;
+ int i, ret = 1;
- tcgetattr(0, &oldtermio);
- tcflush(0, TCIFLUSH);
- termio = oldtermio;
-
+ // NOP signal handler to return from the read
memset(&sa, 0, sizeof(sa));
- sa.sa_handler = handle;
+ sa.sa_handler = generic_signal;
sigaction(SIGINT, &sa, &oldsa);
- termio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
- termio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
- tcsetattr(0, TCSANOW, &termio);
-
- fputs(mesg, stdout);
- fflush(stdout);
-
- while (1) {
- 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)
- {
- buff[i] = '\0';
+ tcflush(0, TCIFLUSH);
+ set_terminal(0, 1, &oldtermio);
+
+ xprintf("%s", mesg);
+
+ for (i=0; i < buflen-1; i++) {
+ if ((ret = read(0, buf+i, 1)) < 0 || (!ret && !i)) {
+ i = 0;
+ ret = 1;
+
break;
- }
- i++;
+ } else if (!ret || buf[i] == '\n' || buf[i] == '\r') {
+ ret = 0;
+
+ break;
+ } else if (buf[i] == 8 || buf[i] == 127) i -= i ? 2 : 1;
}
+
+ // Restore terminal/signal state, terminate string
sigaction(SIGINT, &oldsa, NULL);
tcsetattr(0, TCSANOW, &oldtermio);
- puts("");
- fflush(stdout);
- return 0;
+ buf[i] = 0;
+ xputc('\n');
+
+ return ret;
}
static char *get_nextcolon(char *line, int cnt)
}
/*update_password is used by multiple utilities to update /etc/passwd,
- * /etc/shadow, /etc/group and /etc/gshadow files,
+ * /etc/shadow, /etc/group and /etc/gshadow files,
* which are used as user, group databeses
- * entry can be
+ * 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
+ * 5. entry = NULL, delete the named entry user/group
*/
int update_password(char *filename, char* username, char* entry)
{
struct flock lock;
shadow = strstr(filename, "shadow");
- filenamesfx = xmsprintf("%s+", filename);
+ filenamesfx = xmprintf("%s+", filename);
sfx = strchr(filenamesfx, '+');
exfp = fopen(filename, "r+");
}
*sfx = '-';
- ret = unlink(filenamesfx);
+ unlink(filenamesfx);
ret = link(filename, filenamesfx);
if (ret < 0) error_msg("can't create backup file");
}
ret = 0;
- namesfx = xmsprintf("%s:",username);
+ namesfx = xmprintf("%s:",username);
while ((line = get_line(fileno(exfp))) != NULL)
{
if (strncmp(line, namesfx, strlen(namesfx)))
fprintf(newfp, "%s\n", line);
- else {
+ else if (entry) {
char *current_ptr = NULL;
found = 1;
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")){
+ } else if (!strcmp(toys.which->name, "groupadd") ||
+ !strcmp(toys.which->name, "addgroup") ||
+ !strcmp(toys.which->name, "delgroup") ||
+ !strcmp(toys.which->name, "groupdel")){
current_ptr = get_nextcolon(line, 3); //past gid/admin list
*current_ptr = '\0';
fprintf(newfp, "%s", line);
free(line);
}
free(namesfx);
- if (!found) fprintf(newfp, "%s\n", entry);
+ if (!found && entry) fprintf(newfp, "%s\n", entry);
fcntl(fileno(exfp), F_SETLK, &lock);
fclose(exfp);
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"));
-}
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