/* $OpenBSD: auth_unix.c,v 1.30 2022/02/14 03:38:59 guenther Exp $ */ /* * Copyright (c) 2010, Oracle America, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * Neither the name of the "Oracle America, Inc." nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * auth_unix.c, Implements UNIX style authentication parameters. * * The system is very weak. The client uses no encryption for its * credentials and only sends null verifiers. The server sends backs * null verifiers or optionally a verifier that suggests a new short hand * for the credentials. * */ #include #include #include #include #include #include #include #include #include /* * Unix authenticator operations vector */ static void authunix_nextverf(struct __rpc_auth *); static bool_t authunix_marshal(struct __rpc_auth *, XDR *); static bool_t authunix_validate(struct __rpc_auth *, struct opaque_auth *); static bool_t authunix_refresh(struct __rpc_auth *); static void authunix_destroy(struct __rpc_auth *); static const struct auth_ops auth_unix_ops = { authunix_nextverf, authunix_marshal, authunix_validate, authunix_refresh, authunix_destroy }; /* * This struct is pointed to by the ah_private field of an auth_handle. */ struct audata { struct opaque_auth au_origcred; /* original credentials */ struct opaque_auth au_shcred; /* short hand cred */ u_long au_shfaults; /* short hand cache faults */ char au_marshed[MAX_AUTH_BYTES]; u_int au_mpos; /* xdr pos at end of marshed */ }; #define AUTH_PRIVATE(auth) ((struct audata *)auth->ah_private) static void marshal_new_auth(AUTH *auth); /* * Create a unix style authenticator. * Returns an auth handle with the given stuff in it. */ AUTH * authunix_create(char *machname, int uid, int gid, int len, int *aup_gids) { struct authunix_parms aup; char mymem[MAX_AUTH_BYTES]; struct timeval now; XDR xdrs; AUTH *auth; struct audata *au; /* * Allocate and set up auth handle */ auth = (AUTH *)mem_alloc(sizeof(*auth)); #ifndef KERNEL if (auth == NULL) return (NULL); #endif au = (struct audata *)mem_alloc(sizeof(*au)); #ifndef KERNEL if (au == NULL) { free(auth); return (NULL); } #endif auth->ah_ops = &auth_unix_ops; auth->ah_private = (caddr_t)au; auth->ah_verf = au->au_shcred = _null_auth; au->au_shfaults = 0; /* * fill in param struct from the given params */ (void)WRAP(gettimeofday)(&now, NULL); aup.aup_time = now.tv_sec; aup.aup_machname = machname; aup.aup_uid = uid; aup.aup_gid = gid; aup.aup_len = (u_int)len; aup.aup_gids = aup_gids; /* * Serialize the parameters into origcred */ xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE); if (!xdr_authunix_parms(&xdrs, &aup)) goto authfail; au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs); au->au_origcred.oa_flavor = AUTH_UNIX; #ifdef KERNEL au->au_origcred.oa_base = mem_alloc((u_int) len); #else if ((au->au_origcred.oa_base = mem_alloc((u_int) len)) == NULL) goto authfail; #endif memcpy(au->au_origcred.oa_base, mymem, (u_int)len); /* * set auth handle to reflect new cred. */ auth->ah_cred = au->au_origcred; marshal_new_auth(auth); return (auth); authfail: XDR_DESTROY(&xdrs); free(au); free(auth); return (NULL); } DEF_WEAK(authunix_create); /* * Some servers will refuse mounts if the group list is larger * than it expects (like 8). This allows the application to set * the maximum size of the group list that will be sent. */ static int maxgrplist = NGRPS; void set_rpc_maxgrouplist(int num) { if (num < NGRPS) maxgrplist = num; } /* * Returns an auth handle with parameters determined by doing lots of * syscalls. */ AUTH * authunix_create_default(void) { int len, i; char machname[MAX_MACHINE_NAME + 1]; uid_t uid; gid_t gid; gid_t gids[NGRPS]; int gids2[NGRPS]; if (gethostname(machname, sizeof machname) == -1) return (NULL); machname[MAX_MACHINE_NAME] = 0; uid = geteuid(); gid = getegid(); if ((len = getgroups(NGRPS, gids)) == -1) return (NULL); if (len > maxgrplist) len = maxgrplist; for (i = 0; i < len; i++) gids2[i] = gids[i]; return (authunix_create(machname, uid, gid, len, gids2)); } DEF_WEAK(authunix_create_default); /* * authunix operations */ static void authunix_nextverf(AUTH *auth) { /* no action necessary */ } static bool_t authunix_marshal(AUTH *auth, XDR *xdrs) { struct audata *au = AUTH_PRIVATE(auth); return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos)); } static bool_t authunix_validate(AUTH *auth, struct opaque_auth *verf) { struct audata *au; XDR xdrs; if (verf->oa_flavor == AUTH_SHORT) { au = AUTH_PRIVATE(auth); xdrmem_create(&xdrs, verf->oa_base, verf->oa_length, XDR_DECODE); if (au->au_shcred.oa_base != NULL) { mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length); au->au_shcred.oa_base = NULL; } if (xdr_opaque_auth(&xdrs, &au->au_shcred)) { auth->ah_cred = au->au_shcred; } else { xdrs.x_op = XDR_FREE; (void)xdr_opaque_auth(&xdrs, &au->au_shcred); au->au_shcred.oa_base = NULL; auth->ah_cred = au->au_origcred; } marshal_new_auth(auth); } return (TRUE); } static bool_t authunix_refresh(AUTH *auth) { struct audata *au = AUTH_PRIVATE(auth); struct authunix_parms aup; struct timeval now; XDR xdrs; int stat; if (auth->ah_cred.oa_base == au->au_origcred.oa_base) { /* there is no hope. Punt */ return (FALSE); } au->au_shfaults ++; /* first deserialize the creds back into a struct authunix_parms */ aup.aup_machname = NULL; aup.aup_gids = NULL; xdrmem_create(&xdrs, au->au_origcred.oa_base, au->au_origcred.oa_length, XDR_DECODE); stat = xdr_authunix_parms(&xdrs, &aup); if (! stat) goto done; /* update the time and serialize in place */ (void)WRAP(gettimeofday)(&now, NULL); aup.aup_time = now.tv_sec; xdrs.x_op = XDR_ENCODE; XDR_SETPOS(&xdrs, 0); stat = xdr_authunix_parms(&xdrs, &aup); if (! stat) goto done; auth->ah_cred = au->au_origcred; marshal_new_auth(auth); done: /* free the struct authunix_parms created by deserializing */ xdrs.x_op = XDR_FREE; (void)xdr_authunix_parms(&xdrs, &aup); XDR_DESTROY(&xdrs); return (stat); } static void authunix_destroy(AUTH *auth) { struct audata *au = AUTH_PRIVATE(auth); mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length); if (au->au_shcred.oa_base != NULL) mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length); mem_free(auth->ah_private, sizeof(struct audata)); if (auth->ah_verf.oa_base != NULL) mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length); mem_free((caddr_t)auth, sizeof(*auth)); } /* * Marshals (pre-serializes) an auth struct. * sets private data, au_marshed and au_mpos */ static void marshal_new_auth(AUTH *auth) { XDR xdr_stream; XDR *xdrs = &xdr_stream; struct audata *au = AUTH_PRIVATE(auth); xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE); if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) || (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) { /* XXX nothing we can do */ } else { au->au_mpos = XDR_GETPOS(xdrs); } XDR_DESTROY(xdrs); }