使用OpenSSL / C ++和PHP / Mcrypt进行AES-128-CBC加密：第一个块仅解密

I write the program that has to exchange encrypted data with PHP-based web service. I use C++ with OpenSSL to encrypt data with AES-128 in CBC mode. I send base64-encoded data (IV and ciphertext) to HTTP server and PHP has to decrypt the data with Mcrypt. However, only the 1st block is decrypted successfully, other blocks become garbage. I don't understand at all: how we can decrypt the 1st block only in CBC mode? If IV, key or algorithm settings like key size/block size/rounds count are wrong, we can not receive the 1st block decrypted correctly; if decryption parameters are OK, how is it possible that other blocks are not decrypted? When I decrypt the same ciphertext that PHP fails to decrypt with OpenSSL/C++, decryption succeeds. The same is true for PHP: I can encrypt and decrypt data in CBC mode. But for any reason OpenSSL EVP_aes_128_cbc and mcrypt 'rijndael-128' are not compatible. My decryption code follows:I write the program that has to exchange encryp