int
mm_skey_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_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);

	xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT);
	xfree(challenge);

	return (0);
}

int
mm_answer_rsa_challenge(int sock, Buffer *m)
{
	Key *key = NULL;
	u_char *blob;
	u_int blen;

	debug3("%s entering", __func__);

	if (!authctxt->valid)
		fatal("%s: authctxt not valid", __func__);
	blob = buffer_get_string(m, &blen);
	if (!monitor_allowed_key(blob, blen))
		fatal("%s: bad key, not previously allowed", __func__);
	if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
		fatal("%s: key type mismatch", __func__);
	if ((key = key_from_blob(blob, blen)) == NULL)
		fatal("%s: received bad key", __func__);

	if (ssh1_challenge)
		BN_clear_free(ssh1_challenge);
	ssh1_challenge = auth_rsa_generate_challenge(key);

	buffer_clear(m);
	buffer_put_bignum2(m, ssh1_challenge);

	debug3("%s sending reply", __func__);
	mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);

	monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);

	xfree(blob);
	key_free(key);
	return (0);
}

int
mm_answer_authpassword(int sock, Buffer *m)
{
	static int call_count;
	char *passwd;
	int authenticated;
	u_int plen;

	passwd = buffer_get_string(m, &plen);
	/* Only authenticate if the context is valid */
	authenticated = options.password_authentication &&
	    auth_password(authctxt, passwd);
	memset(passwd, 0, strlen(passwd));
	xfree(passwd);

	buffer_clear(m);
	buffer_put_int(m, authenticated);

	debug3("%s: sending result %d", __func__, authenticated);
	mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);

	call_count++;
	if (plen == 0 && call_count == 1)
		auth_method = "none";
	else
		auth_method = "password";

	/* Causes monitor loop to terminate if authenticated */
	return (authenticated);
}

static char *
get_handle(int fd, u_int expected_id, u_int *len)
{
	Buffer msg;
	u_int type, id;
	char *handle;

	buffer_init(&msg);
	get_msg(fd, &msg);
	type = buffer_get_char(&msg);
	id = buffer_get_int(&msg);

	if (id != expected_id)
		fatal("ID mismatch (%u != %u)", id, expected_id);
	if (type == SSH2_FXP_STATUS) {
		int status = buffer_get_int(&msg);

		error("Couldn't get handle: %s", fx2txt(status));
		return(NULL);
	} else if (type != SSH2_FXP_HANDLE)
		fatal("Expected SSH2_FXP_HANDLE(%u) packet, got %u",
		    SSH2_FXP_HANDLE, type);

	handle = buffer_get_string(&msg, len);
	buffer_free(&msg);

	return(handle);
}

void
mm_jpake_key_confirm(struct modp_group *grp, BIGNUM *s, BIGNUM *step2_val,
    BIGNUM *mypriv2, BIGNUM *mypub1, BIGNUM *mypub2,
    BIGNUM *theirpub1, BIGNUM *theirpub2,
    const u_char *my_id, u_int my_id_len,
    const u_char *their_id, u_int their_id_len,
    const u_char *sess_id, u_int sess_id_len,
    const u_char *theirpriv2_s_proof, u_int theirpriv2_s_proof_len,
    BIGNUM **k,
    u_char **confirm_hash, u_int *confirm_hash_len)
{
	Buffer m;

	debug3("%s entering", __func__);

	buffer_init(&m);
	/* monitor already has all bignums except step2_val */
	buffer_put_bignum2(&m, step2_val);
	/* monitor already knows all the ids */
	buffer_put_string(&m, theirpriv2_s_proof, theirpriv2_s_proof_len);

	mm_request_send(pmonitor->m_recvfd,
	    MONITOR_REQ_JPAKE_KEY_CONFIRM, &m);

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

	/* 'k' is sensitive and stays in the monitor */
	*confirm_hash = buffer_get_string(&m, confirm_hash_len);

	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);
}

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);
	}
	buffer_free(&m);

	return (allowed);
}

OM_uint32
mm_ssh_gssapi_localname(char **lname)
{
	Buffer m;
	OM_uint32 major;

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

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

	major = buffer_get_int(&m);
	*lname = buffer_get_string(&m, NULL);

	if (GSS_ERROR(major)) {
		debug3("%s: gssapi identity mapping failed", __func__);
	} else {
		debug3("%s: gssapi identity mapped to %s", __func__, *lname);
	}

	buffer_free(&m);

	return(major);
}

int
mm_answer_bsdauthrespond(int sock, Buffer *m)
{
	char *response;
	int authok;

	if (!options.kbd_interactive_authentication)
		fatal("%s: kbd-int authentication not enabled", __func__);
	if (authctxt->as == NULL)
		fatal("%s: no bsd auth session", __func__);

	response = buffer_get_string(m, NULL);
	authok = options.challenge_response_authentication &&
	    auth_userresponse(authctxt->as, response, 0);
	authctxt->as = NULL;
	debug3("%s: <%s> = <%d>", __func__, response, authok);
	free(response);

	buffer_clear(m);
	buffer_put_int(m, authok);

	debug3("%s: sending authenticated: %d", __func__, authok);
	mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);

	auth_method = "keyboard-interactive";
	auth_submethod = "bsdauth";

	return (authok != 0);
}

int
mm_answer_skeyrespond(int sock, Buffer *m)
{
	char *response;
	int authok;

	response = buffer_get_string(m, NULL);

	authok = (options.challenge_response_authentication &&
	    authctxt->valid &&
	    skey_haskey(authctxt->pw->pw_name) == 0 &&
	    skey_passcheck(authctxt->pw->pw_name, response) != -1);

	free(response);

	buffer_clear(m);
	buffer_put_int(m, authok);

	debug3("%s: sending authenticated: %d", __func__, authok);
	mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);

	auth_method = "keyboard-interactive";
	auth_submethod = "skey";

	return (authok != 0);
}

int
mm_answer_gss_accept_ctx(int sock, Buffer *m)
{
	gss_buffer_desc in;
	gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
	OM_uint32 major, minor;
	OM_uint32 flags = 0; /* GSI needs this */
	u_int len;

	if (!options.gss_authentication)
		fatal("%s: GSSAPI authentication not enabled", __func__);

	in.value = buffer_get_string(m, &len);
	in.length = len;
	major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
	free(in.value);

	buffer_clear(m);
	buffer_put_int(m, major);
	buffer_put_string(m, out.value, out.length);
	buffer_put_int(m, flags);
	mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);

	gss_release_buffer(&minor, &out);

	if (major == GSS_S_COMPLETE) {
		monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
		monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
		monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
	}
	return (0);
}

int
mm_answer_authpassword(int sock, Buffer *m)
{
	static int call_count;
	char *passwd;
	int authenticated;
	u_int plen;

	if (!options.password_authentication)
		fatal("%s: password authentication not enabled", __func__);
	passwd = buffer_get_string(m, &plen);
	/* Only authenticate if the context is valid */
	authenticated = options.password_authentication &&
	    auth_password(authctxt, passwd);
	explicit_bzero(passwd, strlen(passwd));
	free(passwd);

	buffer_clear(m);
	buffer_put_int(m, authenticated);
#ifdef USE_PAM
	buffer_put_int(m, sshpam_get_maxtries_reached());
#endif

	debug3("%s: sending result %d", __func__, authenticated);
	mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);

	call_count++;
	if (plen == 0 && call_count == 1)
		auth_method = "none";
	else
		auth_method = "password";

	/* Causes monitor loop to terminate if authenticated */
	return (authenticated);
}

int
mm_answer_gss_setup_ctx(int sock, Buffer *m)
{
	gss_OID_desc goid;
	OM_uint32 major;
	u_int len;

	if (!options.gss_authentication)
		fatal("%s: GSSAPI authentication not enabled", __func__);

	goid.elements = buffer_get_string(m, &len);
	goid.length = len;

	major = ssh_gssapi_server_ctx(&gsscontext, &goid);

	free(goid.elements);

	buffer_clear(m);
	buffer_put_int(m, major);

	mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);

	/* Now we have a context, enable the step */
	monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);

	return (0);
}

static int
monitor_valid_userblob(u_char *data, u_int datalen)
{
	Buffer b;
	u_char *p;
	char *userstyle, *cp;
	u_int len;
	int fail = 0;

	buffer_init(&b);
	buffer_append(&b, data, datalen);

	if (datafellows & SSH_OLD_SESSIONID) {
		p = buffer_ptr(&b);
		len = buffer_len(&b);
		if ((session_id2 == NULL) ||
		    (len < session_id2_len) ||
		    (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
			fail++;
		buffer_consume(&b, session_id2_len);
	} else {
		p = buffer_get_string(&b, &len);
		if ((session_id2 == NULL) ||
		    (len != session_id2_len) ||
		    (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
			fail++;
		free(p);
	}
	if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
		fail++;
	cp = buffer_get_cstring(&b, NULL);
	xasprintf(&userstyle, "%s%s%s", authctxt->user,
	    authctxt->style ? ":" : "",
	    authctxt->style ? authctxt->style : "");
	if (strcmp(userstyle, cp) != 0) {
		logit("wrong user name passed to monitor: "
		    "expected %s != %.100s", userstyle, cp);
		fail++;
	}
	free(userstyle);
	free(cp);
	buffer_skip_string(&b);
	if (datafellows & SSH_BUG_PKAUTH) {
		if (!buffer_get_char(&b))
			fail++;
	} else {
		cp = buffer_get_cstring(&b, NULL);
		if (strcmp("publickey", cp) != 0)
			fail++;
		free(cp);
		if (!buffer_get_char(&b))
			fail++;
		buffer_skip_string(&b);
	}
	buffer_skip_string(&b);
	if (buffer_len(&b) != 0)
		fail++;
	buffer_free(&b);
	return (fail == 0);
}

int
mm_answer_pam_respond(int sock, Buffer *m)
{
	char **resp;
	u_int i, num;
	int ret;

	debug3("%s", __func__);
	if (sshpam_ctxt == NULL)
		fatal("%s: no context", __func__);
	sshpam_authok = NULL;
	num = buffer_get_int(m);
	if (num > 0) {
		resp = xcalloc(num, sizeof(char *));
		for (i = 0; i < num; ++i)
			resp[i] = buffer_get_string(m, NULL);
		ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
		for (i = 0; i < num; ++i)
			free(resp[i]);
		free(resp);
	} else {
		ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
	}
	buffer_clear(m);
	buffer_put_int(m, ret);
	mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
	auth_method = "keyboard-interactive";
	auth_submethod = "pam";
	if (ret == 0)
		sshpam_authok = sshpam_ctxt;
	return (0);
}

char *
do_realpath(struct sftp_conn *conn, char *path)
{
	Buffer msg;
	u_int type, expected_id, count, id;
	char *filename, *longname;
	/* LINTED */
	Attrib *a;

	expected_id = id = conn->msg_id++;
	send_string_request(conn->fd_out, id, SSH2_FXP_REALPATH, path,
	    strlen(path));

	buffer_init(&msg);

	get_msg(conn->fd_in, &msg);
	type = buffer_get_char(&msg);
	id = buffer_get_int(&msg);

	if (id != expected_id)
		fatal("ID mismatch (%u != %u)", id, expected_id);

	if (type == SSH2_FXP_STATUS) {
		u_int status = buffer_get_int(&msg);

		error("Couldn't canonicalise: %s", fx2txt(status));
		return(NULL);
	} else if (type != SSH2_FXP_NAME)
		fatal("Expected SSH2_FXP_NAME(%u) packet, got %u",
		    SSH2_FXP_NAME, type);

	count = buffer_get_int(&msg);
	if (count != 1)
		fatal("Got multiple names (%d) from SSH_FXP_REALPATH", count);

	filename = buffer_get_string(&msg, NULL);
	longname = buffer_get_string(&msg, NULL);
	a = decode_attrib(&msg);

	debug3("SSH_FXP_REALPATH %s -> %s", path, filename);

	xfree(longname);

	buffer_free(&msg);

	return(filename);
}

static Key *
key_load_public_rsa1(int fd, const char *filename, char **commentp)
{
    Buffer buffer;
    Key *pub;
    struct stat st;
    char *cp;
    int i;
    off_t len;

    if (fstat(fd, &st) < 0) {
        error("fstat for key file %.200s failed: %.100s",
              filename, strerror(errno));
        return NULL;
    }
    len = st.st_size;

    buffer_init(&buffer);
    cp = buffer_append_space(&buffer, len);

    if (read(fd, cp, (size_t) len) != (size_t) len) {
        debug("Read from key file %.200s failed: %.100s", filename,
              strerror(errno));
        buffer_free(&buffer);
        return NULL;
    }

    /* Check that it is at least big enough to contain the ID string. */
    if (len < sizeof(authfile_id_string)) {
        debug3("Not a RSA1 key file %.200s.", filename);
        buffer_free(&buffer);
        return NULL;
    }
    /*
     * Make sure it begins with the id string.  Consume the id string
     * from the buffer.
     */
    for (i = 0; i < sizeof(authfile_id_string); i++)
        if (buffer_get_char(&buffer) != authfile_id_string[i]) {
            debug3("Not a RSA1 key file %.200s.", filename);
            buffer_free(&buffer);
            return NULL;
        }
    /* Skip cipher type and reserved data. */
    (void) buffer_get_char(&buffer);	/* cipher type */
    (void) buffer_get_int(&buffer);		/* reserved */

    /* Read the public key from the buffer. */
    (void) buffer_get_int(&buffer);
    pub = key_new(KEY_RSA1);
    buffer_get_bignum(&buffer, pub->rsa->n);
    buffer_get_bignum(&buffer, pub->rsa->e);
    if (commentp)
        *commentp = buffer_get_string(&buffer, NULL);
    /* The encrypted private part is not parsed by this function. */

    buffer_free(&buffer);
    return pub;
}

Key *
ssh_get_next_identity(AuthenticationConnection *auth, char **comment, int version)
{
#ifdef WITH_SSH1
	int keybits;
	u_int bits;
#endif
	u_char *blob;
	u_int blen;
	Key *key = NULL;

	/* Return failure if no more entries. */
	if (auth->howmany <= 0)
		return NULL;

	/*
	 * Get the next entry from the packet.  These will abort with a fatal
	 * error if the packet is too short or contains corrupt data.
	 */
	switch (version) {
#ifdef WITH_SSH1
	case 1:
		key = key_new(KEY_RSA1);
		bits = buffer_get_int(&auth->identities);
		buffer_get_bignum(&auth->identities, key->rsa->e);
		buffer_get_bignum(&auth->identities, key->rsa->n);
		*comment = buffer_get_string(&auth->identities, NULL);
		keybits = BN_num_bits(key->rsa->n);
		if (keybits < 0 || bits != (u_int)keybits)
			logit("Warning: identity keysize mismatch: actual %d, announced %u",
			    BN_num_bits(key->rsa->n), bits);
		break;
#endif
	case 2:
		blob = buffer_get_string(&auth->identities, &blen);
		*comment = buffer_get_string(&auth->identities, NULL);
		key = key_from_blob(blob, blen);
		free(blob);
		break;
	default:
		return NULL;
	}
	/* Decrement the number of remaining entries. */
	auth->howmany--;
	return key;
}

int
mm_answer_authserv(int sock, Buffer *m)
{
	monitor_permit_authentications(1);

	authctxt->service = buffer_get_string(m, NULL);
	authctxt->style = buffer_get_string(m, NULL);
	debug3("%s: service=%s, style=%s",
	    __func__, authctxt->service, authctxt->style);

	if (strlen(authctxt->style) == 0) {
		xfree(authctxt->style);
		authctxt->style = NULL;
	}

	return (0);
}

int
mm_answer_rsa_response(int sock, Buffer *m)
{
	Key *key = NULL;
	u_char *blob, *response;
	u_int blen, len;
	int success;

	debug3("%s entering", __func__);

	if (!authctxt->valid)
		fatal("%s: authctxt not valid", __func__);
	if (ssh1_challenge == NULL)
		fatal("%s: no ssh1_challenge", __func__);

	blob = buffer_get_string(m, &blen);
	if (!monitor_allowed_key(blob, blen))
		fatal("%s: bad key, not previously allowed", __func__);
	if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
		fatal("%s: key type mismatch: %d", __func__, key_blobtype);
	if ((key = key_from_blob(blob, blen)) == NULL)
		fatal("%s: received bad key", __func__);
	response = buffer_get_string(m, &len);
	if (len != 16)
		fatal("%s: received bad response to challenge", __func__);
	success = auth_rsa_verify_response(key, ssh1_challenge, response);

	xfree(blob);
	key_free(key);
	xfree(response);

	auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";

	/* reset state */
	BN_clear_free(ssh1_challenge);
	ssh1_challenge = NULL;
	monitor_reset_key_state();

	buffer_clear(m);
	buffer_put_int(m, success);
	mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);

	return (success);
}