get_cred.c

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	ret = decode_Ticket(in_creds->second_ticket.data, 
			    in_creds->second_ticket.length, 
			    &second_ticket_data, &len);
	if(ret)
	    return ret;
	second_ticket = &second_ticket_data;
    }


    if (impersonate_principal) {
	krb5_crypto crypto;
	PA_S4U2Self self;
	krb5_data data;
	void *buf;
	size_t size;

	self.name = impersonate_principal->name;
	self.realm = impersonate_principal->realm;
	self.auth = estrdup("Kerberos");
	
	ret = _krb5_s4u2self_to_checksumdata(context, &self, &data);
	if (ret) {
	    free(self.auth);
	    goto out;
	}

	ret = krb5_crypto_init(context, &krbtgt->session, 0, &crypto);
	if (ret) {
	    free(self.auth);
	    krb5_data_free(&data);
	    goto out;
	}

	ret = krb5_create_checksum(context,
				   crypto,
				   KRB5_KU_OTHER_CKSUM,
				   0,
				   data.data,
				   data.length, 
				   &self.cksum);
	krb5_crypto_destroy(context, crypto);
	krb5_data_free(&data);
	if (ret) {
	    free(self.auth);
	    goto out;
	}

	ASN1_MALLOC_ENCODE(PA_S4U2Self, buf, len, &self, &size, ret);
	free(self.auth);
	free_Checksum(&self.cksum);
	if (ret)
	    goto out;
	if (len != size)
	    krb5_abortx(context, "internal asn1 error");
	
	ret = krb5_padata_add(context, &padata, KRB5_PADATA_S4U2SELF, buf, len);
	if (ret)
	    goto out;
    }

    ret = init_tgs_req (context,
			id,
			addresses,
			flags,
			second_ticket,
			in_creds,
			krbtgt,
			nonce,
			&padata,
			&subkey, 
			&req,
			usage);
    if (ret)
	goto out;

    ASN1_MALLOC_ENCODE(TGS_REQ, enc.data, enc.length, &req, &len, ret);
    if (ret) 
	goto out;
    if(enc.length != len)
	krb5_abortx(context, "internal error in ASN.1 encoder");

    /* don't free addresses */
    req.req_body.addresses = NULL;
    free_TGS_REQ(&req);

    /*
     * Send and receive
     */
    {
	krb5_sendto_ctx stctx;
	ret = krb5_sendto_ctx_alloc(context, &stctx);
	if (ret)
	    return ret;
	krb5_sendto_ctx_set_func(stctx, _krb5_kdc_retry, NULL);

	ret = krb5_sendto_context (context, stctx, &enc,
				   krbtgt->server->name.name_string.val[1],
				   &resp);
	krb5_sendto_ctx_free(context, stctx);
    }
    if(ret)
	goto out;

    memset(&rep, 0, sizeof(rep));
    if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0){
	ret = krb5_copy_principal(context, 
				  in_creds->client, 
				  &out_creds->client);
	if(ret)
	    goto out;
	ret = krb5_copy_principal(context, 
				  in_creds->server, 
				  &out_creds->server);
	if(ret)
	    goto out;
	/* this should go someplace else */
	out_creds->times.endtime = in_creds->times.endtime;

	ret = _krb5_extract_ticket(context,
				   &rep,
				   out_creds,
				   &krbtgt->session,
				   NULL,
				   KRB5_KU_TGS_REP_ENC_PART_SESSION,
				   &krbtgt->addresses,
				   nonce,
				   EXTRACT_TICKET_ALLOW_CNAME_MISMATCH|
				   EXTRACT_TICKET_ALLOW_SERVER_MISMATCH,
				   decrypt_tkt_with_subkey,
				   subkey);
	krb5_free_kdc_rep(context, &rep);
    } else if(krb5_rd_error(context, &resp, &error) == 0) {
	ret = krb5_error_from_rd_error(context, &error, in_creds);
	krb5_free_error_contents(context, &error);
    } else if(resp.data && ((char*)resp.data)[0] == 4) {
	ret = KRB5KRB_AP_ERR_V4_REPLY;
	krb5_clear_error_string(context);
    } else {
	ret = KRB5KRB_AP_ERR_MSG_TYPE;
	krb5_clear_error_string(context);
    }

out:
    if (second_ticket == &second_ticket_data)
	free_Ticket(&second_ticket_data);
    free_METHOD_DATA(&padata);
    krb5_data_free(&resp);
    krb5_data_free(&enc);
    if(subkey){
	krb5_free_keyblock_contents(context, subkey);
	free(subkey);
    }
    return ret;
    
}

static krb5_error_code
get_cred_kdc(krb5_context context, 
	     krb5_ccache id, 
	     krb5_kdc_flags flags,
	     krb5_addresses *addresses, 
	     krb5_creds *in_creds, 
	     krb5_creds *krbtgt,
	     krb5_principal impersonate_principal,
	     Ticket *second_ticket,
	     krb5_creds *out_creds)
{
    krb5_error_code ret;

    ret = get_cred_kdc_usage(context, id, flags, addresses, in_creds,
			     krbtgt, impersonate_principal, second_ticket,
			     out_creds, KRB5_KU_TGS_REQ_AUTH);
    if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY) {
	krb5_clear_error_string (context);
	ret = get_cred_kdc_usage(context, id, flags, addresses, in_creds,
				 krbtgt, impersonate_principal, second_ticket,
				 out_creds, KRB5_KU_AP_REQ_AUTH);
    }
    return ret;
}

/* same as above, just get local addresses first */

static krb5_error_code
get_cred_kdc_la(krb5_context context, krb5_ccache id, krb5_kdc_flags flags, 
		krb5_creds *in_creds, krb5_creds *krbtgt, 
		krb5_principal impersonate_principal, Ticket *second_ticket,
		krb5_creds *out_creds)
{
    krb5_error_code ret;
    krb5_addresses addresses, *addrs = &addresses;
    
    krb5_get_all_client_addrs(context, &addresses);
    /* XXX this sucks. */
    if(addresses.len == 0)
	addrs = NULL;
    ret = get_cred_kdc(context, id, flags, addrs, 
		       in_creds, krbtgt, impersonate_principal, second_ticket,
		       out_creds);
    krb5_free_addresses(context, &addresses);
    return ret;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_get_kdc_cred(krb5_context context,
		  krb5_ccache id,
		  krb5_kdc_flags flags,
		  krb5_addresses *addresses,
		  Ticket  *second_ticket,
		  krb5_creds *in_creds,
		  krb5_creds **out_creds
		  )
{
    krb5_error_code ret;
    krb5_creds *krbtgt;

    *out_creds = calloc(1, sizeof(**out_creds));
    if(*out_creds == NULL) {
	krb5_set_error_string(context, "malloc: out of memory");
	return ENOMEM;
    }
    ret = _krb5_get_krbtgt (context,
			    id,
			    in_creds->server->realm,
			    &krbtgt);
    if(ret) {
	free(*out_creds);
	return ret;
    }
    ret = get_cred_kdc(context, id, flags, addresses, 
		       in_creds, krbtgt, NULL, NULL, *out_creds);
    krb5_free_creds (context, krbtgt);
    if(ret)
	free(*out_creds);
    return ret;
}

static void
not_found(krb5_context context, krb5_const_principal p)
{
    krb5_error_code ret;
    char *str;

    ret = krb5_unparse_name(context, p, &str);
    if(ret) {
	krb5_clear_error_string(context);
	return;
    }
    krb5_set_error_string(context, "Matching credential (%s) not found", str);
    free(str);
}

static krb5_error_code
find_cred(krb5_context context,
	  krb5_ccache id,
	  krb5_principal server,
	  krb5_creds **tgts,
	  krb5_creds *out_creds)
{
    krb5_error_code ret;
    krb5_creds mcreds;

    krb5_cc_clear_mcred(&mcreds);
    mcreds.server = server;
    ret = krb5_cc_retrieve_cred(context, id, KRB5_TC_DONT_MATCH_REALM, 
				&mcreds, out_creds);
    if(ret == 0)
	return 0;
    while(tgts && *tgts){
	if(krb5_compare_creds(context, KRB5_TC_DONT_MATCH_REALM, 
			      &mcreds, *tgts)){
	    ret = krb5_copy_creds_contents(context, *tgts, out_creds);
	    return ret;
	}
	tgts++;
    }
    not_found(context, server);
    return KRB5_CC_NOTFOUND;
}

static krb5_error_code
add_cred(krb5_context context, krb5_creds ***tgts, krb5_creds *tkt)
{
    int i;
    krb5_error_code ret;
    krb5_creds **tmp = *tgts;

    for(i = 0; tmp && tmp[i]; i++); /* XXX */
    tmp = realloc(tmp, (i+2)*sizeof(*tmp));
    if(tmp == NULL) {
	krb5_set_error_string(context, "malloc: out of memory");
	return ENOMEM;
    }
    *tgts = tmp;
    ret = krb5_copy_creds(context, tkt, &tmp[i]);
    tmp[i+1] = NULL;
    return ret;
}

/*
get_cred(server)
	creds = cc_get_cred(server)
	if(creds) return creds
	tgt = cc_get_cred(krbtgt/server_realm@any_realm)
	if(tgt)
		return get_cred_tgt(server, tgt)
	if(client_realm == server_realm)
		return NULL
	tgt = get_cred(krbtgt/server_realm@client_realm)
	while(tgt_inst != server_realm)
		tgt = get_cred(krbtgt/server_realm@tgt_inst)
	return get_cred_tgt(server, tgt)
	*/

static krb5_error_code
get_cred_from_kdc_flags(krb5_context context,
			krb5_kdc_flags flags,
			krb5_ccache ccache,
			krb5_creds *in_creds,
			krb5_principal impersonate_principal,
			Ticket *second_ticket,			
			krb5_creds **out_creds,
			krb5_creds ***ret_tgts)
{
    krb5_error_code ret;
    krb5_creds *tgt, tmp_creds;
    krb5_const_realm client_realm, server_realm, try_realm;

    *out_creds = NULL;

    client_realm = krb5_principal_get_realm(context, in_creds->client);
    server_realm = krb5_principal_get_realm(context, in_creds->server);
    memset(&tmp_creds, 0, sizeof(tmp_creds));
    ret = krb5_copy_principal(context, in_creds->client, &tmp_creds.client);
    if(ret)
	return ret;

    try_realm = krb5_config_get_string(context, NULL, "capaths", 
				       client_realm, server_realm, NULL);
    if (try_realm == NULL)
	try_realm = client_realm;

    ret = krb5_make_principal(context,
			      &tmp_creds.server,
			      try_realm,
			      KRB5_TGS_NAME,
			      server_realm, 
			      NULL);
    if(ret){
	krb5_free_principal(context, tmp_creds.client);
	return ret;
    }
    {
	krb5_creds tgts;
	/* XXX try krb5_cc_retrieve_cred first? */
	ret = find_cred(context, ccache, tmp_creds.server, 
			*ret_tgts, &tgts);
	if(ret == 0){
	    *out_creds = calloc(1, sizeof(**out_creds));
	    if(*out_creds == NULL) {
		krb5_set_error_string(context, "malloc: out of memory");
		ret = ENOMEM;
	    } else {
		krb5_boolean noaddr;

		krb5_appdefault_boolean(context, NULL, tgts.server->realm,
					"no-addresses", FALSE, &noaddr);

		if (noaddr)
		    ret = get_cred_kdc(context, ccache, flags, NULL,
				       in_creds, &tgts,
				       impersonate_principal, 
				       second_ticket,
				       *out_creds);
		else
		    ret = get_cred_kdc_la(context, ccache, flags, 
					  in_creds, &tgts, 
					  impersonate_principal, 
					  second_ticket,
					  *out_creds);
		if (ret) {
		    free (*out_creds);
		    *out_creds = NULL;
		}
	    }
	    krb5_free_cred_contents(context, &tgts);
	    krb5_free_principal(context, tmp_creds.server);
	    krb5_free_principal(context, tmp_creds.client);
	    return ret;
	}
    }
    if(krb5_realm_compare(context, in_creds->client, in_creds->server)) {
	not_found(context, in_creds->server);
	return KRB5_CC_NOTFOUND;
    }
    /* XXX this can loop forever */
    while(1){
	heim_general_string tgt_inst;

	ret = get_cred_from_kdc_flags(context, flags, ccache, &tmp_creds, 
				      NULL, NULL, &tgt, ret_tgts);
	if(ret) {
	    krb5_free_principal(context, tmp_creds.server);
	    krb5_free_principal(context, tmp_creds.client);
	    return ret;
	}
	ret = add_cred(context, ret_tgts, tgt);
	if(ret) {
	    krb5_free_principal(context, tmp_creds.server);
	    krb5_free_principal(context, tmp_creds.client);
	    return ret;
	}
	tgt_inst = tgt->server->name.name_string.val[1];
	if(strcmp(tgt_inst, server_realm) == 0)
	    break;
	krb5_free_principal(context, tmp_creds.server);
	ret = krb5_make_principal(context, &tmp_creds.server, 
				  tgt_inst, KRB5_TGS_NAME, server_realm, NULL);
	if(ret) {
	    krb5_free_principal(context, tmp_creds.server);
	    krb5_free_principal(context, tmp_creds.client);
	    return ret;
	}
	ret = krb5_free_creds(context, tgt);