monitor_wrap.c

OpenSSH 是 SSH （Secure SHell） 协议的免费开源实现。它用安全、加密的网络连接工具代替了 telnet、ftp、 rlogin、rsh 和 rcp 工具。OpenSSH 支持

	debug3("%s: New keys have been sent", __func__);
 skip:
	/* More key context */
	plen = packet_get_keycontext(MODE_OUT, NULL);
	p = xmalloc(plen+1);
	packet_get_keycontext(MODE_OUT, p);
	buffer_put_string(&m, p, plen);
	xfree(p);

	plen = packet_get_keycontext(MODE_IN, NULL);
	p = xmalloc(plen+1);
	packet_get_keycontext(MODE_IN, p);
	buffer_put_string(&m, p, plen);
	xfree(p);

	/* Compression state */
	debug3("%s: Sending compression state", __func__);
	buffer_put_string(&m, &outgoing_stream, sizeof(outgoing_stream));
	buffer_put_string(&m, &incoming_stream, sizeof(incoming_stream));

	/* Network I/O buffers */
	buffer_put_string(&m, buffer_ptr(&input), buffer_len(&input));
	buffer_put_string(&m, buffer_ptr(&output), buffer_len(&output));

	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, &m);
	debug3("%s: Finished sending state", __func__);

	buffer_free(&m);
}

int
mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
{
	Buffer m;
	char *p, *msg;
	int success = 0;

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);

	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);

	success = buffer_get_int(&m);
	if (success == 0) {
		debug3("%s: pty alloc failed", __func__);
		buffer_free(&m);
		return (0);
	}
	p = buffer_get_string(&m, NULL);
	msg = buffer_get_string(&m, NULL);
	buffer_free(&m);

	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
	xfree(p);

	buffer_append(&loginmsg, msg, strlen(msg));
	xfree(msg);

	*ptyfd = mm_receive_fd(pmonitor->m_recvfd);
	*ttyfd = mm_receive_fd(pmonitor->m_recvfd);

	/* Success */
	return (1);
}

void
mm_session_pty_cleanup2(Session *s)
{
	Buffer m;

	if (s->ttyfd == -1)
		return;
	buffer_init(&m);
	buffer_put_cstring(&m, s->tty);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
	buffer_free(&m);

	/* closed dup'ed master */
	if (close(s->ptymaster) < 0)
		error("close(s->ptymaster): %s", strerror(errno));

	/* unlink pty from session */
	s->ttyfd = -1;
}

#ifdef USE_PAM
void
mm_start_pam(Authctxt *authctxt)
{
	Buffer m;

	debug3("%s entering", __func__);
	if (!options.use_pam)
		fatal("UsePAM=no, but ended up in %s anyway", __func__);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, &m);

	buffer_free(&m);
}

u_int
mm_do_pam_account(void)
{
	Buffer m;
	u_int ret;
	char *msg;

	debug3("%s entering", __func__);
	if (!options.use_pam)
		fatal("UsePAM=no, but ended up in %s anyway", __func__);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, &m);

	mm_request_receive_expect(pmonitor->m_recvfd,
	    MONITOR_ANS_PAM_ACCOUNT, &m);
	ret = buffer_get_int(&m);
	msg = buffer_get_string(&m, NULL);
	buffer_append(&loginmsg, msg, strlen(msg));
	xfree(msg);

	buffer_free(&m);

	debug3("%s returning %d", __func__, ret);

	return (ret);
}

void *
mm_sshpam_init_ctx(Authctxt *authctxt)
{
	Buffer m;
	int success;

	debug3("%s", __func__);
	buffer_init(&m);
	buffer_put_cstring(&m, authctxt->user);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, &m);
	debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, &m);
	success = buffer_get_int(&m);
	if (success == 0) {
		debug3("%s: pam_init_ctx failed", __func__);
		buffer_free(&m);
		return (NULL);
	}
	buffer_free(&m);
	return (authctxt);
}

int
mm_sshpam_query(void *ctx, char **name, char **info,
    u_int *num, char ***prompts, u_int **echo_on)
{
	Buffer m;
	int i, 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);
	*num = buffer_get_int(&m);
	*prompts = xmalloc((*num + 1) * sizeof(char *));
	*echo_on = xmalloc((*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);
}

int
mm_sshpam_respond(void *ctx, u_int num, char **resp)
{
	Buffer m;
	int i, ret;

	debug3("%s", __func__);
	buffer_init(&m);
	buffer_put_int(&m, num);
	for (i = 0; i < num; ++i)
		buffer_put_cstring(&m, resp[i]);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, &m);
	debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, &m);
	ret = buffer_get_int(&m);
	debug3("%s: pam_respond returned %d", __func__, ret);
	buffer_free(&m);
	return (ret);
}

void
mm_sshpam_free_ctx(void *ctxtp)
{
	Buffer m;

	debug3("%s", __func__);
	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, &m);
	debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, &m);
	buffer_free(&m);
}
#endif /* USE_PAM */

/* Request process termination */

void
mm_terminate(void)
{
	Buffer m;

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
	buffer_free(&m);
}

int
mm_ssh1_session_key(BIGNUM *num)
{
	int rsafail;
	Buffer m;

	buffer_init(&m);
	buffer_put_bignum2(&m, num);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSKEY, &m);

	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SESSKEY, &m);

	rsafail = buffer_get_int(&m);
	buffer_get_bignum2(&m, num);

	buffer_free(&m);

	return (rsafail);
}

static void
mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
    char ***prompts, u_int **echo_on)
{
	*name = xstrdup("");
	*infotxt = xstrdup("");
	*numprompts = 1;
	*prompts = xmalloc(*numprompts * sizeof(char *));
	*echo_on = xmalloc(*numprompts * sizeof(u_int));
	(*echo_on)[0] = 0;
}

int
mm_bsdauth_query(void *ctx, char **name, char **infotxt,
   u_int *numprompts, char ***prompts, u_int **echo_on)
{
	Buffer m;
	u_int success;
	char *challenge;

	debug3("%s: entering", __func__);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);

	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
	    &m);
	success = buffer_get_int(&m);
	if (success == 0) {
		debug3("%s: no challenge", __func__);
		buffer_free(&m);
		return (-1);
	}

	/* Get the challenge, and format the response */
	challenge  = buffer_get_string(&m, NULL);
	buffer_free(&m);

	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
	(*prompts)[0] = challenge;

	debug3("%s: received challenge: %s", __func__, challenge);

	return (0);
}

int
mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
{
	Buffer m;
	int authok;

	debug3("%s: entering", __func__);
	if (numresponses != 1)
		return (-1);

	buffer_init(&m);
	buffer_put_cstring(&m, responses[0]);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);

	mm_request_receive_expect(pmonitor->m_recvfd,
	    MONITOR_ANS_BSDAUTHRESPOND, &m);

	authok = buffer_get_int(&m);
	buffer_free(&m);

	return ((authok == 0) ? -1 : 0);
}

#ifdef SKEY
int
mm_skey_query(void *ctx, char **name, char **infotxt,
   u_int *numprompts, char ***prompts, u_int **echo_on)
{
	Buffer m;
	int len;
	u_int success;
	char *p, *challenge;

	debug3("%s: entering", __func__);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m);

	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY,
	    &m);
	success = buffer_get_int(&m);
	if (success == 0) {
		debug3("%s: no challenge", __func__);
		buffer_free(&m);
		return (-1);
	}

	/* Get the challenge, and format the response */
	challenge  = buffer_get_string(&m, NULL);
	buffer_free(&m);

	debug3("%s: received challenge: %s", __func__, challenge);

	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);

	len = strlen(challenge) + strlen(SKEY_PROMPT) + 1;
	p = xmalloc(len);
	strlcpy(p, challenge, len);
	strlcat(p, SKEY_PROMPT, len);
	(*prompts)[0] = p;
	xfree(challenge);

	return (0);
}

int
mm_skey_respond(void *ctx, u_int numresponses, char **responses)
{
	Buffer m;
	int authok;

	debug3("%s: entering", __func__);
	if (numresponses != 1)
		return (-1);

	buffer_init(&m);
	buffer_put_cstring(&m, responses[0]);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m);

	mm_request_receive_expect(pmonitor->m_recvfd,
	    MONITOR_ANS_SKEYRESPOND, &m);

	authok = buffer_get_int(&m);
	buffer_free(&m);

	return ((authok == 0) ? -1 : 0);
}
#endif /* SKEY */

void
mm_ssh1_session_id(u_char session_id[16])
{
	Buffer m;
	int i;

	debug3("%s entering", __func__);

	buffer_init(&m);
	for (i = 0; i < 16; i++)
		buffer_put_char(&m, session_id[i]);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSID, &m);
	buffer_free(&m);
}

int
mm_auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
	Buffer m;
	Key *key;
	u_char *blob;
	u_int blen;
	int allowed = 0, have_forced = 0;

	debug3("%s entering", __func__);

	buffer_init(&m);
	buffer_put_bignum2(&m, client_n);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSAKEYALLOWED, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSAKEYALLOWED, &m);

	allowed = buffer_get_int(&m);

	/* fake forced command */
	auth_clear_options();
	have_forced = buffer_get_int(&m);
	forced_command = have_forced ? xstrdup("true") : NULL;

	if (allowed && rkey != NULL) {
		blob = buffer_get_string(&m, &blen);
		if ((key = key_from_blob(blob, blen)) == NULL)
			fatal("%s: key_from_blob failed", __func__);
		*rkey = key;
		xfree(blob);
	}
	mm_send_debug(&m);
	buffer_free(&m);

	return (allowed);
}

BIGNUM *
mm_auth_rsa_generate_challenge(Key *key)
{
	Buffer m;
	BIGNUM *challenge;
	u_char *blob;
	u_int blen;

	debug3("%s entering", __func__);

	if ((challenge = BN_new()) == NULL)
		fatal("%s: BN_new failed", __func__);

	key->type = KEY_RSA;    /* XXX cheat for key_to_blob */
	if (key_to_blob(key, &blob, &blen) == 0)
		fatal("%s: key_to_blob failed", __func__);
	key->type = KEY_RSA1;

	buffer_init(&m);
	buffer_put_string(&m, blob, blen);
	xfree(blob);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSACHALLENGE, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSACHALLENGE, &m);

	buffer_get_bignum2(&m, challenge);
	buffer_free(&m);

	return (challenge);
}

int
mm_auth_rsa_verify_response(Key *key, BIGNUM *p, u_char response[16])
{
	Buffer m;
	u_char *blob;
	u_int blen;
	int success = 0;

	debug3("%s entering", __func__);

	key->type = KEY_RSA;    /* XXX cheat for key_to_blob */
	if (key_to_blob(key, &blob, &blen) == 0)
		fatal("%s: key_to_blob failed", __func__);
	key->type = KEY_RSA1;

	buffer_init(&m);
	buffer_put_string(&m, blob, blen);
	buffer_put_string(&m, response, 16);
	xfree(blob);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSARESPONSE, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSARESPONSE, &m);

	success = buffer_get_int(&m);
	buffer_free(&m);

	return (success);
}

#ifdef SSH_AUDIT_EVENTS
void
mm_audit_event(ssh_audit_event_t event)
{
	Buffer m;

	debug3("%s entering", __func__);

	buffer_init(&m);
	buffer_put_int(&m, event);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, &m);
	buffer_free(&m);
}

void
mm_audit_run_command(const char *command)
{
	Buffer m;

	debug3("%s entering command %s", __func__, command);

	buffer_init(&m);
	buffer_put_cstring(&m, command);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, &m);
	buffer_free(&m);
}
#endif /* SSH_AUDIT_EVENTS */

#ifdef GSSAPI
OM_uint32
mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
{
	Buffer m;
	OM_uint32 major;

	/* Client doesn't get to see the context */
	*ctx = NULL;

	buffer_init(&m);
	buffer_put_string(&m, goid->elements, goid->length);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);

	major = buffer_get_int(&m);

	buffer_free(&m);
	return (major);
}

OM_uint32
mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
    gss_buffer_desc *out, OM_uint32 *flags)
{
	Buffer m;
	OM_uint32 major;
	u_int len;

	buffer_init(&m);
	buffer_put_string(&m, in->value, in->length);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);

	major = buffer_get_int(&m);
	out->value = buffer_get_string(&m, &len);
	out->length = len;
	if (flags)
		*flags = buffer_get_int(&m);

	buffer_free(&m);

	return (major);
}

OM_uint32
mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
{
	Buffer m;
	OM_uint32 major;

	buffer_init(&m);
	buffer_put_string(&m, gssbuf->value, gssbuf->length);
	buffer_put_string(&m, gssmic->value, gssmic->length);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
	    &m);

	major = buffer_get_int(&m);
	buffer_free(&m);
	return(major);
}

int
mm_ssh_gssapi_userok(char *user)
{
	Buffer m;
	int authenticated = 0;

	buffer_init(&m);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
				  &m);

	authenticated = buffer_get_int(&m);

	buffer_free(&m);
	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
	return (authenticated);
}
#endif /* GSSAPI */