initial commit

libTinyEncrypt/libEncrypt_AES.h

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+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+// #define the macros below to 1/0 to enable/disable the mode of operation.
+//
+// CBC enables AES encryption in CBC-mode of operation.
+// CTR enables encryption in counter-mode.
+// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously.
+
+// The #ifndef-guard allows it to be configured before #include'ing or at compile time.
+#ifndef CBC
+#define CBC 1
+#endif
+
+
+#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only
+
+#define AES_KEYLEN 16   // Key length in bytes
+#define AES_keyExpSize 176
+
+struct AES_ctx
+{
+    uint8_t RoundKey[AES_keyExpSize];
+    uint8_t Iv[AES_BLOCKLEN];
+};
+
+void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
+void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
+void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
+
+// buffer size MUST be mutile of AES_BLOCKLEN;
+// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
+// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
+//        no IV should ever be reused with the same key 
+void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+
+