Data Encryption and Decryption

What is the actual problem. I read the text from the file and encrypt it, then I try to decrypt it. And for some reason, he squeezes the beginning of the line. I.e:

Source line: Hello, it is test number one!
Encoded string ?+??hA???<{-????7f??$??
ґЗQЎkч!t is test nuber one! string: ґЗQЎkч!t is test nuber one!

 #define _CRT_SECURE_NO_WARNINGS #include <stdio.h> #include <stdlib.h> #include <wchar.h> #include <Windows.h> #include <WinCrypt.h> #define BLOCK_LENGTH 4097 // Размер буфера 4КБ #define CALG_G28147 26142 // Алгоритм шифрования HCRYPTPROV hProv; //Дескриптор криптопровайдера HCRYPTKEY hSessionKey; //Дескриптор сессионного ключа HCRYPTKEY hDuplicateKey; //Дескриптор дубликата сессионного ключа DWORD hProvType = (DWORD)80; int main() { BYTE pbContent[BLOCK_LENGTH] = { 0 }; // Указатель на содержимое исходного файла DWORD cbContent = 0; // Длина содержимого DWORD bufLen = sizeof(pbContent); char pin[] = "sys"; if (CryptAcquireContext( &hProv, (LPCWSTR)L"Cache", (LPCWSTR)L"Crypto-Pro GOST R 34.10-2012 Cryptographic Service Provider", hProvType, CRYPT_SILENT)) { CryptSetProvParam(hProv, PP_SIGNATURE_PIN, (LPBYTE)pin, 0); } else { printf("\nError AcquireContext\n"); return 1; } if (!CryptGenKey(hProv, CALG_G28147, CRYPT_ENCRYPT | CRYPT_DECRYPT, &hSessionKey)) { printf("Session key does not generated.\n"); } FILE * file = fopen("test.txt", "r"); if (!file){ printf("Unable to open file"); return 1; } FILE * Encrypt = fopen("encrypt.bin", "wb"); if (!Encrypt){ printf("Unable to open Encrypt file"); return 1; } do { if (!CryptDuplicateKey(hSessionKey, NULL, 0, &hDuplicateKey)) { printf("The session key does not duplicated.\n"); } memset(pbContent, 0, sizeof(pbContent)); cbContent = (DWORD)fread(pbContent, 1, BLOCK_LENGTH -1, file); pbContent[cbContent] = '\0'; printf("String: %s syze is %d\n", pbContent, cbContent); if (cbContent) { BOOL bFinal = feof(file); // Зашифрование прочитанного блока на сессионном ключе. if (CryptEncrypt(hDuplicateKey, 0, bFinal, 0, (BYTE*)pbContent, &cbContent, bufLen)) { // Запись зашифрованного блока в файл. if (!fwrite(pbContent, 1, cbContent, Encrypt)) { printf("The encrypted content can not be written to the 'encrypt.bin'\n"); } } else { printf("Encryption failed."); } if (CryptDecrypt(hSessionKey, 0, bFinal, 0, (BYTE*)pbContent, &cbContent)) printf("\nDecrypt is: %s\n", pbContent); } else { printf("Problem reading the file 'test.txt'\n"); } CryptDestroyKey(hDuplicateKey); } while (!feof(file)); fclose(Encrypt); fclose(file); CryptDestroyKey(hSessionKey); getchar(); return 0; } 

I can not understand what the problem is ...