diff options
author | Anders Broman <anders.broman@ericsson.com> | 2005-09-15 05:38:37 +0000 |
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committer | Anders Broman <anders.broman@ericsson.com> | 2005-09-15 05:38:37 +0000 |
commit | 0060eaf3908ebdb5673b914a83ceca316d9591fb (patch) | |
tree | dabe7ca1b969aa3cc512537af5ed1d1e2062e5bd /asn1/spnego | |
parent | 11a05a318aa303af591546020eb9811315dc8071 (diff) | |
download | wireshark-0060eaf3908ebdb5673b914a83ceca316d9591fb.tar.gz wireshark-0060eaf3908ebdb5673b914a83ceca316d9591fb.tar.bz2 wireshark-0060eaf3908ebdb5673b914a83ceca316d9591fb.zip |
Replace the spnego dissector with an asn2eth generated one.
svn path=/trunk/; revision=15810
Diffstat (limited to 'asn1/spnego')
-rw-r--r-- | asn1/spnego/Makefile.nmake | 42 | ||||
-rw-r--r-- | asn1/spnego/packet-spnego-template.c | 1074 | ||||
-rw-r--r-- | asn1/spnego/packet-spnego-template.h | 30 | ||||
-rw-r--r-- | asn1/spnego/spnego.asn | 85 | ||||
-rw-r--r-- | asn1/spnego/spnego.cnf | 128 |
5 files changed, 1359 insertions, 0 deletions
diff --git a/asn1/spnego/Makefile.nmake b/asn1/spnego/Makefile.nmake new file mode 100644 index 0000000000..392f95f102 --- /dev/null +++ b/asn1/spnego/Makefile.nmake @@ -0,0 +1,42 @@ +## Use: $(MAKE) /$(MAKEFLAGS) -f makefile.nmake +# +# $Id$ + +include ../../config.nmake + +UNIX2DOS=$(PERL) ../../tools/unix2dos.pl + +PROTOCOL_NAME=spnego +DISSECTOR_FILES=packet-$(PROTOCOL_NAME).c packet-$(PROTOCOL_NAME).h + +all: generate_dissector + +generate_dissector: $(DISSECTOR_FILES) + +$(DISSECTOR_FILES): ../../tools/asn2eth.py spnego.asn packet-spnego-template.c packet-spnego-template.h spnego.cnf +!IFDEF PYTHON + $(PYTHON) ../../tools/asn2eth.py -X -b -e -p $(PROTOCOL_NAME) -c spnego.cnf -s packet-spnego-template spnego.asn +!ELSE + @echo Error: You need Python to use asn2eth.py + @exit 1 +!ENDIF + +clean: + rm -f parsetab.py $(DISSECTOR_FILES) + +# Fix EOL in generated dissectors. Cygwin's python generates files with +# mixed EOL styles, which can't be commited to the SVN repository. +# Stuff included from template and "cnf" files has "\r\n" on windows, while +# the generated stuff has "\n". + +fix_eol: generate_dissector + move packet-$(PROTOCOL_NAME).c packet-$(PROTOCOL_NAME).c.tmp + move packet-$(PROTOCOL_NAME).h packet-$(PROTOCOL_NAME).h.tmp + $(UNIX2DOS) < packet-$(PROTOCOL_NAME).c.tmp > packet-$(PROTOCOL_NAME).c + $(UNIX2DOS) < packet-$(PROTOCOL_NAME).h.tmp > packet-$(PROTOCOL_NAME).h + del /f packet-$(PROTOCOL_NAME).c.tmp packet-$(PROTOCOL_NAME).h.tmp + +copy_files: generate_dissector fix_eol + xcopy packet-$(PROTOCOL_NAME).c ..\..\epan\dissectors /d + xcopy packet-$(PROTOCOL_NAME).h ..\..\epan\dissectors /d + diff --git a/asn1/spnego/packet-spnego-template.c b/asn1/spnego/packet-spnego-template.c new file mode 100644 index 0000000000..d5ea031b15 --- /dev/null +++ b/asn1/spnego/packet-spnego-template.c @@ -0,0 +1,1074 @@ +/* packet-spnego.c + * Routines for the simple and protected GSS-API negotiation mechanism + * as described in RFC 2478. + * Copyright 2002, Tim Potter <tpot@samba.org> + * Copyright 2002, Richard Sharpe <rsharpe@ns.aus.com> + * Copyright 2003, Richard Sharpe <rsharpe@richardsharpe.com> + * Copyright 2005, Ronnie Sahlberg (krb decryption) + * Copyright 2005, Anders Broman (converted to asn2eth generated dissector) + * + * $Id$ + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * Copyright 1998 Gerald Combs + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +/* The heimdal code for decryption of GSSAPI wrappers using heimdal comes from + Heimdal 1.6 and has been modified for ethereal's requirements. +*/ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <glib.h> +#include <epan/packet.h> +#include "packet-dcerpc.h" +#include "packet-gssapi.h" +#include "packet-kerberos.h" +#include <epan/crypt-rc4.h> +#include <epan/conversation.h> +#include <epan/emem.h> + +#include <stdio.h> +#include <string.h> + +#include "packet-ber.h" + + +#define PNAME "Simple Protected Negotiation" +#define PSNAME "SPNEGO" +#define PFNAME "spnego" + +/* Initialize the protocol and registered fields */ +static int proto_spnego = -1; +static int proto_spnego_krb5 = -1; + + +static int hf_spnego = -1; +static int hf_spnego_wraptoken = -1; +static int hf_spnego_krb5_oid; +static int hf_spnego_krb5 = -1; +static int hf_spnego_krb5_tok_id = -1; +static int hf_spnego_krb5_sgn_alg = -1; +static int hf_spnego_krb5_seal_alg = -1; +static int hf_spnego_krb5_snd_seq = -1; +static int hf_spnego_krb5_sgn_cksum = -1; +static int hf_spnego_krb5_confounder = -1; + +#include "packet-spnego-hf.c" + +/* Global variables */ +gchar MechType_oid[MAX_OID_STR_LEN]; +gssapi_oid_value *next_level_value; +gboolean saw_mechanism = FALSE; + + +/* Initialize the subtree pointers */ +static gint ett_spnego; +static gint ett_spnego_wraptoken; +static gint ett_spnego_krb5 = -1; + +#include "packet-spnego-ett.c" + +static dissector_handle_t data_handle; + +static dissector_handle_t + +gssapi_dissector_handle(gssapi_oid_value *next_level_value) { + if (next_level_value == NULL) { + return NULL; + } + return next_level_value->handle; +} + + +#include "packet-spnego-fn.c" +/* + * This is the SPNEGO KRB5 dissector. It is not true KRB5, but some ASN.1 + * wrapped blob with an OID, USHORT token ID, and a Ticket, that is also + * ASN.1 wrapped by the looks of it. It conforms to RFC1964. + */ + +#define KRB_TOKEN_AP_REQ 0x0001 +#define KRB_TOKEN_AP_REP 0x0002 +#define KRB_TOKEN_AP_ERR 0x0003 +#define KRB_TOKEN_GETMIC 0x0101 +#define KRB_TOKEN_WRAP 0x0102 +#define KRB_TOKEN_DELETE_SEC_CONTEXT 0x0201 + +static const value_string spnego_krb5_tok_id_vals[] = { + { KRB_TOKEN_AP_REQ, "KRB5_AP_REQ"}, + { KRB_TOKEN_AP_REP, "KRB5_AP_REP"}, + { KRB_TOKEN_AP_ERR, "KRB5_ERROR"}, + { KRB_TOKEN_GETMIC, "KRB5_GSS_GetMIC" }, + { KRB_TOKEN_WRAP, "KRB5_GSS_Wrap" }, + { KRB_TOKEN_DELETE_SEC_CONTEXT, "KRB5_GSS_Delete_sec_context" }, + { 0, NULL} +}; + +#define KRB_SGN_ALG_DES_MAC_MD5 0x0000 +#define KRB_SGN_ALG_MD2_5 0x0001 +#define KRB_SGN_ALG_DES_MAC 0x0002 +#define KRB_SGN_ALG_HMAC 0x0011 + +static const value_string spnego_krb5_sgn_alg_vals[] = { + { KRB_SGN_ALG_DES_MAC_MD5, "DES MAC MD5"}, + { KRB_SGN_ALG_MD2_5, "MD2.5"}, + { KRB_SGN_ALG_DES_MAC, "DES MAC"}, + { KRB_SGN_ALG_HMAC, "HMAC"}, + { 0, NULL} +}; + +#define KRB_SEAL_ALG_DES_CBC 0x0000 +#define KRB_SEAL_ALG_RC4 0x0010 +#define KRB_SEAL_ALG_NONE 0xffff + +static const value_string spnego_krb5_seal_alg_vals[] = { + { KRB_SEAL_ALG_DES_CBC, "DES CBC"}, + { KRB_SEAL_ALG_RC4, "RC4"}, + { KRB_SEAL_ALG_NONE, "None"}, + { 0, NULL} +}; + +/* + * XXX - is this for SPNEGO or just GSS-API? + * RFC 1964 is "The Kerberos Version 5 GSS-API Mechanism"; presumably one + * can directly designate Kerberos V5 as a mechanism in GSS-API, rather + * than designating SPNEGO as the mechanism, offering Kerberos V5, and + * getting it accepted. + */ +static int +dissect_spnego_krb5_getmic_base(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree); +static int +dissect_spnego_krb5_wrap_base(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, guint16 token_id); + +static void +dissect_spnego_krb5(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + proto_item *item; + proto_tree *subtree; + int offset = 0; + guint16 token_id; + gchar oid[MAX_OID_STR_LEN]; + gssapi_oid_value *value; + tvbuff_t *krb5_tvb; + gint8 class; + gboolean pc, ind = 0; + gint32 tag; + guint32 len; + + + item = proto_tree_add_item(tree, hf_spnego_krb5, tvb, offset, + -1, FALSE); + + subtree = proto_item_add_subtree(item, ett_spnego_krb5); + + /* + * The KRB5 blob conforms to RFC1964: + * [APPLICATION 0] { + * OID, + * USHORT (0x0001 == AP-REQ, 0x0002 == AP-REP, 0x0003 == ERROR), + * OCTET STRING } + * + * However, for some protocols, the KRB5 blob starts at the SHORT + * and has no DER encoded header etc. + * + * It appears that for some other protocols the KRB5 blob is just + * a Kerberos message, with no [APPLICATION 0] header, no OID, + * and no USHORT. + * + * So: + * + * If we see an [APPLICATION 0] HEADER, we show the OID and + * the USHORT, and then dissect the rest as a Kerberos message. + * + * If we see an [APPLICATION 14] or [APPLICATION 15] header, + * we assume it's an AP-REQ or AP-REP message, and dissect + * it all as a Kerberos message. + * + * Otherwise, we show the USHORT, and then dissect the rest + * as a Kerberos message. + */ + + /* + * Get the first header ... + */ + offset = dissect_ber_identifier(pinfo, subtree, tvb, offset, &class, &pc, &tag); + offset = dissect_ber_length(pinfo, subtree, tvb, offset, &len, &ind); + + if (class == BER_CLASS_APP && pc == 1) { + /* + * [APPLICATION <tag>] + */ + switch (tag) { + + case 0: + /* + * [APPLICATION 0] + */ + + /* Next, the OID */ + offset=dissect_ber_object_identifier(FALSE, pinfo, subtree, tvb, offset, hf_spnego_krb5_oid, oid); + + value = gssapi_lookup_oid_str(oid); + + token_id = tvb_get_letohs(tvb, offset); + proto_tree_add_uint(subtree, hf_spnego_krb5_tok_id, tvb, offset, 2, + token_id); + + offset += 2; + + break; + + case 14: /* [APPLICATION 14] */ + case 15: /* [APPLICATION 15] */ + /* + * No token ID - just dissect as a Kerberos message and + * return. + */ + offset = dissect_kerberos_main(tvb, pinfo, subtree, FALSE, NULL); + return; + + default: + proto_tree_add_text(subtree, tvb, offset, 0, + "Unknown header (class=%d, pc=%d, tag=%d)", + class, pc, tag); + goto done; + } + } else { + /* Next, the token ID ... */ + + token_id = tvb_get_letohs(tvb, offset); + proto_tree_add_uint(subtree, hf_spnego_krb5_tok_id, tvb, offset, 2, + token_id); + + offset += 2; + } + + switch (token_id) { + + case KRB_TOKEN_AP_REQ: + case KRB_TOKEN_AP_REP: + case KRB_TOKEN_AP_ERR: + krb5_tvb = tvb_new_subset(tvb, offset, -1, -1); + offset = dissect_kerberos_main(krb5_tvb, pinfo, subtree, FALSE, NULL); + break; + + case KRB_TOKEN_GETMIC: + offset = dissect_spnego_krb5_getmic_base(tvb, offset, pinfo, subtree); + break; + + case KRB_TOKEN_WRAP: + offset = dissect_spnego_krb5_wrap_base(tvb, offset, pinfo, subtree, token_id); + break; + + case KRB_TOKEN_DELETE_SEC_CONTEXT: + + break; + + default: + + break; + } + + done: + return; +} + +#ifdef HAVE_KERBEROS +#include <epan/crypt-md5.h> + +#ifndef KEYTYPE_ARCFOUR_56 +# define KEYTYPE_ARCFOUR_56 24 +#endif +/* XXX - We should probably do a configure-time check for this instead */ +#ifndef KRB5_KU_USAGE_SEAL +# define KRB5_KU_USAGE_SEAL 22 +#endif + +static int +arcfour_mic_key(void *key_data, size_t key_size, int key_type, + void *cksum_data, size_t cksum_size, + void *key6_data) +{ + guint8 k5_data[16]; + guint8 T[4]; + + memset(T, 0, 4); + + if (key_type == KEYTYPE_ARCFOUR_56) { + guint8 L40[14] = "fortybits"; + + memcpy(L40 + 10, T, sizeof(T)); + md5_hmac( + L40, 14, + key_data, + key_size, + k5_data); + memset(&k5_data[7], 0xAB, 9); + } else { + md5_hmac( + T, 4, + key_data, + key_size, + k5_data); + } + + md5_hmac( + cksum_data, cksum_size, + k5_data, + 16, + key6_data); + + return 0; +} + +static int +usage2arcfour(int usage) +{ + switch (usage) { + case 3: /*KRB5_KU_AS_REP_ENC_PART 3 */ + case 9: /*KRB5_KU_TGS_REP_ENC_PART_SUB_KEY 9 */ + return 8; + case 22: /*KRB5_KU_USAGE_SEAL 22 */ + return 13; + case 23: /*KRB5_KU_USAGE_SIGN 23 */ + return 15; + case 24: /*KRB5_KU_USAGE_SEQ 24 */ + return 0; + default : + return 0; + } +} + +static int +arcfour_mic_cksum(guint8 *key_data, int key_length, + unsigned usage, + u_char sgn_cksum[8], + const void *v1, size_t l1, + const void *v2, size_t l2, + const void *v3, size_t l3) +{ + const guint8 signature[] = "signaturekey"; + guint8 ksign_c[16]; + unsigned char t[4]; + md5_state_t ms; + unsigned char digest[16]; + int rc4_usage; + guint8 cksum[16]; + + rc4_usage=usage2arcfour(usage); + md5_hmac(signature, sizeof(signature), + key_data, key_length, + ksign_c); + md5_init(&ms); + t[0] = (rc4_usage >> 0) & 0xFF; + t[1] = (rc4_usage >> 8) & 0xFF; + t[2] = (rc4_usage >> 16) & 0xFF; + t[3] = (rc4_usage >> 24) & 0xFF; + md5_append(&ms, t, 4); + md5_append(&ms, v1, l1); + md5_append(&ms, v2, l2); + md5_append(&ms, v3, l3); + md5_finish(&ms, digest); + md5_hmac(digest, 16, ksign_c, 16, cksum); + + memcpy(sgn_cksum, cksum, 8); + + return 0; +} + +/* + * Verify padding of a gss wrapped message and return its length. + */ +static int +gssapi_verify_pad(unsigned char *wrapped_data, int wrapped_length, + size_t datalen, + size_t *padlen) +{ + unsigned char *pad; + size_t padlength; + int i; + + pad = wrapped_data + wrapped_length - 1; + padlength = *pad; + + if (padlength > datalen) + return 1; + + for (i = padlength; i > 0 && *pad == padlength; i--, pad--) + ; + if (i != 0) + return 2; + + *padlen = padlength; + + return 0; +} + +static int +decrypt_arcfour(packet_info *pinfo, + guint8 *input_message_buffer, + guint8 *output_message_buffer, + guint8 *key_value, int key_size, int key_type) +{ + guint8 Klocaldata[16]; + int ret; + gint32 seq_number; + size_t datalen; + guint8 k6_data[16], SND_SEQ[8], Confounder[8]; + guint8 cksum_data[8]; + int cmp; + int conf_flag; + size_t padlen = 0; + + datalen = tvb_length(pinfo->gssapi_encrypted_tvb); + + if(tvb_get_ntohs(pinfo->gssapi_wrap_tvb, 4)==0x1000){ + conf_flag=1; + } else if (tvb_get_ntohs(pinfo->gssapi_wrap_tvb, 4)==0xffff){ + conf_flag=0; + } else { + return -3; + } + + if(tvb_get_ntohs(pinfo->gssapi_wrap_tvb, 6)!=0xffff){ + return -4; + } + + ret = arcfour_mic_key(key_value, key_size, key_type, + (void *)tvb_get_ptr(pinfo->gssapi_wrap_tvb, 16, 8), + 8, /* SGN_CKSUM */ + k6_data); + if (ret) { + return -5; + } + + { + rc4_state_struct rc4_state; + + crypt_rc4_init(&rc4_state, k6_data, sizeof(k6_data)); + memcpy(SND_SEQ, (unsigned char *)tvb_get_ptr(pinfo->gssapi_wrap_tvb, 8, 8), 8); + crypt_rc4(&rc4_state, SND_SEQ, 8); + + memset(k6_data, 0, sizeof(k6_data)); + } + + seq_number=g_ntohl(*((guint32 *)SND_SEQ)); + + cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4); + if(cmp){ + cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4); + } + + if (cmp != 0) { + return -6; + } + + { + int i; + + for (i = 0; i < 16; i++) + Klocaldata[i] = ((u_char *)key_value)[i] ^ 0xF0; + } + ret = arcfour_mic_key(Klocaldata,sizeof(Klocaldata),key_type, + SND_SEQ, 4, + k6_data); + memset(Klocaldata, 0, sizeof(Klocaldata)); + if (ret) { + return -7; + } + + if(conf_flag) { + rc4_state_struct rc4_state; + + crypt_rc4_init(&rc4_state, k6_data, sizeof(k6_data)); + memcpy(Confounder, (unsigned char *)tvb_get_ptr(pinfo->gssapi_wrap_tvb, 24, 8), 8); + crypt_rc4(&rc4_state, Confounder, 8); + memcpy(output_message_buffer, input_message_buffer, datalen); + crypt_rc4(&rc4_state, output_message_buffer, datalen); + } else { + memcpy(Confounder, + tvb_get_ptr(pinfo->gssapi_wrap_tvb, 24, 8), + 8); /* Confounder */ + memcpy(output_message_buffer, + input_message_buffer, + datalen); + } + memset(k6_data, 0, sizeof(k6_data)); + + /* only normal (i.e. non DCE style wrapping use padding ? */ + if(pinfo->decrypt_gssapi_tvb==DECRYPT_GSSAPI_NORMAL){ + ret = gssapi_verify_pad(output_message_buffer,datalen,datalen, &padlen); + if (ret) { + return -9; + } + datalen -= padlen; + } + + /* dont know what the checksum looks like for dce style gssapi */ + if(pinfo->decrypt_gssapi_tvb==DECRYPT_GSSAPI_NORMAL){ + ret = arcfour_mic_cksum(key_value, key_size, + KRB5_KU_USAGE_SEAL, + cksum_data, + tvb_get_ptr(pinfo->gssapi_wrap_tvb, 0, 8), 8, + Confounder, sizeof(Confounder), + output_message_buffer, + datalen + padlen); + if (ret) { + return -10; + } + + cmp = memcmp(cksum_data, + tvb_get_ptr(pinfo->gssapi_wrap_tvb, 16, 8), + 8); /* SGN_CKSUM */ + if (cmp) { + return -11; + } + } + + return datalen; +} + + + +#if defined(HAVE_HEIMDAL_KERBEROS) || defined(HAVE_MIT_KERBEROS) + +static void +decrypt_gssapi_krb_arcfour_wrap(proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, int keytype) +{ + int ret; + enc_key_t *ek; + int length; + const guint8 *original_data; + + static int omb_index=0; + static guint8 *omb_arr[4]={NULL,NULL,NULL,NULL}; + static guint8 *cryptocopy=NULL; /* workaround for pre-0.6.1 heimdal bug */ + guint8 *output_message_buffer; + + omb_index++; + if(omb_index>=4){ + omb_index=0; + } + output_message_buffer=omb_arr[omb_index]; + + + length=tvb_length(pinfo->gssapi_encrypted_tvb); + original_data=tvb_get_ptr(pinfo->gssapi_encrypted_tvb, 0, length); + + /* dont do anything if we are not attempting to decrypt data */ +/* + if(!krb_decrypt){ + return; + } +*/ + /* XXX we should only do this for first time, then store somewhere */ + /* XXX We also need to re-read the keytab when the preference changes */ + + cryptocopy=ep_alloc(length); + if(output_message_buffer){ + g_free(output_message_buffer); + output_message_buffer=NULL; + } + output_message_buffer=g_malloc(length); + + for(ek=enc_key_list;ek;ek=ek->next){ + /* shortcircuit and bail out if enctypes are not matching */ + if(ek->keytype!=keytype){ + continue; + } + + /* pre-0.6.1 versions of Heimdal would sometimes change + the cryptotext data even when the decryption failed. + This would obviously not work since we iterate over the + keys. So just give it a copy of the crypto data instead. + This has been seen for RC4-HMAC blobs. + */ + memcpy(cryptocopy, original_data, length); + ret=decrypt_arcfour(pinfo, + cryptocopy, + output_message_buffer, + ek->keyvalue, + ek->keylength, + ek->keytype + ); + if (ret >= 0) { + proto_tree_add_text(tree, NULL, 0, 0, "[Decrypted using: %s]", ek->key_origin); + pinfo->gssapi_decrypted_tvb=tvb_new_real_data( + output_message_buffer, + ret, ret); + tvb_set_child_real_data_tvbuff(tvb, pinfo->gssapi_decrypted_tvb); + add_new_data_source(pinfo, pinfo->gssapi_decrypted_tvb, "Decrypted GSS-Krb5"); + return; + } + } + return; +} +#endif /* HAVE_HEIMDAL_KERBEROS || HAVE_MIT_KERBEROS */ + + +#endif + +/* + * XXX - This is for GSSAPI Wrap tokens ... + */ +static int +dissect_spnego_krb5_wrap_base(tvbuff_t *tvb, int offset, packet_info *pinfo +#ifndef HAVE_KERBEROS + _U_ +#endif + , proto_tree *tree, guint16 token_id +#ifndef HAVE_KERBEROS + _U_ +#endif + ) +{ + guint16 sgn_alg, seal_alg; +#ifdef HAVE_KERBEROS + int start_offset=offset; +#endif + + /* + * The KRB5 blob conforms to RFC1964: + * USHORT (0x0102 == GSS_Wrap) + * and so on } + */ + + /* Now, the sign and seal algorithms ... */ + + sgn_alg = tvb_get_letohs(tvb, offset); + proto_tree_add_uint(tree, hf_spnego_krb5_sgn_alg, tvb, offset, 2, + sgn_alg); + + offset += 2; + + seal_alg = tvb_get_letohs(tvb, offset); + proto_tree_add_uint(tree, hf_spnego_krb5_seal_alg, tvb, offset, 2, + seal_alg); + + offset += 2; + + /* Skip the filler */ + + offset += 2; + + /* Encrypted sequence number */ + + proto_tree_add_item(tree, hf_spnego_krb5_snd_seq, tvb, offset, 8, + TRUE); + + offset += 8; + + /* Checksum of plaintext padded data */ + + proto_tree_add_item(tree, hf_spnego_krb5_sgn_cksum, tvb, offset, 8, + TRUE); + + offset += 8; + + /* + * At least according to draft-brezak-win2k-krb-rc4-hmac-04, + * if the signing algorithm is KRB_SGN_ALG_HMAC, there's an + * extra 8 bytes of "Random confounder" after the checksum. + * It certainly confounds code expecting all Kerberos 5 + * GSS_Wrap() tokens to look the same.... + */ + if (sgn_alg == KRB_SGN_ALG_HMAC) { + proto_tree_add_item(tree, hf_spnego_krb5_confounder, tvb, offset, 8, + TRUE); + offset += 8; + } + + /* Is the data encrypted? */ + pinfo->gssapi_data_encrypted=(seal_alg!=KRB_SEAL_ALG_NONE); + +#ifdef HAVE_KERBEROS +#define GSS_ARCFOUR_WRAP_TOKEN_SIZE 32 + if(pinfo->decrypt_gssapi_tvb){ + /* if the caller did not provide a tvb, then we just use + whatever is left of our current tvb. + */ + if(!pinfo->gssapi_encrypted_tvb){ + int len; + len=tvb_reported_length_remaining(tvb,offset); + if(len>tvb_length_remaining(tvb, offset)){ + /* no point in trying to decrypt, + we dont have the full pdu. + */ + return offset; + } + pinfo->gssapi_encrypted_tvb = tvb_new_subset( + tvb, offset, len, len); + } + + /* if this is KRB5 wrapped rc4-hmac */ + if((token_id==KRB_TOKEN_WRAP) + &&(sgn_alg==KRB_SGN_ALG_HMAC) + &&(seal_alg==KRB_SEAL_ALG_RC4)){ + /* do we need to create a tvb for the wrapper + as well ? + */ + if(!pinfo->gssapi_wrap_tvb){ + pinfo->gssapi_wrap_tvb = tvb_new_subset( + tvb, start_offset-2, + GSS_ARCFOUR_WRAP_TOKEN_SIZE, + GSS_ARCFOUR_WRAP_TOKEN_SIZE); + } +#if defined(HAVE_HEIMDAL_KERBEROS) || defined(HAVE_MIT_KERBEROS) + decrypt_gssapi_krb_arcfour_wrap(tree, + pinfo, + tvb, + 23 /* rc4-hmac */); +#endif /* HAVE_HEIMDAL_KERBEROS || HAVE_MIT_KERBEROS */ + } + } +#endif + /* + * Return the offset past the checksum, so that we know where + * the data we're wrapped around starts. Also, set the length + * of our top-level item to that offset, so it doesn't cover + * the data we're wrapped around. + * + * Note that for DCERPC the GSSAPI blobs comes after the data it wraps, + * not before. + */ + return offset; +} + +/* + * XXX - This is for GSSAPI GetMIC tokens ... + */ +static int +dissect_spnego_krb5_getmic_base(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) +{ + guint16 sgn_alg; + + /* + * The KRB5 blob conforms to RFC1964: + * USHORT (0x0101 == GSS_GetMIC) + * and so on } + */ + + /* Now, the sign algorithm ... */ + + sgn_alg = tvb_get_letohs(tvb, offset); + proto_tree_add_uint(tree, hf_spnego_krb5_sgn_alg, tvb, offset, 2, + sgn_alg); + + offset += 2; + + /* Skip the filler */ + + offset += 4; + + /* Encrypted sequence number */ + + proto_tree_add_item(tree, hf_spnego_krb5_snd_seq, tvb, offset, 8, + TRUE); + + offset += 8; + + /* Checksum of plaintext padded data */ + + proto_tree_add_item(tree, hf_spnego_krb5_sgn_cksum, tvb, offset, 8, + TRUE); + + offset += 8; + + /* + * At least according to draft-brezak-win2k-krb-rc4-hmac-04, + * if the signing algorithm is KRB_SGN_ALG_HMAC, there's an + * extra 8 bytes of "Random confounder" after the checksum. + * It certainly confounds code expecting all Kerberos 5 + * GSS_Wrap() tokens to look the same.... + */ + if (sgn_alg == KRB_SGN_ALG_HMAC) { + proto_tree_add_item(tree, hf_spnego_krb5_confounder, tvb, offset, 8, + TRUE); + + offset += 8; + } + + /* + * Return the offset past the checksum, so that we know where + * the data we're wrapped around starts. Also, set the length + * of our top-level item to that offset, so it doesn't cover + * the data we're wrapped around. + */ + + return offset; +} + +/* + * XXX - is this for SPNEGO or just GSS-API? + * RFC 1964 is "The Kerberos Version 5 GSS-API Mechanism"; presumably one + * can directly designate Kerberos V5 as a mechanism in GSS-API, rather + * than designating SPNEGO as the mechanism, offering Kerberos V5, and + * getting it accepted. + */ +static int +dissect_spnego_krb5_wrap(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree) +{ + proto_item *item; + proto_tree *subtree; + int offset = 0; + guint16 token_id; + + item = proto_tree_add_item(tree, hf_spnego_krb5, tvb, 0, -1, FALSE); + + subtree = proto_item_add_subtree(item, ett_spnego_krb5); + + /* + * The KRB5 blob conforms to RFC1964: + * USHORT (0x0102 == GSS_Wrap) + * and so on } + */ + + /* First, the token ID ... */ + + token_id = tvb_get_letohs(tvb, offset); + proto_tree_add_uint(subtree, hf_spnego_krb5_tok_id, tvb, offset, 2, + token_id); + + offset += 2; + + offset = dissect_spnego_krb5_wrap_base(tvb, offset, pinfo, subtree, token_id); + + /* + * Return the offset past the checksum, so that we know where + * the data we're wrapped around starts. Also, set the length + * of our top-level item to that offset, so it doesn't cover + * the data we're wrapped around. + */ + proto_item_set_len(item, offset); + return offset; +} + +/* Spnego stuff from here */ + +static int +dissect_spnego_wrap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + proto_item *item; + proto_tree *subtree; + + int offset = 0; + + + /* + * We need this later, so lets get it now ... + * It has to be per-frame as there can be more than one GSS-API + * negotiation in a conversation. + */ + + + item = proto_tree_add_item(tree, hf_spnego, tvb, offset, + -1, FALSE); + + subtree = proto_item_add_subtree(item, ett_spnego); + /* + * The TVB contains a [0] header and a sequence that consists of an + * object ID and a blob containing the data ... + * XXX - is this RFC 2743's "Mechanism-Independent Token Format", + * with the "optional" "use in non-initial tokens" being chosen. + * ASN1 code addet to spnego.asn to handle this. + */ + + offset = dissect_spnego_InitialContextToken(FALSE, tvb, offset, pinfo , subtree, -1); + + return offset; +} + + +static void +dissect_spnego(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree) +{ + proto_item *item; + proto_tree *subtree; + int offset = 0; + conversation_t *conversation; + + /* + * We need this later, so lets get it now ... + * It has to be per-frame as there can be more than one GSS-API + * negotiation in a conversation. + */ + + next_level_value = p_get_proto_data(pinfo->fd, proto_spnego); + if (!next_level_value && !pinfo->fd->flags.visited) { + /* + * No handle attached to this frame, but it's the first + * pass, so it'd be attached to the conversation. + * If we have a conversation, try to get the handle, + * and if we get one, attach it to the frame. + */ + conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst, + pinfo->ptype, pinfo->srcport, + pinfo->destport, 0); + + if (conversation) { + next_level_value = conversation_get_proto_data(conversation, + proto_spnego); + if (next_level_value) + p_add_proto_data(pinfo->fd, proto_spnego, next_level_value); + } + } + + item = proto_tree_add_item(parent_tree, hf_spnego, tvb, offset, + -1, FALSE); + + subtree = proto_item_add_subtree(item, ett_spnego); + + /* + * The TVB contains a [0] header and a sequence that consists of an + * object ID and a blob containing the data ... + * Actually, it contains, according to RFC2478: + * NegotiationToken ::= CHOICE { + * negTokenInit [0] NegTokenInit, + * negTokenTarg [1] NegTokenTarg } + * NegTokenInit ::= SEQUENCE { + * mechTypes [0] MechTypeList OPTIONAL, + * reqFlags [1] ContextFlags OPTIONAL, + * mechToken [2] OCTET STRING OPTIONAL, + * mechListMIC [3] OCTET STRING OPTIONAL } + * NegTokenTarg ::= SEQUENCE { + * negResult [0] ENUMERATED { + * accept_completed (0), + * accept_incomplete (1), + * reject (2) } OPTIONAL, + * supportedMech [1] MechType OPTIONAL, + * responseToken [2] OCTET STRING OPTIONAL, + * mechListMIC [3] OCTET STRING OPTIONAL } + * + * Windows typically includes mechTypes and mechListMic ('NONE' + * in the case of NTLMSSP only). + * It seems to duplicate the responseToken into the mechListMic field + * as well. Naughty, naughty. + * + */ + offset = dissect_spnego_NegotiationToken(FALSE, tvb, offset, pinfo, subtree, -1); + +} + +/*--- proto_register_spnego -------------------------------------------*/ +void proto_register_spnego(void) { + + /* List of fields */ + static hf_register_info hf[] = { + { &hf_spnego, + { "SPNEGO", "spnego", FT_NONE, BASE_NONE, NULL, 0x0, + "SPNEGO", HFILL }}, + { &hf_spnego_wraptoken, + { "wrapToken", "spnego.wraptoken", + FT_NONE, BASE_NONE, NULL, 0x0, "SPNEGO wrapToken", + HFILL}}, + { &hf_spnego_krb5, + { "krb5_blob", "spnego.krb5.blob", FT_BYTES, + BASE_NONE, NULL, 0, "krb5_blob", HFILL }}, + {&hf_spnego_krb5_oid, + {"KRB5 OID", "spnego.krb5_oid", FT_STRING, + BASE_NONE, NULL, 0, "KRB5 OID", HFILL }}, + { &hf_spnego_krb5_tok_id, + { "krb5_tok_id", "spnego.krb5.tok_id", FT_UINT16, BASE_HEX, + VALS(spnego_krb5_tok_id_vals), 0, "KRB5 Token Id", HFILL}}, + { &hf_spnego_krb5_sgn_alg, + { "krb5_sgn_alg", "spnego.krb5.sgn_alg", FT_UINT16, BASE_HEX, + VALS(spnego_krb5_sgn_alg_vals), 0, "KRB5 Signing Algorithm", HFILL}}, + { &hf_spnego_krb5_seal_alg, + { "krb5_seal_alg", "spnego.krb5.seal_alg", FT_UINT16, BASE_HEX, + VALS(spnego_krb5_seal_alg_vals), 0, "KRB5 Sealing Algorithm", HFILL}}, + { &hf_spnego_krb5_snd_seq, + { "krb5_snd_seq", "spnego.krb5.snd_seq", FT_BYTES, BASE_NONE, + NULL, 0, "KRB5 Encrypted Sequence Number", HFILL}}, + { &hf_spnego_krb5_sgn_cksum, + { "krb5_sgn_cksum", "spnego.krb5.sgn_cksum", FT_BYTES, BASE_NONE, + NULL, 0, "KRB5 Data Checksum", HFILL}}, + { &hf_spnego_krb5_confounder, + { "krb5_confounder", "spnego.krb5.confounder", FT_BYTES, BASE_NONE, + NULL, 0, "KRB5 Confounder", HFILL}}, + +#include "packet-spnego-hfarr.c" + }; + + /* List of subtrees */ + static gint *ett[] = { + &ett_spnego, + &ett_spnego_wraptoken, + &ett_spnego_krb5, + +#include "packet-spnego-ettarr.c" + }; + + /* Register protocol */ + proto_spnego = proto_register_protocol(PNAME, PSNAME, PFNAME); + + proto_spnego_krb5 = proto_register_protocol("SPNEGO-KRB5", + "SPNEGO-KRB5", + "spnego-krb5"); + /* Register fields and subtrees */ + proto_register_field_array(proto_spnego, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + +} + + +/*--- proto_reg_handoff_spnego ---------------------------------------*/ +void proto_reg_handoff_spnego(void) { + + dissector_handle_t spnego_handle, spnego_wrap_handle; + dissector_handle_t spnego_krb5_handle, spnego_krb5_wrap_handle; + + /* Register protocol with GSS-API module */ + + spnego_handle = create_dissector_handle(dissect_spnego, proto_spnego); + spnego_wrap_handle = new_create_dissector_handle(dissect_spnego_wrap, + proto_spnego); + gssapi_init_oid("1.3.6.1.5.5.2", proto_spnego, ett_spnego, + spnego_handle, spnego_wrap_handle, + "SPNEGO - Simple Protected Negotiation"); + + /* Register both the one MS created and the real one */ + /* + * Thanks to Jean-Baptiste Marchand and Richard B Ward, the + * mystery of the MS KRB5 OID is cleared up. It was due to a library + * that did not handle OID components greater than 16 bits, and was + * fixed in Win2K SP2 as well as WinXP. + * See the archive of <ietf-krb-wg@anl.gov> for the thread topic + * SPNEGO implementation issues. 3-Dec-2002. + */ + spnego_krb5_handle = create_dissector_handle(dissect_spnego_krb5, + proto_spnego_krb5); + spnego_krb5_wrap_handle = new_create_dissector_handle(dissect_spnego_krb5_wrap, + proto_spnego_krb5); + gssapi_init_oid("1.2.840.48018.1.2.2", proto_spnego_krb5, ett_spnego_krb5, + spnego_krb5_handle, spnego_krb5_wrap_handle, + "MS KRB5 - Microsoft Kerberos 5"); + gssapi_init_oid("1.2.840.113554.1.2.2", proto_spnego_krb5, ett_spnego_krb5, + spnego_krb5_handle, spnego_krb5_wrap_handle, + "KRB5 - Kerberos 5"); + gssapi_init_oid("1.2.840.113554.1.2.2.3", proto_spnego_krb5, ett_spnego_krb5, + spnego_krb5_handle, spnego_krb5_wrap_handle, + "KRB5 - Kerberos 5 - User to User"); + + /* + * Find the data handle for some calls + */ + data_handle = find_dissector("data"); + +} diff --git a/asn1/spnego/packet-spnego-template.h b/asn1/spnego/packet-spnego-template.h new file mode 100644 index 0000000000..8b8130f8d9 --- /dev/null +++ b/asn1/spnego/packet-spnego-template.h @@ -0,0 +1,30 @@ +/* packet-spnego.h + * Routines for spnego packet dissection + * + * $Id$ + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * Copyright 1998 Gerald Combs + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#ifndef PACKET_SPNEGO_H +#define PACKET_SPNEGO_H + +/*#include "packet-spnego-exp.h"*/ + +#endif /* PACKET_spnego_H */ diff --git a/asn1/spnego/spnego.asn b/asn1/spnego/spnego.asn new file mode 100644 index 0000000000..8813fea9cc --- /dev/null +++ b/asn1/spnego/spnego.asn @@ -0,0 +1,85 @@ +Spnego {iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) snego(2)} +-- (1.3.6.1.5.5.2) +DEFINITIONS ::= + +BEGIN + +MechType::= OBJECT IDENTIFIER + +NegotiationToken ::= CHOICE { + negTokenInit [0] NegTokenInit, + negTokenTarg [1] NegTokenTarg } + +MechTypeList ::= SEQUENCE OF MechType + +NegTokenInit ::= SEQUENCE { + mechTypes [0] MechTypeList OPTIONAL, + reqFlags [1] ContextFlags OPTIONAL, + mechToken [2] OCTET STRING OPTIONAL, + mechListMIC [3] OCTET STRING OPTIONAL + } + +ContextFlags ::= BIT STRING { + delegFlag (0), + mutualFlag (1), + replayFlag (2), + sequenceFlag (3), + anonFlag (4), + confFlag (5), + integFlag (6) +} + +NegTokenTarg ::= SEQUENCE { + negResult [0] ENUMERATED { + accept-completed (0), + accept-incomplete (1), + reject (2) } OPTIONAL, + supportedMech [1] MechType OPTIONAL, + responseToken [2] OCTET STRING OPTIONAL, + mechListMIC [3] OCTET STRING OPTIONAL +} + +--GSS-API DEFINITIONS ::= +--BEGIN +--MechType ::= OBJECT IDENTIFIER +-- data structure definitions +-- callers must be able to distinguish among +-- InitialContextToken, SubsequentContextToken, +-- PerMsgToken, and SealedMessage data elements +-- based on the usage in which they occur +InitialContextToken ::= + -- option indication (delegation, etc.) indicated within + -- mechanism-specific token +[APPLICATION 0] IMPLICIT SEQUENCE { + thisMech MechType, + innerContextToken InnerContextToken + -- DEFINED BY thisMech + -- contents mechanism-specific + -- ASN.1 structure not required + } + +-- SubsequentContextToken ::= InnerContextToken + +InnerContextToken ::= ANY +-- interpretation based on predecessor InitialContextToken +-- ASN.1 structure not required + +-- PerMsgToken ::= +-- as emitted by GSS_GetMIC and processed by GSS_VerifyMIC +-- ASN.1 structure not required +-- InnerMsgToken + +-- InnerMsgToken ::= ANY + +-- SealedMessage ::= +-- as emitted by GSS_Wrap and processed by GSS_Unwrap +-- includes internal, mechanism-defined indicator +-- of whether or not encrypted +-- ASN.1 structure not required +-- SealedUserData + +-- SealedUserData ::= ANY + +-- END GSS-API DEFINITIONS + +END
\ No newline at end of file diff --git a/asn1/spnego/spnego.cnf b/asn1/spnego/spnego.cnf new file mode 100644 index 0000000000..476e4ce3b3 --- /dev/null +++ b/asn1/spnego/spnego.cnf @@ -0,0 +1,128 @@ +# spnego.cnf +# spnego conformation file + +# $Id$ + +#.EXPORTS + +#.PDU + +#.NO_EMIT + +#.TYPE_RENAME + +#.FIELD_RENAME + +#.FN_PARS MechType + + VAL_PTR = MechType_oid + +#.FN_BODY MechType + + gssapi_oid_value *value; + +%(DEFAULT_BODY)s + + value = gssapi_lookup_oid_str(MechType_oid); + + /* + * Tell our caller the first mechanism we see, so that if + * this is a negTokenInit with a mechToken, it can interpret + * the mechToken according to the first mechType. (There + * might not have been any indication of the mechType + * in prior frames, so we can't necessarily use the + * mechanism from the conversation; i.e., a negTokenInit + * can contain the initial security token for the desired + * mechanism of the initiator - that's the first mechanism + * in the list.) + */ + if (!saw_mechanism) { + if (value) + next_level_value = value; + saw_mechanism = TRUE; + } + +#.FN_BODY InnerContextToken + + conversation_t *conversation; + gssapi_oid_value *next_level_value; + proto_item *item; + proto_tree *subtree; + tvbuff_t *token_tvb; + int len; + + next_level_value = p_get_proto_data(pinfo->fd, proto_spnego); + if (!next_level_value && !pinfo->fd->flags.visited) { + /* + * No handle attached to this frame, but it's the first + * pass, so it'd be attached to the conversation. + * If we have a conversation, try to get the handle, + * and if we get one, attach it to the frame. + */ + conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst, + pinfo->ptype, pinfo->srcport, + pinfo->destport, 0); + + if (conversation) { + next_level_value = conversation_get_proto_data(conversation, + proto_spnego); + if (next_level_value) + p_add_proto_data(pinfo->fd, proto_spnego, next_level_value); + } + } + + next_level_value = gssapi_lookup_oid_str(MechType_oid); + /* + * Now dissect the GSS_Wrap token; it's assumed to be in the + * rest of the tvbuff. + */ + item = proto_tree_add_item(tree, hf_spnego_wraptoken, tvb, offset, + -1, FALSE); + + subtree = proto_item_add_subtree(item, ett_spnego_wraptoken); + + /* + * Now, we should be able to dispatch after creating a new TVB. + * The subdissector must return the length of the part of the + * token it dissected, so we can return the length of the part + * we (and it) dissected. + */ + + token_tvb = tvb_new_subset(tvb, offset, -1, -1); + if (next_level_value->wrap_handle) { + len = call_dissector(next_level_value->wrap_handle, token_tvb, pinfo, subtree); + if (len == 0) + offset = tvb_length(tvb); + else + offset = offset + len; + } else + + offset = tvb_length(tvb); + + +#.FN_HDR MechTypeList + + + saw_mechanism = FALSE; + +#.FN_PARS NegTokenInit/mechToken + + VAL_PTR = &mechToken_tvb + +#.FN_BODY NegTokenInit/mechToken + + tvbuff_t *mechToken_tvb; + + +%(DEFAULT_BODY)s + + + /* + * Now, we should be able to dispatch after creating a new TVB. + */ + + if (next_level_value) + call_dissector(gssapi_dissector_handle(next_level_value), mechToken_tvb, pinfo, tree); + + +#.END |