Update mbedtls to 2.5.1 (#3964)

* Renaming changes:
  * macro prefix "POLARSSL" -> "MBEDTLS"
  * functions now prefixed with "mbedtls_"
  * rename PolarSSL++ -> mbedTLS++
  * rename polarssl submodule

* Use mbedtls' AES-CFB8 implementation.

* Add cSslConfig to wrap mbedtls_ssl_config

* Update cTCPLink and cBlockingSslClientSocket to use cSslConfig

* Use cSslConfig in cHTTPServer

* Use cSslConfig for cMojangAPI::SecureRequest

* CI Fixes

* Set -fomit-frame-pointer on the right target

src/mbedTLS++/AesCfb128Decryptor.cpp

@@ -0,0 +1,55 @@
+
+// AesCfb128Decryptor.cpp
+
+// Implements the cAesCfb128Decryptor class decrypting data using AES CFB-128
+
+#include "Globals.h"
+#include "AesCfb128Decryptor.h"
+
+
+
+
+
+cAesCfb128Decryptor::cAesCfb128Decryptor(void):
+	m_IsValid(false)
+{
+	mbedtls_aes_init(&m_Aes);
+}
+
+
+
+
+
+cAesCfb128Decryptor::~cAesCfb128Decryptor()
+{
+	// Clear the leftover in-memory data, so that they can't be accessed by a backdoor
+	mbedtls_aes_free(&m_Aes);
+}
+
+
+
+
+
+void cAesCfb128Decryptor::Init(const Byte a_Key[16], const Byte a_IV[16])
+{
+	ASSERT(!IsValid());  // Cannot Init twice
+
+	memcpy(m_IV, a_IV, 16);
+	mbedtls_aes_setkey_enc(&m_Aes, a_Key, 128);
+	m_IsValid = true;
+}
+
+
+
+
+
+void cAesCfb128Decryptor::ProcessData(Byte * a_DecryptedOut, const Byte * a_EncryptedIn, size_t a_Length)
+{
+	ASSERT(IsValid());  // Must Init() first
+	mbedtls_aes_crypt_cfb8(&m_Aes, MBEDTLS_AES_DECRYPT, a_Length, m_IV, a_EncryptedIn, a_DecryptedOut);
+}
+
+
+
+
+