tls: added AES code and made it compile. not used yet

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/tls_aes.h b/networking/tls_aes.h
new file mode 100644
index 0000000..ea8ed7e
--- /dev/null
+++ b/networking/tls_aes.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2017 Denys Vlasenko
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ *
+ * Selected few declarations for AES.
+ */
+
+int32 psAesInitKey(const unsigned char *key, uint32 keylen, psAesKey_t *skey);
+void psAesEncryptBlock(const unsigned char *pt, unsigned char *ct,
+				psAesKey_t *skey);
+void psAesDecryptBlock(const unsigned char *ct, unsigned char *pt,
+				psAesKey_t *skey);
+
+int32 psAesInit(psCipherContext_t *ctx, unsigned char *IV,
+				  unsigned char *key, uint32 keylen);
+int32 psAesEncrypt(psCipherContext_t *ctx, unsigned char *pt,
+					 unsigned char *ct, uint32 len);
+int32 psAesDecrypt(psCipherContext_t *ctx, unsigned char *ct,
+					 unsigned char *pt, uint32 len);