static int mag_auth(request_rec *req)
{
const char *type;
struct mag_config *cfg;
const char *auth_header;
char *auth_header_type;
char *auth_header_value;
int ret = HTTP_UNAUTHORIZED;
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_ctx_id_t *pctx;
gss_buffer_desc input = GSS_C_EMPTY_BUFFER;
gss_buffer_desc output = GSS_C_EMPTY_BUFFER;
gss_buffer_desc name = GSS_C_EMPTY_BUFFER;
gss_name_t client = GSS_C_NO_NAME;
gss_cred_id_t acquired_cred = GSS_C_NO_CREDENTIAL;
gss_cred_id_t delegated_cred = GSS_C_NO_CREDENTIAL;
uint32_t flags;
uint32_t vtime;
uint32_t maj, min;
char *reply;
size_t replen;
char *clientname;
gss_OID mech_type = GSS_C_NO_OID;
gss_buffer_desc lname = GSS_C_EMPTY_BUFFER;
struct mag_conn *mc = NULL;
type = ap_auth_type(req);
if ((type == NULL) || (strcasecmp(type, "GSSAPI") != 0)) {
return DECLINED;
}
/* ignore auth for subrequests */
if (!ap_is_initial_req(req)) {
return OK;
}
cfg = ap_get_module_config(req->per_dir_config, &auth_gssapi_module);
if (cfg->ssl_only) {
if (!mag_conn_is_https(req->connection)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
"Not a TLS connection, refusing to authenticate!");
goto done;
}
}
if (cfg->gss_conn_ctx) {
mc = (struct mag_conn *)ap_get_module_config(
req->connection->conn_config,
&auth_gssapi_module);
if (!mc) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0, req,
"Failed to retrieve connection context!");
goto done;
}
}
/* if available, session always supersedes connection bound data */
mag_check_session(req, cfg, &mc);
if (mc) {
/* register the context in the memory pool, so it can be freed
* when the connection/request is terminated */
apr_pool_userdata_set(mc, "mag_conn_ptr",
mag_conn_destroy, mc->parent);
if (mc->established) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG|APLOG_NOERRNO, 0, req,
"Already established context found!");
apr_table_set(req->subprocess_env, "GSS_NAME", mc->gss_name);
req->ap_auth_type = apr_pstrdup(req->pool, "Negotiate");
req->user = apr_pstrdup(req->pool, mc->user_name);
ret = OK;
goto done;
}
pctx = &mc->ctx;
} else {
pctx = &ctx;
}
auth_header = apr_table_get(req->headers_in, "Authorization");
if (!auth_header) goto done;
auth_header_type = ap_getword_white(req->pool, &auth_header);
if (!auth_header_type) goto done;
if (strcasecmp(auth_header_type, "Negotiate") != 0) goto done;
auth_header_value = ap_getword_white(req->pool, &auth_header);
if (!auth_header_value) goto done;
input.length = apr_base64_decode_len(auth_header_value) + 1;
input.value = apr_pcalloc(req->pool, input.length);
if (!input.value) goto done;
input.length = apr_base64_decode(input.value, auth_header_value);
#ifdef HAVE_GSS_ACQUIRE_CRED_FROM
if (cfg->use_s4u2proxy) {
maj = gss_acquire_cred_from(&min, GSS_C_NO_NAME, 0,
GSS_C_NO_OID_SET, GSS_C_BOTH,
cfg->cred_store, &acquired_cred,
NULL, NULL);
if (GSS_ERROR(maj)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req, "%s",
mag_error(req, "gss_acquire_cred_from() failed",
maj, min));
goto done;
}
}
#endif
maj = gss_accept_sec_context(&min, pctx, acquired_cred,
&input, GSS_C_NO_CHANNEL_BINDINGS,
&client, &mech_type, &output, &flags, &vtime,
&delegated_cred);
if (GSS_ERROR(maj)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req, "%s",
mag_error(req, "gss_accept_sec_context() failed",
maj, min));
goto done;
}
if (maj == GSS_S_CONTINUE_NEEDED) {
if (!mc) {
ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
"Mechanism needs continuation but neither "
"GssapiConnectionBound nor "
"GssapiUseSessions are available");
gss_delete_sec_context(&min, pctx, GSS_C_NO_BUFFER);
gss_release_buffer(&min, &output);
output.length = 0;
}
/* auth not complete send token and wait next packet */
goto done;
}
req->ap_auth_type = apr_pstrdup(req->pool, "Negotiate");
/* Always set the GSS name in an env var */
maj = gss_display_name(&min, client, &name, NULL);
if (GSS_ERROR(maj)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req, "%s",
mag_error(req, "gss_accept_sec_context() failed",
maj, min));
goto done;
}
clientname = apr_pstrndup(req->pool, name.value, name.length);
apr_table_set(req->subprocess_env, "GSS_NAME", clientname);
#ifdef HAVE_GSS_STORE_CRED_INTO
if (cfg->deleg_ccache_dir && delegated_cred != GSS_C_NO_CREDENTIAL) {
char *ccachefile = NULL;
mag_store_deleg_creds(req, cfg->deleg_ccache_dir, clientname,
delegated_cred, &ccachefile);
if (ccachefile) {
apr_table_set(req->subprocess_env, "KRB5CCNAME", ccachefile);
}
}
#endif
if (cfg->map_to_local) {
maj = gss_localname(&min, client, mech_type, &lname);
if (maj != GSS_S_COMPLETE) {
ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req, "%s",
mag_error(req, "gss_localname() failed", maj, min));
goto done;
}
req->user = apr_pstrndup(req->pool, lname.value, lname.length);
} else {
req->user = clientname;
}
if (mc) {
mc->user_name = apr_pstrdup(mc->parent, req->user);
mc->gss_name = apr_pstrdup(mc->parent, clientname);
mc->established = true;
if (vtime == GSS_C_INDEFINITE || vtime < MIN_SESS_EXP_TIME) {
vtime = MIN_SESS_EXP_TIME;
}
mc->expiration = time(NULL) + vtime;
mag_attempt_session(req, cfg, mc);
}
ret = OK;
done:
if (ret == HTTP_UNAUTHORIZED) {
if (output.length != 0) {
replen = apr_base64_encode_len(output.length) + 1;
reply = apr_pcalloc(req->pool, 10 + replen);
if (reply) {
memcpy(reply, "Negotiate ", 10);
apr_base64_encode(&reply[10], output.value, output.length);
apr_table_add(req->err_headers_out,
"WWW-Authenticate", reply);
}
} else {
apr_table_add(req->err_headers_out,
"WWW-Authenticate", "Negotiate");
}
}
gss_release_cred(&min, &delegated_cred);
gss_release_buffer(&min, &output);
gss_release_name(&min, &client);
gss_release_buffer(&min, &name);
gss_release_buffer(&min, &lname);
return ret;
}
static int mag_auth(request_rec *req)
{
const char *type;
int auth_type = -1;
struct mag_req_cfg *req_cfg;
struct mag_config *cfg;
const char *auth_header;
char *auth_header_type;
int ret = HTTP_UNAUTHORIZED;
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_ctx_id_t *pctx;
gss_buffer_desc input = GSS_C_EMPTY_BUFFER;
gss_buffer_desc output = GSS_C_EMPTY_BUFFER;
gss_buffer_desc name = GSS_C_EMPTY_BUFFER;
gss_buffer_desc ba_user;
gss_buffer_desc ba_pwd;
gss_name_t client = GSS_C_NO_NAME;
gss_cred_id_t acquired_cred = GSS_C_NO_CREDENTIAL;
gss_cred_id_t delegated_cred = GSS_C_NO_CREDENTIAL;
gss_cred_usage_t cred_usage = GSS_C_ACCEPT;
uint32_t vtime;
uint32_t maj, min;
char *reply;
size_t replen;
gss_OID mech_type = GSS_C_NO_OID;
gss_OID_set desired_mechs = GSS_C_NO_OID_SET;
gss_buffer_desc lname = GSS_C_EMPTY_BUFFER;
struct mag_conn *mc = NULL;
int i;
bool send_auth_header = true;
type = ap_auth_type(req);
if ((type == NULL) || (strcasecmp(type, "GSSAPI") != 0)) {
return DECLINED;
}
req_cfg = mag_init_cfg(req);
cfg = req_cfg->cfg;
desired_mechs = req_cfg->desired_mechs;
/* implicit auth for subrequests if main auth already happened */
if (!ap_is_initial_req(req) && req->main != NULL) {
type = ap_auth_type(req->main);
if ((type != NULL) && (strcasecmp(type, "GSSAPI") == 0)) {
/* warn if the subrequest location and the main request
* location have different configs */
if (cfg != ap_get_module_config(req->main->per_dir_config,
&auth_gssapi_module)) {
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0,
req, "Subrequest authentication bypass on "
"location with different configuration!");
}
if (req->main->user) {
req->user = apr_pstrdup(req->pool, req->main->user);
return OK;
} else {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req,
"The main request is tasked to establish the "
"security context, can't proceed!");
return HTTP_UNAUTHORIZED;
}
} else {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
"Subrequest GSSAPI auth with no auth on the main "
"request. This operation may fail if other "
"subrequests already established a context or the "
"mechanism requires multiple roundtrips.");
}
}
if (cfg->ssl_only) {
if (!mag_conn_is_https(req->connection)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req,
"Not a TLS connection, refusing to authenticate!");
goto done;
}
}
if (cfg->gss_conn_ctx) {
mc = (struct mag_conn *)ap_get_module_config(
req->connection->conn_config,
&auth_gssapi_module);
if (!mc) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
"Failed to retrieve connection context!");
goto done;
}
}
/* if available, session always supersedes connection bound data */
if (req_cfg->use_sessions) {
mag_check_session(req_cfg, &mc);
}
auth_header = apr_table_get(req->headers_in, req_cfg->req_proto);
if (mc) {
if (mc->established &&
(auth_header == NULL) &&
(mc->auth_type != AUTH_TYPE_BASIC)) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
"Already established context found!");
mag_set_req_data(req, cfg, mc);
ret = OK;
goto done;
}
pctx = &mc->ctx;
} else {
/* no preserved mc, create one just for this request */
mc = mag_new_conn_ctx(req->pool);
pctx = &ctx;
}
/* We can proceed only if we do have an auth header */
if (!auth_header) goto done;
auth_header_type = ap_getword_white(req->pool, &auth_header);
if (!auth_header_type) goto done;
/* We got auth header, sending auth header would mean re-auth */
send_auth_header = !cfg->negotiate_once;
for (i = 0; auth_types[i] != NULL; i++) {
if (strcasecmp(auth_header_type, auth_types[i]) == 0) {
auth_type = i;
break;
}
}
switch (auth_type) {
case AUTH_TYPE_NEGOTIATE:
if (!parse_auth_header(req->pool, &auth_header, &input)) {
goto done;
}
break;
case AUTH_TYPE_BASIC:
if (!cfg->use_basic_auth) {
goto done;
}
ba_pwd.value = ap_pbase64decode(req->pool, auth_header);
if (!ba_pwd.value) goto done;
ba_user.value = ap_getword_nulls_nc(req->pool,
(char **)&ba_pwd.value, ':');
if (!ba_user.value) goto done;
if (((char *)ba_user.value)[0] == '\0' ||
((char *)ba_pwd.value)[0] == '\0') {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req,
"Invalid empty user or password for Basic Auth");
goto done;
}
ba_user.length = strlen(ba_user.value);
ba_pwd.length = strlen(ba_pwd.value);
if (mc->is_preserved && mc->established &&
mag_basic_check(req_cfg, mc, ba_user, ba_pwd)) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
"Already established BASIC AUTH context found!");
mag_set_req_data(req, cfg, mc);
ret = OK;
goto done;
}
break;
case AUTH_TYPE_RAW_NTLM:
if (!is_mech_allowed(desired_mechs, gss_mech_ntlmssp,
cfg->gss_conn_ctx)) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
"NTLM Authentication is not allowed!");
goto done;
}
if (!parse_auth_header(req->pool, &auth_header, &input)) {
goto done;
}
desired_mechs = discard_const(gss_mech_set_ntlmssp);
break;
default:
goto done;
}
if (mc->established) {
/* if we are re-authenticating make sure the conn context
* is cleaned up so we do not accidentally reuse an existing
* established context */
mag_conn_clear(mc);
}
mc->auth_type = auth_type;
#ifdef HAVE_CRED_STORE
if (use_s4u2proxy(req_cfg)) {
cred_usage = GSS_C_BOTH;
}
#endif
if (auth_type == AUTH_TYPE_BASIC) {
if (mag_auth_basic(req, cfg, ba_user, ba_pwd,
&client, &mech_type,
&delegated_cred, &vtime)) {
goto complete;
}
goto done;
}
if (!mag_acquire_creds(req, cfg, desired_mechs,
cred_usage, &acquired_cred, NULL)) {
goto done;
}
if (auth_type == AUTH_TYPE_NEGOTIATE &&
cfg->allowed_mechs != GSS_C_NO_OID_SET) {
maj = gss_set_neg_mechs(&min, acquired_cred, cfg->allowed_mechs);
if (GSS_ERROR(maj)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req, "%s",
mag_error(req, "gss_set_neg_mechs() failed",
maj, min));
goto done;
}
}
maj = gss_accept_sec_context(&min, pctx, acquired_cred,
&input, GSS_C_NO_CHANNEL_BINDINGS,
&client, &mech_type, &output, NULL, &vtime,
&delegated_cred);
if (GSS_ERROR(maj)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req, "%s",
mag_error(req, "gss_accept_sec_context() failed",
maj, min));
goto done;
} else if (maj == GSS_S_CONTINUE_NEEDED) {
if (!mc->is_preserved) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req,
"Mechanism needs continuation but neither "
"GssapiConnectionBound nor "
"GssapiUseSessions are available");
gss_release_buffer(&min, &output);
output.length = 0;
}
/* auth not complete send token and wait next packet */
goto done;
}
complete:
maj = gss_display_name(&min, client, &name, NULL);
if (GSS_ERROR(maj)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req, "%s",
mag_error(req, "gss_display_name() failed",
maj, min));
goto done;
}
mc->gss_name = apr_pstrndup(req->pool, name.value, name.length);
if (vtime == GSS_C_INDEFINITE || vtime < MIN_SESS_EXP_TIME) {
vtime = MIN_SESS_EXP_TIME;
}
mc->expiration = time(NULL) + vtime;
mag_get_name_attributes(req, cfg, client, mc);
#ifdef HAVE_CRED_STORE
if (cfg->deleg_ccache_dir && delegated_cred != GSS_C_NO_CREDENTIAL) {
char *ccache_path;
mc->ccname = 0;
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
"requester: %s", mc->gss_name);
ccache_path = get_ccache_name(req, cfg->deleg_ccache_dir, mc->gss_name,
cfg->deleg_ccache_unique, mc);
if (ccache_path == NULL) {
goto done;
}
mag_store_deleg_creds(req, ccache_path, delegated_cred);
mc->delegated = true;
if (!req_cfg->use_sessions && cfg->deleg_ccache_unique) {
/* queue removing ccache to avoid littering filesystem */
apr_pool_cleanup_register(mc->pool, ccache_path,
(int (*)(void *)) unlink,
apr_pool_cleanup_null);
}
/* extract filename from full path */
mc->ccname = strrchr(ccache_path, '/') + 1;
}
#endif
if (cfg->map_to_local) {
maj = gss_localname(&min, client, mech_type, &lname);
if (maj != GSS_S_COMPLETE) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, req, "%s",
mag_error(req, "gss_localname() failed", maj, min));
goto done;
}
mc->user_name = apr_pstrndup(req->pool, lname.value, lname.length);
} else {
mc->user_name = apr_pstrdup(mc->pool, mc->gss_name);
}
mc->established = true;
if (auth_type == AUTH_TYPE_BASIC) {
mag_basic_cache(req_cfg, mc, ba_user, ba_pwd);
}
if (req_cfg->use_sessions) {
mag_attempt_session(req_cfg, mc);
}
/* Now set request data and env vars */
mag_set_req_data(req, cfg, mc);
if (req_cfg->send_persist)
apr_table_set(req->headers_out, "Persistent-Auth",
cfg->gss_conn_ctx ? "true" : "false");
ret = OK;
done:
if ((auth_type != AUTH_TYPE_BASIC) && (output.length != 0)) {
int prefixlen = strlen(mag_str_auth_type(auth_type)) + 1;
replen = apr_base64_encode_len(output.length) + 1;
reply = apr_pcalloc(req->pool, prefixlen + replen);
if (reply) {
memcpy(reply, mag_str_auth_type(auth_type), prefixlen - 1);
reply[prefixlen - 1] = ' ';
apr_base64_encode(&reply[prefixlen], output.value, output.length);
apr_table_add(req->err_headers_out, req_cfg->rep_proto, reply);
}
} else if (ret == HTTP_UNAUTHORIZED) {
if (send_auth_header) {
apr_table_add(req->err_headers_out,
req_cfg->rep_proto, "Negotiate");
if (is_mech_allowed(desired_mechs, gss_mech_ntlmssp,
cfg->gss_conn_ctx)) {
apr_table_add(req->err_headers_out, req_cfg->rep_proto,
"NTLM");
}
}
if (cfg->use_basic_auth) {
apr_table_add(req->err_headers_out, req_cfg->rep_proto,
apr_psprintf(req->pool, "Basic realm=\"%s\"",
ap_auth_name(req)));
}
}
if (ctx != GSS_C_NO_CONTEXT)
gss_delete_sec_context(&min, &ctx, GSS_C_NO_BUFFER);
gss_release_cred(&min, &acquired_cred);
gss_release_cred(&min, &delegated_cred);
gss_release_buffer(&min, &output);
gss_release_name(&min, &client);
gss_release_buffer(&min, &name);
gss_release_buffer(&min, &lname);
return ret;
}
