fs/ceph/auth_x.c - kernel/msm-4.19 - Gitiles


 #include "ceph_debug.h"

 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/slab.h>

 #include "auth_x.h"
 #include "auth_x_protocol.h"
 #include "crypto.h"
 #include "auth.h"
 #include "decode.h"

 #define TEMP_TICKET_BUF_LEN	256

 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed);

 static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
 {
 	struct ceph_x_info *xi = ac->private;
 	int need;

 	ceph_x_validate_tickets(ac, &need);
 	dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
 	     ac->want_keys, need, xi->have_keys);
 	return (ac->want_keys & xi->have_keys) == ac->want_keys;
 }

 static int ceph_x_encrypt_buflen(int ilen)
 {
 	return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
 		sizeof(u32);
 }

 static int ceph_x_encrypt(struct ceph_crypto_key *secret,
 			  void *ibuf, int ilen, void *obuf, size_t olen)
 {
 	struct ceph_x_encrypt_header head = {
 		.struct_v = 1,
 		.magic = cpu_to_le64(CEPHX_ENC_MAGIC)
 	};
 	size_t len = olen - sizeof(u32);
 	int ret;

 	ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
 			    &head, sizeof(head), ibuf, ilen);
 	if (ret)
 		return ret;
 	ceph_encode_32(&obuf, len);
 	return len + sizeof(u32);
 }

 static int ceph_x_decrypt(struct ceph_crypto_key *secret,
 			  void **p, void *end, void *obuf, size_t olen)
 {
 	struct ceph_x_encrypt_header head;
 	size_t head_len = sizeof(head);
 	int len, ret;

 	len = ceph_decode_32(p);
 	if (*p + len > end)
 		return -EINVAL;

 	dout("ceph_x_decrypt len %d\n", len);
 	ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
 			    *p, len);
 	if (ret)
 		return ret;
 	if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
 		return -EPERM;
 	*p += len;
 	return olen;
 }

 /*
  * get existing (or insert new) ticket handler
  */
 struct ceph_x_ticket_handler *get_ticket_handler(struct ceph_auth_client *ac,
 						 int service)
 {
 	struct ceph_x_ticket_handler *th;
 	struct ceph_x_info *xi = ac->private;
 	struct rb_node *parent = NULL, **p = &xi->ticket_handlers.rb_node;

 	while (*p) {
 		parent = *p;
 		th = rb_entry(parent, struct ceph_x_ticket_handler, node);
 		if (service < th->service)
 			p = &(*p)->rb_left;
 		else if (service > th->service)
 			p = &(*p)->rb_right;
 		else
 			return th;
 	}

 	/* add it */
 	th = kzalloc(sizeof(*th), GFP_NOFS);
 	if (!th)
 		return ERR_PTR(-ENOMEM);
 	th->service = service;
 	rb_link_node(&th->node, parent, p);
 	rb_insert_color(&th->node, &xi->ticket_handlers);
 	return th;
 }

 static void remove_ticket_handler(struct ceph_auth_client *ac,
 				  struct ceph_x_ticket_handler *th)
 {
 	struct ceph_x_info *xi = ac->private;

 	dout("remove_ticket_handler %p %d\n", th, th->service);
 	rb_erase(&th->node, &xi->ticket_handlers);
 	ceph_crypto_key_destroy(&th->session_key);
 	if (th->ticket_blob)
 		ceph_buffer_put(th->ticket_blob);
 	kfree(th);
 }

 static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
 				    struct ceph_crypto_key *secret,
 				    void *buf, void *end)
 {
 	struct ceph_x_info *xi = ac->private;
 	int num;
 	void *p = buf;
 	int ret;
 	char *dbuf;
 	char *ticket_buf;
 	u8 struct_v;

 	dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
 	if (!dbuf)
 		return -ENOMEM;

 	ret = -ENOMEM;
 	ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
 	if (!ticket_buf)
 		goto out_dbuf;

 	ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
 	struct_v = ceph_decode_8(&p);
 	if (struct_v != 1)
 		goto bad;
 	num = ceph_decode_32(&p);
 	dout("%d tickets\n", num);
 	while (num--) {
 		int type;
 		u8 struct_v;
 		struct ceph_x_ticket_handler *th;
 		void *dp, *dend;
 		int dlen;
 		char is_enc;
 		struct timespec validity;
 		struct ceph_crypto_key old_key;
 		void *tp, *tpend;
 		struct ceph_timespec new_validity;
 		struct ceph_crypto_key new_session_key;
 		struct ceph_buffer *new_ticket_blob;
 		unsigned long new_expires, new_renew_after;
 		u64 new_secret_id;

 		ceph_decode_need(&p, end, sizeof(u32) + 1, bad);

 		type = ceph_decode_32(&p);
 		dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));

 		struct_v = ceph_decode_8(&p);
 		if (struct_v != 1)
 			goto bad;

 		th = get_ticket_handler(ac, type);
 		if (IS_ERR(th)) {
 			ret = PTR_ERR(th);
 			goto out;
 		}

 		/* blob for me */
 		dlen = ceph_x_decrypt(secret, &p, end, dbuf,
 				      TEMP_TICKET_BUF_LEN);
 		if (dlen <= 0) {
 			ret = dlen;
 			goto out;
 		}
 		dout(" decrypted %d bytes\n", dlen);
 		dend = dbuf + dlen;
 		dp = dbuf;

 		struct_v = ceph_decode_8(&dp);
 		if (struct_v != 1)
 			goto bad;

 		memcpy(&old_key, &th->session_key, sizeof(old_key));
 		ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
 		if (ret)
 			goto out;

 		ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
 		ceph_decode_timespec(&validity, &new_validity);
 		new_expires = get_seconds() + validity.tv_sec;
 		new_renew_after = new_expires - (validity.tv_sec / 4);
 		dout(" expires=%lu renew_after=%lu\n", new_expires,
 		     new_renew_after);

 		/* ticket blob for service */
 		ceph_decode_8_safe(&p, end, is_enc, bad);
 		tp = ticket_buf;
 		if (is_enc) {
 			/* encrypted */
 			dout(" encrypted ticket\n");
 			dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
 					      TEMP_TICKET_BUF_LEN);
 			if (dlen < 0) {
 				ret = dlen;
 				goto out;
 			}
 			dlen = ceph_decode_32(&tp);
 		} else {
 			/* unencrypted */
 			ceph_decode_32_safe(&p, end, dlen, bad);
 			ceph_decode_need(&p, end, dlen, bad);
 			ceph_decode_copy(&p, ticket_buf, dlen);
 		}
 		tpend = tp + dlen;
 		dout(" ticket blob is %d bytes\n", dlen);
 		ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
 		struct_v = ceph_decode_8(&tp);
 		new_secret_id = ceph_decode_64(&tp);
 		ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
 		if (ret)
 			goto out;

 		/* all is well, update our ticket */
 		ceph_crypto_key_destroy(&th->session_key);
 		if (th->ticket_blob)
 			ceph_buffer_put(th->ticket_blob);
 		th->session_key = new_session_key;
 		th->ticket_blob = new_ticket_blob;
 		th->validity = new_validity;
 		th->secret_id = new_secret_id;
 		th->expires = new_expires;
 		th->renew_after = new_renew_after;
 		dout(" got ticket service %d (%s) secret_id %lld len %d\n",
 		     type, ceph_entity_type_name(type), th->secret_id,
 		     (int)th->ticket_blob->vec.iov_len);
 		xi->have_keys |= th->service;
 	}

 	ret = 0;
 out:
 	kfree(ticket_buf);
 out_dbuf:
 	kfree(dbuf);
 	return ret;

 bad:
 	ret = -EINVAL;
 	goto out;
 }

 static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
 				   struct ceph_x_ticket_handler *th,
 				   struct ceph_x_authorizer *au)
 {
 	int maxlen;
 	struct ceph_x_authorize_a *msg_a;
 	struct ceph_x_authorize_b msg_b;
 	void *p, *end;
 	int ret;
 	int ticket_blob_len =
 		(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);

 	dout("build_authorizer for %s %p\n",
 	     ceph_entity_type_name(th->service), au);

 	maxlen = sizeof(*msg_a) + sizeof(msg_b) +
 		ceph_x_encrypt_buflen(ticket_blob_len);
 	dout("  need len %d\n", maxlen);
 	if (au->buf && au->buf->alloc_len < maxlen) {
 		ceph_buffer_put(au->buf);
 		au->buf = NULL;
 	}
 	if (!au->buf) {
 		au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
 		if (!au->buf)
 			return -ENOMEM;
 	}
 	au->service = th->service;

 	msg_a = au->buf->vec.iov_base;
 	msg_a->struct_v = 1;
 	msg_a->global_id = cpu_to_le64(ac->global_id);
 	msg_a->service_id = cpu_to_le32(th->service);
 	msg_a->ticket_blob.struct_v = 1;
 	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
 	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
 	if (ticket_blob_len) {
 		memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
 		       th->ticket_blob->vec.iov_len);
 	}
 	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
 	     le64_to_cpu(msg_a->ticket_blob.secret_id));

 	p = msg_a + 1;
 	p += ticket_blob_len;
 	end = au->buf->vec.iov_base + au->buf->vec.iov_len;

 	get_random_bytes(&au->nonce, sizeof(au->nonce));
 	msg_b.struct_v = 1;
 	msg_b.nonce = cpu_to_le64(au->nonce);
 	ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
 			     p, end - p);
 	if (ret < 0)
 		goto out_buf;
 	p += ret;
 	au->buf->vec.iov_len = p - au->buf->vec.iov_base;
 	dout(" built authorizer nonce %llx len %d\n", au->nonce,
 	     (int)au->buf->vec.iov_len);
 	BUG_ON(au->buf->vec.iov_len > maxlen);
 	return 0;

 out_buf:
 	ceph_buffer_put(au->buf);
 	au->buf = NULL;
 	return ret;
 }

 static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
 				void **p, void *end)
 {
 	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
 	ceph_encode_8(p, 1);
 	ceph_encode_64(p, th->secret_id);
 	if (th->ticket_blob) {
 		const char *buf = th->ticket_blob->vec.iov_base;
 		u32 len = th->ticket_blob->vec.iov_len;

 		ceph_encode_32_safe(p, end, len, bad);
 		ceph_encode_copy_safe(p, end, buf, len, bad);
 	} else {
 		ceph_encode_32_safe(p, end, 0, bad);
 	}

 	return 0;
 bad:
 	return -ERANGE;
 }

 static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed)
 {
 	int want = ac->want_keys;
 	struct ceph_x_info *xi = ac->private;
 	int service;

 	*pneed = ac->want_keys & ~(xi->have_keys);

 	for (service = 1; service <= want; service <<= 1) {
 		struct ceph_x_ticket_handler *th;

 		if (!(ac->want_keys & service))
 			continue;

 		if (*pneed & service)
 			continue;

 		th = get_ticket_handler(ac, service);

 		if (!th) {
 			*pneed |= service;
 			continue;
 		}

 		if (get_seconds() >= th->renew_after)
 			*pneed |= service;
 		if (get_seconds() >= th->expires)
 			xi->have_keys &= ~service;
 	}
 }


 static int ceph_x_build_request(struct ceph_auth_client *ac,
 				void *buf, void *end)
 {
 	struct ceph_x_info *xi = ac->private;
 	int need;
 	struct ceph_x_request_header *head = buf;
 	int ret;
 	struct ceph_x_ticket_handler *th =
 		get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);

 	ceph_x_validate_tickets(ac, &need);

 	dout("build_request want %x have %x need %x\n",
 	     ac->want_keys, xi->have_keys, need);

 	if (need & CEPH_ENTITY_TYPE_AUTH) {
 		struct ceph_x_authenticate *auth = (void *)(head + 1);
 		void *p = auth + 1;
 		struct ceph_x_challenge_blob tmp;
 		char tmp_enc[40];
 		u64 *u;

 		if (p > end)
 			return -ERANGE;

 		dout(" get_auth_session_key\n");
 		head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);

 		/* encrypt and hash */
 		get_random_bytes(&auth->client_challenge, sizeof(u64));
 		tmp.client_challenge = auth->client_challenge;
 		tmp.server_challenge = cpu_to_le64(xi->server_challenge);
 		ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
 				     tmp_enc, sizeof(tmp_enc));
 		if (ret < 0)
 			return ret;

 		auth->struct_v = 1;
 		auth->key = 0;
 		for (u = (u64 *)tmp_enc; u + 1 <= (u64 *)(tmp_enc + ret); u++)
 			auth->key ^= *u;
 		dout(" server_challenge %llx client_challenge %llx key %llx\n",
 		     xi->server_challenge, le64_to_cpu(auth->client_challenge),
 		     le64_to_cpu(auth->key));

 		/* now encode the old ticket if exists */
 		ret = ceph_x_encode_ticket(th, &p, end);
 		if (ret < 0)
 			return ret;

 		return p - buf;
 	}

 	if (need) {
 		void *p = head + 1;
 		struct ceph_x_service_ticket_request *req;

 		if (p > end)
 			return -ERANGE;
 		head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);

 		BUG_ON(!th);
 		ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
 		if (ret)
 			return ret;
 		ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
 				 xi->auth_authorizer.buf->vec.iov_len);

 		req = p;
 		req->keys = cpu_to_le32(need);
 		p += sizeof(*req);
 		return p - buf;
 	}

 	return 0;
 }

 static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
 			       void *buf, void *end)
 {
 	struct ceph_x_info *xi = ac->private;
 	struct ceph_x_reply_header *head = buf;
 	struct ceph_x_ticket_handler *th;
 	int len = end - buf;
 	int op;
 	int ret;

 	if (result)
 		return result;  /* XXX hmm? */

 	if (xi->starting) {
 		/* it's a hello */
 		struct ceph_x_server_challenge *sc = buf;

 		if (len != sizeof(*sc))
 			return -EINVAL;
 		xi->server_challenge = le64_to_cpu(sc->server_challenge);
 		dout("handle_reply got server challenge %llx\n",
 		     xi->server_challenge);
 		xi->starting = false;
 		xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
 		return -EAGAIN;
 	}

 	op = le32_to_cpu(head->op);
 	result = le32_to_cpu(head->result);
 	dout("handle_reply op %d result %d\n", op, result);
 	switch (op) {
 	case CEPHX_GET_AUTH_SESSION_KEY:
 		/* verify auth key */
 		ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
 					       buf + sizeof(*head), end);
 		break;

 	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
 		th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
 		BUG_ON(!th);
 		ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
 					       buf + sizeof(*head), end);
 		break;

 	default:
 		return -EINVAL;
 	}
 	if (ret)
 		return ret;
 	if (ac->want_keys == xi->have_keys)
 		return 0;
 	return -EAGAIN;
 }

 static int ceph_x_create_authorizer(
 	struct ceph_auth_client *ac, int peer_type,
 	struct ceph_authorizer **a,
 	void **buf, size_t *len,
 	void **reply_buf, size_t *reply_len)
 {
 	struct ceph_x_authorizer *au;
 	struct ceph_x_ticket_handler *th;
 	int ret;

 	th = get_ticket_handler(ac, peer_type);
 	if (IS_ERR(th))
 		return PTR_ERR(th);

 	au = kzalloc(sizeof(*au), GFP_NOFS);
 	if (!au)
 		return -ENOMEM;

 	ret = ceph_x_build_authorizer(ac, th, au);
 	if (ret) {
 		kfree(au);
 		return ret;
 	}

 	*a = (struct ceph_authorizer *)au;
 	*buf = au->buf->vec.iov_base;
 	*len = au->buf->vec.iov_len;
 	*reply_buf = au->reply_buf;
 	*reply_len = sizeof(au->reply_buf);
 	return 0;
 }

 static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
 					  struct ceph_authorizer *a, size_t len)
 {
 	struct ceph_x_authorizer *au = (void *)a;
 	struct ceph_x_ticket_handler *th;
 	int ret = 0;
 	struct ceph_x_authorize_reply reply;
 	void *p = au->reply_buf;
 	void *end = p + sizeof(au->reply_buf);

 	th = get_ticket_handler(ac, au->service);
 	if (!th)
 		return -EIO;  /* hrm! */
 	ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
 	if (ret < 0)
 		return ret;
 	if (ret != sizeof(reply))
 		return -EPERM;

 	if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
 		ret = -EPERM;
 	else
 		ret = 0;
 	dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
 	     au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
 	return ret;
 }

 static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
 				      struct ceph_authorizer *a)
 {
 	struct ceph_x_authorizer *au = (void *)a;

 	ceph_buffer_put(au->buf);
 	kfree(au);
 }


 static void ceph_x_reset(struct ceph_auth_client *ac)
 {
 	struct ceph_x_info *xi = ac->private;

 	dout("reset\n");
 	xi->starting = true;
 	xi->server_challenge = 0;
 }

 static void ceph_x_destroy(struct ceph_auth_client *ac)
 {
 	struct ceph_x_info *xi = ac->private;
 	struct rb_node *p;

 	dout("ceph_x_destroy %p\n", ac);
 	ceph_crypto_key_destroy(&xi->secret);

 	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
 		struct ceph_x_ticket_handler *th =
 			rb_entry(p, struct ceph_x_ticket_handler, node);
 		remove_ticket_handler(ac, th);
 	}

 	kfree(ac->private);
 	ac->private = NULL;
 }

 static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
 				   int peer_type)
 {
 	struct ceph_x_ticket_handler *th;

 	th = get_ticket_handler(ac, peer_type);
 	if (th && !IS_ERR(th))
 		remove_ticket_handler(ac, th);
 }


 static const struct ceph_auth_client_ops ceph_x_ops = {
 	.is_authenticated = ceph_x_is_authenticated,
 	.build_request = ceph_x_build_request,
 	.handle_reply = ceph_x_handle_reply,
 	.create_authorizer = ceph_x_create_authorizer,
 	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
 	.destroy_authorizer = ceph_x_destroy_authorizer,
 	.invalidate_authorizer = ceph_x_invalidate_authorizer,
 	.reset =  ceph_x_reset,
 	.destroy = ceph_x_destroy,
 };


 int ceph_x_init(struct ceph_auth_client *ac)
 {
 	struct ceph_x_info *xi;
 	int ret;

 	dout("ceph_x_init %p\n", ac);
 	ret = -ENOMEM;
 	xi = kzalloc(sizeof(*xi), GFP_NOFS);
 	if (!xi)
 		goto out;

 	ret = -EINVAL;
 	if (!ac->secret) {
 		pr_err("no secret set (for auth_x protocol)\n");
 		goto out_nomem;
 	}

 	ret = ceph_crypto_key_unarmor(&xi->secret, ac->secret);
 	if (ret)
 		goto out_nomem;

 	xi->starting = true;
 	xi->ticket_handlers = RB_ROOT;

 	ac->protocol = CEPH_AUTH_CEPHX;
 	ac->private = xi;
 	ac->ops = &ceph_x_ops;
 	return 0;

 out_nomem:
 	kfree(xi);
 out:
 	return ret;
 }

	#include "ceph_debug.h"

	#include <linux/err.h>
	#include <linux/module.h>
	#include <linux/random.h>
	#include <linux/slab.h>

	#include "auth_x.h"
	#include "auth_x_protocol.h"
	#include "crypto.h"
	#include "auth.h"
	#include "decode.h"

	#define TEMP_TICKET_BUF_LEN 256

	static void ceph_x_validate_tickets(struct ceph_auth_client ac, int pneed);

	static int ceph_x_is_authenticated(struct ceph_auth_client *ac)
	{
	struct ceph_x_info *xi = ac->private;
	int need;

	ceph_x_validate_tickets(ac, &need);
	dout("ceph_x_is_authenticated want=%d need=%d have=%d\n",
	ac->want_keys, need, xi->have_keys);
	return (ac->want_keys & xi->have_keys) == ac->want_keys;
	}

	static int ceph_x_encrypt_buflen(int ilen)
	{
	return sizeof(struct ceph_x_encrypt_header) + ilen + 16 +
	sizeof(u32);
	}

	static int ceph_x_encrypt(struct ceph_crypto_key *secret,
	void ibuf, int ilen, void obuf, size_t olen)
	{
	struct ceph_x_encrypt_header head = {
	.struct_v = 1,
	.magic = cpu_to_le64(CEPHX_ENC_MAGIC)
	};
	size_t len = olen - sizeof(u32);
	int ret;

	ret = ceph_encrypt2(secret, obuf + sizeof(u32), &len,
	&head, sizeof(head), ibuf, ilen);
	if (ret)
	return ret;
	ceph_encode_32(&obuf, len);
	return len + sizeof(u32);
	}

	static int ceph_x_decrypt(struct ceph_crypto_key *secret,
	void *p, void end, void *obuf, size_t olen)
	{
	struct ceph_x_encrypt_header head;
	size_t head_len = sizeof(head);
	int len, ret;

	len = ceph_decode_32(p);
	if (*p + len > end)
	return -EINVAL;

	dout("ceph_x_decrypt len %d\n", len);
	ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen,
	*p, len);
	if (ret)
	return ret;
	if (head.struct_v != 1 \|\| le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC)
	return -EPERM;
	*p += len;
	return olen;
	}

	/*
	* get existing (or insert new) ticket handler
	*/
	struct ceph_x_ticket_handler get_ticket_handler(struct ceph_auth_client ac,
	int service)
	{
	struct ceph_x_ticket_handler *th;
	struct ceph_x_info *xi = ac->private;
	struct rb_node parent = NULL, *p = &xi->ticket_handlers.rb_node;

	while (*p) {
	parent = *p;
	th = rb_entry(parent, struct ceph_x_ticket_handler, node);
	if (service < th->service)
	p = &(*p)->rb_left;
	else if (service > th->service)
	p = &(*p)->rb_right;
	else
	return th;
	}

	/* add it */
	th = kzalloc(sizeof(*th), GFP_NOFS);
	if (!th)
	return ERR_PTR(-ENOMEM);
	th->service = service;
	rb_link_node(&th->node, parent, p);
	rb_insert_color(&th->node, &xi->ticket_handlers);
	return th;
	}

	static void remove_ticket_handler(struct ceph_auth_client *ac,
	struct ceph_x_ticket_handler *th)
	{
	struct ceph_x_info *xi = ac->private;

	dout("remove_ticket_handler %p %d\n", th, th->service);
	rb_erase(&th->node, &xi->ticket_handlers);
	ceph_crypto_key_destroy(&th->session_key);
	if (th->ticket_blob)
	ceph_buffer_put(th->ticket_blob);
	kfree(th);
	}

	static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac,
	struct ceph_crypto_key *secret,
	void buf, void end)
	{
	struct ceph_x_info *xi = ac->private;
	int num;
	void *p = buf;
	int ret;
	char *dbuf;
	char *ticket_buf;
	u8 struct_v;

	dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
	if (!dbuf)
	return -ENOMEM;

	ret = -ENOMEM;
	ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS);
	if (!ticket_buf)
	goto out_dbuf;

	ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
	struct_v = ceph_decode_8(&p);
	if (struct_v != 1)
	goto bad;
	num = ceph_decode_32(&p);
	dout("%d tickets\n", num);
	while (num--) {
	int type;
	u8 struct_v;
	struct ceph_x_ticket_handler *th;
	void dp, dend;
	int dlen;
	char is_enc;
	struct timespec validity;
	struct ceph_crypto_key old_key;
	void tp, tpend;
	struct ceph_timespec new_validity;
	struct ceph_crypto_key new_session_key;
	struct ceph_buffer *new_ticket_blob;
	unsigned long new_expires, new_renew_after;
	u64 new_secret_id;

	ceph_decode_need(&p, end, sizeof(u32) + 1, bad);

	type = ceph_decode_32(&p);
	dout(" ticket type %d %s\n", type, ceph_entity_type_name(type));

	struct_v = ceph_decode_8(&p);
	if (struct_v != 1)
	goto bad;

	th = get_ticket_handler(ac, type);
	if (IS_ERR(th)) {
	ret = PTR_ERR(th);
	goto out;
	}

	/* blob for me */
	dlen = ceph_x_decrypt(secret, &p, end, dbuf,
	TEMP_TICKET_BUF_LEN);
	if (dlen <= 0) {
	ret = dlen;
	goto out;
	}
	dout(" decrypted %d bytes\n", dlen);
	dend = dbuf + dlen;
	dp = dbuf;

	struct_v = ceph_decode_8(&dp);
	if (struct_v != 1)
	goto bad;

	memcpy(&old_key, &th->session_key, sizeof(old_key));
	ret = ceph_crypto_key_decode(&new_session_key, &dp, dend);
	if (ret)
	goto out;

	ceph_decode_copy(&dp, &new_validity, sizeof(new_validity));
	ceph_decode_timespec(&validity, &new_validity);
	new_expires = get_seconds() + validity.tv_sec;
	new_renew_after = new_expires - (validity.tv_sec / 4);
	dout(" expires=%lu renew_after=%lu\n", new_expires,
	new_renew_after);

	/* ticket blob for service */
	ceph_decode_8_safe(&p, end, is_enc, bad);
	tp = ticket_buf;
	if (is_enc) {
	/* encrypted */
	dout(" encrypted ticket\n");
	dlen = ceph_x_decrypt(&old_key, &p, end, ticket_buf,
	TEMP_TICKET_BUF_LEN);
	if (dlen < 0) {
	ret = dlen;
	goto out;
	}
	dlen = ceph_decode_32(&tp);
	} else {
	/* unencrypted */
	ceph_decode_32_safe(&p, end, dlen, bad);
	ceph_decode_need(&p, end, dlen, bad);
	ceph_decode_copy(&p, ticket_buf, dlen);
	}
	tpend = tp + dlen;
	dout(" ticket blob is %d bytes\n", dlen);
	ceph_decode_need(&tp, tpend, 1 + sizeof(u64), bad);
	struct_v = ceph_decode_8(&tp);
	new_secret_id = ceph_decode_64(&tp);
	ret = ceph_decode_buffer(&new_ticket_blob, &tp, tpend);
	if (ret)
	goto out;

	/* all is well, update our ticket */
	ceph_crypto_key_destroy(&th->session_key);
	if (th->ticket_blob)
	ceph_buffer_put(th->ticket_blob);
	th->session_key = new_session_key;
	th->ticket_blob = new_ticket_blob;
	th->validity = new_validity;
	th->secret_id = new_secret_id;
	th->expires = new_expires;
	th->renew_after = new_renew_after;
	dout(" got ticket service %d (%s) secret_id %lld len %d\n",
	type, ceph_entity_type_name(type), th->secret_id,
	(int)th->ticket_blob->vec.iov_len);
	xi->have_keys \|= th->service;
	}

	ret = 0;
	out:
	kfree(ticket_buf);
	out_dbuf:
	kfree(dbuf);
	return ret;

	bad:
	ret = -EINVAL;
	goto out;
	}

	static int ceph_x_build_authorizer(struct ceph_auth_client *ac,
	struct ceph_x_ticket_handler *th,
	struct ceph_x_authorizer *au)
	{
	int maxlen;
	struct ceph_x_authorize_a *msg_a;
	struct ceph_x_authorize_b msg_b;
	void p, end;
	int ret;
	int ticket_blob_len =
	(th->ticket_blob ? th->ticket_blob->vec.iov_len : 0);

	dout("build_authorizer for %s %p\n",
	ceph_entity_type_name(th->service), au);

	maxlen = sizeof(*msg_a) + sizeof(msg_b) +
	ceph_x_encrypt_buflen(ticket_blob_len);
	dout(" need len %d\n", maxlen);
	if (au->buf && au->buf->alloc_len < maxlen) {
	ceph_buffer_put(au->buf);
	au->buf = NULL;
	}
	if (!au->buf) {
	au->buf = ceph_buffer_new(maxlen, GFP_NOFS);
	if (!au->buf)
	return -ENOMEM;
	}
	au->service = th->service;

	msg_a = au->buf->vec.iov_base;
	msg_a->struct_v = 1;
	msg_a->global_id = cpu_to_le64(ac->global_id);
	msg_a->service_id = cpu_to_le32(th->service);
	msg_a->ticket_blob.struct_v = 1;
	msg_a->ticket_blob.secret_id = cpu_to_le64(th->secret_id);
	msg_a->ticket_blob.blob_len = cpu_to_le32(ticket_blob_len);
	if (ticket_blob_len) {
	memcpy(msg_a->ticket_blob.blob, th->ticket_blob->vec.iov_base,
	th->ticket_blob->vec.iov_len);
	}
	dout(" th %p secret_id %lld %lld\n", th, th->secret_id,
	le64_to_cpu(msg_a->ticket_blob.secret_id));

	p = msg_a + 1;
	p += ticket_blob_len;
	end = au->buf->vec.iov_base + au->buf->vec.iov_len;

	get_random_bytes(&au->nonce, sizeof(au->nonce));
	msg_b.struct_v = 1;
	msg_b.nonce = cpu_to_le64(au->nonce);
	ret = ceph_x_encrypt(&th->session_key, &msg_b, sizeof(msg_b),
	p, end - p);
	if (ret < 0)
	goto out_buf;
	p += ret;
	au->buf->vec.iov_len = p - au->buf->vec.iov_base;
	dout(" built authorizer nonce %llx len %d\n", au->nonce,
	(int)au->buf->vec.iov_len);
	BUG_ON(au->buf->vec.iov_len > maxlen);
	return 0;

	out_buf:
	ceph_buffer_put(au->buf);
	au->buf = NULL;
	return ret;
	}

	static int ceph_x_encode_ticket(struct ceph_x_ticket_handler *th,
	void *p, void end)
	{
	ceph_decode_need(p, end, 1 + sizeof(u64), bad);
	ceph_encode_8(p, 1);
	ceph_encode_64(p, th->secret_id);
	if (th->ticket_blob) {
	const char *buf = th->ticket_blob->vec.iov_base;
	u32 len = th->ticket_blob->vec.iov_len;

	ceph_encode_32_safe(p, end, len, bad);
	ceph_encode_copy_safe(p, end, buf, len, bad);
	} else {
	ceph_encode_32_safe(p, end, 0, bad);
	}

	return 0;
	bad:
	return -ERANGE;
	}

	static void ceph_x_validate_tickets(struct ceph_auth_client ac, int pneed)
	{
	int want = ac->want_keys;
	struct ceph_x_info *xi = ac->private;
	int service;

	*pneed = ac->want_keys & ~(xi->have_keys);

	for (service = 1; service <= want; service <<= 1) {
	struct ceph_x_ticket_handler *th;

	if (!(ac->want_keys & service))
	continue;

	if (*pneed & service)
	continue;

	th = get_ticket_handler(ac, service);

	if (!th) {
	*pneed \|= service;
	continue;
	}

	if (get_seconds() >= th->renew_after)
	*pneed \|= service;
	if (get_seconds() >= th->expires)
	xi->have_keys &= ~service;
	}
	}


	static int ceph_x_build_request(struct ceph_auth_client *ac,
	void buf, void end)
	{
	struct ceph_x_info *xi = ac->private;
	int need;
	struct ceph_x_request_header *head = buf;
	int ret;
	struct ceph_x_ticket_handler *th =
	get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);

	ceph_x_validate_tickets(ac, &need);

	dout("build_request want %x have %x need %x\n",
	ac->want_keys, xi->have_keys, need);

	if (need & CEPH_ENTITY_TYPE_AUTH) {
	struct ceph_x_authenticate auth = (void )(head + 1);
	void *p = auth + 1;
	struct ceph_x_challenge_blob tmp;
	char tmp_enc[40];
	u64 *u;

	if (p > end)
	return -ERANGE;

	dout(" get_auth_session_key\n");
	head->op = cpu_to_le16(CEPHX_GET_AUTH_SESSION_KEY);

	/* encrypt and hash */
	get_random_bytes(&auth->client_challenge, sizeof(u64));
	tmp.client_challenge = auth->client_challenge;
	tmp.server_challenge = cpu_to_le64(xi->server_challenge);
	ret = ceph_x_encrypt(&xi->secret, &tmp, sizeof(tmp),
	tmp_enc, sizeof(tmp_enc));
	if (ret < 0)
	return ret;

	auth->struct_v = 1;
	auth->key = 0;
	for (u = (u64 )tmp_enc; u + 1 <= (u64 )(tmp_enc + ret); u++)
	auth->key ^= *u;
	dout(" server_challenge %llx client_challenge %llx key %llx\n",
	xi->server_challenge, le64_to_cpu(auth->client_challenge),
	le64_to_cpu(auth->key));

	/* now encode the old ticket if exists */
	ret = ceph_x_encode_ticket(th, &p, end);
	if (ret < 0)
	return ret;

	return p - buf;
	}

	if (need) {
	void *p = head + 1;
	struct ceph_x_service_ticket_request *req;

	if (p > end)
	return -ERANGE;
	head->op = cpu_to_le16(CEPHX_GET_PRINCIPAL_SESSION_KEY);

	BUG_ON(!th);
	ret = ceph_x_build_authorizer(ac, th, &xi->auth_authorizer);
	if (ret)
	return ret;
	ceph_encode_copy(&p, xi->auth_authorizer.buf->vec.iov_base,
	xi->auth_authorizer.buf->vec.iov_len);

	req = p;
	req->keys = cpu_to_le32(need);
	p += sizeof(*req);
	return p - buf;
	}

	return 0;
	}

	static int ceph_x_handle_reply(struct ceph_auth_client *ac, int result,
	void buf, void end)
	{
	struct ceph_x_info *xi = ac->private;
	struct ceph_x_reply_header *head = buf;
	struct ceph_x_ticket_handler *th;
	int len = end - buf;
	int op;
	int ret;

	if (result)
	return result; /* XXX hmm? */

	if (xi->starting) {
	/* it's a hello */
	struct ceph_x_server_challenge *sc = buf;

	if (len != sizeof(*sc))
	return -EINVAL;
	xi->server_challenge = le64_to_cpu(sc->server_challenge);
	dout("handle_reply got server challenge %llx\n",
	xi->server_challenge);
	xi->starting = false;
	xi->have_keys &= ~CEPH_ENTITY_TYPE_AUTH;
	return -EAGAIN;
	}

	op = le32_to_cpu(head->op);
	result = le32_to_cpu(head->result);
	dout("handle_reply op %d result %d\n", op, result);
	switch (op) {
	case CEPHX_GET_AUTH_SESSION_KEY:
	/* verify auth key */
	ret = ceph_x_proc_ticket_reply(ac, &xi->secret,
	buf + sizeof(*head), end);
	break;

	case CEPHX_GET_PRINCIPAL_SESSION_KEY:
	th = get_ticket_handler(ac, CEPH_ENTITY_TYPE_AUTH);
	BUG_ON(!th);
	ret = ceph_x_proc_ticket_reply(ac, &th->session_key,
	buf + sizeof(*head), end);
	break;

	default:
	return -EINVAL;
	}
	if (ret)
	return ret;
	if (ac->want_keys == xi->have_keys)
	return 0;
	return -EAGAIN;
	}

	static int ceph_x_create_authorizer(
	struct ceph_auth_client *ac, int peer_type,
	struct ceph_authorizer **a,
	void *buf, size_t len,
	void *reply_buf, size_t reply_len)
	{
	struct ceph_x_authorizer *au;
	struct ceph_x_ticket_handler *th;
	int ret;

	th = get_ticket_handler(ac, peer_type);
	if (IS_ERR(th))
	return PTR_ERR(th);

	au = kzalloc(sizeof(*au), GFP_NOFS);
	if (!au)
	return -ENOMEM;

	ret = ceph_x_build_authorizer(ac, th, au);
	if (ret) {
	kfree(au);
	return ret;
	}

	a = (struct ceph_authorizer )au;
	*buf = au->buf->vec.iov_base;
	*len = au->buf->vec.iov_len;
	*reply_buf = au->reply_buf;
	*reply_len = sizeof(au->reply_buf);
	return 0;
	}

	static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac,
	struct ceph_authorizer *a, size_t len)
	{
	struct ceph_x_authorizer au = (void )a;
	struct ceph_x_ticket_handler *th;
	int ret = 0;
	struct ceph_x_authorize_reply reply;
	void *p = au->reply_buf;
	void *end = p + sizeof(au->reply_buf);

	th = get_ticket_handler(ac, au->service);
	if (!th)
	return -EIO; /* hrm! */
	ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply));
	if (ret < 0)
	return ret;
	if (ret != sizeof(reply))
	return -EPERM;

	if (au->nonce + 1 != le64_to_cpu(reply.nonce_plus_one))
	ret = -EPERM;
	else
	ret = 0;
	dout("verify_authorizer_reply nonce %llx got %llx ret %d\n",
	au->nonce, le64_to_cpu(reply.nonce_plus_one), ret);
	return ret;
	}

	static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
	struct ceph_authorizer *a)
	{
	struct ceph_x_authorizer au = (void )a;

	ceph_buffer_put(au->buf);
	kfree(au);
	}


	static void ceph_x_reset(struct ceph_auth_client *ac)
	{
	struct ceph_x_info *xi = ac->private;

	dout("reset\n");
	xi->starting = true;
	xi->server_challenge = 0;
	}

	static void ceph_x_destroy(struct ceph_auth_client *ac)
	{
	struct ceph_x_info *xi = ac->private;
	struct rb_node *p;

	dout("ceph_x_destroy %p\n", ac);
	ceph_crypto_key_destroy(&xi->secret);

	while ((p = rb_first(&xi->ticket_handlers)) != NULL) {
	struct ceph_x_ticket_handler *th =
	rb_entry(p, struct ceph_x_ticket_handler, node);
	remove_ticket_handler(ac, th);
	}

	kfree(ac->private);
	ac->private = NULL;
	}

	static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
	int peer_type)
	{
	struct ceph_x_ticket_handler *th;

	th = get_ticket_handler(ac, peer_type);
	if (th && !IS_ERR(th))
	remove_ticket_handler(ac, th);
	}


	static const struct ceph_auth_client_ops ceph_x_ops = {
	.is_authenticated = ceph_x_is_authenticated,
	.build_request = ceph_x_build_request,
	.handle_reply = ceph_x_handle_reply,
	.create_authorizer = ceph_x_create_authorizer,
	.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
	.destroy_authorizer = ceph_x_destroy_authorizer,
	.invalidate_authorizer = ceph_x_invalidate_authorizer,
	.reset = ceph_x_reset,
	.destroy = ceph_x_destroy,
	};


	int ceph_x_init(struct ceph_auth_client *ac)
	{
	struct ceph_x_info *xi;
	int ret;

	dout("ceph_x_init %p\n", ac);
	ret = -ENOMEM;
	xi = kzalloc(sizeof(*xi), GFP_NOFS);
	if (!xi)
	goto out;

	ret = -EINVAL;
	if (!ac->secret) {
	pr_err("no secret set (for auth_x protocol)\n");
	goto out_nomem;
	}

	ret = ceph_crypto_key_unarmor(&xi->secret, ac->secret);
	if (ret)
	goto out_nomem;

	xi->starting = true;
	xi->ticket_handlers = RB_ROOT;

	ac->protocol = CEPH_AUTH_CEPHX;
	ac->private = xi;
	ac->ops = &ceph_x_ops;
	return 0;

	out_nomem:
	kfree(xi);
	out:
	return ret;
	}