Custom user callbacks (custom requests)

src/wh_client.c

@@ -23,6 +23,7 @@
 /* Message definitions */
 #include "wolfhsm/wh_message.h"
 #include "wolfhsm/wh_message_comm.h"
+#include "wolfhsm/wh_message_customcb.h"
 
 #include "wolfhsm/wh_client.h"
 
@@ -34,7 +35,7 @@ int wh_Client_Init(whClientContext* c, const whClientConfig* config)
     }
 
     memset(c, 0, sizeof(*c));
-    
+
     if (    ((rc = wh_CommClient_Init(c->comm, config->comm)) == 0) &&
             ((rc = wolfCrypt_Init()) == 0) &&
             ((rc = wc_CryptoCb_RegisterDevice(WOLFHSM_DEV_ID, wolfHSM_CryptoCb, c)) == 0) &&
@@ -201,3 +202,110 @@ int wh_Client_Echo(whClientContext* c, uint16_t snd_len, const void* snd_data,
     return rc;
 }
 
+int wh_Client_CustomCbRequest(whClientContext* c, const whMessageCustomCb_Request* req)
+{
+    if (NULL == c || req == NULL || req->id >= WH_CUSTOM_CB_NUM_CALLBACKS) {
+        return WH_ERROR_BADARGS;
+    }
+
+    return wh_Client_SendRequest(c, WH_MESSAGE_GROUP_CUSTOM, req->id,
+                                 sizeof(*req), req);
+}
+
+int wh_Client_CustomCbResponse(whClientContext*          c,
+                             whMessageCustomCb_Response* outResp)
+{
+    whMessageCustomCb_Response resp;
+    uint16_t                 resp_group  = 0;
+    uint16_t                 resp_action = 0;
+    uint16_t                 resp_size   = 0;
+    int32_t                  rc          = 0;
+
+    if (NULL == c || outResp == NULL) {
+        return WH_ERROR_BADARGS;
+    }
+
+    rc =
+        wh_Client_RecvResponse(c, &resp_group, &resp_action, &resp_size, &resp);
+    if (rc != WH_ERROR_OK) {
+        return rc;
+    }
+
+    if (resp_size != sizeof(resp) || resp_group != WH_MESSAGE_GROUP_CUSTOM ||
+        resp_action >= WH_CUSTOM_CB_NUM_CALLBACKS) {
+        /* message invalid */
+        return WH_ERROR_ABORTED;
+    }
+
+    memcpy(outResp, &resp, sizeof(resp));
+
+    return WH_ERROR_OK;
+}
+
+int wh_Client_CustomCheckRegisteredRequest(whClientContext* c, uint32_t id)
+{
+    whMessageCustomCb_Request req = {0};
+
+    if (c == NULL || id >= WH_CUSTOM_CB_NUM_CALLBACKS) {
+        return WH_ERROR_BADARGS;
+    }
+
+    req.id = id;
+    req.type = WH_MESSAGE_CUSTOM_CB_TYPE_QUERY;
+
+    return wh_Client_SendRequest(c, WH_MESSAGE_GROUP_CUSTOM, req.id,
+                                 sizeof(req), &req);
+}
+
+
+int wh_Client_CustomCbCheckRegisteredResponse(whClientContext* c, uint16_t* outId, int* responseError)
+{
+    int rc = 0;
+    whMessageCustomCb_Response resp = {0};
+
+    if (c == NULL || outId == NULL || responseError == NULL) {
+        return WH_ERROR_BADARGS;
+    }
+
+    rc = wh_Client_CustomCbResponse(c, &resp);
+    if (rc != WH_ERROR_OK) {
+        return rc;
+    }
+
+    if (resp.type != WH_MESSAGE_CUSTOM_CB_TYPE_QUERY) {
+        /* message invalid */
+        return WH_ERROR_ABORTED;
+    }
+
+    if (resp.err != WH_ERROR_OK && resp.err != WH_ERROR_NO_HANDLER) {
+        /* error codes that aren't related to the query should be fatal */
+        return WH_ERROR_ABORTED;
+    }
+
+    *outId = resp.id;
+    *responseError = resp.err;
+
+    return WH_ERROR_OK;
+}
+
+
+int wh_Client_CustomCbCheckRegistered(whClientContext* c, uint16_t id, int* responseError)
+{
+    int rc = 0;
+
+    if (NULL == c || NULL == responseError || id >= WH_CUSTOM_CB_NUM_CALLBACKS) {
+        return WH_ERROR_BADARGS;
+    }
+
+    do {
+        rc = wh_Client_CustomCheckRegisteredRequest(c, id);
+    } while (rc == WH_ERROR_NOTREADY);
+
+    if (rc == WH_ERROR_OK) {
+        do {
+            rc = wh_Client_CustomCbCheckRegisteredResponse(c, &id, responseError);
+        } while (rc == WH_ERROR_NOTREADY);
+    }
+
+    return rc;
+}

src/wh_message_customcb.c

@@ -0,0 +1,84 @@
+#include <stddef.h>
+#include <string.h>
+
+#include "wolfhsm/wh_message_customcb.h"
+#include "wolfhsm/wh_error.h"
+#include "wolfhsm/wh_comm.h"
+
+
+static void _translateCustomData(uint16_t magic, uint32_t translatedType,
+                                 const whMessageCustomCb_Data* src,
+                                 whMessageCustomCb_Data*       dst)
+{
+    if (translatedType < WH_MESSAGE_CUSTOM_CB_TYPE_USER_DEFINED_START) {
+        switch (translatedType) {
+            case WH_MESSAGE_CUSTOM_CB_TYPE_QUERY: {
+                /* right now, no further translations required */
+            } break;
+            case WH_MESSAGE_CUSTOM_CB_TYPE_DMA32: {
+                dst->dma32.client_addr =
+                    wh_Translate32(magic, src->dma32.client_addr);
+                dst->dma32.client_sz =
+                    wh_Translate32(magic, src->dma32.client_sz);
+                dst->dma32.server_addr =
+                    wh_Translate32(magic, src->dma32.server_addr);
+                dst->dma32.server_sz =
+                    wh_Translate32(magic, src->dma32.server_sz);
+            } break;
+            case WH_MESSAGE_CUSTOM_CB_TYPE_DMA64: {
+                dst->dma64.client_addr =
+                    wh_Translate64(magic, src->dma64.client_addr);
+                dst->dma64.client_sz =
+                    wh_Translate64(magic, src->dma64.client_sz);
+                dst->dma64.server_addr =
+                    wh_Translate64(magic, src->dma64.server_addr);
+                dst->dma64.server_sz =
+                    wh_Translate64(magic, src->dma64.server_sz);
+            } break;
+            default: {
+                /* reserved message types - no translation for now */
+            } break;
+        }
+    }
+    else {
+        /* use memmove in case data is translated "in place" */
+        memmove(dst->buffer.data, src->buffer.data, sizeof(dst->buffer.data));
+    }
+}
+
+
+int wh_MessageCustomCb_TranslateRequest(uint16_t                         magic,
+                                        const whMessageCustomCb_Request* src,
+                                        whMessageCustomCb_Request*       dst)
+{
+    if ((src == NULL) || (dst == NULL)) {
+        return WH_ERROR_BADARGS;
+    }
+
+    dst->id   = wh_Translate32(magic, src->id);
+    dst->type = wh_Translate32(magic, src->type);
+    _translateCustomData(magic, dst->type, &src->data, &dst->data);
+
+    return WH_ERROR_OK;
+}
+
+
+int wh_MessageCustomCb_TranslateResponse(uint16_t magic,
+                                         const whMessageCustomCb_Response* src,
+                                         whMessageCustomCb_Response*       dst)
+{
+    if ((src == NULL) || (dst == NULL)) {
+        return WH_ERROR_BADARGS;
+    }
+
+    dst->rc  = wh_Translate32(magic, src->rc);
+    dst->err = wh_Translate32(magic, src->err);
+
+    /* TODO: should we continue to translate responses for err != 0?
+     * Probably still should...*/
+    dst->id   = wh_Translate32(magic, src->id);
+    dst->type = wh_Translate32(magic, src->type);
+    _translateCustomData(magic, dst->type, &src->data, &dst->data);
+
+    return WH_ERROR_OK;
+}

src/wh_server.c

@@ -18,8 +18,8 @@
 
 /* Server API's */
 #include "wolfhsm/wh_server.h"
-#include "wolfhsm/wh_server_crypto.h"
 #include "wolfhsm/wh_server_internal.h"
+#include "wolfhsm/wh_server_crypto.h"
 #if defined(WOLFHSM_SHE_EXTENSION)
 #include "wolfhsm/wh_server_she.h"
 #endif
@@ -44,11 +44,6 @@ static int _wh_Server_HandleSheRequest(whServerContext* server,
         uint16_t req_size, const void* req_packet,
         uint16_t *out_resp_size, void* resp_packet);
 #endif
-static int _wh_Server_HandleCustomRequest(whServerContext* server,
-        uint16_t magic, uint16_t action, uint16_t seq,
-        uint16_t req_size, const void* req_packet,
-        uint16_t *out_resp_size, void* resp_packet);
-
 
 int wh_Server_Init(whServerContext* server, whServerConfig* config)
 {
@@ -215,20 +210,7 @@ static int _wh_Server_HandleSheRequest(whServerContext* server,
 }
 #endif
 
-static int _wh_Server_HandleCustomRequest(whServerContext* server,
-        uint16_t magic, uint16_t action, uint16_t seq,
-        uint16_t req_size, const void* req_packet,
-        uint16_t *out_resp_size, void* resp_packet)
-{
-    int rc = 0;
-    switch (action) {
-    /* TODO: Add custom/user callback message handling here */
-    default:
-        /* Unknown request. Respond with empty packet */
-        *out_resp_size = 0;
-    }
-    return rc;
-}
+
 
 int wh_Server_HandleRequestMessage(whServerContext* server)
 {
@@ -266,11 +248,11 @@ int wh_Server_HandleRequestMessage(whServerContext* server)
             rc = _wh_Server_HandleKeyRequest(server, magic, action, seq,
                     size, data, &size, data);
         break;
-        
+
         case WH_MESSAGE_GROUP_CRYPTO:
             rc = wh_Server_HandleCryptoRequest(server, action, data, &size);
         break;
-        
+
         case WH_MESSAGE_GROUP_PKCS11:
             rc = _wh_Server_HandlePkcs11Request(server, magic, action, seq,
                     size, data, &size, data);
@@ -283,7 +265,7 @@ int wh_Server_HandleRequestMessage(whServerContext* server)
 #endif
 
         case WH_MESSAGE_GROUP_CUSTOM:
-            rc = _wh_Server_HandleCustomRequest(server, magic, action, seq,
+            rc = wh_Server_HandleCustomCbRequest(server, magic, action, seq,
                     size, data, &size, data);
             break;
 

src/wh_server_customcb.c

@@ -0,0 +1,81 @@
+#include "wolfhsm/wh_server.h"
+#include "wolfhsm/wh_common.h"
+#include "wolfhsm/wh_error.h"
+#include "wolfhsm/wh_message.h"
+#include "wolfhsm/wh_message_customcb.h"
+
+
+int wh_Server_RegisterCustomCb(whServerContext* server, uint16_t action,
+                               whServerCustomCb handler)
+{
+    if (NULL == server || NULL == handler ||
+        action >= WH_CUSTOM_CB_NUM_CALLBACKS) {
+        return WH_ERROR_BADARGS;
+    }
+
+    server->customHandlerTable[action] = handler;
+
+    return WH_ERROR_OK;
+}
+
+
+int wh_Server_HandleCustomCbRequest(whServerContext* server, uint16_t magic,
+                                    uint16_t action, uint16_t seq,
+                                    uint16_t req_size, const void* req_packet,
+                                    uint16_t* out_resp_size, void* resp_packet)
+{
+    int                        rc   = 0;
+    whMessageCustomCb_Request  req  = {0};
+    whMessageCustomCb_Response resp = {0};
+
+    if (NULL == server || NULL == req_packet || NULL == resp_packet ||
+        out_resp_size == NULL) {
+        return WH_ERROR_BADARGS;
+    }
+
+    if (action >= WH_CUSTOM_CB_NUM_CALLBACKS) {
+        /* Invalid callback index  */
+        /* TODO: is this the appropriate error to return? */
+        return WH_ERROR_BADARGS;
+    }
+
+    if (req_size != sizeof(whMessageCustomCb_Request)) {
+        /* Request is malformed */
+        return WH_ERROR_ABORTED;
+    }
+
+    /* Translate the request */
+    if ((rc = wh_MessageCustomCb_TranslateRequest(magic, req_packet, &req)) !=
+        WH_ERROR_OK) {
+        return rc;
+    }
+
+    if (server->customHandlerTable[action] != NULL) {
+        /* If this isn't a query to check if the callback exists, invoke the
+         * registered callback, storing the return value in the reponse  */
+        if (req.type != WH_MESSAGE_CUSTOM_CB_TYPE_QUERY) {
+            resp.rc = server->customHandlerTable[action](server, &req, &resp);
+        }
+        /* TODO: propagate other wolfHSM error codes (requires modifiying caller
+         * function) once generic server code supports it */
+        resp.err = WH_ERROR_OK;
+    }
+    else {
+        /* No callback was registered, populate response error. We must
+         * return success to ensure the "error" response is sent  */
+        resp.err = WH_ERROR_NO_HANDLER;
+    }
+
+    /* tag response with requested callback ID for client-side bookkeeping*/
+    resp.id = req.id;
+
+    /* Translate the response */
+    if ((rc = wh_MessageCustomCb_TranslateResponse(
+             magic, &resp, resp_packet)) != WH_ERROR_OK) {
+        return rc;
+    }
+
+    *out_resp_size = sizeof(resp);
+
+    return WH_ERROR_OK;
+}

test/Makefile

@@ -80,11 +80,13 @@ SRC_C += \
             $(WOLFHSM_DIR)/src/wh_flash_unit.c \
             $(WOLFHSM_DIR)/src/wh_message_comm.c \
             $(WOLFHSM_DIR)/src/wh_message_nvm.c \
+            $(WOLFHSM_DIR)/src/wh_message_customcb.c \
             $(WOLFHSM_DIR)/src/wh_nvm.c \
             $(WOLFHSM_DIR)/src/wh_nvm_flash.c \
             $(WOLFHSM_DIR)/src/wh_server.c \
             $(WOLFHSM_DIR)/src/wh_server_nvm.c \
             $(WOLFHSM_DIR)/src/wh_server_crypto.c \
+            $(WOLFHSM_DIR)/src/wh_server_customcb.c \
             $(WOLFHSM_DIR)/src/wh_client_cryptocb.c \
             $(WOLFHSM_DIR)/src/wh_transport_mem.c \
             $(WOLFHSM_DIR)/src/wh_flash_ramsim.c