implemented aes key validation

src/cryptography/AES.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "tlibc/collections/Array.h"
 #include "tlibc/errors.h"
+#include "tlibc/magic.h"
 #include "bearssl_block.h"
 #include "cryptography.h"
 
@@ -15,7 +16,9 @@
 #define AESStream_DEFAULT_CLASS (&br_aes_big_ctr_vtable)
 
 
+#define __AES_BLOCK_KEY_CHECKSUM_SIZE br_sha256_SIZE
 typedef struct EncryptedBlockHeader {
+    u8 key_checksum[__AES_BLOCK_KEY_CHECKSUM_SIZE];
     u8 padding_size;
 } ATTRIBUTE_ALIGNED(16) EncryptedBlockHeader;
 
@@ -32,6 +35,7 @@ typedef struct AESBlockEncryptor {
     u8 enc_keys[sizeof(br_aes_big_cbcenc_keys)];
     u8 buf[__AES_BUFFER_SIZE];
     u8 iv[__AES_BLOCK_IV_SIZE];
+    u8 key_checksum[__AES_BLOCK_KEY_CHECKSUM_SIZE];
     br_hmac_drbg_context rng_ctx;
 } AESBlockEncryptor;
 
@@ -59,6 +63,7 @@ typedef struct AESBlockDecryptor {
     u8 dec_keys[sizeof(br_aes_big_cbcdec_keys)];
     u8 buf[__AES_BUFFER_SIZE];
     u8 iv[__AES_BLOCK_IV_SIZE];
+    u8 key_checksum[__AES_BLOCK_KEY_CHECKSUM_SIZE];
 } AESBlockDecryptor;
 
 /// @param key supported sizes: 16, 24, 32
@@ -85,6 +90,7 @@ typedef struct AESStreamEncryptor {
     u8 ctr_keys[sizeof(br_aes_big_ctr_keys)];
     u8 buf[__AES_BUFFER_SIZE];
     u8 iv[__AES_STREAM_IV_SIZE];
+    u8 key_checksum[__AES_BLOCK_KEY_CHECKSUM_SIZE];
     u32 block_counter;
 } AESStreamEncryptor;
 
@@ -97,7 +103,7 @@ void AESStreamEncryptor_construct(AESStreamEncryptor* ptr, Array(u8) key, const
 void AESStreamEncryptor_changeKey(AESStreamEncryptor* ptr, Array(u8) key);
 
 /// use this only at the beginning of the stream
-#define AESStreamEncryptor_calcDstSize(src_size) (src_size + __AES_STREAM_IV_SIZE)
+#define AESStreamEncryptor_calcDstSize(src_size) (__AES_STREAM_IV_SIZE + __AES_BLOCK_KEY_CHECKSUM_SIZE + src_size)
 
 /// @brief If ptr->block_counter == 0, writes random IV to `dst`. After that writes encrypted data to dst.
 /// @param src array of any size
@@ -114,6 +120,7 @@ typedef struct AESStreamDecryptor {
     u8 ctr_keys[sizeof(br_aes_big_ctr_keys)];
     u8 buf[__AES_BUFFER_SIZE];
     u8 iv[__AES_STREAM_IV_SIZE];
+    u8 key_checksum[__AES_BLOCK_KEY_CHECKSUM_SIZE];
     u32 block_counter;
 } AESStreamDecryptor;