fixed connection bugs

src/cryptography/AES.c

@@ -176,7 +176,6 @@ void AESStreamDecryptor_construct(AESStreamDecryptor* ptr, Array(u8) key, const
 
 Result(u32) AESStreamDecryptor_decrypt(AESStreamDecryptor* ptr, Array(u8) src, Array(u8) dst){
     Deferral(4);
-    try_assert(src.size >= AESStreamEncryptor_calcDstSize(0));
     u32 decrypted_size = __AESStreamDecryptor_calcDstSize(src.size);
     try_assert(dst.size >= decrypted_size);
 

src/cryptography/AES.h

@@ -88,6 +88,7 @@ typedef struct AESStreamEncryptor {
 /// @param dec_class &br_aes_XXX_ctr_vtable
 void AESStreamEncryptor_construct(AESStreamEncryptor* ptr, Array(u8) key, const br_block_ctr_class* ctr_class);
 
+/// use this only at the beginning of the stream
 #define AESStreamEncryptor_calcDstSize(src_size) (src_size + __AES_BLOCK_IV_SIZE)
 
 /// @brief If ptr->block_counter == 0, writes random IV to `dst`. After that writes encrypted data to dst.
@@ -114,7 +115,7 @@ typedef struct AESStreamDecryptor {
 void AESStreamDecryptor_construct(AESStreamDecryptor* ptr, Array(u8) key, const br_block_ctr_class* ctr_class);
 
 /// @brief Reads IV from `src`, then decrypts data and writes it to dst
-/// @param src array of size at least AESStreamEncryptor_calcDstSize(0).
+/// @param src array of any size
 /// @param dst array of size >= src.size
 /// @return size of decrypted data
 Result(u32) AESStreamDecryptor_decrypt(AESStreamDecryptor* ptr, Array(u8) src, Array(u8) dst);

src/cryptography/RSA.c

@@ -180,14 +180,15 @@ void RSAEncryptor_construct(RSAEncryptor* ptr, const br_rsa_public_key* pk){
 }
 
 Result(u32) RSAEncryptor_encrypt(RSAEncryptor* ptr, Array(u8) src, Array(u8) dst){
-    const u32 max_src_size = RSAEncryptor_calcMaxSrcSize(ptr->pk->nlen * 8, 256);
+    u32 key_size_bytes = ptr->pk->nlen;
+    const u32 max_src_size = RSAEncryptor_calcMaxSrcSize(key_size_bytes * 8, 256);
     if(src.size > max_src_size){  
         return RESULT_ERROR_FMT("src.size (%u) must be <= %u (use RSAEncryptor_calcMaxSrcSize)", 
             src.size, max_src_size);
     }
-    if(dst.size < ptr->pk->nlen){
+    if(dst.size < key_size_bytes){
         return RESULT_ERROR_FMT("dst.size (%u) must be >= %u (key length in bytes)", 
-            dst.size, (u32)ptr->pk->nlen);
+            dst.size, key_size_bytes);
     }
     size_t sz = br_rsa_i31_oaep_encrypt(
         &ptr->rng.vtable, &br_sha256_vtable, 
@@ -207,18 +208,26 @@ void RSADecryptor_construct(RSADecryptor* ptr, const br_rsa_private_key* sk){
     ptr->sk = sk;
 }
 
-Result(u32) RSADecryptor_decrypt(RSADecryptor* ptr, Array(u8) buf){
-    if(buf.size != ptr->sk->n_bitlen/8){
-        return RESULT_ERROR_FMT("buf.size (%u) must be == %u (key length in bytes)", 
-            buf.size, ptr->sk->n_bitlen/8);
+Result(u32) RSADecryptor_decrypt(RSADecryptor* ptr, Array(u8) src, Array(u8) dst){
+    u32 key_size_bits = ptr->sk->n_bitlen;
+    if(src.size != key_size_bits/8){
+        return RESULT_ERROR_FMT("src.size (%u) must be == %u (key length in bytes)", 
+            src.size, key_size_bits/8);
     }
 
-    size_t sz = buf.size;
+    const u32 max_src_size = RSAEncryptor_calcMaxSrcSize(key_size_bits, 256);
+    if(dst.size < max_src_size){  
+        return RESULT_ERROR_FMT("dst.size (%u) must be >= %u (use RSAEncryptor_calcMaxSrcSize)", 
+            dst.size, max_src_size);
+    }
+
+    memcpy(dst.data, src.data, src.size);
+    size_t sz = src.size;
     size_t r = br_rsa_i31_oaep_decrypt(
         &br_sha256_vtable, 
         NULL, 0,
         ptr->sk,
-        buf.data, &sz);
+        dst.data, &sz);
     
     if(r == 0){
         return RESULT_ERROR("RSA encryption failed", false);

src/cryptography/RSA.h

@@ -101,6 +101,7 @@ typedef struct RSADecryptor {
 /// RSA OAEP encryption with SHA256 hashing algorithm
 void RSADecryptor_construct(RSADecryptor* ptr, const br_rsa_private_key* sk);
 
-/// @param buf buffer with size == key size in bytes
+/// @param src buffer with size == key size in bytes
+/// @param dst buffer with size >= `RSAEncryptor_calcMaxSrcSize(key_size_bits, 256)`
 /// @return size of decrypted data
-Result(u32) RSADecryptor_decrypt(RSADecryptor* ptr, Array(u8) buf);
+Result(u32) RSADecryptor_decrypt(RSADecryptor* ptr, Array(u8) src, Array(u8) dst);