Different result of aes encryption c++ and php - php

Question

I'm going to implement AES encryption between CPP and PHP. But the result of each of them is different with each other and therefore they cannot decode each other. I use the OpenSsl library for encryption.
my php code:
$key = '1234567890123456';
$iv = '1234567890123456';
$enc = openssl_encrypt("hello wolrd", 'aes-256-cbc', $key, OPENSSL_RAW_DATA, $iv);
$decrypted = openssl_decrypt($enc, 'aes-256-cbc', $key, OPENSSL_RAW_DATA, $iv);
and result: ��.�+'W�x�#�
my cpp code:
int aes_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
unsigned char *iv, unsigned char *ciphertext)
{
EVP_CIPHER_CTX *ctx;
int len;
int ciphertext_len;
/* Create and initialise the context */
if(!(ctx = EVP_CIPHER_CTX_new()))
handleErrors();
/*
* Initialise the encryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher
* In this example we are using 256 bit AES (i.e. a 256 bit key). The
* IV size for *most* modes is the same as the block size. For AES this
* is 128 bits
*/
if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv))
handleErrors();
/*
* Provide the message to be encrypted, and obtain the encrypted output.
* EVP_EncryptUpdate can be called multiple times if necessary
*/
if(1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len))
handleErrors();
ciphertext_len = len;
/*
* Finalise the encryption. Further ciphertext bytes may be written at
* this stage.
*/
if(1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len))
handleErrors();
ciphertext_len += len;
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
return ciphertext_len;
}
int aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
unsigned char *iv, unsigned char *plaintext)
{
EVP_CIPHER_CTX *ctx;
int len;
int plaintext_len;
/* Create and initialise the context */
if(!(ctx = EVP_CIPHER_CTX_new()))
handleErrors();
/*
* Initialise the decryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher
* In this example we are using 256 bit AES (i.e. a 256 bit key). The
* IV size for *most* modes is the same as the block size. For AES this
* is 128 bits
*/
if(1 != EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv))
handleErrors();
/*
* Provide the message to be decrypted, and obtain the plaintext output.
* EVP_DecryptUpdate can be called multiple times if necessary.
*/
if(1 != EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len))
handleErrors();
plaintext_len = len;
/*
* Finalise the decryption. Further plaintext bytes may be written at
* this stage.
*/
if(1 != EVP_DecryptFinal_ex(ctx, plaintext + len, &len))
handleErrors();
plaintext_len += len;
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
return plaintext_len;
}
/* A 256 bit key */
unsigned char *key = (unsigned char*)"1234567890123456";
/* A 128 bit IV */
unsigned char *iv = (unsigned char*)"1234567890123456";
/* Message to be encrypted */
unsigned char *plaintext = (unsigned char*)"hello wolrd";
/* Buffer for ciphertext. Ensure the buffer is long enough for the
* ciphertext which may be longer than the plaintext, dependant on the
* algorithm and mode
*/
unsigned char ciphertext[256];
/* Buffer for the decrypted text */
unsigned char decryptedtext[256];
int decryptedtext_len, ciphertext_len;
printf("Plaintext is:\n%s\n", plaintext);
/* Encrypt the plaintext */
ciphertext_len = aes_encrypt(plaintext, strlen((const char*)plaintext), key, iv,
ciphertext);
/* Do something useful with the ciphertext here */
printf("Ciphertext is %d bytes long:\n", ciphertext_len);
BIO_dump_fp(stdout, (const char*)ciphertext, ciphertext_len);
/* Decrypt the ciphertext */
decryptedtext_len = aes_decrypt(ciphertext, ciphertext_len, key, iv,
decryptedtext);
/* Add a NULL terminator. We are expecting printable text */
decryptedtext[decryptedtext_len] = '\0';
and result: �'^{�'ی�u�E��##�s
what is the problem?