/*
 * Copyright (c) 2006 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden). 
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 *
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 *
 * 3. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE. 
 */

#include "krb5_locl.h"
RCSID("$Id$");
#include "digest_asn1.h"

struct krb5_digest {
    char *cbtype;
    char *cbbinding;

    DigestInit init;
    DigestInitReply initReply;
    DigestRequest request;
    DigestResponse response;
};

krb5_error_code
krb5_digest_alloc(krb5_context context, krb5_digest *digest)
{
    krb5_digest d;

    d = calloc(1, sizeof(*d));
    if (d == NULL) {
	*digest = NULL;
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest = d;

    return 0;
}

void
krb5_digest_free(krb5_digest digest)
{
    if (digest == NULL)
	return;
    free_DigestInit(&digest->init);
    free_DigestInitReply(&digest->initReply);
    free_DigestRequest(&digest->request);
    free_DigestResponse(&digest->response);
    memset(digest, 0, sizeof(*digest));
    free(digest);
    return;
}

krb5_error_code
krb5_digest_set_server_cb(krb5_context context,
			  krb5_digest digest,
			  const char *type,
			  const char *binding)
{
    if (digest->init.channel) {
	krb5_set_error_string(context, "server channel binding already set");
	return EINVAL;
    }
    digest->init.channel = calloc(1, sizeof(*digest->init.channel));
    if (digest->init.channel == NULL)
	goto error;

    digest->init.channel->cb_type = strdup(type);
    if (digest->init.channel->cb_type == NULL)
	goto error;

    digest->init.channel->cb_binding = strdup(binding);
    if (digest->init.channel->cb_binding == NULL) 
	goto error;
    return 0;
error:
    if (digest->init.channel) {
	free(digest->init.channel->cb_type);
	free(digest->init.channel->cb_binding);
	free(digest->init.channel);
	digest->init.channel = NULL;
    }
    krb5_set_error_string(context, "out of memory");
    return ENOMEM;
}

krb5_error_code
krb5_digest_set_type(krb5_context context,
		     krb5_digest digest,
		     const char *type)
{
    if (digest->init.type) {
	krb5_set_error_string(context, "client type already set");
	return EINVAL;
    }
    digest->init.type = strdup(type);
    if (digest->init.type == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_hostname(krb5_context context,
			 krb5_digest digest,
			 const char *hostname)
{
    if (digest->init.hostname) {
	krb5_set_error_string(context, "server hostname already set");
	return EINVAL;
    }
    digest->init.hostname = malloc(sizeof(*digest->init.hostname));
    if (digest->init.hostname == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->init.hostname = strdup(hostname);
    if (*digest->init.hostname == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->init.hostname);
	digest->init.hostname = NULL;
	return ENOMEM;
    }
    return 0;
}

const char *
krb5_digest_get_server_nonce(krb5_context context,
			     krb5_digest digest)
{
    return digest->initReply.nonce;
}

krb5_error_code
krb5_digest_set_server_nonce(krb5_context context,
			     krb5_digest digest,
			     const char *nonce)
{
    if (digest->request.serverNonce) {
	krb5_set_error_string(context, "nonce already set");
	return EINVAL;
    }
    digest->request.serverNonce = strdup(nonce);
    if (digest->request.serverNonce == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    return 0;
}

const char *
krb5_digest_get_opaque(krb5_context context,
		       krb5_digest digest)
{
    return digest->initReply.opaque;
}

krb5_error_code
krb5_digest_set_opaque(krb5_context context,
		       krb5_digest digest,
		       const char *opaque)
{
    if (digest->request.opaque) {
	krb5_set_error_string(context, "opaque already set");
	return EINVAL;
    }
    digest->request.opaque = strdup(opaque);
    if (digest->request.opaque == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    return 0;
}

const char *
krb5_digest_get_identifier(krb5_context context,
			   krb5_digest digest)
{
    if (digest->initReply.identifier == NULL)
	return NULL;
    return *digest->initReply.identifier;
}

krb5_error_code
krb5_digest_set_identifier(krb5_context context,
			   krb5_digest digest,
			   const char *id)
{
    if (digest->request.identifier) {
	krb5_set_error_string(context, "identifier already set");
	return EINVAL;
    }
    digest->request.identifier = calloc(1, sizeof(*digest->request.identifier));
    if (digest->request.identifier == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.identifier = strdup(id);
    if (*digest->request.identifier == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.identifier);
	digest->request.identifier = NULL;
	return ENOMEM;
    }
    return 0;
}

static krb5_error_code
digest_request(krb5_context context,
	       krb5_digest digest,
	       krb5_realm realm,
	       krb5_ccache ccache,
	       krb5_key_usage usage,
	       const DigestReqInner *ireq,
	       DigestRepInner *irep)
{
    DigestREQ req;
    DigestREP rep;
    krb5_error_code ret;
    krb5_data data, data2;
    size_t size;
    krb5_crypto crypto = NULL;
    krb5_auth_context ac = NULL;
    krb5_principal principal = NULL;
    krb5_ccache id = NULL;
    krb5_realm r = NULL;

    krb5_data_zero(&data);
    krb5_data_zero(&data2);
    memset(&req, 0, sizeof(req));
    memset(&rep, 0, sizeof(rep));

    if (ccache == NULL) {
	ret = krb5_cc_default(context, &id);
	if (ret)
	    goto out;
    } else
	id = ccache;

    if (realm == NULL) {
	ret = krb5_get_default_realm(context, &r);
	if (ret)
	    goto out;
    } else
	r = realm;

    /*
     *
     */

    ret = krb5_make_principal(context, &principal, 
			      r, KRB5_DIGEST_NAME, r, NULL);
    if (ret)
	goto out;

    ASN1_MALLOC_ENCODE(DigestReqInner, data.data, data.length,
		       ireq, &size, ret);
    if (ret) {
	krb5_set_error_string(context,
			      "Failed to encode digest inner request");
	goto out;
    }
    if (size != data.length)
	krb5_abortx(context, "ASN.1 internal encoder error");

    ret = krb5_mk_req_exact(context, &ac, 
			    AP_OPTS_USE_SUBKEY|AP_OPTS_MUTUAL_REQUIRED,
			    principal, NULL, id, &req.apReq);
    if (ret)
	goto out;

    {
	krb5_keyblock *key;

	ret = krb5_auth_con_getlocalsubkey(context, ac, &key);
	if (ret)
	    goto out;
	if (key == NULL) {
	    krb5_set_error_string(context, "Digest failed to get local subkey");
	    ret = EINVAL;
	    goto out;
	}

	ret = krb5_crypto_init(context, key, 0, &crypto);
	krb5_free_keyblock (context, key);
	if (ret)
	    goto out;
    }

    ret = krb5_encrypt_EncryptedData(context, crypto, usage,
				     data.data, data.length, 0, 
				     &req.innerReq);
    if (ret)
	goto out;

    krb5_data_free(&data);

    ASN1_MALLOC_ENCODE(DigestREQ, data.data, data.length,
		       &req, &size, ret);
    if (ret) {
	krb5_set_error_string(context, "Failed to encode DigestREQest");
	goto out;
    }
    if (size != data.length)
	krb5_abortx(context, "ASN.1 internal encoder error");

    ret = krb5_sendto_kdc(context, &data, &r, &data2);
    if (ret)
	goto out;

    free_DigestResponse(&digest->response);

    ret = decode_DigestREP(data2.data, data2.length, &rep, NULL);
    if (ret) {
	krb5_set_error_string(context, "Failed to parse digest response");
	goto out;
    }

    {
	krb5_ap_rep_enc_part *repl;

	ret = krb5_rd_rep(context, ac, &rep.apRep, &repl);
	if (ret)
	    goto out;

	krb5_free_ap_rep_enc_part(context, repl);
    }
    {
	krb5_keyblock *key;

	ret = krb5_auth_con_getremotesubkey(context, ac, &key);
	if (ret)
	    goto out;
	if (key == NULL) {
	    ret = EINVAL;
	    krb5_set_error_string(context, 
				  "Digest reply have no remote subkey");
	    goto out;
	}

	krb5_crypto_destroy(context, crypto);
	ret = krb5_crypto_init(context, key, 0, &crypto);
	krb5_free_keyblock (context, key);
	if (ret)
	    goto out;
    }

    krb5_data_free(&data);
    ret = krb5_decrypt_EncryptedData(context, crypto, usage,
				     &rep.innerRep, &data);
    if (ret)
	goto out;
    
    ret = decode_DigestRepInner(data.data, data.length, irep, NULL);
    if (ret) {
	krb5_set_error_string(context, "Failed to decode digest inner reply");
	goto out;
    }

out:
    if (ccache == NULL && id)
	krb5_cc_close(context, id);
    if (realm == NULL && r)
	free(r);
    if (crypto)
	krb5_crypto_destroy(context, crypto);
    if (ac)
	krb5_auth_con_free(context, ac);
    if (principal)
	krb5_free_principal(context, principal);

    krb5_data_free(&data);
    krb5_data_free(&data2);

    free_DigestREQ(&req);
    free_DigestREP(&rep);

    return ret;
}

krb5_error_code
krb5_digest_init_request(krb5_context context,
			 krb5_digest digest,
			 krb5_realm realm,
			 krb5_ccache ccache)
{
    DigestReqInner ireq;
    DigestRepInner irep;
    krb5_error_code ret;

    memset(&ireq, 0, sizeof(ireq));
    memset(&irep, 0, sizeof(irep));

    if (digest->init.type == NULL) {
	krb5_set_error_string(context, "Type missing from init req");
	return EINVAL;
    }

    ireq.element = choice_DigestReqInner_init;
    ireq.u.init = digest->init;

    ret = digest_request(context, digest, realm, ccache,
			 KRB5_KU_DIGEST_ENCRYPT, &ireq, &irep);
    if (ret)
	goto out;

    if (irep.element == choice_DigestRepInner_error) {
	krb5_set_error_string(context, "Digest init error: %s",
			      irep.u.error.reason);
	ret = irep.u.error.code;
	goto out;
    }

    if (irep.element != choice_DigestRepInner_initReply) {
	krb5_set_error_string(context, "digest reply not an initReply");
	ret = EINVAL;
	goto out;
    }

    ret = copy_DigestInitReply(&irep.u.initReply, &digest->initReply);
    if (ret) {
	krb5_set_error_string(context, "Failed to copy initReply");
	goto out;
    }

out:
    free_DigestRepInner(&irep);

    return ret;
}


krb5_error_code
krb5_digest_set_client_nonce(krb5_context context,
			     krb5_digest digest,
			     const char *nonce)
{
    if (digest->request.clientNonce) {
	krb5_set_error_string(context, "clientNonce already set");
	return EINVAL;
    }
    digest->request.clientNonce = 
	calloc(1, sizeof(*digest->request.clientNonce));
    if (digest->request.clientNonce == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.clientNonce = strdup(nonce);
    if (*digest->request.clientNonce == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.clientNonce);
	digest->request.clientNonce = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_digest(krb5_context context,
		       krb5_digest digest,
		       const char *dgst)
{
    if (digest->request.digest) {
	krb5_set_error_string(context, "digest already set");
	return EINVAL;
    }
    digest->request.digest = strdup(dgst);
    if (digest->request.digest == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_username(krb5_context context,
			 krb5_digest digest,
			 const char *username)
{
    if (digest->request.username) {
	krb5_set_error_string(context, "username already set");
	return EINVAL;
    }
    digest->request.username = strdup(username);
    if (digest->request.username == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_authid(krb5_context context,
		       krb5_digest digest,
		       const char *authid)
{
    if (digest->request.authid) {
	krb5_set_error_string(context, "authid already set");
	return EINVAL;
    }
    digest->request.authid = malloc(sizeof(*digest->request.authid));
    if (digest->request.authid == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.authid = strdup(authid);
    if (*digest->request.authid == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.authid);
	digest->request.authid = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_authentication_user(krb5_context context,
				    krb5_digest digest,
				    krb5_principal authentication_user)
{
    krb5_error_code ret;

    if (digest->request.authentication_user) {
	krb5_set_error_string(context, "authentication_user already set");
	return EINVAL;
    }
    ret = krb5_copy_principal(context,
			      authentication_user,
			      &digest->request.authentication_user);
    if (digest->request.authentication_user == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_realm(krb5_context context,
		      krb5_digest digest,
		      const char *realm)
{
    if (digest->request.realm) {
	krb5_set_error_string(context, "realm already set");
	return EINVAL;
    }
    digest->request.realm = malloc(sizeof(*digest->request.realm));
    if (digest->request.realm == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.realm = strdup(realm);
    if (*digest->request.realm == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.realm);
	digest->request.realm = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_method(krb5_context context,
		       krb5_digest digest,
		       const char *method)
{
    if (digest->request.method) {
	krb5_set_error_string(context, "method already set");
	return EINVAL;
    }
    digest->request.method = malloc(sizeof(*digest->request.method));
    if (digest->request.method == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.method = strdup(method);
    if (*digest->request.method == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.method);
	digest->request.method = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_uri(krb5_context context,
		    krb5_digest digest,
		    const char *uri)
{
    if (digest->request.uri) {
	krb5_set_error_string(context, "uri already set");
	return EINVAL;
    }
    digest->request.uri = malloc(sizeof(*digest->request.uri));
    if (digest->request.uri == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.uri = strdup(uri);
    if (*digest->request.uri == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.uri);
	digest->request.uri = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_nonceCount(krb5_context context,
			   krb5_digest digest,
			   const char *nonce_count)
{
    if (digest->request.nonceCount) {
	krb5_set_error_string(context, "nonceCount already set");
	return EINVAL;
    }
    digest->request.nonceCount = 
	malloc(sizeof(*digest->request.nonceCount));
    if (digest->request.nonceCount == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.nonceCount = strdup(nonce_count);
    if (*digest->request.nonceCount == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.nonceCount);
	digest->request.nonceCount = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_set_qop(krb5_context context,
		    krb5_digest digest,
		    const char *qop)
{
    if (digest->request.qop) {
	krb5_set_error_string(context, "qop already set");
	return EINVAL;
    }
    digest->request.qop = malloc(sizeof(*digest->request.qop));
    if (digest->request.qop == NULL) {
	krb5_set_error_string(context, "out of memory");
	return ENOMEM;
    }
    *digest->request.qop = strdup(qop);
    if (*digest->request.qop == NULL) {
	krb5_set_error_string(context, "out of memory");
	free(digest->request.qop);
	digest->request.qop = NULL;
	return ENOMEM;
    }
    return 0;
}

krb5_error_code
krb5_digest_request(krb5_context context,
		    krb5_digest digest,
		    krb5_realm realm,
		    krb5_ccache ccache)
{
    DigestReqInner ireq;
    DigestRepInner irep;
    krb5_error_code ret;

    memset(&ireq, 0, sizeof(ireq));
    memset(&irep, 0, sizeof(irep));

    ireq.element = choice_DigestReqInner_digestRequest;
    ireq.u.digestRequest = digest->request;

    if (digest->request.type == NULL) {
	if (digest->init.type == NULL) {
	    krb5_set_error_string(context, "Type missing from req");
	    return EINVAL;
	}
	ireq.u.digestRequest.type = digest->init.type;
    }

    if (ireq.u.digestRequest.digest == NULL)
	ireq.u.digestRequest.digest = "md5";

    ret = digest_request(context, digest, realm, ccache,
			 KRB5_KU_DIGEST_ENCRYPT, &ireq, &irep);
    if (ret)
	return ret;

    if (irep.element == choice_DigestRepInner_error) {
	krb5_set_error_string(context, "Digest response error: %s",
			      irep.u.error.reason);
	ret = irep.u.error.code;
	goto out;
    }

    if (irep.element != choice_DigestRepInner_response) {
	krb5_set_error_string(context, "digest reply not an DigestResponse");
	ret = EINVAL;
	goto out;
    }

    ret = copy_DigestResponse(&irep.u.response, &digest->response);
    if (ret) {
	krb5_set_error_string(context, "Failed to copy initReply");
	goto out;
    }

out:
    free_DigestRepInner(&irep);

    return ret;
}

const char *
krb5_digest_get_responseData(krb5_context context,
			     krb5_digest digest)
{
    return digest->response.responseData;
}

const char *
krb5_digest_get_rsp(krb5_context context,
		    krb5_digest digest)
{
    if (digest->response.rsp == NULL)
	return NULL;
    return *digest->response.rsp;
}

krb5_error_code
krb5_digest_get_tickets(krb5_context context,
			krb5_digest digest,
			Ticket **tickets)
{
    *tickets = NULL;
    return 0;
}


krb5_error_code
krb5_digest_get_client_binding(krb5_context context,
			       krb5_digest digest,
			       char **type,
			       char **binding)
{
    if (digest->response.channel) {
	*type = strdup(digest->response.channel->cb_type);
	*binding = strdup(digest->response.channel->cb_binding);
	if (*type == NULL || *binding == NULL) {
	    free(*type);
	    free(*binding);
	    krb5_set_error_string(context, "out of memory");
	    return ENOMEM;
	}
    } else {
	*type = NULL;
	*binding = NULL;
    }
    return 0;
}

krb5_error_code
krb5_digest_get_a1_hash(krb5_context context,
			krb5_digest digest,
			krb5_data *data)
{
    krb5_error_code ret;

    krb5_data_zero(data);
    if (digest->response.hash_a1 == NULL)
	return 0;
    ret = der_copy_octet_string(digest->response.hash_a1, data);
    if (ret)
	krb5_clear_error_string(context);

    return ret;
}