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Diffstat (limited to '')
| -rw-r--r-- | src/auth_unix.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/src/auth_unix.c b/src/auth_unix.c new file mode 100644 index 0000000..fc2be02 --- /dev/null +++ b/src/auth_unix.c @@ -0,0 +1,424 @@ +/* + * Copyright (c) 2009, Sun Microsystems, Inc. + * All rights reserved. + * + * 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 Sun Microsystems, 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. + * + * Copyright (C) 1984, Sun Microsystems, Inc. + * + * The system is very weak. The client uses no encryption for it's + * 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 <pthread.h> +#include <reentrant.h> +#include <sys/param.h> + +#include <assert.h> +#include <err.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> + +#include <rpc/clnt.h> +#include <rpc/types.h> +#include <rpc/xdr.h> +#include <rpc/auth.h> +#include <rpc/auth_unix.h> + +/* auth_unix.c */ +static void authunix_nextverf (AUTH *); +static bool_t authunix_marshal (AUTH *, XDR *); +static bool_t authunix_validate (AUTH *, struct opaque_auth *); +static bool_t authunix_refresh (AUTH *, void *); +static void authunix_destroy (AUTH *); +static void marshal_new_auth (AUTH *); +static struct auth_ops *authunix_ops (void); + +/* + * 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) + +/* + * Create a unix style authenticator. + * Returns an auth handle with the given stuff in it. + */ +AUTH * +authunix_create(machname, uid, gid, len, aup_gids) + char *machname; + uid_t uid; + gid_t gid; + int len; + gid_t *aup_gids; +{ + struct authunix_parms aup; + char mymem[MAX_AUTH_BYTES]; + struct timeval now; + XDR xdrs; + AUTH *auth; + struct audata *au; + + memset(&rpc_createerr, 0, sizeof(rpc_createerr)); + + /* + * Allocate and set up auth handle + */ + au = NULL; + auth = mem_alloc(sizeof(*auth)); +#ifndef _KERNEL + if (auth == NULL) { + rpc_createerr.cf_stat = RPC_SYSTEMERROR; + rpc_createerr.cf_error.re_errno = ENOMEM; + goto cleanup_authunix_create; + } +#endif + au = mem_alloc(sizeof(*au)); +#ifndef _KERNEL + if (au == NULL) { + rpc_createerr.cf_stat = RPC_SYSTEMERROR; + rpc_createerr.cf_error.re_errno = ENOMEM; + goto cleanup_authunix_create; + } +#endif + auth->ah_ops = authunix_ops(); + auth->ah_private = (caddr_t)au; + auth->ah_verf = au->au_shcred = _null_auth; + au->au_shfaults = 0; + au->au_origcred.oa_base = NULL; + + /* + * fill in param struct from the given params + */ + (void)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)) { + rpc_createerr.cf_stat = RPC_CANTENCODEARGS; + goto cleanup_authunix_create; + } + 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) { + rpc_createerr.cf_stat = RPC_SYSTEMERROR; + rpc_createerr.cf_error.re_errno = ENOMEM; + goto cleanup_authunix_create; + } +#endif + memmove(au->au_origcred.oa_base, mymem, (size_t)len); + + /* + * set auth handle to reflect new cred. + */ + auth->ah_cred = au->au_origcred; + marshal_new_auth(auth); + return (auth); +#ifndef _KERNEL + cleanup_authunix_create: + if (auth) + mem_free(auth, sizeof(*auth)); + if (au) { + if (au->au_origcred.oa_base) + mem_free(au->au_origcred.oa_base, (u_int)len); + mem_free(au, sizeof(*au)); + } + return (NULL); +#endif +} + +/* + * Returns an auth handle with parameters determined by doing lots of + * syscalls. + */ +AUTH * +authunix_create_default() +{ + int len; + char machname[MAXHOSTNAMELEN + 1]; + uid_t uid; + gid_t gid, *gids; + AUTH *result; + + memset(&rpc_createerr, 0, sizeof(rpc_createerr)); + + if (gethostname(machname, sizeof machname) == -1) { + rpc_createerr.cf_error.re_errno = errno; + goto out_err; + } + machname[sizeof(machname) - 1] = 0; + uid = geteuid(); + gid = getegid(); + + /* According to glibc comments, an intervening setgroups(2) + * call can increase the number of supplemental groups between + * these two getgroups(2) calls. */ +retry: + len = getgroups(0, NULL); + if (len == -1) { + rpc_createerr.cf_error.re_errno = errno; + goto out_err; + } + + /* Bump allocation size. A zero allocation size may result in a + * NULL calloc(3) result, which is not reliably distinguishable + * from a memory allocation error. */ + gids = calloc(len + 1, sizeof(gid_t)); + if (gids == NULL) { + rpc_createerr.cf_error.re_errno = ENOMEM; + goto out_err; + } + + len = getgroups(len, gids); + if (len == -1) { + rpc_createerr.cf_error.re_errno = errno; + free(gids); + if (rpc_createerr.cf_error.re_errno == EINVAL) { + rpc_createerr.cf_error.re_errno = 0; + goto retry; + } + goto out_err; + } + + /* + * AUTH_UNIX sends on the wire only the first NGRPS groups in the + * supplemental groups list. + */ + if (len > NGRPS) + len = NGRPS; + + /* XXX: interface problem; those should all have been unsigned */ + result = authunix_create(machname, uid, gid, len, gids); + free(gids); + return result; + +out_err: + rpc_createerr.cf_stat = RPC_SYSTEMERROR; + return NULL; +} + +/* + * authunix operations + */ + +/* ARGSUSED */ +static void +authunix_nextverf(auth) + AUTH *auth; +{ + /* no action necessary */ +} + +static bool_t +authunix_marshal(auth, xdrs) + AUTH *auth; + XDR *xdrs; +{ + struct audata *au; + + assert(auth != NULL); + assert(xdrs != NULL); + + au = AUTH_PRIVATE(auth); + return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos)); +} + +static bool_t +authunix_validate(auth, verf) + AUTH *auth; + struct opaque_auth *verf; +{ + struct audata *au; + XDR xdrs; + + assert(auth != NULL); + assert(verf != NULL); + + 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, void *dummy) +{ + struct audata *au = AUTH_PRIVATE(auth); + struct authunix_parms aup; + struct timeval now; + XDR xdrs; + int stat; + + assert(auth != NULL); + + 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)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 *auth; +{ + struct audata *au; + + assert(auth != NULL); + + 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(auth, sizeof(*auth)); +} + +/* + * Marshals (pre-serializes) an auth struct. + * sets private data, au_marshed and au_mpos + */ +static void +marshal_new_auth(auth) + AUTH *auth; +{ + XDR xdr_stream; + XDR *xdrs = &xdr_stream; + struct audata *au; + + assert(auth != NULL); + + 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)))) + warnx("auth_none.c - Fatal marshalling problem"); + else + au->au_mpos = XDR_GETPOS(xdrs); + XDR_DESTROY(xdrs); +} + +static bool_t +authunix_wrap(AUTH *auth, XDR *xdrs, xdrproc_t xfunc, caddr_t xwhere) +{ + return ((*xfunc)(xdrs, xwhere)); +} + +static struct auth_ops * +authunix_ops() +{ + static struct auth_ops ops; + extern mutex_t ops_lock; + + /* VARIABLES PROTECTED BY ops_lock: ops */ + + mutex_lock(&ops_lock); + if (ops.ah_nextverf == NULL) { + ops.ah_nextverf = authunix_nextverf; + ops.ah_marshal = authunix_marshal; + ops.ah_validate = authunix_validate; + ops.ah_refresh = authunix_refresh; + ops.ah_destroy = authunix_destroy; + ops.ah_wrap = authunix_wrap; + ops.ah_unwrap = authunix_wrap; + } + mutex_unlock(&ops_lock); + return (&ops); +} |