diff options
Diffstat (limited to 'source3/rpc_server/samr/srv_samr_chgpasswd.c')
| -rw-r--r-- | source3/rpc_server/samr/srv_samr_chgpasswd.c | 1132 |
1 files changed, 1132 insertions, 0 deletions
diff --git a/source3/rpc_server/samr/srv_samr_chgpasswd.c b/source3/rpc_server/samr/srv_samr_chgpasswd.c new file mode 100644 index 0000000000..85a63a5630 --- /dev/null +++ b/source3/rpc_server/samr/srv_samr_chgpasswd.c @@ -0,0 +1,1132 @@ +/* + Unix SMB/CIFS implementation. + Samba utility functions + Copyright (C) Andrew Tridgell 1992-1998 + Copyright (C) Andrew Bartlett 2001-2004 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/* These comments regard the code to change the user's unix password: */ + +/* fork a child process to exec passwd and write to its + * tty to change a users password. This is running as the + * user who is attempting to change the password. + */ + +/* + * This code was copied/borrowed and stolen from various sources. + * The primary source was the poppasswd.c from the authors of POPMail. This software + * was included as a client to change passwords using the 'passwd' program + * on the remote machine. + * + * This code has been hacked by Bob Nance (nance@niehs.nih.gov) and Evan Patterson + * (patters2@niehs.nih.gov) at the National Institute of Environmental Health Sciences + * and rights to modify, distribute or incorporate this change to the CAP suite or + * using it for any other reason are granted, so long as this disclaimer is left intact. + */ + +/* + This code was hacked considerably for inclusion in Samba, primarily + by Andrew.Tridgell@anu.edu.au. The biggest change was the addition + of the "password chat" option, which allows the easy runtime + specification of the expected sequence of events to change a + password. + */ + +#include "includes.h" +#include "../libcli/auth/libcli_auth.h" +#include "../lib/crypto/arcfour.h" +#include "rpc_server/samr/srv_samr_util.h" + +#if ALLOW_CHANGE_PASSWORD + +static int findpty(char **slave) +{ + int master = -1; + char *line = NULL; + SMB_STRUCT_DIR *dirp = NULL; + const char *dpname; + + *slave = NULL; + +#if defined(HAVE_GRANTPT) + /* Try to open /dev/ptmx. If that fails, fall through to old method. */ + if ((master = sys_open("/dev/ptmx", O_RDWR, 0)) >= 0) { + grantpt(master); + unlockpt(master); + line = (char *)ptsname(master); + if (line) { + *slave = SMB_STRDUP(line); + } + + if (*slave == NULL) { + DEBUG(0, + ("findpty: Unable to create master/slave pty pair.\n")); + /* Stop fd leak on error. */ + close(master); + return -1; + } else { + DEBUG(10, + ("findpty: Allocated slave pty %s\n", *slave)); + return (master); + } + } +#endif /* HAVE_GRANTPT */ + + line = SMB_STRDUP("/dev/ptyXX"); + if (!line) { + return (-1); + } + + dirp = sys_opendir("/dev"); + if (!dirp) { + SAFE_FREE(line); + return (-1); + } + + while ((dpname = readdirname(dirp)) != NULL) { + if (strncmp(dpname, "pty", 3) == 0 && strlen(dpname) == 5) { + DEBUG(3, + ("pty: try to open %s, line was %s\n", dpname, + line)); + line[8] = dpname[3]; + line[9] = dpname[4]; + if ((master = sys_open(line, O_RDWR, 0)) >= 0) { + DEBUG(3, ("pty: opened %s\n", line)); + line[5] = 't'; + *slave = line; + sys_closedir(dirp); + return (master); + } + } + } + sys_closedir(dirp); + SAFE_FREE(line); + return (-1); +} + +static int dochild(int master, const char *slavedev, const struct passwd *pass, + const char *passwordprogram, bool as_root) +{ + int slave; + struct termios stermios; + gid_t gid; + uid_t uid; + char * const eptrs[1] = { NULL }; + + if (pass == NULL) + { + DEBUG(0, + ("dochild: user doesn't exist in the UNIX password database.\n")); + return False; + } + + gid = pass->pw_gid; + uid = pass->pw_uid; + + gain_root_privilege(); + + /* Start new session - gets rid of controlling terminal. */ + if (setsid() < 0) + { + DEBUG(3, + ("Weirdness, couldn't let go of controlling terminal\n")); + return (False); + } + + /* Open slave pty and acquire as new controlling terminal. */ + if ((slave = sys_open(slavedev, O_RDWR, 0)) < 0) + { + DEBUG(3, ("More weirdness, could not open %s\n", slavedev)); + return (False); + } +#if defined(TIOCSCTTY) && !defined(SUNOS5) + /* + * On patched Solaris 10 TIOCSCTTY is defined but seems not to work, + * see the discussion under + * https://bugzilla.samba.org/show_bug.cgi?id=5366. + */ + if (ioctl(slave, TIOCSCTTY, 0) < 0) + { + DEBUG(3, ("Error in ioctl call for slave pty\n")); + /* return(False); */ + } +#elif defined(I_PUSH) && defined(I_FIND) + if (ioctl(slave, I_FIND, "ptem") == 0) { + ioctl(slave, I_PUSH, "ptem"); + } + if (ioctl(slave, I_FIND, "ldterm") == 0) { + ioctl(slave, I_PUSH, "ldterm"); + } +#endif + + /* Close master. */ + close(master); + + /* Make slave stdin/out/err of child. */ + + if (dup2(slave, STDIN_FILENO) != STDIN_FILENO) + { + DEBUG(3, ("Could not re-direct stdin\n")); + return (False); + } + if (dup2(slave, STDOUT_FILENO) != STDOUT_FILENO) + { + DEBUG(3, ("Could not re-direct stdout\n")); + return (False); + } + if (dup2(slave, STDERR_FILENO) != STDERR_FILENO) + { + DEBUG(3, ("Could not re-direct stderr\n")); + return (False); + } + if (slave > 2) + close(slave); + + /* Set proper terminal attributes - no echo, canonical input processing, + no map NL to CR/NL on output. */ + + if (tcgetattr(0, &stermios) < 0) + { + DEBUG(3, + ("could not read default terminal attributes on pty\n")); + return (False); + } + stermios.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL); + stermios.c_lflag |= ICANON; +#ifdef ONLCR + stermios.c_oflag &= ~(ONLCR); +#endif + if (tcsetattr(0, TCSANOW, &stermios) < 0) + { + DEBUG(3, ("could not set attributes of pty\n")); + return (False); + } + + /* make us completely into the right uid */ + if (!as_root) + { + become_user_permanently(uid, gid); + } + + DEBUG(10, + ("Invoking '%s' as password change program.\n", + passwordprogram)); + + /* execl() password-change application */ + if (execle("/bin/sh", "sh", "-c", passwordprogram, NULL, eptrs) < 0) + { + DEBUG(3, ("Bad status returned from %s\n", passwordprogram)); + return (False); + } + return (True); +} + +static int expect(int master, char *issue, char *expected) +{ + char buffer[1024]; + int attempts, timeout, nread; + size_t len; + bool match = False; + + for (attempts = 0; attempts < 2; attempts++) { + NTSTATUS status; + if (!strequal(issue, ".")) { + if (lp_passwd_chat_debug()) + DEBUG(100, ("expect: sending [%s]\n", issue)); + + if ((len = sys_write(master, issue, strlen(issue))) != strlen(issue)) { + DEBUG(2,("expect: (short) write returned %d\n", + (int)len )); + return False; + } + } + + if (strequal(expected, ".")) + return True; + + /* Initial timeout. */ + timeout = lp_passwd_chat_timeout() * 1000; + nread = 0; + buffer[nread] = 0; + + while (True) { + status = read_fd_with_timeout( + master, buffer + nread, 1, + sizeof(buffer) - nread - 1, + timeout, &len); + + if (!NT_STATUS_IS_OK(status)) { + DEBUG(2, ("expect: read error %s\n", + nt_errstr(status))); + break; + } + nread += len; + buffer[nread] = 0; + + { + /* Eat leading/trailing whitespace before match. */ + char *str = SMB_STRDUP(buffer); + if (!str) { + DEBUG(2,("expect: ENOMEM\n")); + return False; + } + trim_char(str, ' ', ' '); + + if ((match = unix_wild_match(expected, str)) == True) { + /* Now data has started to return, lower timeout. */ + timeout = lp_passwd_chat_timeout() * 100; + } + SAFE_FREE(str); + } + } + + if (lp_passwd_chat_debug()) + DEBUG(100, ("expect: expected [%s] received [%s] match %s\n", + expected, buffer, match ? "yes" : "no" )); + + if (match) + break; + + if (!NT_STATUS_IS_OK(status)) { + DEBUG(2, ("expect: %s\n", nt_errstr(status))); + return False; + } + } + + DEBUG(10,("expect: returning %s\n", match ? "True" : "False" )); + return match; +} + +static void pwd_sub(char *buf) +{ + all_string_sub(buf, "\\n", "\n", 0); + all_string_sub(buf, "\\r", "\r", 0); + all_string_sub(buf, "\\s", " ", 0); + all_string_sub(buf, "\\t", "\t", 0); +} + +static int talktochild(int master, const char *seq) +{ + TALLOC_CTX *frame = talloc_stackframe(); + int count = 0; + char *issue; + char *expected; + + issue = talloc_strdup(frame, "."); + if (!issue) { + TALLOC_FREE(frame); + return false; + } + + while (next_token_talloc(frame, &seq, &expected, NULL)) { + pwd_sub(expected); + count++; + + if (!expect(master, issue, expected)) { + DEBUG(3, ("Response %d incorrect\n", count)); + TALLOC_FREE(frame); + return false; + } + + if (!next_token_talloc(frame, &seq, &issue, NULL)) { + issue = talloc_strdup(frame, "."); + if (!issue) { + TALLOC_FREE(frame); + return false; + } + } + pwd_sub(issue); + } + + if (!strequal(issue, ".")) { + /* we have one final issue to send */ + expected = talloc_strdup(frame, "."); + if (!expected) { + TALLOC_FREE(frame); + return false; + } + if (!expect(master, issue, expected)) { + TALLOC_FREE(frame); + return False; + } + } + TALLOC_FREE(frame); + return (count > 0); +} + +static bool chat_with_program(char *passwordprogram, const struct passwd *pass, + char *chatsequence, bool as_root) +{ + char *slavedev = NULL; + int master; + pid_t pid, wpid; + int wstat; + bool chstat = False; + + if (pass == NULL) { + DEBUG(0, ("chat_with_program: user doesn't exist in the UNIX password database.\n")); + return False; + } + + /* allocate a pseudo-terminal device */ + if ((master = findpty(&slavedev)) < 0) { + DEBUG(3, ("chat_with_program: Cannot Allocate pty for password change: %s\n", pass->pw_name)); + return (False); + } + + /* + * We need to temporarily stop CatchChild from eating + * SIGCLD signals as it also eats the exit status code. JRA. + */ + + CatchChildLeaveStatus(); + + if ((pid = sys_fork()) < 0) { + DEBUG(3, ("chat_with_program: Cannot fork() child for password change: %s\n", pass->pw_name)); + SAFE_FREE(slavedev); + close(master); + CatchChild(); + return (False); + } + + /* we now have a pty */ + if (pid > 0) { /* This is the parent process */ + /* Don't need this anymore in parent. */ + SAFE_FREE(slavedev); + + if ((chstat = talktochild(master, chatsequence)) == False) { + DEBUG(3, ("chat_with_program: Child failed to change password: %s\n", pass->pw_name)); + kill(pid, SIGKILL); /* be sure to end this process */ + } + + while ((wpid = sys_waitpid(pid, &wstat, 0)) < 0) { + if (errno == EINTR) { + errno = 0; + continue; + } + break; + } + + if (wpid < 0) { + DEBUG(3, ("chat_with_program: The process is no longer waiting!\n\n")); + close(master); + CatchChild(); + return (False); + } + + /* + * Go back to ignoring children. + */ + CatchChild(); + + close(master); + + if (pid != wpid) { + DEBUG(3, ("chat_with_program: We were waiting for the wrong process ID\n")); + return (False); + } + if (WIFEXITED(wstat) && (WEXITSTATUS(wstat) != 0)) { + DEBUG(3, ("chat_with_program: The process exited with status %d \ +while we were waiting\n", WEXITSTATUS(wstat))); + return (False); + } +#if defined(WIFSIGNALLED) && defined(WTERMSIG) + else if (WIFSIGNALLED(wstat)) { + DEBUG(3, ("chat_with_program: The process was killed by signal %d \ +while we were waiting\n", WTERMSIG(wstat))); + return (False); + } +#endif + } else { + /* CHILD */ + + /* + * Lose any elevated privileges. + */ + drop_effective_capability(KERNEL_OPLOCK_CAPABILITY); + drop_effective_capability(DMAPI_ACCESS_CAPABILITY); + + /* make sure it doesn't freeze */ + alarm(20); + + if (as_root) + become_root(); + + DEBUG(3, ("chat_with_program: Dochild for user %s (uid=%d,gid=%d) (as_root = %s)\n", pass->pw_name, + (int)getuid(), (int)getgid(), BOOLSTR(as_root) )); + chstat = dochild(master, slavedev, pass, passwordprogram, as_root); + + if (as_root) + unbecome_root(); + + /* + * The child should never return from dochild() .... + */ + + DEBUG(0, ("chat_with_program: Error: dochild() returned %d\n", chstat)); + exit(1); + } + + if (chstat) + DEBUG(3, ("chat_with_program: Password change %ssuccessful for user %s\n", + (chstat ? "" : "un"), pass->pw_name)); + return (chstat); +} + +bool chgpasswd(const char *name, const char *rhost, const struct passwd *pass, + const char *oldpass, const char *newpass, bool as_root) +{ + char *passwordprogram = NULL; + char *chatsequence = NULL; + size_t i; + size_t len; + TALLOC_CTX *ctx = talloc_tos(); + + if (!oldpass) { + oldpass = ""; + } + + DEBUG(3, ("chgpasswd: Password change (as_root=%s) for user: %s\n", BOOLSTR(as_root), name)); + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("chgpasswd: Passwords: old=%s new=%s\n", oldpass, newpass)); +#endif + + /* Take the passed information and test it for minimum criteria */ + + /* Password is same as old password */ + if (strcmp(oldpass, newpass) == 0) { + /* don't allow same password */ + DEBUG(2, ("chgpasswd: Password Change: %s, New password is same as old\n", name)); /* log the attempt */ + return (False); /* inform the user */ + } + + /* + * Check the old and new passwords don't contain any control + * characters. + */ + + len = strlen(oldpass); + for (i = 0; i < len; i++) { + if (iscntrl((int)oldpass[i])) { + DEBUG(0, ("chgpasswd: oldpass contains control characters (disallowed).\n")); + return False; + } + } + + len = strlen(newpass); + for (i = 0; i < len; i++) { + if (iscntrl((int)newpass[i])) { + DEBUG(0, ("chgpasswd: newpass contains control characters (disallowed).\n")); + return False; + } + } + +#ifdef WITH_PAM + if (lp_pam_password_change()) { + bool ret; +#ifdef HAVE_SETLOCALE + const char *prevlocale = setlocale(LC_ALL, "C"); +#endif + + if (as_root) + become_root(); + + if (pass) { + ret = smb_pam_passchange(pass->pw_name, rhost, + oldpass, newpass); + } else { + ret = smb_pam_passchange(name, rhost, oldpass, + newpass); + } + + if (as_root) + unbecome_root(); + +#ifdef HAVE_SETLOCALE + setlocale(LC_ALL, prevlocale); +#endif + + return ret; + } +#endif + + /* A non-PAM password change just doen't make sense without a valid local user */ + + if (pass == NULL) { + DEBUG(0, ("chgpasswd: user %s doesn't exist in the UNIX password database.\n", name)); + return false; + } + + passwordprogram = talloc_strdup(ctx, lp_passwd_program()); + if (!passwordprogram || !*passwordprogram) { + DEBUG(2, ("chgpasswd: Null password program - no password changing\n")); + return false; + } + chatsequence = talloc_strdup(ctx, lp_passwd_chat()); + if (!chatsequence || !*chatsequence) { + DEBUG(2, ("chgpasswd: Null chat sequence - no password changing\n")); + return false; + } + + if (as_root) { + /* The password program *must* contain the user name to work. Fail if not. */ + if (strstr_m(passwordprogram, "%u") == NULL) { + DEBUG(0,("chgpasswd: Running as root the 'passwd program' parameter *MUST* contain \ +the string %%u, and the given string %s does not.\n", passwordprogram )); + return false; + } + } + + passwordprogram = talloc_string_sub(ctx, passwordprogram, "%u", name); + if (!passwordprogram) { + return false; + } + + /* note that we do NOT substitute the %o and %n in the password program + as this would open up a security hole where the user could use + a new password containing shell escape characters */ + + chatsequence = talloc_string_sub(ctx, chatsequence, "%u", name); + if (!chatsequence) { + return false; + } + chatsequence = talloc_all_string_sub(ctx, + chatsequence, + "%o", + oldpass); + if (!chatsequence) { + return false; + } + chatsequence = talloc_all_string_sub(ctx, + chatsequence, + "%n", + newpass); + return chat_with_program(passwordprogram, + pass, + chatsequence, + as_root); +} + +#else /* ALLOW_CHANGE_PASSWORD */ + +bool chgpasswd(const char *name, const struct passwd *pass, + const char *oldpass, const char *newpass, bool as_root) +{ + DEBUG(0, ("chgpasswd: Unix Password changing not compiled in (user=%s)\n", name)); + return (False); +} +#endif /* ALLOW_CHANGE_PASSWORD */ + +/*********************************************************** + Decrypt and verify a user password change. + + The 516 byte long buffers are encrypted with the old NT and + old LM passwords, and if the NT passwords are present, both + buffers contain a unicode string. + + After decrypting the buffers, check the password is correct by + matching the old hashed passwords with the passwords in the passdb. + +************************************************************/ + +static NTSTATUS check_oem_password(const char *user, + uchar password_encrypted_with_lm_hash[516], + const uchar old_lm_hash_encrypted[16], + uchar password_encrypted_with_nt_hash[516], + const uchar old_nt_hash_encrypted[16], + struct samu *sampass, + char **pp_new_passwd) +{ + uchar null_pw[16]; + uchar null_ntpw[16]; + uint8 *password_encrypted; + const uint8 *encryption_key; + const uint8 *lanman_pw, *nt_pw; + uint32 acct_ctrl; + size_t new_pw_len; + uchar new_nt_hash[16]; + uchar new_lm_hash[16]; + uchar verifier[16]; + char no_pw[2]; + + bool nt_pass_set = (password_encrypted_with_nt_hash && old_nt_hash_encrypted); + bool lm_pass_set = (password_encrypted_with_lm_hash && old_lm_hash_encrypted); + + acct_ctrl = pdb_get_acct_ctrl(sampass); +#if 0 + /* I am convinced this check here is wrong, it is valid to + * change a password of a user that has a disabled account - gd */ + + if (acct_ctrl & ACB_DISABLED) { + DEBUG(2,("check_lanman_password: account %s disabled.\n", user)); + return NT_STATUS_ACCOUNT_DISABLED; + } +#endif + if ((acct_ctrl & ACB_PWNOTREQ) && lp_null_passwords()) { + /* construct a null password (in case one is needed */ + no_pw[0] = 0; + no_pw[1] = 0; + nt_lm_owf_gen(no_pw, null_ntpw, null_pw); + lanman_pw = null_pw; + nt_pw = null_pw; + + } else { + /* save pointers to passwords so we don't have to keep looking them up */ + if (lp_lanman_auth()) { + lanman_pw = pdb_get_lanman_passwd(sampass); + } else { + lanman_pw = NULL; + } + nt_pw = pdb_get_nt_passwd(sampass); + } + + if (nt_pw && nt_pass_set) { + /* IDEAL Case: passwords are in unicode, and we can + * read use the password encrypted with the NT hash + */ + password_encrypted = password_encrypted_with_nt_hash; + encryption_key = nt_pw; + } else if (lanman_pw && lm_pass_set) { + /* password may still be in unicode, but use LM hash version */ + password_encrypted = password_encrypted_with_lm_hash; + encryption_key = lanman_pw; + } else if (nt_pass_set) { + DEBUG(1, ("NT password change supplied for user %s, but we have no NT password to check it with\n", + user)); + return NT_STATUS_WRONG_PASSWORD; + } else if (lm_pass_set) { + if (lp_lanman_auth()) { + DEBUG(1, ("LM password change supplied for user %s, but we have no LanMan password to check it with\n", + user)); + } else { + DEBUG(1, ("LM password change supplied for user %s, but we have disabled LanMan authentication\n", + user)); + } + return NT_STATUS_WRONG_PASSWORD; + } else { + DEBUG(1, ("password change requested for user %s, but no password supplied!\n", + user)); + return NT_STATUS_WRONG_PASSWORD; + } + + /* + * Decrypt the password with the key + */ + arcfour_crypt( password_encrypted, encryption_key, 516); + + if (!decode_pw_buffer(talloc_tos(), + password_encrypted, + pp_new_passwd, + &new_pw_len, + nt_pass_set ? CH_UTF16 : CH_DOS)) { + return NT_STATUS_WRONG_PASSWORD; + } + + /* + * To ensure we got the correct new password, hash it and + * use it as a key to test the passed old password. + */ + + if (nt_pass_set) { + /* NT passwords, verify the NT hash. */ + + /* Calculate the MD4 hash (NT compatible) of the password */ + memset(new_nt_hash, '\0', 16); + E_md4hash(*pp_new_passwd, new_nt_hash); + + if (nt_pw) { + /* + * check the NT verifier + */ + E_old_pw_hash(new_nt_hash, nt_pw, verifier); + if (memcmp(verifier, old_nt_hash_encrypted, 16)) { + DEBUG(0, ("check_oem_password: old nt " + "password doesn't match.\n")); + return NT_STATUS_WRONG_PASSWORD; + } + + /* We could check the LM password here, but there is + * little point, we already know the password is + * correct, and the LM password might not even be + * present. */ + + /* Further, LM hash generation algorithms + * differ with charset, so we could + * incorrectly fail a perfectly valid password + * change */ +#ifdef DEBUG_PASSWORD + DEBUG(100, + ("check_oem_password: password %s ok\n", *pp_new_passwd)); +#endif + return NT_STATUS_OK; + } + + if (lanman_pw) { + /* + * check the lm verifier + */ + E_old_pw_hash(new_nt_hash, lanman_pw, verifier); + if (memcmp(verifier, old_lm_hash_encrypted, 16)) { + DEBUG(0,("check_oem_password: old lm password doesn't match.\n")); + return NT_STATUS_WRONG_PASSWORD; + } +#ifdef DEBUG_PASSWORD + DEBUG(100, + ("check_oem_password: password %s ok\n", *pp_new_passwd)); +#endif + return NT_STATUS_OK; + } + } + + if (lanman_pw && lm_pass_set) { + + E_deshash(*pp_new_passwd, new_lm_hash); + + /* + * check the lm verifier + */ + E_old_pw_hash(new_lm_hash, lanman_pw, verifier); + if (memcmp(verifier, old_lm_hash_encrypted, 16)) { + DEBUG(0,("check_oem_password: old lm password doesn't match.\n")); + return NT_STATUS_WRONG_PASSWORD; + } + +#ifdef DEBUG_PASSWORD + DEBUG(100, + ("check_oem_password: password %s ok\n", *pp_new_passwd)); +#endif + return NT_STATUS_OK; + } + + /* should not be reached */ + return NT_STATUS_WRONG_PASSWORD; +} + +static bool password_in_history(uint8_t nt_pw[NT_HASH_LEN], + uint32_t pw_history_len, + const uint8_t *pw_history) +{ + static const uint8_t zero_md5_nt_pw[SALTED_MD5_HASH_LEN] = { 0, }; + int i; + + dump_data(100, nt_pw, NT_HASH_LEN); + dump_data(100, pw_history, PW_HISTORY_ENTRY_LEN * pw_history_len); + + for (i=0; i<pw_history_len; i++) { + uint8_t new_nt_pw_salted_md5_hash[SALTED_MD5_HASH_LEN]; + const uint8_t *current_salt; + const uint8_t *old_nt_pw_salted_md5_hash; + + current_salt = &pw_history[i*PW_HISTORY_ENTRY_LEN]; + old_nt_pw_salted_md5_hash = current_salt + PW_HISTORY_SALT_LEN; + + if (memcmp(zero_md5_nt_pw, old_nt_pw_salted_md5_hash, + SALTED_MD5_HASH_LEN) == 0) { + /* Ignore zero valued entries. */ + continue; + } + + if (memcmp(zero_md5_nt_pw, current_salt, + PW_HISTORY_SALT_LEN) == 0) + { + /* + * New format: zero salt and then plain nt hash. + * Directly compare the hashes. + */ + if (memcmp(nt_pw, old_nt_pw_salted_md5_hash, + SALTED_MD5_HASH_LEN) == 0) + { + return true; + } + } else { + /* + * Old format: md5sum of salted nt hash. + * Create salted version of new pw to compare. + */ + E_md5hash(current_salt, nt_pw, new_nt_pw_salted_md5_hash); + + if (memcmp(new_nt_pw_salted_md5_hash, + old_nt_pw_salted_md5_hash, + SALTED_MD5_HASH_LEN) == 0) { + return true; + } + } + } + return false; +} + +/*********************************************************** + This routine takes the given password and checks it against + the password history. Returns True if this password has been + found in the history list. +************************************************************/ + +static bool check_passwd_history(struct samu *sampass, const char *plaintext) +{ + uchar new_nt_p16[NT_HASH_LEN]; + const uint8 *nt_pw; + const uint8 *pwhistory; + uint32 pwHisLen, curr_pwHisLen; + + pdb_get_account_policy(PDB_POLICY_PASSWORD_HISTORY, &pwHisLen); + if (pwHisLen == 0) { + return False; + } + + pwhistory = pdb_get_pw_history(sampass, &curr_pwHisLen); + if (!pwhistory || curr_pwHisLen == 0) { + return False; + } + + /* Only examine the minimum of the current history len and + the stored history len. Avoids race conditions. */ + pwHisLen = MIN(pwHisLen,curr_pwHisLen); + + nt_pw = pdb_get_nt_passwd(sampass); + + E_md4hash(plaintext, new_nt_p16); + + if (!memcmp(nt_pw, new_nt_p16, NT_HASH_LEN)) { + DEBUG(10,("check_passwd_history: proposed new password for user %s is the same as the current password !\n", + pdb_get_username(sampass) )); + return True; + } + + if (password_in_history(new_nt_p16, pwHisLen, pwhistory)) { + DEBUG(1,("check_passwd_history: proposed new password for " + "user %s found in history list !\n", + pdb_get_username(sampass) )); + return true; + } + return false; +} + +/*********************************************************** +************************************************************/ + +NTSTATUS check_password_complexity(const char *username, + const char *password, + enum samPwdChangeReason *samr_reject_reason) +{ + TALLOC_CTX *tosctx = talloc_tos(); + int check_ret; + char *cmd; + + /* Use external script to check password complexity */ + if ((lp_check_password_script() == NULL) + || (*(lp_check_password_script()) == '\0')) { + return NT_STATUS_OK; + } + + cmd = talloc_string_sub(tosctx, lp_check_password_script(), "%u", + username); + if (!cmd) { + return NT_STATUS_PASSWORD_RESTRICTION; + } + + check_ret = smbrunsecret(cmd, password); + DEBUG(5,("check_password_complexity: check password script (%s) " + "returned [%d]\n", cmd, check_ret)); + TALLOC_FREE(cmd); + + if (check_ret != 0) { + DEBUG(1,("check_password_complexity: " + "check password script said new password is not good " + "enough!\n")); + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_NOT_COMPLEX; + } + return NT_STATUS_PASSWORD_RESTRICTION; + } + + return NT_STATUS_OK; +} + +/*********************************************************** + Code to change the oem password. Changes both the lanman + and NT hashes. Old_passwd is almost always NULL. + NOTE this function is designed to be called as root. Check the old password + is correct before calling. JRA. +************************************************************/ + +static NTSTATUS change_oem_password(struct samu *hnd, const char *rhost, + char *old_passwd, char *new_passwd, + bool as_root, + enum samPwdChangeReason *samr_reject_reason) +{ + uint32 min_len; + uint32 refuse; + TALLOC_CTX *tosctx = talloc_tos(); + struct passwd *pass = NULL; + const char *username = pdb_get_username(hnd); + time_t can_change_time = pdb_get_pass_can_change_time(hnd); + NTSTATUS status; + + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_NO_ERROR; + } + + /* check to see if the secdesc has previously been set to disallow */ + if (!pdb_get_pass_can_change(hnd)) { + DEBUG(1, ("user %s does not have permissions to change password\n", username)); + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_NO_ERROR; + } + return NT_STATUS_ACCOUNT_RESTRICTION; + } + + /* check to see if it is a Machine account and if the policy + * denies machines to change the password. * + * Should we deny also SRVTRUST and/or DOMSTRUST ? .SSS. */ + if (pdb_get_acct_ctrl(hnd) & ACB_WSTRUST) { + if (pdb_get_account_policy(PDB_POLICY_REFUSE_MACHINE_PW_CHANGE, &refuse) && refuse) { + DEBUG(1, ("Machine %s cannot change password now, " + "denied by Refuse Machine Password Change policy\n", + username)); + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_NO_ERROR; + } + return NT_STATUS_ACCOUNT_RESTRICTION; + } + } + + /* removed calculation here, because passdb now calculates + based on policy. jmcd */ + if ((can_change_time != 0) && (time(NULL) < can_change_time)) { + DEBUG(1, ("user %s cannot change password now, must " + "wait until %s\n", username, + http_timestring(tosctx, can_change_time))); + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_NO_ERROR; + } + return NT_STATUS_ACCOUNT_RESTRICTION; + } + + if (pdb_get_account_policy(PDB_POLICY_MIN_PASSWORD_LEN, &min_len) && (str_charnum(new_passwd) < min_len)) { + DEBUG(1, ("user %s cannot change password - password too short\n", + username)); + DEBUGADD(1, (" account policy min password len = %d\n", min_len)); + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_PASSWORD_TOO_SHORT; + } + return NT_STATUS_PASSWORD_RESTRICTION; +/* return NT_STATUS_PWD_TOO_SHORT; */ + } + + if (check_passwd_history(hnd,new_passwd)) { + if (samr_reject_reason) { + *samr_reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY; + } + return NT_STATUS_PASSWORD_RESTRICTION; + } + + pass = Get_Pwnam_alloc(tosctx, username); + if (!pass) { + DEBUG(1, ("change_oem_password: Username %s does not exist in system !?!\n", username)); + return NT_STATUS_ACCESS_DENIED; + } + + status = check_password_complexity(username, new_passwd, samr_reject_reason); + if (!NT_STATUS_IS_OK(status)) { + TALLOC_FREE(pass); + return status; + } + + /* + * If unix password sync was requested, attempt to change + * the /etc/passwd database first. Return failure if this cannot + * be done. + * + * This occurs before the oem change, because we don't want to + * update it if chgpasswd failed. + * + * Conditional on lp_unix_password_sync() because we don't want + * to touch the unix db unless we have admin permission. + */ + + if(lp_unix_password_sync() && + !chgpasswd(username, rhost, pass, old_passwd, new_passwd, + as_root)) { + TALLOC_FREE(pass); + return NT_STATUS_ACCESS_DENIED; + } + + TALLOC_FREE(pass); + + if (!pdb_set_plaintext_passwd (hnd, new_passwd)) { + return NT_STATUS_ACCESS_DENIED; + } + + /* Now write it into the file. */ + return pdb_update_sam_account (hnd); +} + +/*********************************************************** + Code to check and change the OEM hashed password. +************************************************************/ + +NTSTATUS pass_oem_change(char *user, const char *rhost, + uchar password_encrypted_with_lm_hash[516], + const uchar old_lm_hash_encrypted[16], + uchar password_encrypted_with_nt_hash[516], + const uchar old_nt_hash_encrypted[16], + enum samPwdChangeReason *reject_reason) +{ + char *new_passwd = NULL; + struct samu *sampass = NULL; + NTSTATUS nt_status; + bool ret = false; + + if (!(sampass = samu_new(NULL))) { + return NT_STATUS_NO_MEMORY; + } + + become_root(); + ret = pdb_getsampwnam(sampass, user); + unbecome_root(); + + if (ret == false) { + DEBUG(0,("pass_oem_change: getsmbpwnam returned NULL\n")); + TALLOC_FREE(sampass); + return NT_STATUS_NO_SUCH_USER; + } + + nt_status = check_oem_password(user, + password_encrypted_with_lm_hash, + old_lm_hash_encrypted, + password_encrypted_with_nt_hash, + old_nt_hash_encrypted, + sampass, + &new_passwd); + + if (!NT_STATUS_IS_OK(nt_status)) { + TALLOC_FREE(sampass); + return nt_status; + } + + /* We've already checked the old password here.... */ + become_root(); + nt_status = change_oem_password(sampass, rhost, NULL, new_passwd, + True, reject_reason); + unbecome_root(); + + memset(new_passwd, 0, strlen(new_passwd)); + + TALLOC_FREE(sampass); + + return nt_status; +} |