libimcv: Allow pts_t.get_my_public_value() to fail

src/libimcv/plugins/imc_attestation/imc_attestation_process.c

@@ -137,7 +137,11 @@ bool imc_attestation_process(pa_tnc_attr_t *attr, imc_msg_t *msg,
 			{
 				return FALSE;
 			}
-			pts->get_my_public_value(pts, &responder_value, &responder_nonce);
+			if (!pts->get_my_public_value(pts, &responder_value,
+										  &responder_nonce))
+			{
+				return FALSE;
+			}
 
 			/* Send DH Nonce Parameters Response attribute */
 			attr = tcg_pts_attr_dh_nonce_params_resp_create(selected_dh_group,

src/libimcv/plugins/imv_attestation/imv_attestation_build.c

@@ -69,7 +69,11 @@ bool imv_attestation_build(imv_msg_t *out_msg, imv_state_t *state,
 
 			/* Send DH nonce finish attribute */
 			selected_algorithm = pts->get_meas_algorithm(pts);
-			pts->get_my_public_value(pts, &initiator_value, &initiator_nonce);
+			if (!pts->get_my_public_value(pts, &initiator_value,
+										  &initiator_nonce))
+			{
+				return FALSE;
+			}
 			attr = tcg_pts_attr_dh_nonce_finish_create(selected_algorithm,
 											initiator_value, initiator_nonce);
 			attr->set_noskip_flag(attr, TRUE);

src/libimcv/pts/pts.c

@@ -224,11 +224,12 @@ METHOD(pts_t, create_dh_nonce, bool,
 	return TRUE;
 }
 
-METHOD(pts_t, get_my_public_value, void,
+METHOD(pts_t, get_my_public_value, bool,
 	private_pts_t *this, chunk_t *value, chunk_t *nonce)
 {
 	this->dh->get_my_public_value(this->dh, value);
 	*nonce = this->is_imc ? this->responder_nonce : this->initiator_nonce;
+	return TRUE;
 }
 
 METHOD(pts_t, set_peer_public_value, void,

src/libimcv/pts/pts.h

@@ -143,8 +143,9 @@ struct pts_t {
 	 *
 	 * @param value				My public DH value
 	 * @param nonce				My DH nonce
+	 * @return					TRUE if public value retrieved successfully
 	 */
-	void (*get_my_public_value)(pts_t *this, chunk_t *value, chunk_t *nonce);
+	bool (*get_my_public_value)(pts_t *this, chunk_t *value, chunk_t *nonce);
 
 	/**
 	 * Set peer Diffie.Hellman public value