extmod/axtls-include: Add axtls_os_port.h to customise axTLS.

Signed-off-by: Damien George <damien@micropython.org>

extmod/axtls-include/axtls_os_port.h

@@ -0,0 +1,55 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef AXTLS_OS_PORT_H
+#define AXTLS_OS_PORT_H
+
+#include <errno.h>
+#include "py/stream.h"
+#include "extmod/crypto-algorithms/sha256.h"
+
+#define SSL_CTX_MUTEX_INIT(mutex)
+#define SSL_CTX_MUTEX_DESTROY(mutex)
+#define SSL_CTX_LOCK(mutex)
+#define SSL_CTX_UNLOCK(mutex)
+
+#define SOCKET_READ(s, buf, size)       mp_stream_posix_read((void *)s, buf, size)
+#define SOCKET_WRITE(s, buf, size)      mp_stream_posix_write((void *)s, buf, size)
+#define SOCKET_CLOSE(A)                 UNUSED
+#define SOCKET_ERRNO()                  errno
+
+#define SHA256_CTX                      CRYAL_SHA256_CTX
+#define SHA256_Init(ctx)                sha256_init(ctx)
+#define SHA256_Update(ctx, buf, size)   sha256_update(ctx, buf, size)
+#define SHA256_Final(hash, ctx)         sha256_final(ctx, hash)
+
+#define TTY_FLUSH()
+
+#ifdef WDEV_HWRNG
+// For esp8266 port: use the hardware RNG.
+#define PLATFORM_RNG_U8()               (*WDEV_HWRNG)
+#endif
+
+#endif // AXTLS_OS_PORT_H