diff options
| -rw-r--r-- | editors/patch.c | 2 | ||||
| -rw-r--r-- | libbb/bb_askpass.c | 2 | ||||
| -rw-r--r-- | libbb/get_line_from_file.c | 14 | ||||
| -rw-r--r-- | libbb/obscure.c | 10 | ||||
| -rw-r--r-- | loginutils/passwd.c | 532 |
5 files changed, 264 insertions, 296 deletions
diff --git a/editors/patch.c b/editors/patch.c index f11f8a1..8e885d0 100644 --- a/editors/patch.c +++ b/editors/patch.c @@ -117,12 +117,14 @@ int patch_main(int argc, char **argv) free(patch_line); patch_line = xmalloc_fgets(patch_file); } + /* FIXME: patch_line NULL check?? */ /* Extract the filename used before the patch was generated */ original_filename = extract_filename(patch_line, patch_level); free(patch_line); patch_line = xmalloc_fgets(patch_file); + /* FIXME: NULL check?? */ if (strncmp(patch_line, "+++ ", 4) != 0) { ret = 2; bb_error_msg("invalid patch"); diff --git a/libbb/bb_askpass.c b/libbb/bb_askpass.c index cf384e5..097a0a2 100644 --- a/libbb/bb_askpass.c +++ b/libbb/bb_askpass.c @@ -60,7 +60,7 @@ char *bb_askpass(int timeout, const char * prompt) (read did not overwrite it) */ do { if (passwd[i] == '\r' || passwd[i] == '\n') - passwd[i] = 0; + passwd[i] = '\0'; } while (passwd[i++]); } diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c index 969d808..b424d59 100644 --- a/libbb/get_line_from_file.c +++ b/libbb/get_line_from_file.c @@ -9,11 +9,9 @@ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ -#include <stdio.h> -#include <stdlib.h> #include "libbb.h" -/* get_line_from_file() - This function reads an entire line from a text file, +/* This function reads an entire line from a text file, * up to a newline or NUL byte. It returns a malloc'ed char * which must be * stored and free'ed by the caller. If end is null '\n' isn't considered * end of line. If end isn't null, length of the chunk read is stored in it. */ @@ -37,10 +35,12 @@ char *bb_get_chunk_from_file(FILE * file, int *end) if (end) *end = idx; if (linebuf) { - if (ferror(file)) { - free(linebuf); - return NULL; - } + // huh, is fgets discards prior data on error like this? + // I don't think so.... + //if (ferror(file)) { + // free(linebuf); + // return NULL; + //} linebuf = xrealloc(linebuf, idx+1); linebuf[idx] = 0; } diff --git a/libbb/obscure.c b/libbb/obscure.c index 7d839d6..2599095 100644 --- a/libbb/obscure.c +++ b/libbb/obscure.c @@ -157,14 +157,14 @@ static const char *obscure_msg(const char *old_p, const char *new_p, const struc return NULL; } -int obscure(const char *old, const char *newval, const struct passwd *pwdp) +int obscure(const char *old, const char *newval, const struct passwd *pw) { const char *msg; - if ((msg = obscure_msg(old, newval, pwdp))) { - printf("Bad password: %s.\n", msg); - /* If user is root warn only */ - return getuid() ? 1 : 0; + msg = obscure_msg(old, newval, pw); + if (msg) { + printf("Bad password: %s\n", msg); + return 1; } return 0; } diff --git a/loginutils/passwd.c b/loginutils/passwd.c index 2811ab7..41033e5 100644 --- a/loginutils/passwd.c +++ b/loginutils/passwd.c @@ -6,122 +6,234 @@ #include "busybox.h" #include <syslog.h> -static char crypt_passwd[128]; -static int create_backup(const char *backup, FILE * fp); -static int new_password(const struct passwd *pw, int amroot, int algo); -static void set_filesize_limit(int blocks); +static void nuke_str(char *str) +{ + if (str) memset(str, 0, strlen(str)); +} -static int get_algo(char *a) +static int i64c(int i) { - int x = 1; /* standard: MD5 */ + if (i <= 0) + return '.'; + if (i == 1) + return '/'; + if (i >= 2 && i < 12) + return ('0' - 2 + i); + if (i >= 12 && i < 38) + return ('A' - 12 + i); + if (i >= 38 && i < 63) + return ('a' - 38 + i); + return 'z'; +} + +static char *crypt_make_salt(void) +{ + time_t now; + static unsigned long x; + static char result[3]; + + time(&now); + x += now + getpid() + clock(); + result[0] = i64c(((x >> 18) ^ (x >> 6)) & 077); + result[1] = i64c(((x >> 12) ^ x) & 077); + result[2] = '\0'; + return result; +} + + +static char* new_password(const struct passwd *pw, const char *old_crypted, + uid_t myuid, int algo) +{ + char salt[sizeof("$N$XXXXXXXX")]; /* "$N$XXXXXXXX" or "XX" */ + char *orig = ""; + char *newp = NULL; + char *cipher = NULL; + char *cp = NULL; + char *ret = NULL; /* failure so far */ + + if (myuid && old_crypted[0]) { + orig = bb_askpass(0, "Old password:"); /* returns ptr to static */ + if (!orig) + goto err_ret; + cipher = pw_encrypt(orig, old_crypted); /* returns ptr to static */ + if (strcmp(cipher, old_crypted) != 0) { + syslog(LOG_WARNING, "incorrect password for '%s'", + pw->pw_name); + bb_do_delay(FAIL_DELAY); + puts("Incorrect password"); + goto err_ret; + } + } + orig = xstrdup(orig); /* or else bb_askpass() will destroy it */ + newp = bb_askpass(0, "Enter the new password (minimum of 5 characters).\n" + "Please use a combination of upper and lower case letters and numbers.\n" + "Enter new password:"); /* returns ptr to static */ + if (!newp) + goto err_ret; + newp = xstrdup(newp); /* we are going to bb_askpass() again, so save it */ + if (obscure(orig, newp, pw)) { + if (myuid) + goto err_ret; /* non-root is not allowed to have weak passwd */ + puts("\nWarning: weak password (continuing)"); + } + + cp = bb_askpass(0, "Re-enter new password:"); + if (!cp) + goto err_ret; + if (strcmp(cp, newp)) { + puts("Passwords do not match"); + goto err_ret; + } + + memset(salt, 0, sizeof(salt)); + if (algo == 1) { /* MD5 */ + strcpy(salt, "$1$"); + strcat(salt, crypt_make_salt()); + strcat(salt, crypt_make_salt()); + strcat(salt, crypt_make_salt()); + } + strcat(salt, crypt_make_salt()); + ret = xstrdup(pw_encrypt(newp, salt)); /* returns ptr to static */ + /* whee, success! */ + + err_ret: + nuke_str(orig); + if (ENABLE_FEATURE_CLEAN_UP) free(orig); + nuke_str(newp); + if (ENABLE_FEATURE_CLEAN_UP) free(newp); + nuke_str(cipher); + nuke_str(cp); + return ret; +} + + +static void set_filesize_limit(int blocks) +{ + struct rlimit rlimit_fsize; + + rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * blocks; + setrlimit(RLIMIT_FSIZE, &rlimit_fsize); +} + + +#if 0 +static int get_algo(char *a) +{ + /* standard: MD5 */ + int x = 1; if (strcasecmp(a, "des") == 0) x = 0; return x; } +#endif -static int update_passwd(const struct passwd *pw, const char *crypt_pw) +static int update_passwd(const char *filename, const char *username, + const char *new_pw) { - char filename[1024]; - char buf[1025]; - char buffer[80]; - char username[32]; - char *pw_rest; - int mask; - int continued; - FILE *fp; - FILE *out_fp; struct stat sb; struct flock lock; - -#if ENABLE_FEATURE_SHADOWPASSWDS - if (access(bb_path_shadow_file, F_OK) == 0) { - snprintf(filename, sizeof filename, "%s", bb_path_shadow_file); - } else -#endif - { - snprintf(filename, sizeof filename, "%s", bb_path_passwd_file); + FILE *old_fp; + FILE *new_fp; + char *new_name; + char *last_char; + unsigned user_len; + int old_fd; + int new_fd; + int i; + int ret = 1; /* failure */ + + /* New passwd file, "/etc/passwd+" for now */ + new_name = xasprintf("%s+", filename); + last_char = &new_name[strlen(new_name)-1]; + username = xasprintf("%s:", username); + user_len = strlen(username); + + old_fp = fopen(filename, "r+"); + if (!old_fp) + goto free_mem; + old_fd = fileno(old_fp); + + /* Try to create "/etc/passwd+". Wait if it exists. */ + i = 30; + do { + // FIXME: on last iteration try w/o O_EXCL but with O_TRUNC? + new_fd = open(new_name, O_WRONLY|O_CREAT|O_EXCL,0600); + if (new_fd >= 0) goto created; + if (errno != EEXIST) break; + usleep(100000); /* 0.1 sec */ + } while (--i); + bb_perror_msg("cannot create '%s'", new_name); + goto close_old_fp; + created: + if (!fstat(old_fd, &sb)) { + fchmod(new_fd, sb.st_mode & 0777); /* ignore errors */ + fchown(new_fd, sb.st_uid, sb.st_gid); } - - fp = fopen(filename, "r+"); - if (fp == 0 || fstat(fileno(fp), &sb)) { - /* return 0; */ - return 1; + new_fp = fdopen(new_fd, "w"); + if (!new_fp) { + close(new_fd); + goto unlink_new; } + /* Backup file is "/etc/passwd-" */ + last_char[0] = '-'; + /* Delete old one, create new as a hardlink to current */ + i = (unlink(new_name) && errno != ENOENT); + if (i || link(filename, new_name)) + bb_perror_msg("warning: cannot create backup copy '%s'", new_name); + last_char[0] = '+'; + /* Lock the password file before updating */ lock.l_type = F_WRLCK; lock.l_whence = SEEK_SET; lock.l_start = 0; lock.l_len = 0; - if (fcntl(fileno(fp), F_SETLK, &lock) < 0) { - bb_perror_msg("%s", filename); - return 1; - } + if (fcntl(old_fd, F_SETLK, &lock) < 0) + bb_perror_msg("warning: cannot lock '%s'", filename); lock.l_type = F_UNLCK; - snprintf(buf, sizeof buf, "%s-", filename); - if (create_backup(buf, fp)) { - fcntl(fileno(fp), F_SETLK, &lock); - fclose(fp); - return 1; + /* Read current password file, write updated one */ + while (1) { + char *line = xmalloc_fgets(old_fp); + if (!line) break; /* EOF/error */ + if (strncmp(username, line, user_len) == 0) { + /* we have a match with "username:"... */ + const char *cp = line + user_len; + /* now cp -> old passwd, skip it: */ + cp = strchr(cp, ':'); + if (!cp) cp = ""; + /* now cp -> ':' after old passwd or -> "" */ + fprintf(new_fp, "%s%s%s", username, new_pw, cp); + /* Erase password in memory */ + } else + fputs(line, new_fp); + free(line); } - snprintf(buf, sizeof buf, "%s+", filename); - mask = umask(0777); - out_fp = fopen(buf, "w"); - umask(mask); - if ((!out_fp) || (fchmod(fileno(out_fp), sb.st_mode & 0777)) - || (fchown(fileno(out_fp), sb.st_uid, sb.st_gid))) { - fcntl(fileno(fp), F_SETLK, &lock); - fclose(fp); - fclose(out_fp); - return 1; + fcntl(old_fd, F_SETLK, &lock); + + /* We do want all of them to execute, thus | instead of || */ + if ((ferror(old_fp) | fflush(new_fp) | fsync(new_fd) | fclose(new_fp)) + || rename(new_name, filename) + ) { + /* At least one of those failed */ + goto unlink_new; } + ret = 0; /* whee, success! */ - continued = 0; - snprintf(username, sizeof username, "%s:", pw->pw_name); - rewind(fp); - while (!feof(fp)) { - fgets(buffer, sizeof buffer, fp); - if (!continued) { /* Check to see if we're updating this line. */ - if (strncmp(username, buffer, strlen(username)) == 0) { - /* we have a match. */ - pw_rest = strchr(buffer, ':'); - *pw_rest++ = '\0'; - pw_rest = strchr(pw_rest, ':'); - fprintf(out_fp, "%s:%s%s", buffer, crypt_pw, pw_rest); - } else { - fputs(buffer, out_fp); - } - } else { - fputs(buffer, out_fp); - } - if (buffer[strlen(buffer) - 1] == '\n') { - continued = 0; - } else { - continued = 1; - } - memset(buffer, 0, sizeof buffer); - } + unlink_new: + if (ret) unlink(new_name); - if (fflush(out_fp) || fsync(fileno(out_fp)) || fclose(out_fp)) { - unlink(buf); - fcntl(fileno(fp), F_SETLK, &lock); - fclose(fp); - return 1; - } - if (rename(buf, filename) < 0) { - fcntl(fileno(fp), F_SETLK, &lock); - fclose(fp); - return 1; - } else { - fcntl(fileno(fp), F_SETLK, &lock); - fclose(fp); - return 0; - } + close_old_fp: + fclose(old_fp); + + free_mem: + if (ENABLE_FEATURE_CLEAN_UP) free(new_name); + if (ENABLE_FEATURE_CLEAN_UP) free((char*)username); + return ret; } @@ -133,79 +245,88 @@ int passwd_main(int argc, char **argv) OPT_unlock = 0x4, /* -u - unlock account */ OPT_delete = 0x8, /* -d - delete password */ OPT_lud = 0xe, + STATE_ALGO_md5 = 0x10, + STATE_ALGO_des = 0x20, }; unsigned opt; - char *opt_a; - int amroot; - char *cp; - char *np; - char *name; + char *opt_a = ""; + const char *filename; char *myname; - int algo = 1; + char *name; + char *oldp; + char *newp = NULL; /* gcc happiness */ const struct passwd *pw; + uid_t myuid; - amroot = (getuid() == 0); - openlog("passwd", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH); + openlog("passwd", LOG_NOWAIT, LOG_AUTH); opt = getopt32(argc, argv, "a:lud", &opt_a); argc -= optind; argv += optind; - if (opt & OPT_algo) algo = get_algo(opt_a); // -a - if ((opt & OPT_lud) && (!argc || !amroot)) + + if (strcasecmp(opt_a, "des") == 0) /* -a */ + opt |= STATE_ALGO_des; + else + opt |= STATE_ALGO_md5; + myuid = getuid(); + if ((opt & OPT_lud) && (!argc || myuid)) bb_show_usage(); - myname = xstrdup(bb_getpwuid(NULL, getuid(), -1)); + myname = xstrdup(bb_getpwuid(NULL, myuid, -1)); name = myname; if (argc) name = argv[0]; pw = getpwnam(name); - if (!pw) { - bb_error_msg_and_die("unknown user %s", name); - } - if (!amroot && pw->pw_uid != getuid()) { + if (!pw) bb_error_msg_and_die("unknown user %s", name); + if (myuid && pw->pw_uid != myuid) { syslog(LOG_WARNING, "can't change pwd for '%s'", name); bb_error_msg_and_die("permission denied"); } + + filename = bb_path_passwd_file; + oldp = pw->pw_passwd; if (ENABLE_FEATURE_SHADOWPASSWDS) { struct spwd *sp = getspnam(name); - if (!sp) bb_error_msg_and_die("unknown user %s", name); - cp = sp->sp_pwdp; - } else cp = pw->pw_passwd; + if (!sp) { + bb_error_msg("no shadow record for user %s found, " + "changing ordinary password instead", name); + } else { + filename = bb_path_shadow_file; + oldp = sp->sp_pwdp; + } + } - np = name; - safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd)); + /* Decide what the new password will be */ if (!(opt & OPT_lud)) { - if (!amroot) { - if (cp[0] == '!') { - syslog(LOG_WARNING, "password locked for '%s'", np); - bb_error_msg_and_die("the password for %s cannot be changed", np); + if (myuid) { + if (oldp[0] == '!') { + syslog(LOG_WARNING, "password locked for '%s'", name); + bb_error_msg_and_die("the password for %s cannot be changed", name); } } printf("Changing password for %s\n", name); - if (new_password(pw, amroot, algo)) { + newp = new_password(pw, oldp, + myuid, + opt & STATE_ALGO_md5); + if (!newp) { bb_error_msg_and_die("the password for %s is unchanged", name); } } else if (opt & OPT_lock) { - if (crypt_passwd[0] != '!') { - memmove(&crypt_passwd[1], crypt_passwd, - sizeof crypt_passwd - 1); - crypt_passwd[sizeof crypt_passwd - 1] = '\0'; - crypt_passwd[0] = '!'; - } + if (oldp[0] == '!') goto skip; + newp = xasprintf("!%s", oldp); } else if (opt & OPT_unlock) { - if (crypt_passwd[0] == '!') { - memmove(crypt_passwd, &crypt_passwd[1], - sizeof crypt_passwd - 1); - } + if (oldp[0] != '!') goto skip; + newp = xstrdup(oldp + 1); } else if (opt & OPT_delete) { - crypt_passwd[0] = '\0'; + newp = xstrdup(""); } + set_filesize_limit(30000); signal(SIGHUP, SIG_IGN); signal(SIGINT, SIG_IGN); signal(SIGQUIT, SIG_IGN); umask(077); xsetuid(0); - if (!update_passwd(pw, crypt_passwd)) { + if (update_passwd(filename, name, newp) == 0) { syslog(LOG_INFO, "password for '%s' changed by user '%s'", name, myname); puts("Password changed"); @@ -213,164 +334,9 @@ int passwd_main(int argc, char **argv) syslog(LOG_WARNING, "cannot update password file"); bb_error_msg_and_die("cannot update password file"); } - if (ENABLE_FEATURE_CLEAN_UP) free(myname); - return 0; -} - - - -static int create_backup(const char *backup, FILE * fp) -{ - struct stat sb; - struct utimbuf ub; - FILE *bkfp; - int c, mask; - - if (fstat(fileno(fp), &sb)) - /* return -1; */ - return 1; - - mask = umask(077); - bkfp = fopen(backup, "w"); - umask(mask); - if (!bkfp) - /* return -1; */ - return 1; - - /* TODO: faster copy, not one-char-at-a-time. --marekm */ - rewind(fp); - while ((c = getc(fp)) != EOF) { - if (putc(c, bkfp) == EOF) - break; - } - if (c != EOF || fflush(bkfp)) { - fclose(bkfp); - /* return -1; */ - return 1; - } - if (fclose(bkfp)) - /* return -1; */ - return 1; - ub.actime = sb.st_atime; - ub.modtime = sb.st_mtime; - utime(backup, &ub); - return 0; -} - -static int i64c(int i) -{ - if (i <= 0) - return '.'; - if (i == 1) - return '/'; - if (i >= 2 && i < 12) - return ('0' - 2 + i); - if (i >= 12 && i < 38) - return ('A' - 12 + i); - if (i >= 38 && i < 63) - return ('a' - 38 + i); - return 'z'; -} - -static char *crypt_make_salt(void) -{ - time_t now; - static unsigned long x; - static char result[3]; - - time(&now); - x += now + getpid() + clock(); - result[0] = i64c(((x >> 18) ^ (x >> 6)) & 077); - result[1] = i64c(((x >> 12) ^ x) & 077); - result[2] = '\0'; - return result; -} - - -static int new_password(const struct passwd *pw, int amroot, int algo) -{ - char *clear; - char *cipher; - char *cp; - char salt[12]; /* "$N$XXXXXXXX" or "XX" */ - char orig[200]; - char pass[200]; - - if (!amroot && crypt_passwd[0]) { - clear = bb_askpass(0, "Old password:"); - if (!clear) { - /* return -1; */ - return 1; - } - cipher = pw_encrypt(clear, crypt_passwd); - if (strcmp(cipher, crypt_passwd) != 0) { - syslog(LOG_WARNING, "incorrect password for '%s'", - pw->pw_name); - bb_do_delay(FAIL_DELAY); - puts("Incorrect password"); - /* return -1; */ - return 1; - } - safe_strncpy(orig, clear, sizeof(orig)); - memset(clear, 0, strlen(clear)); - memset(cipher, 0, strlen(cipher)); - } else { - orig[0] = '\0'; - } - cp = bb_askpass(0, "Enter the new password (minimum of 5 characters).\n" - "Please use a combination of upper and lower case letters and numbers.\n" - "Enter new password: "); - if (!cp ) { - memset(orig, 0, sizeof orig); - /* return -1; */ - return 1; - } - safe_strncpy(pass, cp, sizeof(pass)); - memset(cp, 0, strlen(cp)); - /* if (!obscure(orig, pass, pw)) { */ - if (obscure(orig, pass, pw)) { - if (amroot) { - puts("\nWarning: weak password (continuing)"); - } else { - /* return -1; */ - return 1; - } - } - cp = bb_askpass(0, "Re-enter new password: "); - if (!cp) { - memset(orig, 0, sizeof orig); - /* return -1; */ - return 1; - } - if (strcmp(cp, pass)) { - puts("Passwords do not match"); - /* return -1; */ - return 1; - } - memset(cp, 0, strlen(cp)); - memset(orig, 0, sizeof(orig)); - memset(salt, 0, sizeof(salt)); - - if (algo == 1) { - strcpy(salt, "$1$"); - strcat(salt, crypt_make_salt()); - strcat(salt, crypt_make_salt()); - strcat(salt, crypt_make_salt()); - } - - strcat(salt, crypt_make_salt()); - cp = pw_encrypt(pass, salt); - - memset(pass, 0, sizeof pass); - safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd)); + if (ENABLE_FEATURE_CLEAN_UP) free(newp); +skip: + if (ENABLE_FEATURE_CLEAN_UP) free(myname); return 0; } - -static void set_filesize_limit(int blocks) -{ - struct rlimit rlimit_fsize; - - rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * blocks; - setrlimit(RLIMIT_FSIZE, &rlimit_fsize); -} |