int mm_sshpam_query(void *ctx, char **name, char **info, u_int *num, char ***prompts, u_int **echo_on) { Buffer m; u_int i; int ret; debug3("%s", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, &m); debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, &m); ret = buffer_get_int(&m); debug3("%s: pam_query returned %d", __func__, ret); *name = buffer_get_string(&m, NULL); *info = buffer_get_string(&m, NULL); sshpam_set_maxtries_reached(buffer_get_int(&m)); *num = buffer_get_int(&m); if (*num > PAM_MAX_NUM_MSG) fatal("%s: recieved %u PAM messages, expected <= %u", __func__, *num, PAM_MAX_NUM_MSG); *prompts = xcalloc((*num + 1), sizeof(char *)); *echo_on = xcalloc((*num + 1), sizeof(u_int)); for (i = 0; i < *num; ++i) { (*prompts)[i] = buffer_get_string(&m, NULL); (*echo_on)[i] = buffer_get_int(&m); } buffer_free(&m); return (ret); }
/* Do the password authentication */ int mm_auth_password(Authctxt *authctxt, char *password) { Buffer m; int authenticated = 0; debug3("%s entering", __func__); buffer_init(&m); buffer_put_cstring(&m, password); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m); debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m); authenticated = buffer_get_int(&m); #ifdef USE_PAM sshpam_set_maxtries_reached(buffer_get_int(&m)); #endif buffer_free(&m); debug3("%s: user %sauthenticated", __func__, authenticated ? "" : "not "); return (authenticated); }
/* * Attempt password authentication via PAM */ int sshpam_auth_passwd(Authctxt *authctxt, const char *password) { int flags = (options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0); char *fake = NULL; if (!options.use_pam || sshpam_handle == NULL) fatal("PAM: %s called when PAM disabled or failed to " "initialise.", __func__); sshpam_password = password; sshpam_authctxt = authctxt; /* * If the user logging in is invalid, or is root but is not permitted * by PermitRootLogin, use an invalid password to prevent leaking * information via timing (eg if the PAM config has a delay on fail). */ if (!authctxt->valid || (authctxt->pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)) sshpam_password = fake = fake_password(password); sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&passwd_conv); if (sshpam_err != PAM_SUCCESS) fatal("PAM: %s: failed to set PAM_CONV: %s", __func__, pam_strerror(sshpam_handle, sshpam_err)); sshpam_err = pam_authenticate(sshpam_handle, flags); sshpam_password = NULL; free(fake); if (sshpam_err == PAM_MAXTRIES) sshpam_set_maxtries_reached(1); if (sshpam_err == PAM_SUCCESS && authctxt->valid) { debug("PAM: password authentication accepted for %.100s", authctxt->user); return 1; } else { debug("PAM: password authentication failed for %.100s: %s", authctxt->valid ? authctxt->user : "******", pam_strerror(sshpam_handle, sshpam_err)); return 0; } }
static int sshpam_query(void *ctx, char **name, char **info, u_int *num, char ***prompts, u_int **echo_on) { struct ssh *ssh = active_state; /* XXX */ Buffer buffer; struct pam_ctxt *ctxt = ctx; size_t plen; u_char type; char *msg; size_t len, mlen; debug3("PAM: %s entering", __func__); buffer_init(&buffer); *name = xstrdup(""); *info = xstrdup(""); *prompts = xmalloc(sizeof(char *)); **prompts = NULL; plen = 0; *echo_on = xmalloc(sizeof(u_int)); while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { type = buffer_get_char(&buffer); msg = buffer_get_string(&buffer, NULL); mlen = strlen(msg); switch (type) { case PAM_PROMPT_ECHO_ON: case PAM_PROMPT_ECHO_OFF: *num = 1; len = plen + mlen + 1; **prompts = xreallocarray(**prompts, 1, len); strlcpy(**prompts + plen, msg, len - plen); plen += mlen; **echo_on = (type == PAM_PROMPT_ECHO_ON); free(msg); return (0); case PAM_ERROR_MSG: case PAM_TEXT_INFO: /* accumulate messages */ len = plen + mlen + 2; **prompts = xreallocarray(**prompts, 1, len); strlcpy(**prompts + plen, msg, len - plen); plen += mlen; strlcat(**prompts + plen, "\n", len - plen); plen++; free(msg); break; case PAM_ACCT_EXPIRED: case PAM_MAXTRIES: if (type == PAM_ACCT_EXPIRED) sshpam_account_status = 0; if (type == PAM_MAXTRIES) sshpam_set_maxtries_reached(1); /* FALLTHROUGH */ case PAM_AUTH_ERR: debug3("PAM: %s", pam_strerror(sshpam_handle, type)); if (**prompts != NULL && strlen(**prompts) != 0) { *info = **prompts; **prompts = NULL; *num = 0; **echo_on = 0; ctxt->pam_done = -1; free(msg); return 0; } /* FALLTHROUGH */ case PAM_SUCCESS: if (**prompts != NULL) { /* drain any accumulated messages */ debug("PAM: %s", **prompts); buffer_append(&loginmsg, **prompts, strlen(**prompts)); free(**prompts); **prompts = NULL; } if (type == PAM_SUCCESS) { if (!sshpam_authctxt->valid || (sshpam_authctxt->pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)) fatal("Internal error: PAM auth " "succeeded when it should have " "failed"); import_environments(&buffer); *num = 0; **echo_on = 0; ctxt->pam_done = 1; free(msg); return (0); } error("PAM: %s for %s%.100s from %.100s", msg, sshpam_authctxt->valid ? "" : "illegal user ", sshpam_authctxt->user, auth_get_canonical_hostname(ssh, options.use_dns)); /* FALLTHROUGH */ default: *num = 0; **echo_on = 0; free(msg); ctxt->pam_done = -1; return (-1); } } return (-1); }
/* * Authentication thread. */ static void * sshpam_thread(void *ctxtp) { struct pam_ctxt *ctxt = ctxtp; Buffer buffer; struct pam_conv sshpam_conv; int flags = (options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0); #ifndef UNSUPPORTED_POSIX_THREADS_HACK extern char **environ; char **env_from_pam; u_int i; const char *pam_user; const char **ptr_pam_user = &pam_user; char *tz = getenv("TZ"); sshpam_err = pam_get_item(sshpam_handle, PAM_USER, (sshpam_const void **)ptr_pam_user); if (sshpam_err != PAM_SUCCESS) goto auth_fail; environ[0] = NULL; if (tz != NULL) if (setenv("TZ", tz, 1) == -1) error("PAM: could not set TZ environment: %s", strerror(errno)); if (sshpam_authctxt != NULL) { setproctitle("%s [pam]", sshpam_authctxt->valid ? pam_user : "******"); } #endif sshpam_conv.conv = sshpam_thread_conv; sshpam_conv.appdata_ptr = ctxt; if (sshpam_authctxt == NULL) fatal("%s: PAM authctxt not initialized", __func__); buffer_init(&buffer); sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&sshpam_conv); if (sshpam_err != PAM_SUCCESS) goto auth_fail; sshpam_err = pam_authenticate(sshpam_handle, flags); if (sshpam_err == PAM_MAXTRIES) sshpam_set_maxtries_reached(1); if (sshpam_err != PAM_SUCCESS) goto auth_fail; if (compat20) { if (!do_pam_account()) { sshpam_err = PAM_ACCT_EXPIRED; goto auth_fail; } if (sshpam_authctxt->force_pwchange) { sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); if (sshpam_err != PAM_SUCCESS) goto auth_fail; sshpam_password_change_required(0); } } buffer_put_cstring(&buffer, "OK"); #ifndef UNSUPPORTED_POSIX_THREADS_HACK /* Export variables set by do_pam_account */ buffer_put_int(&buffer, sshpam_account_status); buffer_put_int(&buffer, sshpam_authctxt->force_pwchange); /* Export any environment strings set in child */ for(i = 0; environ[i] != NULL; i++) ; /* Count */ buffer_put_int(&buffer, i); for(i = 0; environ[i] != NULL; i++) buffer_put_cstring(&buffer, environ[i]); /* Export any environment strings set by PAM in child */ env_from_pam = pam_getenvlist(sshpam_handle); for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) ; /* Count */ buffer_put_int(&buffer, i); for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) buffer_put_cstring(&buffer, env_from_pam[i]); #endif /* UNSUPPORTED_POSIX_THREADS_HACK */ /* XXX - can't do much about an error here */ ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); buffer_free(&buffer); pthread_exit(NULL); auth_fail: buffer_put_cstring(&buffer, pam_strerror(sshpam_handle, sshpam_err)); /* XXX - can't do much about an error here */ if (sshpam_err == PAM_ACCT_EXPIRED) ssh_msg_send(ctxt->pam_csock, PAM_ACCT_EXPIRED, &buffer); else if (sshpam_maxtries_reached) ssh_msg_send(ctxt->pam_csock, PAM_MAXTRIES, &buffer); else ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); buffer_free(&buffer); pthread_exit(NULL); return (NULL); /* Avoid warning for non-pthread case */ }