First Publicly Shared Version of ODKiTEE v15

oemcrypto_ta/oemcrypto_session_table.c

@@ -0,0 +1,106 @@
+/* Copyright 2019 Google LLC. All Rights Reserved. This file and proprietary
+   source code may only be used and distributed under the Widevine Master
+   License Agreement. */
+
+#include "oemcrypto_session_table.h"
+
+#include "stdint.h"
+#include "string.h"
+
+#include "assert_interface.h"
+#include "logging_interface.h"
+#include "oemcrypto_key.h"
+
+static SessionTable session_table;
+static uint32_t open_session_count = 0;
+static bool session_table_initialized = false;
+
+OEMCryptoResult InitializeSessionTable(void) {
+  ASSERT(MAX_NUMBER_OF_SESSIONS > 0, "MAX_NUMBER_OF_SESSIONS must be > 0");
+  ASSERT(MAX_NUMBER_OF_SESSIONS <= UINT32_MAX - 1,
+         "MAX_NUMBER_OF_SESSIONS is too large");
+  if (session_table_initialized) {
+    return OEMCrypto_ERROR_INIT_FAILED;
+  }
+  session_table.first_free_session = 0;
+  for (uint32_t i = 0; i < MAX_NUMBER_OF_SESSIONS; i++) {
+    session_table.next_free_session[i] = i + 1;
+    session_table.is_free[i] = true;
+    memset(&session_table.sessions[i], 0, sizeof(OEMCryptoSession));
+  }
+  session_table_initialized = true;
+  open_session_count = 0;
+  return OEMCrypto_SUCCESS;
+}
+
+uint32_t MaxNumberOfSessions(void) { return MAX_NUMBER_OF_SESSIONS; }
+
+OEMCryptoResult NumberOfOpenSessions(uint32_t* num_open_sessions) {
+  ASSERT(num_open_sessions != NULL, "num_open_sessions is NULL");
+  if (!session_table_initialized) {
+    return OEMCrypto_ERROR_SYSTEM_INVALIDATED;
+  }
+  *num_open_sessions = open_session_count;
+  return OEMCrypto_SUCCESS;
+}
+
+OEMCryptoResult GrabSession(uint32_t* index) {
+  ASSERT(index != NULL, "index is NULL");
+  if (!session_table_initialized) {
+    return OEMCrypto_ERROR_SYSTEM_INVALIDATED;
+  }
+  if (session_table.first_free_session == MAX_NUMBER_OF_SESSIONS) {
+    return OEMCrypto_ERROR_TOO_MANY_SESSIONS;
+  }
+  *index = session_table.first_free_session;
+  session_table.first_free_session = session_table.next_free_session[*index];
+  session_table.is_free[*index] = false;
+  open_session_count++;
+  return InitializeSession(&session_table.sessions[*index], *index);
+}
+
+OEMCryptoResult GetSession(uint32_t index, OEMCryptoSession** session) {
+  ASSERT(session != NULL, "session is NULL");
+  if (!session_table_initialized) {
+    return OEMCrypto_ERROR_SYSTEM_INVALIDATED;
+  }
+  if (index >= MAX_NUMBER_OF_SESSIONS || session_table.is_free[index]) {
+    return OEMCrypto_ERROR_INVALID_SESSION;
+  }
+  *session = &session_table.sessions[index];
+  return OEMCrypto_SUCCESS;
+}
+
+OEMCryptoResult FreeSession(uint32_t index) {
+  if (!session_table_initialized) {
+    return OEMCrypto_ERROR_SYSTEM_INVALIDATED;
+  }
+  if (index >= MAX_NUMBER_OF_SESSIONS || session_table.is_free[index]) {
+    return OEMCrypto_ERROR_INVALID_SESSION;
+  }
+  session_table.next_free_session[index] = session_table.first_free_session;
+  session_table.is_free[index] = true;
+  session_table.first_free_session = index;
+  open_session_count--;
+  return TerminateSession(&session_table.sessions[index]);
+}
+
+OEMCryptoResult TerminateSessionTable(void) {
+  if (!session_table_initialized) {
+    return OEMCrypto_ERROR_TERMINATE_FAILED;
+  }
+  OEMCryptoResult result = OEMCrypto_SUCCESS;
+  for (int i = 0; i < MAX_NUMBER_OF_SESSIONS; i++) {
+    if (!session_table.is_free[i]) {
+      result = OEMCrypto_ERROR_TERMINATE_FAILED;
+      /* Attempt to free the session. */
+      OEMCryptoResult free_result = FreeSession(i);
+      if (free_result != OEMCrypto_SUCCESS) {
+        LOGE("Could not free session %d with error: %d", i, free_result);
+      }
+    }
+  }
+  session_table_initialized = false;
+  open_session_count = 0;
+  return result;
+}