From edccfc91928c323f18febb7b90e41e0ddbfd8c7c Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Thu, 15 Mar 2007 19:18:18 +0000 Subject: r21845: Refactor the sessionsetupX code a little to allow us to return a NT_STATUS_TIME_DIFFERENCE_AT_DC error to a client when there's clock skew. Will help people debug this. Prepare us for being able to return the correct sessionsetupX "NT_STATUS_MORE_PROCESSING_REQUIRED" error with associated krb5 clock skew error to allow clients to re-sync time with us when we're eventually able to be a KDC. Jeremy. (This used to be commit c426340fc79a6b446033433b8de599130adffe28) --- source3/smbd/sesssetup.c | 235 ++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 193 insertions(+), 42 deletions(-) (limited to 'source3/smbd') diff --git a/source3/smbd/sesssetup.c b/source3/smbd/sesssetup.c index 7a5f8be47f..e678d959d8 100644 --- a/source3/smbd/sesssetup.c +++ b/source3/smbd/sesssetup.c @@ -158,13 +158,75 @@ static NTSTATUS check_guest_password(auth_serversupplied_info **server_info) #ifdef HAVE_KRB5 + +#if 0 +/* Experiment that failed. See "only happens with a KDC" comment below. */ +/**************************************************************************** + Cerate a clock skew error blob for a Windows client. +****************************************************************************/ + +static BOOL make_krb5_skew_error(DATA_BLOB *pblob_out) +{ + krb5_context context = NULL; + krb5_error_code kerr = 0; + krb5_data reply; + krb5_principal host_princ = NULL; + char *host_princ_s = NULL; + BOOL ret = False; + + *pblob_out = data_blob(NULL,0); + + kerr = krb5_init_context(&context); + if (kerr) { + return False; + } + /* Create server principal. */ + asprintf(&host_princ_s, "%s$@%s", global_myname(), lp_realm()); + if (!host_princ_s) { + goto out; + } + strlower_m(host_princ_s); + + kerr = smb_krb5_parse_name(context, host_princ_s, &host_princ); + if (kerr) { + DEBUG(10,("make_krb5_skew_error: smb_krb5_parse_name failed for name %s: Error %s\n", + host_princ_s, error_message(kerr) )); + goto out; + } + + kerr = smb_krb5_mk_error(context, KRB5KRB_AP_ERR_SKEW, host_princ, &reply); + if (kerr) { + DEBUG(10,("make_krb5_skew_error: smb_krb5_mk_error failed: Error %s\n", + error_message(kerr) )); + goto out; + } + + *pblob_out = data_blob(reply.data, reply.length); + kerberos_free_data_contents(context,&reply); + ret = True; + + out: + + if (host_princ_s) { + SAFE_FREE(host_princ_s); + } + if (host_princ) { + krb5_free_principal(context, host_princ); + } + krb5_free_context(context); + return ret; +} +#endif + /**************************************************************************** -reply to a session setup spnego negotiate packet for kerberos + Reply to a session setup spnego negotiate packet for kerberos. ****************************************************************************/ + static int reply_spnego_kerberos(connection_struct *conn, char *inbuf, char *outbuf, int length, int bufsize, - DATA_BLOB *secblob) + DATA_BLOB *secblob, + BOOL *p_invalidate_vuid) { TALLOC_CTX *mem_ctx; DATA_BLOB ticket; @@ -191,9 +253,13 @@ static int reply_spnego_kerberos(connection_struct *conn, ZERO_STRUCT(ap_rep_wrapped); ZERO_STRUCT(response); + /* Normally we will always invalidate the intermediate vuid. */ + *p_invalidate_vuid = True; + mem_ctx = talloc_init("reply_spnego_kerberos"); - if (mem_ctx == NULL) + if (mem_ctx == NULL) { return ERROR_NT(nt_status_squash(NT_STATUS_NO_MEMORY)); + } if (!spnego_parse_krb5_wrap(*secblob, &ticket, tok_id)) { talloc_destroy(mem_ctx); @@ -205,9 +271,50 @@ static int reply_spnego_kerberos(connection_struct *conn, data_blob_free(&ticket); if (!NT_STATUS_IS_OK(ret)) { - DEBUG(1,("Failed to verify incoming ticket!\n")); +#if 0 + /* Experiment that failed. See "only happens with a KDC" comment below. */ + + if (NT_STATUS_EQUAL(ret, NT_STATUS_TIME_DIFFERENCE_AT_DC)) { + + /* + * Windows in this case returns NT_STATUS_MORE_PROCESSING_REQUIRED + * with a negTokenTarg blob containing an krb5_error struct ASN1 encoded + * containing KRB5KRB_AP_ERR_SKEW. The client then fixes its + * clock and continues rather than giving an error. JRA. + * -- Looks like this only happens with a KDC. JRA. + */ + + BOOL ok = make_krb5_skew_error(&ap_rep); + if (!ok) { + talloc_destroy(mem_ctx); + return ERROR_NT(nt_status_squash(NT_STATUS_LOGON_FAILURE)); + } + ap_rep_wrapped = spnego_gen_krb5_wrap(ap_rep, TOK_ID_KRB_ERROR); + response = spnego_gen_auth_response(&ap_rep_wrapped, ret, OID_KERBEROS5_OLD); + reply_sesssetup_blob(conn, outbuf, response, NT_STATUS_MORE_PROCESSING_REQUIRED); + + /* + * In this one case we don't invalidate the intermediate vuid. + * as we're expecting the client to re-use it for the next + * sessionsetupX packet. JRA. + */ + + *p_invalidate_vuid = False; + + data_blob_free(&ap_rep); + data_blob_free(&ap_rep_wrapped); + data_blob_free(&response); + talloc_destroy(mem_ctx); + return -1; /* already replied */ + } +#else + if (!NT_STATUS_EQUAL(ret, NT_STATUS_TIME_DIFFERENCE_AT_DC)) { + ret = NT_STATUS_LOGON_FAILURE; + } +#endif + DEBUG(1,("Failed to verify incoming ticket with error %s!\n", nt_errstr(ret))); talloc_destroy(mem_ctx); - return ERROR_NT(nt_status_squash(NT_STATUS_LOGON_FAILURE)); + return ERROR_NT(nt_status_squash(ret)); } DEBUG(3,("Ticket name is [%s]\n", client)); @@ -523,32 +630,19 @@ static BOOL reply_spnego_ntlmssp(connection_struct *conn, char *inbuf, char *out } /**************************************************************************** - Reply to a session setup spnego negotiate packet. + Is this a krb5 mechanism ? ****************************************************************************/ -static int reply_spnego_negotiate(connection_struct *conn, - char *inbuf, - char *outbuf, - uint16 vuid, - int length, int bufsize, - DATA_BLOB blob1, - AUTH_NTLMSSP_STATE **auth_ntlmssp_state) +static NTSTATUS parse_spnego_mechanisms(DATA_BLOB blob_in, DATA_BLOB *pblob_out, BOOL *p_is_krb5) { char *OIDs[ASN1_MAX_OIDS]; - DATA_BLOB secblob; int i; - DATA_BLOB chal; -#ifdef HAVE_KRB5 - BOOL got_kerberos_mechanism = False; -#endif - NTSTATUS nt_status; - /* parse out the OIDs and the first sec blob */ - if (!parse_negTokenTarg(blob1, OIDs, &secblob)) { - /* Kill the intermediate vuid */ - invalidate_vuid(vuid); + *p_is_krb5 = False; - return ERROR_NT(nt_status_squash(NT_STATUS_LOGON_FAILURE)); + /* parse out the OIDs and the first sec blob */ + if (!parse_negTokenTarg(blob_in, OIDs, pblob_out)) { + return NT_STATUS_LOGON_FAILURE; } /* only look at the first OID for determining the mechToken -- @@ -564,24 +658,53 @@ static int reply_spnego_negotiate(connection_struct *conn, #ifdef HAVE_KRB5 if (strcmp(OID_KERBEROS5, OIDs[0]) == 0 || strcmp(OID_KERBEROS5_OLD, OIDs[0]) == 0) { - got_kerberos_mechanism = True; + *p_is_krb5 = True; } #endif for (i=0;OIDs[i];i++) { - DEBUG(3,("Got OID %s\n", OIDs[i])); + DEBUG(5,("parse_spnego_mechanisms: Got OID %s\n", OIDs[i])); free(OIDs[i]); } - DEBUG(3,("Got secblob of size %lu\n", (unsigned long)secblob.length)); + return NT_STATUS_OK; +} + +/**************************************************************************** + Reply to a session setup spnego negotiate packet. +****************************************************************************/ + +static int reply_spnego_negotiate(connection_struct *conn, + char *inbuf, + char *outbuf, + uint16 vuid, + int length, int bufsize, + DATA_BLOB blob1, + AUTH_NTLMSSP_STATE **auth_ntlmssp_state) +{ + DATA_BLOB secblob; + DATA_BLOB chal; + BOOL got_kerberos_mechanism = False; + NTSTATUS status; + + status = parse_spnego_mechanisms(blob1, &secblob, &got_kerberos_mechanism); + if (!NT_STATUS_IS_OK(status)) { + /* Kill the intermediate vuid */ + invalidate_vuid(vuid); + return ERROR_NT(nt_status_squash(status)); + } + + DEBUG(3,("reply_spnego_negotiate: Got secblob of size %lu\n", (unsigned long)secblob.length)); #ifdef HAVE_KRB5 if ( got_kerberos_mechanism && ((lp_security()==SEC_ADS) || lp_use_kerberos_keytab()) ) { + BOOL destroy_vuid = True; int ret = reply_spnego_kerberos(conn, inbuf, outbuf, - length, bufsize, &secblob); + length, bufsize, &secblob, &destroy_vuid); data_blob_free(&secblob); - /* Kill the intermediate vuid */ - invalidate_vuid(vuid); - + if (destroy_vuid) { + /* Kill the intermediate vuid */ + invalidate_vuid(vuid); + } return ret; } #endif @@ -590,28 +713,27 @@ static int reply_spnego_negotiate(connection_struct *conn, auth_ntlmssp_end(auth_ntlmssp_state); } - nt_status = auth_ntlmssp_start(auth_ntlmssp_state); - if (!NT_STATUS_IS_OK(nt_status)) { + status = auth_ntlmssp_start(auth_ntlmssp_state); + if (!NT_STATUS_IS_OK(status)) { /* Kill the intermediate vuid */ invalidate_vuid(vuid); - - return ERROR_NT(nt_status_squash(nt_status)); + return ERROR_NT(nt_status_squash(status)); } - nt_status = auth_ntlmssp_update(*auth_ntlmssp_state, + status = auth_ntlmssp_update(*auth_ntlmssp_state, secblob, &chal); data_blob_free(&secblob); reply_spnego_ntlmssp(conn, inbuf, outbuf, vuid, auth_ntlmssp_state, - &chal, nt_status, True); + &chal, status, True); data_blob_free(&chal); /* already replied */ return -1; } - + /**************************************************************************** Reply to a session setup spnego auth packet. ****************************************************************************/ @@ -622,8 +744,10 @@ static int reply_spnego_auth(connection_struct *conn, char *inbuf, char *outbuf, DATA_BLOB blob1, AUTH_NTLMSSP_STATE **auth_ntlmssp_state) { - DATA_BLOB auth, auth_reply; - NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER; + DATA_BLOB auth = data_blob(NULL,0); + DATA_BLOB auth_reply = data_blob(NULL,0); + DATA_BLOB secblob = data_blob(NULL,0); + NTSTATUS status = NT_STATUS_INVALID_PARAMETER; if (!spnego_parse_auth(blob1, &auth)) { #if 0 @@ -634,6 +758,33 @@ static int reply_spnego_auth(connection_struct *conn, char *inbuf, char *outbuf, return ERROR_NT(nt_status_squash(NT_STATUS_INVALID_PARAMETER)); } + + if (auth.data[0] == ASN1_APPLICATION(0)) { + /* Might be a second negTokenTarg packet */ + + BOOL got_krb5_mechanism = False; + status = parse_spnego_mechanisms(auth, &secblob, &got_krb5_mechanism); + if (NT_STATUS_IS_OK(status)) { + DEBUG(3,("reply_spnego_auth: Got secblob of size %lu\n", (unsigned long)secblob.length)); +#ifdef HAVE_KRB5 + if ( got_krb5_mechanism && ((lp_security()==SEC_ADS) || lp_use_kerberos_keytab()) ) { + BOOL destroy_vuid = True; + int ret = reply_spnego_kerberos(conn, inbuf, outbuf, + length, bufsize, &secblob, &destroy_vuid); + data_blob_free(&secblob); + data_blob_free(&auth); + if (destroy_vuid) { + /* Kill the intermediate vuid */ + invalidate_vuid(vuid); + } + return ret; + } +#endif + } + } + + /* If we get here it wasn't a negTokenTarg auth packet. */ + data_blob_free(&secblob); if (!*auth_ntlmssp_state) { /* Kill the intermediate vuid */ @@ -643,14 +794,14 @@ static int reply_spnego_auth(connection_struct *conn, char *inbuf, char *outbuf, return ERROR_NT(nt_status_squash(NT_STATUS_INVALID_PARAMETER)); } - nt_status = auth_ntlmssp_update(*auth_ntlmssp_state, + status = auth_ntlmssp_update(*auth_ntlmssp_state, auth, &auth_reply); data_blob_free(&auth); reply_spnego_ntlmssp(conn, inbuf, outbuf, vuid, auth_ntlmssp_state, - &auth_reply, nt_status, True); + &auth_reply, status, True); data_blob_free(&auth_reply); -- cgit