net: lwm2m: Do not enforce canonical CBOR decoding

Our decoder can handle decoding of non-deterministic CBOR just fine.
There is no need to block valid CBOR if the server does not produce
length-first deterministic CBOR.

Signed-off-by: Seppo Takalo <[email protected]>

Author: SeppoTakalo

subsys/net/lib/lwm2m/lwm2m_rw_cbor.c

@@ -237,6 +237,8 @@ static int get_s64(struct lwm2m_input_context *in, int64_t *value)
 {
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_int64_decode(states, value)) {
 		LOG_WRN("unable to decode a 64-bit integer value");
 		return -EBADMSG;
@@ -253,6 +255,8 @@ static int get_s32(struct lwm2m_input_context *in, int32_t *value)
 {
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_int32_decode(states, value)) {
 		LOG_WRN("unable to decode a 32-bit integer value, err: %d",
 				states->constant_state->error);
@@ -270,6 +274,8 @@ static int get_float(struct lwm2m_input_context *in, double *value)
 {
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_float_decode(states, value)) {
 		LOG_ERR("unable to decode a floating-point value");
 		return -EBADMSG;
@@ -289,6 +295,8 @@ static int get_string(struct lwm2m_input_context *in, uint8_t *value, size_t buf
 
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_tstr_decode(states, &hndl)) {
 		LOG_WRN("unable to decode a string");
 		return -EBADMSG;
@@ -318,6 +326,8 @@ static int get_time_string(struct lwm2m_input_context *in, int64_t *value)
 
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_tstr_decode(states, &hndl)) {
 		return -EBADMSG;
 	}
@@ -336,6 +346,8 @@ static int get_time_numerical(struct lwm2m_input_context *in, int64_t *value)
 {
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_int64_decode(states, value)) {
 		LOG_WRN("unable to decode seconds since Epoch");
 		return -EBADMSG;
@@ -355,6 +367,8 @@ static int get_time(struct lwm2m_input_context *in, time_t *value)
 
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	success = zcbor_tag_decode(states, &tag);
 
 	if (success) {
@@ -405,6 +419,8 @@ static int get_bool(struct lwm2m_input_context *in, bool *value)
 {
 	ZCBOR_STATE_D(states, 0, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	if (!zcbor_bool_decode(states, value)) {
 		LOG_WRN("unable to decode a boolean value");
 		return -EBADMSG;
@@ -425,6 +441,8 @@ static int get_opaque(struct lwm2m_input_context *in, uint8_t *value, size_t buf
 
 	ZCBOR_STATE_D(states, 1, ICTX_BUF_R_PTR(in), ICTX_BUF_R_LEFT_SZ(in),  1, 0);
 
+	states->constant_state->enforce_canonical = false;
+
 	/* Get the CBOR header only on first read. */
 	if (opaque->offset == 0) {
 		ret = zcbor_bstr_start_decode_fragment(states, &hndl);

subsys/net/lib/lwm2m/lwm2m_senml_cbor_decode.c

@@ -212,6 +212,8 @@ static bool decode_lwm2m_senml(zcbor_state_t *state, struct lwm2m_senml *result)
 {
 	zcbor_log("%s\r\n", __func__);
 
+	state->constant_state->enforce_canonical = false;
+
 	bool res =
 		(((zcbor_list_start_decode(state) &&
 		   ((zcbor_multi_decode(