[Bounty] variant of PBKDF2-HMAC-SHA256 needed

[crypto]

I couldn't find a loop in the AES step.

The decryption part consists mainly of calls to these 3 sdk functions (sdk named 'mbed TLS'):

/**
* \brief PKCS#5 PBKDF2 using HMAC
*
* \param ctx Generic HMAC context
* \param password Password to use when generating key
* \param plen Length of password
* \param salt Salt to use when generating key
* \param slen Length of salt
* \param iteration_count Iteration count
* \param key_length Length of generated key in bytes
* \param output Generated key. Must be at least as big as key_length
*
* \returns 0 on success, or a MBEDTLS_ERR_XXX code if verification fails.
*/
int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx, const unsigned char *password,
size_t plen, const unsigned char *salt, size_t slen,
unsigned int iteration_count,
uint32_t key_length, unsigned char *output );

/**
* \brief AES key schedule (decryption)
*
* \param ctx AES context to be initialized
* \param key decryption key
* \param keybits must be 128, 192 or 256
*
* \return 0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
*/
int mbedtls_aes_setkey_dec( mbedtls_aes_context *ctx, const unsigned char *key,
unsigned int keybits );

/**
* \brief AES-CBC buffer encryption/decryption
* Length should be a multiple of the block
* size (16 bytes)
*
* \note Upon exit, the content of the IV is updated so that you can
* call the function same function again on the following
* block(s) of data and get the same result as if it was
* encrypted in one call. This allows a "streaming" usage.
* If on the other hand you need to retain the contents of the
* IV, you should either save it manually or use the cipher
* module instead.
*
* \param ctx AES context
* \param mode MBEDTLS_AES_ENCRYPT or MBEDTLS_AES_DECRYPT
* \param length length of the input data
* \param iv initialization vector (updated after use)
* \param input buffer holding the input data
* \param output buffer holding the output data
*
* \return 0 if successful, or MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH
*/
int mbedtls_aes_crypt_cbc( mbedtls_aes_context *ctx,
int mode,
size_t length,
unsigned char iv[16],
const unsigned char *input,
unsigned char *output );

This looks pretty straight to me. Input data is key (unknown), salt (known), iv (known), iteration_count (known), input (crypted data).

Any idea which hashcat algo would be easiest to modify for this?