1 /* Copyright (C) 2014 mod_auth_gssapi authors - See COPYING for (C) terms */
3 #include "mod_auth_gssapi.h"
4 #include "asn1c/GSSSessionData.h"
6 APLOG_USE_MODULE(auth_gssapi);
8 static APR_OPTIONAL_FN_TYPE(ap_session_load) *mag_sess_load_fn = NULL;
9 static APR_OPTIONAL_FN_TYPE(ap_session_get) *mag_sess_get_fn = NULL;
10 static APR_OPTIONAL_FN_TYPE(ap_session_set) *mag_sess_set_fn = NULL;
12 void mag_post_config_session(void)
14 mag_sess_load_fn = APR_RETRIEVE_OPTIONAL_FN(ap_session_load);
15 mag_sess_get_fn = APR_RETRIEVE_OPTIONAL_FN(ap_session_get);
16 mag_sess_set_fn = APR_RETRIEVE_OPTIONAL_FN(ap_session_set);
19 static apr_status_t mag_session_load(request_rec *req, session_rec **sess)
21 if (mag_sess_load_fn) {
22 return mag_sess_load_fn(req, sess);
27 static apr_status_t mag_session_get(request_rec *req, session_rec *sess,
28 const char *key, const char **value)
30 if (mag_sess_get_fn) {
31 return mag_sess_get_fn(req, sess, key, value);
36 static apr_status_t mag_session_set(request_rec *req, session_rec *sess,
37 const char *key, const char *value)
39 if (mag_sess_set_fn) {
40 return mag_sess_set_fn(req, sess, key, value);
45 static bool encode_GSSSessionData(apr_pool_t *mempool,
46 GSSSessionData_t *gsessdata,
47 unsigned char **buf, int *len)
50 unsigned char *buffer = NULL;
54 /* dry run to compute the size */
55 rval = der_encode(&asn_DEF_GSSSessionData, gsessdata, NULL, NULL);
56 if (rval.encoded == -1) goto done;
58 buflen = rval.encoded;
59 buffer = apr_pcalloc(mempool, buflen);
62 rval = der_encode_to_buffer(&asn_DEF_GSSSessionData,
63 gsessdata, buffer, buflen);
64 if (rval.encoded == -1) goto done;
74 static GSSSessionData_t *decode_GSSSessionData(void *buf, size_t len)
76 GSSSessionData_t *gsessdata = NULL;
79 rval = ber_decode(NULL, &asn_DEF_GSSSessionData,
80 (void **)&gsessdata, buf, len);
81 if (rval.code == RC_OK) {
87 #define MAG_BEARER_KEY "MagBearerToken"
89 void mag_check_session(struct mag_req_cfg *cfg, struct mag_conn **conn)
91 request_rec *req = cfg->req;
94 session_rec *sess = NULL;
95 const char *sessval = NULL;
97 struct databuf ctxbuf = { 0 };
98 struct databuf cipherbuf = { 0 };
99 GSSSessionData_t *gsessdata;
102 rc = mag_session_load(req, &sess);
103 if (rc != OK || sess == NULL) {
104 ap_log_rerror(APLOG_MARK, APLOG_INFO|APLOG_NOERRNO, 0, req,
105 "Sessions not available, no cookies!");
111 *conn = mc = mag_new_conn_ctx(req->pool);
112 mc->is_preserved = true;
115 rc = mag_session_get(req, sess, MAG_BEARER_KEY, &sessval);
117 ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
118 "Failed to get session data!");
122 /* no session established, just return */
126 if (!cfg->mag_skey) {
127 ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, req,
128 "Session key not available, no cookies!");
129 /* we do not have a key, just return */
134 declen = apr_base64_decode_len(sessval);
135 cipherbuf.value = apr_palloc(req->pool, declen);
136 if (!cipherbuf.value) return;
137 cipherbuf.length = (int)apr_base64_decode((char *)cipherbuf.value, sessval);
139 rc = UNSEAL_BUFFER(req->pool, cfg->mag_skey, &cipherbuf, &ctxbuf);
141 ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
142 "Failed to unseal session data!");
146 gsessdata = decode_GSSSessionData(ctxbuf.value, ctxbuf.length);
148 ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
149 "Failed to unpack session data!");
154 if (gsessdata->established != 0) mc->established = true;
155 if (gsessdata->delegated != 0) mc->delegated = true;
158 expiration = gsessdata->expiration;
159 if (expiration < time(NULL)) {
160 /* credentials fully expired, return nothing */
161 mc->established = false;
166 mc->user_name = apr_pstrndup(mc->pool,
167 (char *)gsessdata->username.buf,
168 gsessdata->username.size);
169 if (!mc->user_name) goto done;
172 mc->gss_name = apr_pstrndup(mc->pool,
173 (char *)gsessdata->gssname.buf,
174 gsessdata->gssname.size);
175 if (!mc->gss_name) goto done;
177 mc->basic_hash.length = gsessdata->basichash.size;
178 mc->basic_hash.value = apr_palloc(mc->pool, mc->basic_hash.length);
179 memcpy(mc->basic_hash.value,
180 gsessdata->basichash.buf, gsessdata->basichash.size);
182 /* OK we have a valid token */
183 mc->established = true;
186 ASN_STRUCT_FREE(asn_DEF_GSSSessionData, gsessdata);
189 void mag_attempt_session(struct mag_req_cfg *cfg, struct mag_conn *mc)
191 request_rec *req = cfg->req;
192 session_rec *sess = NULL;
193 struct databuf plainbuf = { 0 };
194 struct databuf cipherbuf = { 0 };
195 struct databuf ctxbuf = { 0 };
196 GSSSessionData_t gsessdata = { 0 };
200 /* we save the session only if the authentication is established */
202 if (!mc->established) return;
203 rc = mag_session_load(req, &sess);
204 if (rc != OK || sess == NULL) {
205 ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, req,
206 "Sessions not available, can't send cookies!");
210 if (!cfg->mag_skey) {
211 ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, req,
212 "Session key not available, aborting.");
216 gsessdata.established = mc->established?1:0;
217 gsessdata.delegated = mc->delegated?1:0;
218 gsessdata.expiration = mc->expiration;
219 if (OCTET_STRING_fromString(&gsessdata.username, mc->user_name) != 0)
221 if (OCTET_STRING_fromString(&gsessdata.gssname, mc->gss_name) != 0)
223 if (OCTET_STRING_fromBuf(&gsessdata.basichash,
224 (const char *)mc->basic_hash.value,
225 mc->basic_hash.length) != 0)
227 ret = encode_GSSSessionData(req->pool, &gsessdata,
228 &plainbuf.value, &plainbuf.length);
230 ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
231 "Failed to pack session data!");
235 rc = SEAL_BUFFER(req->pool, cfg->mag_skey, &plainbuf, &cipherbuf);
237 ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
238 "Failed to seal session data!");
242 ctxbuf.length = apr_base64_encode_len(cipherbuf.length);
243 ctxbuf.value = apr_pcalloc(req->pool, ctxbuf.length);
244 if (!ctxbuf.value) goto done;
246 ctxbuf.length = apr_base64_encode((char *)ctxbuf.value,
247 (char *)cipherbuf.value,
250 rc = mag_session_set(req, sess, MAG_BEARER_KEY, (char *)ctxbuf.value);
252 ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
253 "Failed to set session data!");
257 ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_GSSSessionData, &gsessdata);
260 static int mag_basic_hmac(struct seal_key *key, unsigned char *mac,
261 gss_buffer_desc user, gss_buffer_desc pwd)
263 struct databuf hmacbuf = { mac, 0 };
264 int data_size = user.length + pwd.length + 1;
265 unsigned char data[data_size];
266 struct databuf databuf = { data, data_size };
268 memcpy(data, user.value, user.length);
269 data[user.length] = '\0';
270 memcpy(&data[user.length + 1], pwd.value, pwd.length);
272 return HMAC_BUFFER(key, &databuf, &hmacbuf);
275 static int mag_get_mac_size(struct mag_req_cfg *cfg)
277 if (!cfg->mag_skey) {
278 ap_log_perror(APLOG_MARK, APLOG_INFO, 0, cfg->cfg->pool,
279 "Session key not available, aborting!");
283 return get_mac_size(cfg->mag_skey);
286 bool mag_basic_check(struct mag_req_cfg *cfg, struct mag_conn *mc,
287 gss_buffer_desc user, gss_buffer_desc pwd)
289 int mac_size = mag_get_mac_size(cfg);
290 unsigned char mac[mac_size];
294 if (mac_size == 0) return false;
295 if (mc->basic_hash.value == NULL) return false;
297 ret = mag_basic_hmac(cfg->mag_skey, mac, user, pwd);
298 if (ret != 0) goto done;
300 for (i = 0, j = 0; i < mac_size; i++) {
301 if (mc->basic_hash.value[i] != mac[i]) j++;
303 if (j == 0) res = true;
307 mc->basic_hash.value = NULL;
308 mc->basic_hash.length = 0;
313 void mag_basic_cache(struct mag_req_cfg *cfg, struct mag_conn *mc,
314 gss_buffer_desc user, gss_buffer_desc pwd)
316 int mac_size = mag_get_mac_size(cfg);
317 unsigned char mac[mac_size];
320 ret = mag_basic_hmac(cfg->mag_skey, mac, user, pwd);
321 if (ret != 0) return;
323 mc->basic_hash.length = mac_size;
324 mc->basic_hash.value = apr_palloc(mc->pool, mac_size);
325 memcpy(mc->basic_hash.value, mac, mac_size);