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-rw-r--r--lib/lib.h5
-rw-r--r--lib/password.c142
2 files changed, 147 insertions, 0 deletions
diff --git a/lib/lib.h b/lib/lib.h
index 8028737e..de2e214c 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -168,3 +168,8 @@ int sig_to_num(char *pidstr);
char *num_to_sig(int sig);
mode_t string_to_mode(char *mode_str, mode_t base);
+
+// password helper functions
+int read_passwd(char * buff, int buflen, char* mesg);
+int update_passwd(char *filename, char* username, char* encrypted);
+
diff --git a/lib/password.c b/lib/password.c
new file mode 100644
index 00000000..2b11144e
--- /dev/null
+++ b/lib/password.c
@@ -0,0 +1,142 @@
+/* vi: set sw=4 ts=4 :
+ * pwdutils.c - password read/update helper functions.
+ *
+ * Copyright 2012 Ashwini Kumar <ak.ashwini@gmail.com>
+ */
+
+#include "toys.h"
+#include <time.h>
+
+
+int read_passwd(char * buff, int buflen, char* mesg)
+{
+ int i = 0;
+ struct termios termio, oldtermio;
+ tcgetattr(0, &oldtermio);
+ tcflush(0, TCIFLUSH);
+ termio = oldtermio;
+
+ 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;
+ tcsetattr(0, TCSANOW, &oldtermio);
+ return 1;
+ }
+ else if ( ret == 0 || buff[i] == '\n' ||
+ buff[i] == '\r' || buflen == i+1) {
+ buff[i] = '\0';
+ break;
+ }
+ i++;
+ }
+
+ tcsetattr(0, TCSANOW, &oldtermio);
+ puts("");
+ fflush(stdout);
+ return 0;
+}
+
+static char *get_nextcolon(const char *line, char delim)
+{
+ char *current_ptr = NULL;
+ if((current_ptr = strchr(line, ':')) == NULL)
+ error_exit("Invalid Entry\n");
+ return current_ptr;
+}
+
+int update_passwd(char *filename, char* username, char* encrypted)
+{
+ char *filenamesfx = NULL, *namesfx = NULL;
+ char *shadow = NULL, *sfx = NULL;
+ FILE *exfp, *newfp;
+ int ret = -1; //fail
+ struct flock lock;
+ char *line = NULL;
+
+ shadow = strstr(filename, "shadow");
+ filenamesfx = xmsprintf("%s+", filename);
+ sfx = strchr(filenamesfx, '+');
+
+ exfp = fopen(filename, "r+");
+ if(!exfp) {
+ perror_msg("Couldn't open file %s",filename);
+ goto free_storage;
+ }
+
+ *sfx = '-';
+ ret = unlink(filenamesfx);
+ ret = link(filename, filenamesfx);
+ if(ret < 0) error_msg("can't create backup file");
+
+ *sfx = '+';
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+
+ ret = fcntl(fileno(exfp), F_SETLK, &lock);
+ 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) {
+ error_msg("couldn't open file for writing");
+ ret = -1;
+ fclose(exfp);
+ goto free_storage;
+ }
+
+ ret = 0;
+ namesfx = xmsprintf("%s:",username);
+ while((line = get_line(fileno(exfp))) != NULL)
+ {
+ if(strncmp(line, namesfx, strlen(namesfx)) != 0)
+ 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);
+ }
+ else {
+ fprintf(newfp, "%s\n",current_ptr);
+ }
+ }
+
+ free(line);
+ }
+ free(namesfx);
+ fcntl(fileno(exfp), F_SETLK, &lock);
+ fclose(exfp);
+
+ errno = 0;
+ fflush(newfp);
+ fsync(fileno(newfp));
+ fclose(newfp);
+ rename(filenamesfx, filename);
+ if(errno) {
+ perror_msg("File Writing/Saving failed: ");
+ unlink(filenamesfx);
+ ret = -1;
+ }
+
+free_storage:
+ free(filenamesfx);
+ return ret;
+}