diff options
Diffstat (limited to 'source4/heimdal/lib/gssapi/mech/gss_accept_sec_context.c')
| -rw-r--r-- | source4/heimdal/lib/gssapi/mech/gss_accept_sec_context.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/source4/heimdal/lib/gssapi/mech/gss_accept_sec_context.c b/source4/heimdal/lib/gssapi/mech/gss_accept_sec_context.c new file mode 100644 index 0000000000..5fa102193e --- /dev/null +++ b/source4/heimdal/lib/gssapi/mech/gss_accept_sec_context.c @@ -0,0 +1,291 @@ +/*- + * Copyright (c) 2005 Doug Rabson + * All rights reserved. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. + * + * $FreeBSD: src/lib/libgssapi/gss_accept_sec_context.c,v 1.1 2005/12/29 14:40:20 dfr Exp $ + */ + +#include "mech_locl.h" +RCSID("$Id$"); + +static OM_uint32 +parse_header(const gss_buffer_t input_token, gss_OID mech_oid) +{ + unsigned char *p = input_token->value; + size_t len = input_token->length; + size_t a, b; + + /* + * Token must start with [APPLICATION 0] SEQUENCE. + * But if it doesn't assume it is DCE-STYLE Kerberos! + */ + if (len == 0) + return (GSS_S_DEFECTIVE_TOKEN); + + p++; + len--; + + /* + * Decode the length and make sure it agrees with the + * token length. + */ + if (len == 0) + return (GSS_S_DEFECTIVE_TOKEN); + if ((*p & 0x80) == 0) { + a = *p; + p++; + len--; + } else { + b = *p & 0x7f; + p++; + len--; + if (len < b) + return (GSS_S_DEFECTIVE_TOKEN); + a = 0; + while (b) { + a = (a << 8) | *p; + p++; + len--; + b--; + } + } + if (a != len) + return (GSS_S_DEFECTIVE_TOKEN); + + /* + * Decode the OID for the mechanism. Simplify life by + * assuming that the OID length is less than 128 bytes. + */ + if (len < 2 || *p != 0x06) + return (GSS_S_DEFECTIVE_TOKEN); + if ((p[1] & 0x80) || p[1] > (len - 2)) + return (GSS_S_DEFECTIVE_TOKEN); + mech_oid->length = p[1]; + p += 2; + len -= 2; + mech_oid->elements = p; + + return GSS_S_COMPLETE; +} + +static gss_OID_desc krb5_mechanism = + {9, rk_UNCONST("\x2a\x86\x48\x86\xf7\x12\x01\x02\x02")}; +static gss_OID_desc ntlm_mechanism = + {10, rk_UNCONST("\x2b\x06\x01\x04\x01\x82\x37\x02\x02\x0a")}; +static gss_OID_desc spnego_mechanism = + {6, rk_UNCONST("\x2b\x06\x01\x05\x05\x02")}; + +static OM_uint32 +choose_mech(const gss_buffer_t input, gss_OID mech_oid) +{ + OM_uint32 status; + + /* + * First try to parse the gssapi token header and see if it's a + * correct header, use that in the first hand. + */ + + status = parse_header(input, mech_oid); + if (status == GSS_S_COMPLETE) + return GSS_S_COMPLETE; + + /* + * Lets guess what mech is really is, callback function to mech ?? + */ + + if (input->length > 8 && + memcmp((const char *)input->value, "NTLMSSP\x00", 8) == 0) + { + *mech_oid = ntlm_mechanism; + return GSS_S_COMPLETE; + } else if (input->length != 0 && + ((const char *)input->value)[0] == 0x6E) + { + /* Could be a raw AP-REQ (check for APPLICATION tag) */ + *mech_oid = krb5_mechanism; + return GSS_S_COMPLETE; + } else if (input->length == 0) { + /* + * There is the a wierd mode of SPNEGO (in CIFS and + * SASL GSS-SPENGO where the first token is zero + * length and the acceptor returns a mech_list, lets + * hope that is what is happening now. + */ + *mech_oid = spnego_mechanism; + return GSS_S_COMPLETE; + } + return status; +} + + +OM_uint32 gss_accept_sec_context(OM_uint32 *minor_status, + gss_ctx_id_t *context_handle, + const gss_cred_id_t acceptor_cred_handle, + const gss_buffer_t input_token, + const gss_channel_bindings_t input_chan_bindings, + gss_name_t *src_name, + gss_OID *mech_type, + gss_buffer_t output_token, + OM_uint32 *ret_flags, + OM_uint32 *time_rec, + gss_cred_id_t *delegated_cred_handle) +{ + OM_uint32 major_status, mech_ret_flags, junk; + gssapi_mech_interface m; + struct _gss_context *ctx = (struct _gss_context *) *context_handle; + struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle; + struct _gss_mechanism_cred *mc; + gss_cred_id_t acceptor_mc, delegated_mc; + gss_name_t src_mn; + + *minor_status = 0; + if (src_name) + *src_name = GSS_C_NO_NAME; + if (mech_type) + *mech_type = GSS_C_NO_OID; + if (ret_flags) + *ret_flags = 0; + if (time_rec) + *time_rec = 0; + if (delegated_cred_handle) + *delegated_cred_handle = GSS_C_NO_CREDENTIAL; + _mg_buffer_zero(output_token); + + + /* + * If this is the first call (*context_handle is NULL), we must + * parse the input token to figure out the mechanism to use. + */ + if (*context_handle == GSS_C_NO_CONTEXT) { + gss_OID_desc mech_oid; + + major_status = choose_mech(input_token, &mech_oid); + if (major_status != GSS_S_COMPLETE) + return major_status; + + /* + * Now that we have a mechanism, we can find the + * implementation. + */ + ctx = malloc(sizeof(struct _gss_context)); + if (!ctx) { + *minor_status = ENOMEM; + return (GSS_S_DEFECTIVE_TOKEN); + } + memset(ctx, 0, sizeof(struct _gss_context)); + m = ctx->gc_mech = __gss_get_mechanism(&mech_oid); + if (!m) { + free(ctx); + return (GSS_S_BAD_MECH); + } + *context_handle = (gss_ctx_id_t) ctx; + } else { + m = ctx->gc_mech; + } + + if (cred) { + SLIST_FOREACH(mc, &cred->gc_mc, gmc_link) + if (mc->gmc_mech == m) + break; + if (!mc) { + gss_delete_sec_context(&junk, context_handle, NULL); + return (GSS_S_BAD_MECH); + } + acceptor_mc = mc->gmc_cred; + } else { + acceptor_mc = GSS_C_NO_CREDENTIAL; + } + delegated_mc = GSS_C_NO_CREDENTIAL; + + mech_ret_flags = 0; + major_status = m->gm_accept_sec_context(minor_status, + &ctx->gc_ctx, + acceptor_mc, + input_token, + input_chan_bindings, + &src_mn, + mech_type, + output_token, + &mech_ret_flags, + time_rec, + &delegated_mc); + if (major_status != GSS_S_COMPLETE && + major_status != GSS_S_CONTINUE_NEEDED) + { + _gss_mg_error(m, major_status, *minor_status); + gss_delete_sec_context(&junk, context_handle, NULL); + return (major_status); + } + + if (src_name && src_mn) { + /* + * Make a new name and mark it as an MN. + */ + struct _gss_name *name = _gss_make_name(m, src_mn); + + if (!name) { + m->gm_release_name(minor_status, &src_mn); + gss_delete_sec_context(&junk, context_handle, NULL); + return (GSS_S_FAILURE); + } + *src_name = (gss_name_t) name; + } else if (src_mn) { + m->gm_release_name(minor_status, &src_mn); + } + + if (mech_ret_flags & GSS_C_DELEG_FLAG) { + if (!delegated_cred_handle) { + m->gm_release_cred(minor_status, &delegated_mc); + *ret_flags &= ~GSS_C_DELEG_FLAG; + } else if (delegated_mc) { + struct _gss_cred *dcred; + struct _gss_mechanism_cred *dmc; + + dcred = malloc(sizeof(struct _gss_cred)); + if (!dcred) { + *minor_status = ENOMEM; + gss_delete_sec_context(&junk, context_handle, NULL); + return (GSS_S_FAILURE); + } + SLIST_INIT(&dcred->gc_mc); + dmc = malloc(sizeof(struct _gss_mechanism_cred)); + if (!dmc) { + free(dcred); + *minor_status = ENOMEM; + gss_delete_sec_context(&junk, context_handle, NULL); + return (GSS_S_FAILURE); + } + dmc->gmc_mech = m; + dmc->gmc_mech_oid = &m->gm_mech_oid; + dmc->gmc_cred = delegated_mc; + SLIST_INSERT_HEAD(&dcred->gc_mc, dmc, gmc_link); + + *delegated_cred_handle = (gss_cred_id_t) dcred; + } + } + + if (ret_flags) + *ret_flags = mech_ret_flags; + return (major_status); +} |