/* Unix SMB/CIFS implementation. simple kerberos5/SPNEGO routines Copyright (C) Andrew Tridgell 2001 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002 Copyright (C) Luke Howard 2003 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 3 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, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #include "../libcli/auth/spnego.h" #include "smb_krb5.h" /* generate a negTokenInit packet given a GUID, a list of supported OIDs (the mechanisms) and a principal name string */ DATA_BLOB spnego_gen_negTokenInit(char guid[16], const char *OIDs[], const char *principal) { int i; ASN1_DATA *data; DATA_BLOB ret; data = asn1_init(talloc_tos()); if (data == NULL) { return data_blob_null; } asn1_write(data, guid, 16); asn1_push_tag(data,ASN1_APPLICATION(0)); asn1_write_OID(data,OID_SPNEGO); asn1_push_tag(data,ASN1_CONTEXT(0)); asn1_push_tag(data,ASN1_SEQUENCE(0)); asn1_push_tag(data,ASN1_CONTEXT(0)); asn1_push_tag(data,ASN1_SEQUENCE(0)); for (i=0; OIDs[i]; i++) { asn1_write_OID(data,OIDs[i]); } asn1_pop_tag(data); asn1_pop_tag(data); asn1_push_tag(data, ASN1_CONTEXT(3)); asn1_push_tag(data, ASN1_SEQUENCE(0)); asn1_push_tag(data, ASN1_CONTEXT(0)); asn1_write_GeneralString(data,principal); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); if (data->has_error) { DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs)); } ret = data_blob(data->data, data->length); asn1_free(data); return ret; } /* Generate a negTokenInit as used by the client side ... It has a mechType (OID), and a mechToken (a security blob) ... Really, we need to break out the NTLMSSP stuff as well, because it could be raw in the packets! */ DATA_BLOB gen_negTokenInit(const char *OID, DATA_BLOB blob) { ASN1_DATA *data; DATA_BLOB ret; data = asn1_init(talloc_tos()); if (data == NULL) { return data_blob_null; } asn1_push_tag(data, ASN1_APPLICATION(0)); asn1_write_OID(data,OID_SPNEGO); asn1_push_tag(data, ASN1_CONTEXT(0)); asn1_push_tag(data, ASN1_SEQUENCE(0)); asn1_push_tag(data, ASN1_CONTEXT(0)); asn1_push_tag(data, ASN1_SEQUENCE(0)); asn1_write_OID(data, OID); asn1_pop_tag(data); asn1_pop_tag(data); asn1_push_tag(data, ASN1_CONTEXT(2)); asn1_write_OctetString(data,blob.data,blob.length); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); if (data->has_error) { DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs)); } ret = data_blob(data->data, data->length); asn1_free(data); return ret; } /* parse a negTokenInit packet giving a GUID, a list of supported OIDs (the mechanisms) and a principal name string */ bool spnego_parse_negTokenInit(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], char **principal) { int i; bool ret; ASN1_DATA *data; data = asn1_init(talloc_tos()); if (data == NULL) { return false; } asn1_load(data, blob); asn1_start_tag(data,ASN1_APPLICATION(0)); asn1_check_OID(data,OID_SPNEGO); asn1_start_tag(data,ASN1_CONTEXT(0)); asn1_start_tag(data,ASN1_SEQUENCE(0)); asn1_start_tag(data,ASN1_CONTEXT(0)); asn1_start_tag(data,ASN1_SEQUENCE(0)); for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) { const char *oid_str = NULL; asn1_read_OID(data,talloc_autofree_context(),&oid_str); OIDs[i] = CONST_DISCARD(char *, oid_str); } OIDs[i] = NULL; asn1_end_tag(data); asn1_end_tag(data); *principal = NULL; if (asn1_tag_remaining(data) > 0) { asn1_start_tag(data, ASN1_CONTEXT(3)); asn1_start_tag(data, ASN1_SEQUENCE(0)); asn1_start_tag(data, ASN1_CONTEXT(0)); asn1_read_GeneralString(data,talloc_autofree_context(),principal); asn1_end_tag(data); asn1_end_tag(data); asn1_end_tag(data); } asn1_end_tag(data); asn1_end_tag(data); asn1_end_tag(data); ret = !data->has_error; if (data->has_error) { int j; TALLOC_FREE(*principal); for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) { TALLOC_FREE(OIDs[j]); } } asn1_free(data); return ret; } /* generate a negTokenTarg packet given a list of OIDs and a security blob */ DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob) { int i; ASN1_DATA *data; DATA_BLOB ret; data = asn1_init(talloc_tos()); if (data == NULL) { return data_blob_null; } asn1_push_tag(data, ASN1_APPLICATION(0)); asn1_write_OID(data,OID_SPNEGO); asn1_push_tag(data, ASN1_CONTEXT(0)); asn1_push_tag(data, ASN1_SEQUENCE(0)); asn1_push_tag(data, ASN1_CONTEXT(0)); asn1_push_tag(data, ASN1_SEQUENCE(0)); for (i=0; OIDs[i]; i++) { asn1_write_OID(data,OIDs[i]); } asn1_pop_tag(data); asn1_pop_tag(data); asn1_push_tag(data, ASN1_CONTEXT(2)); asn1_write_OctetString(data,blob.data,blob.length); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); if (data->has_error) { DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs)); } ret = data_blob(data->data, data->length); asn1_free(data); return ret; } /* parse a negTokenTarg packet giving a list of OIDs and a security blob */ bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob) { int i; ASN1_DATA *data; data = asn1_init(talloc_tos()); if (data == NULL) { return false; } asn1_load(data, blob); asn1_start_tag(data, ASN1_APPLICATION(0)); asn1_check_OID(data,OID_SPNEGO); asn1_start_tag(data, ASN1_CONTEXT(0)); asn1_start_tag(data, ASN1_SEQUENCE(0)); asn1_start_tag(data, ASN1_CONTEXT(0)); asn1_start_tag(data, ASN1_SEQUENCE(0)); for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) { const char *oid_str = NULL; asn1_read_OID(data,talloc_autofree_context(),&oid_str); OIDs[i] = CONST_DISCARD(char *, oid_str); } OIDs[i] = NULL; asn1_end_tag(data); asn1_end_tag(data); /* Skip any optional req_flags that are sent per RFC 4178 */ if (asn1_peek_tag(data, ASN1_CONTEXT(1))) { uint8 flags; asn1_start_tag(data, ASN1_CONTEXT(1)); asn1_start_tag(data, ASN1_BIT_STRING); while (asn1_tag_remaining(data) > 0) asn1_read_uint8(data, &flags); asn1_end_tag(data); asn1_end_tag(data); } asn1_start_tag(data, ASN1_CONTEXT(2)); asn1_read_OctetString(data,talloc_autofree_context(),secblob); asn1_end_tag(data); asn1_end_tag(data); asn1_end_tag(data); asn1_end_tag(data); if (data->has_error) { int j; data_blob_free(secblob); for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) { TALLOC_FREE(OIDs[j]); } DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs)); asn1_free(data); return False; } asn1_free(data); return True; } /* generate a krb5 GSS-API wrapper packet given a ticket */ DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2]) { ASN1_DATA *data; DATA_BLOB ret; data = asn1_init(talloc_tos()); if (data == NULL) { return data_blob_null; } asn1_push_tag(data, ASN1_APPLICATION(0)); asn1_write_OID(data, OID_KERBEROS5); asn1_write(data, tok_id, 2); asn1_write(data, ticket.data, ticket.length); asn1_pop_tag(data); if (data->has_error) { DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs)); } ret = data_blob(data->data, data->length); asn1_free(data); return ret; } /* parse a krb5 GSS-API wrapper packet giving a ticket */ bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2]) { bool ret; ASN1_DATA *data; int data_remaining; data = asn1_init(talloc_tos()); if (data == NULL) { return false; } asn1_load(data, blob); asn1_start_tag(data, ASN1_APPLICATION(0)); asn1_check_OID(data, OID_KERBEROS5); data_remaining = asn1_tag_remaining(data); if (data_remaining < 3) { data->has_error = True; } else { asn1_read(data, tok_id, 2); data_remaining -= 2; *ticket = data_blob(NULL, data_remaining); asn1_read(data, ticket->data, ticket->length); } asn1_end_tag(data); ret = !data->has_error; if (data->has_error) { data_blob_free(ticket); } asn1_free(data); return ret; } /* generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY kerberos session setup */ int spnego_gen_negTokenTarg(const char *principal, int time_offset, DATA_BLOB *targ, DATA_BLOB *session_key_krb5, uint32 extra_ap_opts, time_t *expire_time) { int retval; DATA_BLOB tkt, tkt_wrapped; const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL}; /* get a kerberos ticket for the service and extract the session key */ retval = cli_krb5_get_ticket(principal, time_offset, &tkt, session_key_krb5, extra_ap_opts, NULL, expire_time, NULL); if (retval) return retval; /* wrap that up in a nice GSS-API wrapping */ tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ); /* and wrap that in a shiny SPNEGO wrapper */ *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped); data_blob_free(&tkt_wrapped); data_blob_free(&tkt); return retval; } /* parse a spnego NTLMSSP challenge packet giving two security blobs */ bool spnego_parse_challenge(const DATA_BLOB blob, DATA_BLOB *chal1, DATA_BLOB *chal2) { bool ret; ASN1_DATA *data; ZERO_STRUCTP(chal1); ZERO_STRUCTP(chal2); data = asn1_init(talloc_tos()); if (data == NULL) { return false; } asn1_load(data, blob); asn1_start_tag(data,ASN1_CONTEXT(1)); asn1_start_tag(data,ASN1_SEQUENCE(0)); asn1_start_tag(data,ASN1_CONTEXT(0)); asn1_check_enumerated(data,1); asn1_end_tag(data); asn1_start_tag(data,ASN1_CONTEXT(1)); asn1_check_OID(data, OID_NTLMSSP); asn1_end_tag(data); asn1_start_tag(data,ASN1_CONTEXT(2)); asn1_read_OctetString(data, talloc_autofree_context(), chal1); asn1_end_tag(data); /* the second challenge is optional (XP doesn't send it) */ if (asn1_tag_remaining(data)) { asn1_start_tag(data,ASN1_CONTEXT(3)); asn1_read_OctetString(data, talloc_autofree_context(), chal2); asn1_end_tag(data); } asn1_end_tag(data); asn1_end_tag(data); ret = !data->has_error; if (data->has_error) { data_blob_free(chal1); data_blob_free(chal2); } asn1_free(data); return ret; } /* generate a SPNEGO auth packet. This will contain the encrypted passwords */ DATA_BLOB spnego_gen_auth(DATA_BLOB blob) { ASN1_DATA *data; DATA_BLOB ret; data = asn1_init(talloc_tos()); if (data == NULL) { return data_blob_null; } asn1_push_tag(data, ASN1_CONTEXT(1)); asn1_push_tag(data, ASN1_SEQUENCE(0)); asn1_push_tag(data, ASN1_CONTEXT(2)); asn1_write_OctetString(data,blob.data,blob.length); asn1_pop_tag(data); asn1_pop_tag(data); asn1_pop_tag(data); ret = data_blob(data->data, data->length); asn1_free(data); return ret; } /* parse a SPNEGO auth packet. This contains the encrypted passwords */ bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth) { ssize_t len; struct spnego_data token; len = spnego_read_data(talloc_tos(), blob, &token); if (len == -1) { DEBUG(3,("spnego_parse_auth: spnego_read_data failed\n")); return false; } if (token.type != SPNEGO_NEG_TOKEN_TARG) { DEBUG(3,("spnego_parse_auth: wrong token type: %d\n", token.type)); spnego_free_data(&token); return false; } *auth = data_blob_talloc(talloc_tos(), token.negTokenTarg.responseToken.data, token.negTokenTarg.responseToken.length); spnego_free_data(&token); return true; } /* generate a minimal SPNEGO response packet. Doesn't contain much. */ DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status, const char *mechOID) { ASN1_DATA *data; DATA_BLOB ret; uint8 negResult; if (NT_STATUS_IS_OK(nt_status)) { negResult = SPNEGO_ACCEPT_COMPLETED; } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { negResult = SPNEGO_ACCEPT_INCOMPLETE; } else { negResult = SPNEGO_REJECT; } data = asn1_init(talloc_tos()); if (data == NULL) { return data_blob_null; } asn1_push_tag(data, ASN1_CONTEXT(1)); asn1_push_tag(data, ASN1_SEQUENCE(0)); asn1_push_tag(data, ASN1_CONTEXT(0)); asn1_write_enumerated(data, negResult); asn1_pop_tag(data); if (mechOID) { asn1_push_tag(data,ASN1_CONTEXT(1)); asn1_write_OID(data, mechOID); asn1_pop_tag(data); } if (reply && reply->data != NULL) { asn1_push_tag(data,ASN1_CONTEXT(2)); asn1_write_OctetString(data, reply->data, reply->length); asn1_pop_tag(data); } asn1_pop_tag(data); asn1_pop_tag(data); ret = data_blob(data->data, data->length); asn1_free(data); return ret; } /* parse a SPNEGO auth packet. This contains the encrypted passwords */ bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status, const char *mechOID, DATA_BLOB *auth) { ASN1_DATA *data; uint8 negResult; if (NT_STATUS_IS_OK(nt_status)) { negResult = SPNEGO_ACCEPT_COMPLETED; } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { negResult = SPNEGO_ACCEPT_INCOMPLETE; } else { negResult = SPNEGO_REJECT; } data = asn1_init(talloc_tos()); if (data == NULL) { return false; } asn1_load(data, blob); asn1_start_tag(data, ASN1_CONTEXT(1)); asn1_start_tag(data, ASN1_SEQUENCE(0)); asn1_start_tag(data, ASN1_CONTEXT(0)); asn1_check_enumerated(data, negResult); asn1_end_tag(data); *auth = data_blob_null; if (asn1_tag_remaining(data)) { asn1_start_tag(data,ASN1_CONTEXT(1)); asn1_check_OID(data, mechOID); asn1_end_tag(data); if (asn1_tag_remaining(data)) { asn1_start_tag(data,ASN1_CONTEXT(2)); asn1_read_OctetString(data, talloc_autofree_context(), auth); asn1_end_tag(data); } } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) { data->has_error = 1; } /* Binding against Win2K DC returns a duplicate of the responseToken in * the optional mechListMIC field. This is a bug in Win2K. We ignore * this field if it exists. Win2K8 may return a proper mechListMIC at * which point we need to implement the integrity checking. */ if (asn1_tag_remaining(data)) { DATA_BLOB mechList = data_blob_null; asn1_start_tag(data, ASN1_CONTEXT(3)); asn1_read_OctetString(data, talloc_autofree_context(), &mechList); asn1_end_tag(data); data_blob_free(&mechList); DEBUG(5,("spnego_parse_auth_response received mechListMIC, " "ignoring.\n")); } asn1_end_tag(data); asn1_end_tag(data); if (data->has_error) { DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs)); asn1_free(data); data_blob_free(auth); return False; } asn1_free(data); return True; }