static krb5_error_code
ec_process(krb5_context context, krb5_clpreauth_moddata moddata,
krb5_clpreauth_modreq modreq, krb5_get_init_creds_opt *opt,
krb5_clpreauth_callbacks cb,
krb5_clpreauth_rock rock, krb5_kdc_req *request,
krb5_data *encoded_request_body,
krb5_data *encoded_previous_request, krb5_pa_data *padata,
krb5_prompter_fct prompter, void *prompter_data,
krb5_pa_data ***out_padata)
{
krb5_error_code retval = 0;
krb5_keyblock *challenge_key = NULL, *armor_key, *as_key;
armor_key = cb->fast_armor(context, rock);
if (armor_key == NULL)
return ENOENT;
retval = cb->get_as_key(context, rock, &as_key);
if (retval == 0 && padata->length) {
krb5_enc_data *enc = NULL;
krb5_data scratch;
scratch.length = padata->length;
scratch.data = (char *) padata->contents;
retval = krb5_c_fx_cf2_simple(context,armor_key, "kdcchallengearmor",
as_key, "challengelongterm",
&challenge_key);
if (retval == 0)
retval = decode_krb5_enc_data(&scratch, &enc);
scratch.data = NULL;
if (retval == 0) {
scratch.data = malloc(enc->ciphertext.length);
scratch.length = enc->ciphertext.length;
if (scratch.data == NULL)
retval = ENOMEM;
}
if (retval == 0)
retval = krb5_c_decrypt(context, challenge_key,
KRB5_KEYUSAGE_ENC_CHALLENGE_KDC, NULL,
enc, &scratch);
/*
* Per draft 11 of the preauth framework, the client MAY but is not
* required to actually check the timestamp from the KDC other than to
* confirm it decrypts. This code does not perform that check.
*/
if (scratch.data)
krb5_free_data_contents(context, &scratch);
/* If we had a callback to assert that the KDC is verified, we would
* call it here. */
if (enc)
krb5_free_enc_data(context, enc);
} else if (retval == 0) { /*No padata; we send*/
krb5_enc_data enc;
krb5_pa_data **pa = NULL;
krb5_data *encoded_ts = NULL;
krb5_pa_enc_ts ts;
enc.ciphertext.data = NULL;
/* Use the timestamp from the preauth-required error if possible.
* This time should always be secured by the FAST channel. */
retval = cb->get_preauth_time(context, rock, FALSE, &ts.patimestamp,
&ts.pausec);
if (retval == 0)
retval = encode_krb5_pa_enc_ts(&ts, &encoded_ts);
if (retval == 0)
retval = krb5_c_fx_cf2_simple(context,
armor_key, "clientchallengearmor",
as_key, "challengelongterm",
&challenge_key);
if (retval == 0)
retval = krb5_encrypt_helper(context, challenge_key,
KRB5_KEYUSAGE_ENC_CHALLENGE_CLIENT,
encoded_ts, &enc);
if (encoded_ts)
krb5_free_data(context, encoded_ts);
encoded_ts = NULL;
if (retval == 0) {
retval = encode_krb5_enc_data(&enc, &encoded_ts);
krb5_free_data_contents(context, &enc.ciphertext);
}
if (retval == 0) {
pa = calloc(2, sizeof(krb5_pa_data *));
if (pa == NULL)
retval = ENOMEM;
}
if (retval == 0) {
pa[0] = calloc(1, sizeof(krb5_pa_data));
if (pa[0] == NULL)
retval = ENOMEM;
}
if (retval == 0) {
pa[0]->length = encoded_ts->length;
pa[0]->contents = (unsigned char *) encoded_ts->data;
pa[0]->pa_type = KRB5_PADATA_ENCRYPTED_CHALLENGE;
encoded_ts->data = NULL;
*out_padata = pa;
pa = NULL;
}
free(pa);
krb5_free_data(context, encoded_ts);
}
if (challenge_key)
krb5_free_keyblock(context, challenge_key);
return retval;
}
static krb5_error_code
otp_client_process(krb5_context context, krb5_clpreauth_moddata moddata,
krb5_clpreauth_modreq modreq, krb5_get_init_creds_opt *opt,
krb5_clpreauth_callbacks cb, krb5_clpreauth_rock rock,
krb5_kdc_req *request, krb5_data *encoded_request_body,
krb5_data *encoded_previous_request, krb5_pa_data *pa_data,
krb5_prompter_fct prompter, void *prompter_data,
krb5_pa_data ***pa_data_out)
{
krb5_pa_otp_challenge *chl = NULL;
krb5_otp_tokeninfo *ti = NULL;
krb5_keyblock *as_key = NULL;
krb5_pa_otp_req *req = NULL;
krb5_error_code retval = 0;
krb5_data value, pin;
const char *answer;
if (modreq == NULL)
return ENOMEM;
chl = *(krb5_pa_otp_challenge **)modreq;
*pa_data_out = NULL;
/* Get FAST armor key. */
as_key = cb->fast_armor(context, rock);
if (as_key == NULL)
return ENOENT;
/* Use FAST armor key as response key. */
retval = cb->set_as_key(context, rock, as_key);
if (retval != 0)
return retval;
/* Attempt to get token selection from the responder. */
pin = empty_data();
value = empty_data();
answer = cb->get_responder_answer(context, rock,
KRB5_RESPONDER_QUESTION_OTP);
retval = codec_decode_answer(context, answer, chl->tokeninfo, &ti, &value,
&pin);
if (retval != 0) {
/* If the responder doesn't have a token selection,
* we need to select the token via prompting. */
retval = prompt_for_token(context, prompter, prompter_data,
chl->tokeninfo, &ti, &value, &pin);
if (retval != 0)
goto error;
}
/* Make the request. */
retval = make_request(context, ti, &value, &pin, &req);
if (retval != 0)
goto error;
/* Save information about the token which was used. */
save_config_tokeninfo(context, cb, rock, ti);
/* Encrypt the challenge's nonce and set it in the request. */
retval = encrypt_nonce(context, as_key, chl, req);
if (retval != 0)
goto error;
/* Encode the request into the pa_data output. */
retval = set_pa_data(req, pa_data_out);
error:
krb5_free_data_contents(context, &value);
krb5_free_data_contents(context, &pin);
k5_free_pa_otp_req(context, req);
return retval;
}