/* svc_auth_gss.c Copyright (c) 2000 The Regents of the University of Michigan. All rights reserved. Copyright (c) 2000 Dug Song . All rights reserved, all wrongs reversed. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. 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. 3. Neither the name of the University 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 ``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 REGENTS 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. $Id: svc_auth_gss.c,v 1.1 2004/06/07 21:09:38 marius Exp $ */ #include #include #include #include #ifdef HAVE_KRB5 #include #include #elif HAVE_HEIMDAL #include #define gss_nt_service_name GSS_C_NT_HOSTBASED_SERVICE #endif extern SVCAUTH svc_auth_none; /* * from mit-krb5-1.2.1 mechglue/mglueP.h: * Array of context IDs typed by mechanism OID */ typedef struct gss_union_ctx_id_t { gss_OID mech_type; gss_ctx_id_t internal_ctx_id; } gss_union_ctx_id_desc, *gss_union_ctx_id_t; static bool_t svcauth_gss_destroy(); static bool_t svcauth_gss_wrap(); static bool_t svcauth_gss_unwrap(); struct svc_auth_ops svc_auth_gss_ops = { svcauth_gss_wrap, svcauth_gss_unwrap, svcauth_gss_destroy }; struct svc_rpc_gss_data { bool_t established; /* context established */ gss_ctx_id_t ctx; /* context id */ struct rpc_gss_sec sec; /* security triple */ gss_buffer_desc cname; /* GSS client name */ u_int seq; /* sequence number */ u_int win; /* sequence window */ u_int seqlast; /* last sequence number */ u_int32_t seqmask; /* bitmask of seqnums */ gss_name_t client_name; /* unparsed name string */ }; #define SVCAUTH_PRIVATE(auth) \ ((struct svc_rpc_gss_data *)(auth)->svc_ah_private) /* Global server credentials. */ gss_cred_id_t _svcauth_gss_creds; static gss_name_t _svcauth_gss_name = NULL; bool_t svcauth_gss_set_svc_name(gss_name_t name) { OM_uint32 maj_stat, min_stat; log_debug("in svcauth_gss_set_svc_name()"); if (_svcauth_gss_name != NULL) { maj_stat = gss_release_name(&min_stat, &_svcauth_gss_name); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_release_name", maj_stat, min_stat); return (FALSE); } _svcauth_gss_name = NULL; } maj_stat = gss_duplicate_name(&min_stat, name, &_svcauth_gss_name); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_duplicate_name", maj_stat, min_stat); return (FALSE); } return (TRUE); } static bool_t svcauth_gss_import_name(char *service) { gss_name_t name; gss_buffer_desc namebuf; OM_uint32 maj_stat, min_stat; log_debug("in svcauth_gss_import_name()"); namebuf.value = service; namebuf.length = strlen(service); maj_stat = gss_import_name(&min_stat, &namebuf, (gss_OID)gss_nt_service_name, &name); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_import_name", maj_stat, min_stat); return (FALSE); } if (svcauth_gss_set_svc_name(name) != TRUE) { gss_release_name(&min_stat, &name); return (FALSE); } return (TRUE); } static bool_t svcauth_gss_acquire_cred(void) { OM_uint32 maj_stat, min_stat; log_debug("in svcauth_gss_acquire_cred()"); maj_stat = gss_acquire_cred(&min_stat, _svcauth_gss_name, 0, GSS_C_NULL_OID_SET, GSS_C_ACCEPT, &_svcauth_gss_creds, NULL, NULL); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_acquire_cred", maj_stat, min_stat); return (FALSE); } return (TRUE); } static bool_t svcauth_gss_release_cred(void) { OM_uint32 maj_stat, min_stat; log_debug("in svcauth_gss_release_cred()"); maj_stat = gss_release_cred(&min_stat, &_svcauth_gss_creds); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_release_cred", maj_stat, min_stat); return (FALSE); } _svcauth_gss_creds = NULL; return (TRUE); } static bool_t svcauth_gss_accept_sec_context(struct svc_req *rqst, struct rpc_gss_init_res *gr) { struct svc_rpc_gss_data *gd; struct rpc_gss_cred *gc; gss_buffer_desc recv_tok, seqbuf, checksum; gss_OID mech; OM_uint32 maj_stat = 0, min_stat = 0, ret_flags, seq; log_debug("in svcauth_gss_accept_context()"); gd = SVCAUTH_PRIVATE(rqst->rq_xprt->xp_auth); gc = (struct rpc_gss_cred *)rqst->rq_clntcred; memset(gr, 0, sizeof(*gr)); /* Deserialize arguments. */ memset(&recv_tok, 0, sizeof(recv_tok)); if (!svc_getargs(rqst->rq_xprt, xdr_rpc_gss_init_args, (caddr_t)&recv_tok)) return (FALSE); gr->gr_major = gss_accept_sec_context(&gr->gr_minor, &gd->ctx, _svcauth_gss_creds, &recv_tok, GSS_C_NO_CHANNEL_BINDINGS, &gd->client_name, &mech, &gr->gr_token, &ret_flags, NULL, NULL); if (gr->gr_major != GSS_S_COMPLETE && gr->gr_major != GSS_S_CONTINUE_NEEDED) { log_status("accept_sec_context", gr->gr_major, gr->gr_minor); gd->ctx = GSS_C_NO_CONTEXT; gss_release_buffer(&min_stat, &gr->gr_token); return (FALSE); } /* ANDROS: krb5 mechglue returns ctx of size 8 - two pointers, * one to the mechanism oid, one to the internal_ctx_id */ if ((gr->gr_ctx.value = mem_alloc(sizeof(gss_union_ctx_id_desc))) == NULL) { fprintf(stderr, "svcauth_gss_accept_context: out of memory\n"); return (FALSE); } memcpy(gr->gr_ctx.value, gd->ctx, sizeof(gss_union_ctx_id_desc)); gr->gr_ctx.length = sizeof(gss_union_ctx_id_desc); /* ANDROS: change for debugging linux kernel version... gr->gr_win = sizeof(gd->seqmask) * 8; */ gr->gr_win = 0x00000005; /* Save client info. */ gd->sec.mech = mech; gd->sec.qop = GSS_C_QOP_DEFAULT; gd->sec.svc = gc->gc_svc; gd->seq = gc->gc_seq; gd->win = gr->gr_win; if (gr->gr_major == GSS_S_COMPLETE) { #ifdef SPKM /* spkm3: no src_name (anonymous) */ if (!g_OID_equal(&spkm3oid, mech)) { #endif maj_stat = gss_display_name(&min_stat, gd->client_name, &gd->cname, &gd->sec.mech); #ifdef SPKM } #endif if (maj_stat != GSS_S_COMPLETE) { log_status("display_name", maj_stat, min_stat); return (FALSE); } #ifdef DEBUG #ifdef HAVE_KRB5 { gss_buffer_desc mechname; gss_oid_to_str(&min_stat, mech, &mechname); log_debug("accepted context for %.*s with " "", gd->cname.length, (char *)gd->cname.value, mechname.length, (char *)mechname.value, gd->sec.qop, gd->sec.svc); gss_release_buffer(&min_stat, &mechname); } #elif HAVE_HEIMDAL log_debug("accepted context for %.*s with " "", gd->cname.length, (char *)gd->cname.value, gd->sec.qop, gd->sec.svc); #endif #endif /* DEBUG */ seq = htonl(gr->gr_win); seqbuf.value = &seq; seqbuf.length = sizeof(seq); maj_stat = gss_sign(&min_stat, gd->ctx, GSS_C_QOP_DEFAULT, &seqbuf, &checksum); if (maj_stat != GSS_S_COMPLETE) return (FALSE); rqst->rq_xprt->xp_verf.oa_flavor = RPCSEC_GSS; rqst->rq_xprt->xp_verf.oa_base = checksum.value; rqst->rq_xprt->xp_verf.oa_length = checksum.length; } return (TRUE); } static bool_t svcauth_gss_validate(struct svc_rpc_gss_data *gd, struct rpc_msg *msg) { struct opaque_auth *oa; gss_buffer_desc rpcbuf, checksum; OM_uint32 maj_stat, min_stat, qop_state; u_char rpchdr[128]; int32_t *buf; log_debug("in svcauth_gss_validate()"); memset(rpchdr, 0, sizeof(rpchdr)); /* XXX - Reconstruct RPC header for signing (from xdr_callmsg). */ buf = (int32_t *)rpchdr; IXDR_PUT_LONG(buf, msg->rm_xid); IXDR_PUT_ENUM(buf, msg->rm_direction); IXDR_PUT_LONG(buf, msg->rm_call.cb_rpcvers); IXDR_PUT_LONG(buf, msg->rm_call.cb_prog); IXDR_PUT_LONG(buf, msg->rm_call.cb_vers); IXDR_PUT_LONG(buf, msg->rm_call.cb_proc); oa = &msg->rm_call.cb_cred; IXDR_PUT_ENUM(buf, oa->oa_flavor); IXDR_PUT_LONG(buf, oa->oa_length); if (oa->oa_length) { memcpy((caddr_t)buf, oa->oa_base, oa->oa_length); buf += RNDUP(oa->oa_length) / sizeof(int32_t); } rpcbuf.value = rpchdr; rpcbuf.length = (u_char *)buf - rpchdr; checksum.value = msg->rm_call.cb_verf.oa_base; checksum.length = msg->rm_call.cb_verf.oa_length; maj_stat = gss_verify_mic(&min_stat, gd->ctx, &rpcbuf, &checksum, &qop_state); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_verify_mic", maj_stat, min_stat); return (FALSE); } return (TRUE); } bool_t svcauth_gss_nextverf(struct svc_req *rqst, u_int num) { struct svc_rpc_gss_data *gd; gss_buffer_desc signbuf, checksum; OM_uint32 maj_stat, min_stat; log_debug("in svcauth_gss_nextverf()"); if (rqst->rq_xprt->xp_auth == NULL) return (FALSE); gd = SVCAUTH_PRIVATE(rqst->rq_xprt->xp_auth); signbuf.value = # signbuf.length = sizeof(num); maj_stat = gss_get_mic(&min_stat, gd->ctx, gd->sec.qop, &signbuf, &checksum); if (maj_stat != GSS_S_COMPLETE) { log_status("gss_get_mic", maj_stat, min_stat); return (FALSE); } rqst->rq_xprt->xp_verf.oa_flavor = RPCSEC_GSS; rqst->rq_xprt->xp_verf.oa_base = (caddr_t)checksum.value; rqst->rq_xprt->xp_verf.oa_length = (u_int)checksum.length; return (TRUE); } enum auth_stat _svcauth_gss(struct svc_req *rqst, struct rpc_msg *msg, bool_t *no_dispatch) { XDR xdrs; SVCAUTH *auth; struct svc_rpc_gss_data *gd; struct rpc_gss_cred *gc; struct rpc_gss_init_res gr; int call_stat, offset; log_debug("in svcauth_gss()"); /* Initialize reply. */ rqst->rq_xprt->xp_verf = _null_auth; /* Allocate and set up server auth handle. */ if (rqst->rq_xprt->xp_auth == NULL || rqst->rq_xprt->xp_auth == &svc_auth_none) { if ((auth = calloc(sizeof(*auth), 1)) == NULL) { fprintf(stderr, "svcauth_gss: out_of_memory\n"); return (AUTH_FAILED); } if ((gd = calloc(sizeof(*gd), 1)) == NULL) { fprintf(stderr, "svcauth_gss: out_of_memory\n"); return (AUTH_FAILED); } auth->svc_ah_ops = &svc_auth_gss_ops; SVCAUTH_PRIVATE(auth) = gd; rqst->rq_xprt->xp_auth = auth; } else gd = SVCAUTH_PRIVATE(rqst->rq_xprt->xp_auth); /* Deserialize client credentials. */ if (rqst->rq_cred.oa_length <= 0) return (AUTH_BADCRED); gc = (struct rpc_gss_cred *)rqst->rq_clntcred; memset(gc, 0, sizeof(*gc)); xdrmem_create(&xdrs, rqst->rq_cred.oa_base, rqst->rq_cred.oa_length, XDR_DECODE); if (!xdr_rpc_gss_cred(&xdrs, gc)) { XDR_DESTROY(&xdrs); return (AUTH_BADCRED); } XDR_DESTROY(&xdrs); /* Check version. */ if (gc->gc_v != RPCSEC_GSS_VERSION) return (AUTH_BADCRED); /* Check RPCSEC_GSS service. */ if (gc->gc_svc != RPCSEC_GSS_SVC_NONE && gc->gc_svc != RPCSEC_GSS_SVC_INTEGRITY && gc->gc_svc != RPCSEC_GSS_SVC_PRIVACY) return (AUTH_BADCRED); /* Check sequence number. */ if (gd->established) { if (gc->gc_seq > MAXSEQ) return (RPCSEC_GSS_CTXPROBLEM); if ((offset = gd->seqlast - gc->gc_seq) < 0) { gd->seqlast = gc->gc_seq; offset = 0 - offset; gd->seqmask <<= offset; offset = 0; } else if (offset >= gd->win || (gd->seqmask & (1 << offset))) { *no_dispatch = 1; return (RPCSEC_GSS_CTXPROBLEM); } gd->seq = gc->gc_seq; gd->seqmask |= (1 << offset); } if (gd->established) { rqst->rq_clntname = (char *)gd->client_name; rqst->rq_svcname = (char *)gd->ctx; } /* Handle RPCSEC_GSS control procedure. */ switch (gc->gc_proc) { case RPCSEC_GSS_INIT: case RPCSEC_GSS_CONTINUE_INIT: if (rqst->rq_proc != NULLPROC) return (AUTH_FAILED); /* XXX ? */ if (_svcauth_gss_name == NULL) { if (!svcauth_gss_import_name("nfs")) return (AUTH_FAILED); } if (!svcauth_gss_acquire_cred()) return (AUTH_FAILED); if (!svcauth_gss_accept_sec_context(rqst, &gr)) return (AUTH_REJECTEDCRED); if (!svcauth_gss_nextverf(rqst, htonl(gr.gr_win))) return (AUTH_FAILED); *no_dispatch = TRUE; call_stat = svc_sendreply(rqst->rq_xprt, xdr_rpc_gss_init_res, (caddr_t)&gr); if (!call_stat) return (AUTH_FAILED); if (gr.gr_major == GSS_S_COMPLETE) gd->established = TRUE; break; case RPCSEC_GSS_DATA: if (!svcauth_gss_validate(gd, msg)) return (RPCSEC_GSS_CREDPROBLEM); if (!svcauth_gss_nextverf(rqst, htonl(gc->gc_seq))) return (AUTH_FAILED); break; case RPCSEC_GSS_DESTROY: if (rqst->rq_proc != NULLPROC) return (AUTH_FAILED); /* XXX ? */ if (!svcauth_gss_validate(gd, msg)) return (RPCSEC_GSS_CREDPROBLEM); if (!svcauth_gss_nextverf(rqst, htonl(gc->gc_seq))) return (AUTH_FAILED); if (!svcauth_gss_release_cred()) return (AUTH_FAILED); SVCAUTH_DESTROY(rqst->rq_xprt->xp_auth); rqst->rq_xprt->xp_auth = &svc_auth_none; break; default: return (AUTH_REJECTEDCRED); break; } return (AUTH_OK); } bool_t svcauth_gss_destroy(SVCAUTH *auth) { struct svc_rpc_gss_data *gd; OM_uint32 min_stat; log_debug("in svcauth_gss_destroy()"); gd = SVCAUTH_PRIVATE(auth); gss_delete_sec_context(&min_stat, &gd->ctx, GSS_C_NO_BUFFER); gss_release_buffer(&min_stat, &gd->cname); if (gd->client_name) gss_release_name(&min_stat, &gd->client_name); mem_free(gd, sizeof(*gd)); mem_free(auth, sizeof(*auth)); return (TRUE); } bool_t svcauth_gss_wrap(SVCAUTH *auth, XDR *xdrs, xdrproc_t xdr_func, caddr_t xdr_ptr) { struct svc_rpc_gss_data *gd; log_debug("in svcauth_gss_wrap()"); gd = SVCAUTH_PRIVATE(auth); if (!gd->established || gd->sec.svc == RPCSEC_GSS_SVC_NONE) { return ((*xdr_func)(xdrs, xdr_ptr)); } return (xdr_rpc_gss_data(xdrs, xdr_func, xdr_ptr, gd->ctx, gd->sec.qop, gd->sec.svc, gd->seq)); } bool_t svcauth_gss_unwrap(SVCAUTH *auth, XDR *xdrs, xdrproc_t xdr_func, caddr_t xdr_ptr) { struct svc_rpc_gss_data *gd; log_debug("in svcauth_gss_unwrap()"); gd = SVCAUTH_PRIVATE(auth); if (!gd->established || gd->sec.svc == RPCSEC_GSS_SVC_NONE) { return ((*xdr_func)(xdrs, xdr_ptr)); } return (xdr_rpc_gss_data(xdrs, xdr_func, xdr_ptr, gd->ctx, gd->sec.qop, gd->sec.svc, gd->seq)); } char * svcauth_gss_get_principal(SVCAUTH *auth) { struct svc_rpc_gss_data *gd; char *pname; gd = SVCAUTH_PRIVATE(auth); if (gd->cname.length == 0) return (NULL); if ((pname = malloc(gd->cname.length + 1)) == NULL) return (NULL); memcpy(pname, gd->cname.value, gd->cname.length); pname[gd->cname.length] = '\0'; return (pname); }