diff options
Diffstat (limited to 'sunrpc/svcauth_des.c')
| -rw-r--r-- | sunrpc/svcauth_des.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/sunrpc/svcauth_des.c b/sunrpc/svcauth_des.c new file mode 100644 index 0000000000..3547830267 --- /dev/null +++ b/sunrpc/svcauth_des.c @@ -0,0 +1,548 @@ +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)svcauth_des.c 2.3 89/07/11 4.0 RPCSRC; from 1.15 88/02/08 SMI"; +#endif + +/* + * Copyright (c) 1988 by Sun Microsystems, Inc. + */ + +/* + * Sun RPC is a product of Sun Microsystems, Inc. and is provided for + * unrestricted use provided that this legend is included on all tape + * media and as a part of the software program in whole or part. Users + * may copy or modify Sun RPC without charge, but are not authorized + * to license or distribute it to anyone else except as part of a product or + * program developed by the user. + * + * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE + * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR + * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. + * + * Sun RPC is provided with no support and without any obligation on the + * part of Sun Microsystems, Inc. to assist in its use, correction, + * modification or enhancement. + * + * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE + * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC + * OR ANY PART THEREOF. + * + * In no event will Sun Microsystems, Inc. be liable for any lost revenue + * or profits or other special, indirect and consequential damages, even if + * Sun has been advised of the possibility of such damages. + * + * Sun Microsystems, Inc. + * 2550 Garcia Avenue + * Mountain View, California 94043 + */ + +/* + * svcauth_des.c, server-side des authentication + * + * We insure for the service the following: + * (1) The timestamp microseconds do not exceed 1 million. + * (2) The timestamp plus the window is less than the current time. + * (3) The timestamp is not less than the one previously + * seen in the current session. + * + * It is up to the server to determine if the window size is + * too small . + * + */ + +#include <string.h> +#include <sys/param.h> +#include <netinet/in.h> +#include <rpc/types.h> +#include <rpc/xdr.h> +#include <rpc/auth.h> +#include <rpc/auth_des.h> +#include <rpc/svc_auth.h> +#include <rpc/svc.h> +#include <rpc/des_crypt.h> + +#define debug(msg) /*printf("svcauth_des: %s\n", msg) */ + +#define USEC_PER_SEC ((u_long) 1000000L) +#define BEFORE(t1, t2) timercmp(t1, t2, <) + +/* + * LRU cache of conversation keys and some other useful items. + */ +#define AUTHDES_CACHESZ 64 +struct cache_entry + { + des_block key; /* conversation key */ + char *rname; /* client's name */ + u_int window; /* credential lifetime window */ + struct timeval laststamp; /* detect replays of creds */ + char *localcred; /* generic local credential */ + }; +static struct cache_entry *authdes_cache /* [AUTHDES_CACHESZ] */ ; +static short *authdes_lru /* [AUTHDES_CACHESZ] */ ; + +static void cache_init (void); /* initialize the cache */ +static short cache_spot (des_block *, char *, struct timeval *); + /* find an entry in the cache */ +static void cache_ref (short sid); /* note that sid was ref'd */ + +static void invalidate (char *cred); /* invalidate entry in cache */ + +/* + * cache statistics + */ +struct + { + u_long ncachehits; /* times cache hit, and is not replay */ + u_long ncachereplays; /* times cache hit, and is replay */ + u_long ncachemisses; /* times cache missed */ + } +svcauthdes_stats; + +/* + * Service side authenticator for AUTH_DES + */ +enum auth_stat +_svcauth_des (register struct svc_req *rqst, register struct rpc_msg *msg) +{ + register long *ixdr; + des_block cryptbuf[2]; + register struct authdes_cred *cred; + struct authdes_verf verf; + int status; + register struct cache_entry *entry; + short sid = 0; + des_block *sessionkey; + des_block ivec; + u_int window; + struct timeval timestamp; + u_long namelen; + struct area + { + struct authdes_cred area_cred; + char area_netname[MAXNETNAMELEN + 1]; + } + *area; + + if (authdes_cache == NULL) + cache_init (); + + area = (struct area *) rqst->rq_clntcred; + cred = (struct authdes_cred *) &area->area_cred; + + /* + * Get the credential + */ + ixdr = (long *) msg->rm_call.cb_cred.oa_base; + cred->adc_namekind = IXDR_GET_ENUM (ixdr, enum authdes_namekind); + switch (cred->adc_namekind) + { + case ADN_FULLNAME: + namelen = IXDR_GET_U_LONG (ixdr); + if (namelen > MAXNETNAMELEN) + { + return AUTH_BADCRED; + } + cred->adc_fullname.name = area->area_netname; + bcopy ((char *) ixdr, cred->adc_fullname.name, + (u_int) namelen); + cred->adc_fullname.name[namelen] = 0; + ixdr += (RNDUP (namelen) / BYTES_PER_XDR_UNIT); + cred->adc_fullname.key.key.high = (u_long) * ixdr++; + cred->adc_fullname.key.key.low = (u_long) * ixdr++; + cred->adc_fullname.window = (u_long) * ixdr++; + break; + case ADN_NICKNAME: + cred->adc_nickname = (u_long) * ixdr++; + break; + default: + return AUTH_BADCRED; + } + + /* + * Get the verifier + */ + ixdr = (long *) msg->rm_call.cb_verf.oa_base; + verf.adv_xtimestamp.key.high = (u_long) * ixdr++; + verf.adv_xtimestamp.key.low = (u_long) * ixdr++; + verf.adv_int_u = (u_long) * ixdr++; + + + /* + * Get the conversation key + */ + if (cred->adc_namekind == ADN_FULLNAME) + { + sessionkey = &cred->adc_fullname.key; + if (key_decryptsession (cred->adc_fullname.name, + sessionkey) < 0) + { + debug ("decryptsessionkey"); + return AUTH_BADCRED; /* key not found */ + } + } + else + { /* ADN_NICKNAME */ + sid = (short) cred->adc_nickname; + if (sid >= AUTHDES_CACHESZ) + { + debug ("bad nickname"); + return AUTH_BADCRED; /* garbled credential */ + } + sessionkey = &authdes_cache[sid].key; + } + + + /* + * Decrypt the timestamp + */ + cryptbuf[0] = verf.adv_xtimestamp; + if (cred->adc_namekind == ADN_FULLNAME) + { + cryptbuf[1].key.high = cred->adc_fullname.window; + cryptbuf[1].key.low = verf.adv_winverf; + ivec.key.high = ivec.key.low = 0; + status = cbc_crypt ((char *) sessionkey, (char *) cryptbuf, + 2 * sizeof (des_block), DES_DECRYPT | DES_HW, + (char *) &ivec); + } + else + { + status = ecb_crypt ((char *) sessionkey, (char *) cryptbuf, + sizeof (des_block), DES_DECRYPT | DES_HW); + } + if (DES_FAILED (status)) + { + debug ("decryption failure"); + return AUTH_FAILED; /* system error */ + } + + /* + * XDR the decrypted timestamp + */ + ixdr = (long *) cryptbuf; + timestamp.tv_sec = IXDR_GET_LONG (ixdr); + timestamp.tv_usec = IXDR_GET_LONG (ixdr); + + /* + * Check for valid credentials and verifiers. + * They could be invalid because the key was flushed + * out of the cache, and so a new session should begin. + * Be sure and send AUTH_REJECTED{CRED, VERF} if this is the case. + */ + { + struct timeval current; + int nick; + u_int winverf; + + if (cred->adc_namekind == ADN_FULLNAME) + { + window = IXDR_GET_U_LONG (ixdr); + winverf = IXDR_GET_U_LONG (ixdr); + if (winverf != window - 1) + { + debug ("window verifier mismatch"); + return AUTH_BADCRED; /* garbled credential */ + } + sid = cache_spot (sessionkey, cred->adc_fullname.name, + ×tamp); + if (sid < 0) + { + debug ("replayed credential"); + return AUTH_REJECTEDCRED; /* replay */ + } + nick = 0; + } + else + { /* ADN_NICKNAME */ + window = authdes_cache[sid].window; + nick = 1; + } + + if ((u_long) timestamp.tv_usec >= USEC_PER_SEC) + { + debug ("invalid usecs"); + /* cached out (bad key), or garbled verifier */ + return nick ? AUTH_REJECTEDVERF : AUTH_BADVERF; + } + if (nick && BEFORE (×tamp, + &authdes_cache[sid].laststamp)) + { + debug ("timestamp before last seen"); + return (AUTH_REJECTEDVERF); /* replay */ + } + gettimeofday (¤t, (struct timezone *) NULL); + current.tv_sec -= window; /* allow for expiration */ + if (!BEFORE (¤t, ×tamp)) + { + debug ("timestamp expired"); + /* replay, or garbled credential */ + return nick ? AUTH_REJECTEDVERF : AUTH_BADCRED; + } + } + + /* + * Set up the reply verifier + */ + verf.adv_nickname = (u_long) sid; + + /* + * xdr the timestamp before encrypting + */ + ixdr = (long *) cryptbuf; + IXDR_PUT_LONG (ixdr, timestamp.tv_sec - 1); + IXDR_PUT_LONG (ixdr, timestamp.tv_usec); + + /* + * encrypt the timestamp + */ + status = ecb_crypt ((char *) sessionkey, (char *) cryptbuf, + sizeof (des_block), DES_ENCRYPT | DES_HW); + if (DES_FAILED (status)) + { + debug ("encryption failure"); + return AUTH_FAILED; /* system error */ + } + verf.adv_xtimestamp = cryptbuf[0]; + + /* + * Serialize the reply verifier, and update rqst + */ + ixdr = (long *) msg->rm_call.cb_verf.oa_base; + *ixdr++ = (long) verf.adv_xtimestamp.key.high; + *ixdr++ = (long) verf.adv_xtimestamp.key.low; + *ixdr++ = (long) verf.adv_int_u; + + rqst->rq_xprt->xp_verf.oa_flavor = AUTH_DES; + rqst->rq_xprt->xp_verf.oa_base = msg->rm_call.cb_verf.oa_base; + rqst->rq_xprt->xp_verf.oa_length = + (char *) ixdr - msg->rm_call.cb_verf.oa_base; + + /* + * We succeeded, commit the data to the cache now and + * finish cooking the credential. + */ + entry = &authdes_cache[sid]; + entry->laststamp = timestamp; + cache_ref (sid); + if (cred->adc_namekind == ADN_FULLNAME) + { + cred->adc_fullname.window = window; + cred->adc_nickname = (u_long) sid; /* save nickname */ + if (entry->rname != NULL) + { + mem_free (entry->rname, strlen (entry->rname) + 1); + } + entry->rname = mem_alloc ((u_int) strlen (cred->adc_fullname.name) + + 1); + if (entry->rname != NULL) + { + strcpy (entry->rname, cred->adc_fullname.name); + } + else + { + debug ("out of memory"); + } + entry->key = *sessionkey; + entry->window = window; + invalidate (entry->localcred); /* mark any cached cred invalid */ + } + else + { /* ADN_NICKNAME */ + /* + * nicknames are cooked into fullnames + */ + cred->adc_namekind = ADN_FULLNAME; + cred->adc_fullname.name = entry->rname; + cred->adc_fullname.key = entry->key; + cred->adc_fullname.window = entry->window; + } + return AUTH_OK; /* we made it! */ +} + + +/* + * Initialize the cache + */ +static void +cache_init (void) +{ + register int i; + + authdes_cache = (struct cache_entry *) + mem_alloc (sizeof (struct cache_entry) * AUTHDES_CACHESZ); + bzero ((char *) authdes_cache, + sizeof (struct cache_entry) * AUTHDES_CACHESZ); + + authdes_lru = (short *) mem_alloc (sizeof (short) * AUTHDES_CACHESZ); + /* + * Initialize the lru list + */ + for (i = 0; i < AUTHDES_CACHESZ; i++) + { + authdes_lru[i] = i; + } +} + + +/* + * Find the lru victim + */ +static short +cache_victim (void) +{ + return (authdes_lru[AUTHDES_CACHESZ - 1]); +} + +/* + * Note that sid was referenced + */ +static void +cache_ref (register short sid) +{ + register int i; + register short curr; + register short prev; + + prev = authdes_lru[0]; + authdes_lru[0] = sid; + for (i = 1; prev != sid; i++) + { + curr = authdes_lru[i]; + authdes_lru[i] = prev; + prev = curr; + } +} + + +/* + * Find a spot in the cache for a credential containing + * the items given. Return -1 if a replay is detected, otherwise + * return the spot in the cache. + */ +static short +cache_spot (register des_block * key, char *name, struct timeval *timestamp) +{ + register struct cache_entry *cp; + register int i; + register u_long hi; + + hi = key->key.high; + for (cp = authdes_cache, i = 0; i < AUTHDES_CACHESZ; i++, cp++) + { + if (cp->key.key.high == hi && + cp->key.key.low == key->key.low && + cp->rname != NULL && + bcmp (cp->rname, name, strlen (name) + 1) == 0) + { + if (BEFORE (timestamp, &cp->laststamp)) + { + svcauthdes_stats.ncachereplays++; + return -1; /* replay */ + } + svcauthdes_stats.ncachehits++; + return i; /* refresh */ + } + } + svcauthdes_stats.ncachemisses++; + return cache_victim (); /* new credential */ +} + + +/* + * Local credential handling stuff. + * NOTE: bsd unix dependent. + * Other operating systems should put something else here. + */ +#define UNKNOWN -2 /* grouplen, if cached cred is unknown user */ +#define INVALID -1 /* grouplen, if cache entry is invalid */ + +struct bsdcred +{ + uid_t uid; /* cached uid */ + gid_t gid; /* cached gid */ + short grouplen; /* length of cached groups */ + gid_t groups[NGROUPS]; /* cached groups */ +}; + +/* + * Map a des credential into a unix cred. + * We cache the credential here so the application does + * not have to make an rpc call every time to interpret + * the credential. + */ +int +authdes_getucred (const struct authdes_cred *adc, uid_t * uid, gid_t * gid, + short *grouplen, gid_t * groups) +{ + unsigned sid; + register int i; + uid_t i_uid; + gid_t i_gid; + int i_grouplen; + struct bsdcred *cred; + + sid = adc->adc_nickname; + if (sid >= AUTHDES_CACHESZ) + { + debug ("invalid nickname"); + return 0; + } + cred = (struct bsdcred *) authdes_cache[sid].localcred; + if (cred == NULL) + { + cred = (struct bsdcred *) mem_alloc (sizeof (struct bsdcred)); + authdes_cache[sid].localcred = (char *) cred; + cred->grouplen = INVALID; + } + if (cred->grouplen == INVALID) + { + /* + * not in cache: lookup + */ + if (!netname2user (adc->adc_fullname.name, &i_uid, &i_gid, + &i_grouplen, groups)) + { + debug ("unknown netname"); + cred->grouplen = UNKNOWN; /* mark as lookup up, but not found */ + return 0; + } + debug ("missed ucred cache"); + *uid = cred->uid = i_uid; + *gid = cred->gid = i_gid; + *grouplen = cred->grouplen = i_grouplen; + for (i = i_grouplen - 1; i >= 0; i--) + { + cred->groups[i] = groups[i]; /* int to short */ + } + return 1; + } + else if (cred->grouplen == UNKNOWN) + { + /* + * Already lookup up, but no match found + */ + return 0; + } + + /* + * cached credentials + */ + *uid = cred->uid; + *gid = cred->gid; + *grouplen = cred->grouplen; + for (i = cred->grouplen - 1; i >= 0; i--) + { + groups[i] = cred->groups[i]; /* short to int */ + } + return 1; +} + +static void +invalidate (char *cred) +{ + if (cred == NULL) + { + return; + } + ((struct bsdcred *) cred)->grouplen = INVALID; +} |