lib: Move encryption control from QoS to name

This removes the flow encryption option (cypher_s) from the qosspec.

The configuration file is configured in the security options (default
/etc/ouroboros/security/). For this poc, encryption can be disabled
client or server side by putting an enc.cfg file. If that file is
present in the client folder, the client will require encryption. If
that file is present on the server side, the server will require
encryption and reject non-encrypted flows.

Encryption is now configured outside of any application control.

Example: /etc/ouroboros/security/client/oping/enc.cfg exists:

irmd(II): Encryption enabled for oping.
irmd(DB): File /etc/ouroboros/security/client/oping/crt.pem does not exist.
irmd(II): No security info for oping.
irmd(DB): Generated ephemeral keys for 87474.
irmd/oap(PP): OAP_HDR [caf203681d997941 @ 2025-09-02 17:08:05 (UTC) ] -->
irmd/oap(PP):   Certificate: <none>
irmd/oap(PP):   Ephemeral Public Key: [91 bytes]
irmd/oap(PP):   Data: <none>
irmd/oap(PP):   Signature: <none>

Example: /etc/ouroboros/security/client/oping/enc.cfg does not exist:

irmd(II): Allocating flow for 87506 to oping.
irmd(DB): File /etc/ouroboros/security/client/oping/enc.cfg does not exist.
irmd(DB): File /etc/ouroboros/security/client/oping/crt.pem does not exist.
irmd(II): No security info for oping.
irmd/oap(PP): OAP_HDR [e84bb9d7c3d9c002 @ 2025-09-02 17:08:30 (UTC) ] -->
irmd/oap(PP):   Certificate: <none>
irmd/oap(PP):   Ephemeral Public Key: <none>
irmd/oap(PP):   Data: <none>
irmd/oap(PP):   Signature: <none>

Example: /etc/ouroboros/security/server/oping/enc.cfg exists:

irmd(II): Flow request arrived for oping.
irmd(DB): IPCP 88112 accepting flow 7 for oping.
irmd(II): Encryption enabled for oping.
irmd(DB): File /etc/ouroboros/security/server/oping/crt.pem does not exist.
irmd(II): No security info for oping.
irmd/oap(PP): OAP_HDR [3c717b3f31dff8df @ 2025-09-02 17:13:06 (UTC) ] <--
irmd/oap(PP):   Certificate: <none>
irmd/oap(PP):   Ephemeral Public Key: <none>
irmd/oap(PP):   Data: <none>
irmd/oap(PP):   Signature: <none>
irmd(WW): Encryption required but no key provided.

The server side will pass the ECRYPT to the client:
$ oping -l
Ouroboros ping server started.
Failed to accept flow: -1008

$ oping -n oping -c 1
Failed to allocate flow: -1008.

Encryption on flows can now be changed at runtime without needing to
touch/reconfigure/restart the process.

Note: The ECRYPT result is passed on via the flow allocator responses
through the IPCP (discovered/fixed some endianness issues), but the
reason for rejecting the flow can be considered N+1 information... We
may move that information up into the OAP header at some point.

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

1 files changed, 72 insertions, 45 deletions

diff --git a/src/irmd/main.c b/src/irmd/main.c
index 05f9236f..834a7a8c 100644
--- a/src/irmd/main.c
+++ b/src/irmd/main.c
@@ -455,12 +455,18 @@ static void name_update_sec_paths(struct name_info * info)
 
         assert(info != NULL);
 
+        if (strlen(info->s.enc) == 0)
+                sprintf(info->s.enc, "%s/%s/enc.cfg", srv_dir, info->name);
+
         if (strlen(info->s.crt) == 0)
                 sprintf(info->s.crt, "%s/%s/crt.pem", srv_dir, info->name);
 
         if (strlen(info->s.key) == 0)
                 sprintf(info->s.key, "%s/%s/key.pem", srv_dir, info->name);
 
+        if (strlen(info->c.enc) == 0)
+                sprintf(info->c.enc, "%s/%s/enc.cfg", cli_dir, info->name);
+
         if (strlen(info->c.crt) == 0)
                 sprintf(info->c.crt, "%s/%s/crt.pem", cli_dir, info->name);
 
@@ -816,7 +822,8 @@ static bool file_exists(const char * path)
 static int load_credentials(const char *                  name,
                             const struct name_sec_paths * paths,
                             void **                       pkp,
-                            void **                       crt)
+                            void **                       crt,
+                            bool *                        crypt)
 {
         assert(paths != NULL);
         assert(pkp != NULL);
@@ -825,6 +832,11 @@ static int load_credentials(const char *                  name,
         *pkp = NULL;
         *crt = NULL;
 
+        /* TODO: Allow configuration. For now, encrypt if path exists */
+        *crypt = file_exists(paths->enc);
+        if (*crypt)
+                log_info("Encryption enabled for %s.", name);
+
         if (!file_exists(paths->crt) || !file_exists(paths->key)) {
                 log_info("No security info for %s.", name);
                 return 0;
@@ -853,7 +865,8 @@ static int load_credentials(const char *                  name,
 
 static int load_srv_credentials(const char * name,
                                 void **      pkp,
-                                void **      crt)
+                                void **      crt,
+                                bool *       crypt)
 {
         struct name_info info;
 
@@ -866,12 +879,13 @@ static int load_srv_credentials(const char * name,
                 return -ENAME;
         }
 
-        return load_credentials(name, &info.s, pkp, crt);
+        return load_credentials(name, &info.s, pkp, crt, crypt);
 }
 
 static int load_cli_credentials(const char * name,
                                 void **      pkp,
-                                void **      crt)
+                                void **      crt,
+                                bool *       crypt)
 {
         struct name_info info;
 
@@ -884,7 +898,7 @@ static int load_cli_credentials(const char * name,
                 return -ENAME;
         }
 
-        return load_credentials(name, &info.c, pkp, crt);
+        return load_credentials(name, &info.c, pkp, crt, crypt);
 }
 
 #define ID_IS_EQUAL(id1, id2) (memcmp(id1, id2, OAP_ID_SIZE) == 0)
@@ -1029,14 +1043,15 @@ static int flow_accept(struct flow_info * flow,
                        buffer_t *         data,
                        struct timespec *  abstime)
 {
-        struct oap_hdr   oap_hdr;             /* incoming request           */
-        struct oap_hdr   r_oap_hdr;           /* outgoing response          */
-        uint8_t          buf[MSGBUFSZ];       /* buffer for local ephkey    */
-        buffer_t         lpk = BUF_INIT;      /* local ephemeral pubkey     */
-        char             name[NAME_SIZE + 1]; /* name for flow              */
-        void *           pkp = NULL;          /* signing private key        */
-        void *           crt = NULL;          /* signing certificate        */
-        int              err;
+        struct oap_hdr oap_hdr;             /* incoming request           */
+        struct oap_hdr r_oap_hdr;           /* outgoing response          */
+        uint8_t        buf[MSGBUFSZ];       /* buffer for local ephkey    */
+        buffer_t       lpk = BUF_INIT;      /* local ephemeral pubkey     */
+        char           name[NAME_SIZE + 1]; /* name for flow              */
+        void *         pkp = NULL;          /* signing private key        */
+        void *         crt = NULL;          /* signing certificate        */
+        int            err;
+        bool           crypt;
 
         /* piggyback of user data not yet implemented */
         assert(data != NULL && BUF_IS_EMPTY(data));
@@ -1082,12 +1097,18 @@ static int flow_accept(struct flow_info * flow,
         if (reg_get_name_for_flow_id(name, flow->id) < 0) {
                 log_err("Failed to get name for flow %d.", flow->id);
                 err = -EIPCP;
-                goto fail_oap_hdr;
+                goto fail_cred;
         }
 
         log_dbg("IPCP %d accepting flow %d for %s.",
                  flow->n_pid, flow->id, name);
 
+        if (load_srv_credentials(name, &pkp, &crt, &crypt) < 0) {
+                log_err("Failed to load security keys for %s.", name);
+                err = -EAUTH;
+                goto fail_cred;
+        }
+
         if (oap_hdr_decode(oap_hdr.hdr, &oap_hdr) < 0) {
                 log_err("Failed to decode OAP header from %s.", name);
                 err = -EIPCP;
@@ -1101,10 +1122,16 @@ static int flow_accept(struct flow_info * flow,
                 goto fail_oap_hdr;
         }
 
-        if (flow->qs.cypher_s != 0) {     /* crypto requested           */
-                uint8_t * s;              /* symmetric encryption key   */
-                ssize_t   key_len;        /* length of local pubkey     */
-                void *    pkp = NULL;     /* ephemeral private key pair */
+        if (crypt && oap_hdr.eph.len == 0) {
+                log_warn("Encryption required but no key provided.");
+                err = -ECRYPT;
+                goto fail_oap_hdr;
+        }
+
+        if (oap_hdr.eph.len > 0) {    /* crypto requested           */
+                uint8_t * s;          /* symmetric encryption key   */
+                ssize_t   key_len;    /* length of local pubkey     */
+                void *    pkp = NULL; /* ephemeral private key pair */
 
                 s = malloc(SYMMKEYSZ);
                 if (s == NULL) {
@@ -1140,12 +1167,6 @@ static int flow_accept(struct flow_info * flow,
                 crypt_dh_pkp_destroy(pkp);
         }
 
-        if (load_srv_credentials(name, &pkp, &crt) < 0) {
-                log_err("Failed to load security keys for %s.", name);
-                err = -EAUTH;
-                goto fail_cred;
-        }
-
         if (oap_hdr_init(oap_hdr.id, pkp, crt, lpk, *data, &r_oap_hdr) < 0) {
                 log_err("Failed to create OAP header.");
                 err = -ENOMEM;
@@ -1178,15 +1199,15 @@ static int flow_accept(struct flow_info * flow,
         return 0;
 
  fail_r_oap_hdr:
-        crypt_free_crt(crt);
-        crypt_free_key(pkp);
- fail_cred:
         freebuf(*symmkey);
  fail_derive:
         clrbuf(lpk);
  fail_keys:
         oap_hdr_fini(&oap_hdr);
  fail_oap_hdr:
+        crypt_free_crt(crt);
+        crypt_free_key(pkp);
+ fail_cred:
         assert(lpk.data == NULL && lpk.len == 0);
         ipcp_flow_alloc_resp(flow, err, lpk);
  fail_wait:
@@ -1354,11 +1375,14 @@ static int flow_alloc(struct flow_info * flow,
         uint8_t        idbuf[OAP_ID_SIZE];
         buffer_t       id;
         int            err;
+        bool           crypt;
 
         /* piggyback of user data not yet implemented */
         assert(data != NULL && BUF_IS_EMPTY(data));
         assert(symmkey != NULL && BUF_IS_EMPTY(symmkey));
 
+        log_info("Allocating flow for %d to %s.", flow->n_pid, dst);
+
         if (random_buffer(idbuf, OAP_ID_SIZE) < 0) {
                 log_err("Failed to generate ID.");
                 err = -EIRMD;
@@ -1368,7 +1392,13 @@ static int flow_alloc(struct flow_info * flow,
         id.data = idbuf;
         id.len  = OAP_ID_SIZE;
 
-        if (flow->qs.cypher_s > 0) {
+        if (load_cli_credentials(dst, &cpkp, &ccrt, &crypt) < 0) {
+                log_err("Failed to load security keys for %s.", dst);
+                err = -EAUTH;
+                goto fail_cred;
+        }
+
+        if (crypt > 0) {
                 ssize_t key_len;
 
                 s = malloc(SYMMKEYSZ);
@@ -1391,12 +1421,6 @@ static int flow_alloc(struct flow_info * flow,
                 log_dbg("Generated ephemeral keys for %d.", flow->n_pid);
         }
 
-        if (load_cli_credentials(dst, &cpkp, &ccrt) < 0) {
-                log_err("Failed to load security keys for %s.", dst);
-                err = -EAUTH;
-                goto fail_cred;
-        }
-
         if (oap_hdr_init(id, cpkp, ccrt, lpk, *data, &oap_hdr) < 0) {
                 log_err("Failed to create OAP header.");
                 err = -ENOMEM;
@@ -1405,9 +1429,6 @@ static int flow_alloc(struct flow_info * flow,
 #ifdef DEBUG_PROTO_OAP
         debug_oap_hdr_snd(&oap_hdr);
 #endif
-
-        log_info("Allocating flow for %d to %s.", flow->n_pid, dst);
-
         if (reg_create_flow(flow) < 0) {
                 log_err("Failed to create flow.");
                 err = -EBADF;
@@ -1447,11 +1468,16 @@ static int flow_alloc(struct flow_info * flow,
 
         if (err == -1) {
                 log_dbg("Flow allocation terminated.");
-                err = -EPIPE;
+                err = -EIPCP;
                 goto fail_alloc;
         }
 
-        assert(err == 0);
+        log_dbg("Response received for flow %d to %s.", flow->id, dst);
+
+        if (err < 0) {
+                log_warn("Flow allocation rejected for %s: %d.", dst, err);
+                goto fail_alloc;
+        }
 
         if (oap_hdr_decode(r_oap_hdr.hdr, &r_oap_hdr) < 0) {
                 log_err("Failed to decode OAP header.");
@@ -1463,6 +1489,7 @@ static int flow_alloc(struct flow_info * flow,
 #endif
         if (irm_check_oap_hdr(&r_oap_hdr, flow->mpl) < 0) {
                 log_err("OAP header failed replay check.");
+                err = -EAUTH;
                 goto fail_r_oap_hdr;
         }
 
@@ -1472,7 +1499,7 @@ static int flow_alloc(struct flow_info * flow,
                 goto fail_r_oap_hdr;
         }
 
-        if (flow->qs.cypher_s != 0) { /* crypto requested */
+        if (lpk.len > 0) { /* crypto requested */
                 if (crypt_dh_derive(pkp, r_oap_hdr.eph, s) < 0) {
                         log_err("Failed to derive secret for %d.", flow->id);
                         err = -ECRYPT;
@@ -1508,13 +1535,13 @@ static int flow_alloc(struct flow_info * flow,
  fail_flow:
         oap_hdr_fini(&oap_hdr);
  fail_oap_hdr:
-        crypt_free_crt(ccrt);
-        crypt_free_key(cpkp);
- fail_cred:
         crypt_dh_pkp_destroy(pkp);
  fail_pkp:
         free(s);
  fail_malloc:
+        crypt_free_crt(ccrt);
+        crypt_free_key(cpkp);
+ fail_cred:
         clrbuf(id);
  fail_id:
         return err;
@@ -1616,9 +1643,9 @@ static int flow_alloc_reply(struct flow_info * flow,
                             int                response,
                             buffer_t *         data)
 {
-        flow->state = response ? FLOW_DEALLOCATED : FLOW_ALLOCATED;
+        flow->state = response != 0 ? FLOW_DEALLOCATED : FLOW_ALLOCATED;
 
-        if (reg_respond_alloc(flow, data) < 0) {
+        if (reg_respond_alloc(flow, data, response) < 0) {
                 log_err("Failed to reply to flow %d.", flow->id);
                 flow->state = FLOW_DEALLOCATED;
                 return -EBADF;