libtock-sync: hmac: use ywf

Author: bradjc

libtock-sync/crypto/hmac.c

@@ -1,41 +1,37 @@
 #include "hmac.h"
 
-struct hmac_data {
-  bool fired;
-  returncode_t ret;
-};
-
-static struct hmac_data result = {.fired = false};
-
-static void hmac_cb_hmac(returncode_t ret) {
-  result.fired = true;
-  result.ret   = ret;
-}
-
 returncode_t libtocksync_hmac_simple(libtock_hmac_algorithm_t hmac_type,
                                      uint8_t* key_buffer, uint32_t key_length,
                                      uint8_t* input_buffer, uint32_t input_length,
                                      uint8_t* hmac_buffer, uint32_t hmac_length) {
   returncode_t ret;
 
-  result.fired = false;
+  ret = libtock_hmac_command_set_algorithm((uint32_t) hmac_type);
+  if (ret != RETURNCODE_SUCCESS) return ret;
 
-  ret = libtock_hmac_simple(hmac_type, key_buffer, key_length, input_buffer, input_length, hmac_buffer, hmac_length,
-                            hmac_cb_hmac);
+  ret = libtock_hmac_set_readonly_allow_key_buffer(key_buffer, key_length);
   if (ret != RETURNCODE_SUCCESS) return ret;
 
-  // Wait for the callback.
-  yield_for(&result.fired);
-  if (result.ret != RETURNCODE_SUCCESS) return result.ret;
+  ret = libtock_hmac_set_readonly_allow_data_buffer(input_buffer, input_length);
+  if (ret != RETURNCODE_SUCCESS) goto exit1;
 
-  ret = libtock_hmac_set_readonly_allow_key_buffer(NULL, 0);
-  if (ret != RETURNCODE_SUCCESS) return ret;
+  ret = libtock_hmac_set_readwrite_allow_destination_buffer(hmac_buffer, hmac_length);
+  if (ret != RETURNCODE_SUCCESS) goto exit2;
 
-  ret = libtock_hmac_set_readonly_allow_data_buffer(NULL, 0);
-  if (ret != RETURNCODE_SUCCESS) return ret;
+  ret = libtock_hmac_command_run();
+  if (ret != RETURNCODE_SUCCESS) goto exit3;
 
-  ret = libtock_hmac_set_readwrite_allow_destination_buffer(NULL, 0);
-  if (ret != RETURNCODE_SUCCESS) return ret;
+  // Wait for the operation.
+  ret = libtocksync_hmac_yield_wait_for();
+
+exit3:
+  libtock_hmac_set_readwrite_allow_destination_buffer(NULL, 0);
+
+exit2:
+  libtock_hmac_set_readonly_allow_data_buffer(NULL, 0);
+
+exit1:
+  libtock_hmac_set_readonly_allow_key_buffer(NULL, 0);
 
-  return RETURNCODE_SUCCESS;
+  return ret;
 }

libtock-sync/crypto/hmac.h

@@ -1,8 +1,10 @@
 #pragma once
 
-#include <libtock/crypto/hmac.h>
+#include <libtock/crypto/hmac_types.h>
 #include <libtock/tock.h>
 
+#include "syscalls/hmac_syscalls.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif

libtock-sync/crypto/syscalls/hmac_syscalls.c

@@ -0,0 +1,8 @@
+#include "hmac_syscalls.h"
+
+returncode_t libtocksync_hmac_yield_wait_for(void) {
+  yield_waitfor_return_t ret;
+  ret = yield_wait_for(DRIVER_NUM_HMAC, 0);
+
+  return (returncode_t) ret.data0;
+}

libtock-sync/crypto/syscalls/hmac_syscalls.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <libtock/crypto/syscalls/hmac_syscalls.h>
+#include <libtock/tock.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Wait for an HMAC operation to finish.
+returncode_t libtocksync_hmac_yield_wait_for(void);
+
+#ifdef __cplusplus
+}
+#endif

libtock/crypto/hmac.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "../tock.h"
+#include "hmac_types.h"
 #include "syscalls/hmac_syscalls.h"
 
 #ifdef __cplusplus
@@ -12,13 +13,6 @@ extern "C" {
 // - `arg1` (`returncode_t`): Status from computing the HMAC.
 typedef void (*libtock_hmac_callback_hmac)(returncode_t);
 
-typedef enum {
-  LIBTOCK_HMAC_SHA256 = 0,
-  LIBTOCK_HMAC_SHA384 = 1,
-  LIBTOCK_HMAC_SHA512 = 2,
-} libtock_hmac_algorithm_t;
-
-
 
 // Compute an HMAC using `keyb_buffer` over `input_buffer` and store the result
 // in `hash_buffer`.

libtock/crypto/hmac_types.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "../tock.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum {
+  LIBTOCK_HMAC_SHA256 = 0,
+  LIBTOCK_HMAC_SHA384 = 1,
+  LIBTOCK_HMAC_SHA512 = 2,
+} libtock_hmac_algorithm_t;
+
+#ifdef __cplusplus
+}
+#endif