lws_system: auth token handling using buflist

include/libwebsockets/lws-system.h

@@ -81,16 +81,25 @@ typedef enum { /* keep system_state_names[] in sync in context.c */
 					  * LWS_SYSTATE_POLICY_VALID */
 } lws_system_states_t;
 
+typedef enum {
+	LWSSYS_AUTH_GET,
+	LWSSYS_AUTH_TOTAL_LENGTH,
+	LWSSYS_AUTH_APPEND,
+	LWSSYS_AUTH_FREE,
+} lws_system_auth_op_t;
+
+typedef int (*lws_system_auth_cb_t)(struct lws_context *context, int idx,
+				    size_t ofs, uint8_t *buf, size_t *plen,
+				    lws_system_auth_op_t set);
+
 typedef struct lws_system_ops {
 	int (*get_info)(lws_system_item_t i, lws_system_arg_t *arg);
 	int (*reboot)(void);
 	int (*set_clock)(lws_usec_t us);
-	int (*auth)(int idx, uint8_t *buf, size_t *plen, int set);
-	/**< Systemwide ephemeral auth tokens get or set... set *plen to max
-	 * size for get, will be set to actual size on return of 0, return 1
-	 * means token is too big for buffer.  idx is token index if multiple.
-	 * Auth tokens are potentially large, and should be stored as binary
-	 * and converted to a transport format like hex.  */
+	lws_system_auth_cb_t auth;
+	/**< Systemwide auth token management. For set, content may be appended
+	 * incrementally safely.  For get, content may be read out in arbitrary
+	 * fragments using \p ofs. */
 } lws_system_ops_t;
 
 /**
@@ -136,6 +145,7 @@ lws_system_get_info(struct lws_context *context, lws_system_item_t item,
  *
  * \param context: the lws_context
  * \param idx: which auth token
+ * \param ofs: offset in source to copy from
  * \param buf: where to store result, or NULL
  * \param buflen: size of buf
  * \param flags: how to write the result
@@ -148,8 +158,8 @@ lws_system_get_info(struct lws_context *context, lws_system_item_t item,
  * writing anything.  *buflen is still set to the size of the auth token.
  */
 LWS_EXTERN LWS_VISIBLE int
-lws_system_get_auth(struct lws_context *context, int idx, uint8_t *buf,
-		    size_t buflen, int flags);
+lws_system_get_auth(struct lws_context *context, int idx, size_t ofs,
+		    uint8_t *buf, size_t buflen, int flags);
 
 /**
  * lws_system_get_ops() - get ahold of the system ops struct from the context

lib/core/private-lib-core.h

@@ -309,6 +309,8 @@ struct lws_context {
 	lws_async_dns_t		async_dns;
 #endif
 
+	struct lws_buflist *auth_token[2];
+
 #if defined(LWS_WITH_NETWORK)
 	lws_state_manager_t		mgr_system;
 	lws_state_notify_link_t		protocols_notify;

lib/roles/h2/http2.c

@@ -2310,7 +2310,7 @@ lws_h2_client_handshake(struct lws *wsi)
 
 		strcpy((char *)q, "bearer ");
 
-		n = lws_system_get_auth(wsi->context, 0, q + 7,
+		n = lws_system_get_auth(wsi->context, 0, 0, q + 7,
 					lws_ptr_diff(qend, q + 7),
 					wsi->flags & LCCSCF_H2_HEXIFY_AUTH_TOKEN ?
 							LWSSYSGAUTH_HEX : 0);

lib/system/system.c

@@ -24,7 +24,9 @@
 
 #include <private-lib-core.h>
 
+#if defined(LWS_WITH_NETWORK)
 static const char *hex = "0123456789ABCDEF";
+#endif
 
 int
 lws_system_get_info(struct lws_context *context, lws_system_item_t item,
@@ -42,20 +44,68 @@ lws_system_get_ops(struct lws_context *context)
 	return context->system_ops;
 }
 
+#if defined(LWS_WITH_NETWORK)
 int
-lws_system_get_auth(struct lws_context *context, int idx, uint8_t *buf,
-		    size_t buflen, int flags)
+lws_system_auth_default_cb(struct lws_context *context, int idx, size_t ofs,
+			   uint8_t *buf, size_t *plen, lws_system_auth_op_t op)
+{
+	int n;
+
+	if (idx >= (int)LWS_ARRAY_SIZE(context->auth_token))
+		return -1;
+
+	switch (op) {
+	case LWSSYS_AUTH_GET:
+		if (!context->auth_token[idx])
+			return -1;
+
+		if (!buf) /* we just need to tell him that it exists */
+			return -2;
+
+		n = lws_buflist_linear_copy(&context->auth_token[idx], ofs, buf,
+					    *plen);
+		if (n < 0)
+			return -2;
+
+		*plen = (size_t)n;
+
+		return 0;
+
+	case LWSSYS_AUTH_TOTAL_LENGTH:
+		*plen = lws_buflist_total_len(&context->auth_token[idx]);
+		return 0;
+
+	case LWSSYS_AUTH_APPEND:
+		if (lws_buflist_append_segment(&context->auth_token[idx], buf,
+					       *plen) < 0)
+			return -1;
+
+		return 0;
+
+	case LWSSYS_AUTH_FREE:
+		lws_buflist_destroy_all_segments(&context->auth_token[idx]);
+		return 0;
+
+	default:
+		break;
+	}
+
+	return -1;
+}
+
+int
+lws_system_get_auth(struct lws_context *context, int idx, size_t ofs,
+		    uint8_t *buf, size_t buflen, int flags)
 {
 	size_t bl = buflen;
 	uint8_t *p, b;
 	int n;
 
-	if (!context->system_ops || !context->system_ops->auth) {
-		lwsl_err("%s: add auth system op\n", __func__);
-		return -1;
-	}
-
-	if (context->system_ops->auth(idx, buf, &buflen, 0) < 0) {
+	if (!context->system_ops || !context->system_ops->auth)
+		n = lws_system_auth_default_cb(context, idx, ofs, buf, &buflen, 0);
+	else
+		n = context->system_ops->auth(context, idx, ofs, buf, &buflen, 0);
+	if (n < 0) {
 		if (buf)
 			lwsl_err("%s: auth get failed\n", __func__);
 		return -1;
@@ -63,7 +113,8 @@ lws_system_get_auth(struct lws_context *context, int idx, uint8_t *buf,
 
 	if (buf && (flags & LWSSYSGAUTH_HEX)) {
 		if (bl < (buflen * 2) + 1) {
-			lwsl_err("%s: auth in hex oversize %d\n", __func__, (int)bl);
+			lwsl_err("%s: auth in hex oversize %d\n", __func__,
+					(int)bl);
 			return -1;
 		}
 
@@ -84,4 +135,4 @@ lws_system_get_auth(struct lws_context *context, int idx, uint8_t *buf,
 
 	return (int)buflen;
 }
-
+#endif