source: openpam/trunk/lib/liboath/oath_key.c @ 772

/*-
 * Copyright (c) 2013 Universitetet i Oslo
 * 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. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $Id: oath_key.c 772 2014-03-09 11:45:05Z des $
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <sys/types.h>

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>

#include <security/pam_appl.h>
#include <security/openpam.h>

#include "openpam_strlcmp.h"

#include <security/oath.h>

struct oath_key *
oath_key_from_file(const char *filename)
{
        struct oath_key *key;
        FILE *f;
        char *line;
        size_t len;

        if ((f = fopen(filename, "r")) == NULL)
                return (NULL);
        /* get first non-empty non-comment line */
        line = openpam_readline(f, NULL, &len);
        if (strlcmp("otpauth://", line, len) == 0) {
                key = oath_key_from_uri(line);
        } else {
                openpam_log(PAM_LOG_ERROR,
                    "unrecognized key file format: %s", filename);
                key = NULL;
        }
        fclose(f);
        return (key);
}

char *
oath_key_to_uri(const struct oath_key *key)
{
        const char *hash;
        char *tmp, *uri;
        size_t kslen, urilen;

        switch (key->hash) {
        case oh_sha1:
                hash = "SHA1";
                break;
        case oh_sha256:
                hash = "SHA256";
                break;
        case oh_sha512:
                hash = "SHA512";
                break;
        case oh_md5:
                hash = "MD5";
                break;
        default:
                return (NULL);
        }

        /* XXX the label should be URI-encoded */
        if (key->mode == om_hotp) {
                urilen = asprintf(&uri, "otpauth://%s/%s?"
                    "algorithm=%s&digits=%d&counter=%ju&secret=",
                    "hotp", key->label, hash, key->digits,
                    (uintmax_t)key->counter);
        } else if (key->mode == om_totp) {
                urilen = asprintf(&uri, "otpauth://%s/%s?"
                    "algorithm=%s&digits=%d&period=%u&lastused=%ju&secret=",
                    "totp", key->label, hash, key->digits, key->timestep,
                    (uintmax_t)key->lastused);
        } else {
                /* unreachable */
                return (NULL);
        }

        /* compute length of base32-encoded key and append it */
        kslen = base32_enclen(key->keylen) + 1;
        if ((tmp = realloc(uri, urilen + kslen)) == NULL) {
                free(uri);
                return (NULL);
        }
        uri = tmp;
        if (base32_enc((char *)key->key, key->keylen, uri + urilen, &kslen) != 0) {
                free(uri);
                return (NULL);
        }

        return (uri);
}