/*
 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
 */

/* LOGIN is a PLAIN-like authenticator, but for older deployments. */

/* Login SASL plugin
 * Rob Siemborski (SASLv2 Conversion)
 * contributed by Rainer Schoepf <schoepf@uni-mainz.de>
 * based on PLAIN, by Tim Martin <tmartin@andrew.cmu.edu>
 * $Id: login.c,v 1.25 2003/02/13 19:56:04 rjs3 Exp $
 */
/*
 * Copyright (c) 1998-2003 Carnegie Mellon University.  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 "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any other legal
 *    details, please contact
 *      Office of Technology Transfer
 *      Carnegie Mellon University
 *      5000 Forbes Avenue
 *      Pittsburgh, PA  15213-3890
 *      (412) 268-4387, fax: (412) 268-7395
 *      tech-transfer@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <config.h>
#include <stdio.h>
#include <ctype.h>
#include <sasl.h>
#include <saslplug.h>

#include "plugin_common.h"

#ifndef _SUN_SDK_
#ifdef WIN32
/* This must be after sasl.h */
# include "saslLOGIN.h"
#endif /* WIN32 */
#endif /* !_SUN_SDK_ */

/*****************************  Common Section  *****************************/

#ifndef _SUN_SDK_
static const char plugin_id[] = "$Id: login.c,v 1.25 2003/02/13 19:56:04 rjs3 Exp $";
#endif /* !_SUN_SDK_ */

/*****************************  Server Section  *****************************/

typedef struct context {
    int state;

    char *username;
    size_t username_len;
} server_context_t;

static int login_server_mech_new(void *glob_context __attribute__((unused)),
                                 sasl_server_params_t *sparams,
                                 const char *challenge __attribute__((unused)),
                                 unsigned challen __attribute__((unused)),
                                 void **conn_context)
{
    server_context_t *text;

    /* holds state are in */
    text = sparams->utils->malloc(sizeof(server_context_t));
    if (text == NULL) {
        MEMERROR( sparams->utils );
        return SASL_NOMEM;
    }

    memset(text, 0, sizeof(server_context_t));

    text->state = 1;

    *conn_context = text;

    return SASL_OK;
}

#define USERNAME_CHALLENGE "Username:"
#define PASSWORD_CHALLENGE "Password:"

static int login_server_mech_step(void *conn_context,
                                  sasl_server_params_t *params,
                                  const char *clientin,
                                  unsigned clientinlen,
                                  const char **serverout,
                                  unsigned *serveroutlen,
                                  sasl_out_params_t *oparams)
{
    server_context_t *text = (server_context_t *) conn_context;

    *serverout = NULL;
    *serveroutlen = 0;

    switch (text->state) {

    case 1:
        text->state = 2;

        /* Check inlen, (possibly we have already the user name) */
        /* In this case fall through to state 2 */
        if (clientinlen == 0) {
            /* demand username */

            *serveroutlen = strlen(USERNAME_CHALLENGE);
            *serverout = USERNAME_CHALLENGE;

            return SASL_CONTINUE;
        }
        /* FALLTHROUGH */

    case 2:
        /* Catch really long usernames */
        if (clientinlen > 1024) {
#ifdef _SUN_SDK_
            params->utils->log(params->utils->conn, SASL_LOG_ERR,
                "username too long (>1024 characters)");
#else
            SETERROR(params->utils, "username too long (>1024 characters)");
#endif  /* _SUN_SDK_ */
            return SASL_BADPROT;
        }

        /* get username */
        text->username =
            params->utils->malloc(sizeof(sasl_secret_t) + clientinlen + 1);
        if (!text->username) {
            MEMERROR( params->utils );
            return SASL_NOMEM;
        }

        strncpy(text->username, clientin, clientinlen);
        text->username_len = clientinlen;
        text->username[clientinlen] = '\0';

        /* demand password */
        *serveroutlen = strlen(PASSWORD_CHALLENGE);
        *serverout = PASSWORD_CHALLENGE;

        text->state = 3;

        return SASL_CONTINUE;


    case 3: {
        sasl_secret_t *password;
        int result;

        /* Catch really long passwords */
        if (clientinlen > 1024) {
#ifdef _SUN_SDK_
            params->utils->log(params->utils->conn, SASL_LOG_ERR,
                     "clientinlen is > 1024 characters in LOGIN plugin");
#else
            SETERROR(params->utils,
                     "clientinlen is > 1024 characters in LOGIN plugin");
#endif  /* _SUN_SDK_ */
            return SASL_BADPROT;
        }

        /* get password */
        password =
            params->utils->malloc(sizeof(sasl_secret_t) + clientinlen + 1);
        if (!password) {
            MEMERROR(params->utils);
            return SASL_NOMEM;
        }

        strncpy((char *)password->data, clientin, clientinlen);
        password->data[clientinlen] = '\0';
        password->len = clientinlen;

        /* canonicalize username first, so that password verification is
         * done against the canonical id */
        result = params->canon_user(params->utils->conn, text->username,
                                    text->username_len,
                                    SASL_CU_AUTHID | SASL_CU_AUTHZID, oparams);
        if (result != SASL_OK) {
                _plug_free_secret(params->utils, &password);
                return result;
        }

        /* verify_password - return sasl_ok on success */
        result = params->utils->checkpass(params->utils->conn,
                                        oparams->authid, oparams->alen,
                                        (char *)password->data, password->len);

        if (result != SASL_OK) {
            _plug_free_secret(params->utils, &password);
            return result;
        }

        if (params->transition) {
            params->transition(params->utils->conn,
                               (char *)password->data, password->len);
        }

        _plug_free_secret(params->utils, &password);

        *serverout = NULL;
        *serveroutlen = 0;

        oparams->doneflag = 1;
        oparams->mech_ssf = 0;
        oparams->maxoutbuf = 0;
        oparams->encode_context = NULL;
        oparams->encode = NULL;
        oparams->decode_context = NULL;
        oparams->decode = NULL;
        oparams->param_version = 0;

        return SASL_OK;
    }


    default:
        params->utils->log(NULL, SASL_LOG_ERR,
                           "Invalid LOGIN server step %d\n", text->state);
        return SASL_FAIL;
    }

    return SASL_FAIL; /* should never get here */
}

static void login_server_mech_dispose(void *conn_context,
                                      const sasl_utils_t *utils)
{
    server_context_t *text = (server_context_t *) conn_context;

    if (!text) return;

    if (text->username) utils->free(text->username);

    utils->free(text);
}

static sasl_server_plug_t login_server_plugins[] =
{
    {
        "LOGIN",                        /* mech_name */
        0,                              /* max_ssf */
        SASL_SEC_NOANONYMOUS,           /* security_flags */
        0,                              /* features */
        NULL,                           /* glob_context */
        &login_server_mech_new,         /* mech_new */
        &login_server_mech_step,        /* mech_step */
        &login_server_mech_dispose,     /* mech_dispose */
        NULL,                           /* mech_free */
        NULL,                           /* setpass */
        NULL,                           /* user_query */
        NULL,                           /* idle */
        NULL,                           /* mech_avail */
        NULL                            /* spare */
    }
};

int login_server_plug_init(sasl_utils_t *utils,
                           int maxversion,
                           int *out_version,
                           sasl_server_plug_t **pluglist,
                           int *plugcount)
{
    if (maxversion < SASL_SERVER_PLUG_VERSION) {
        SETERROR(utils, "LOGIN version mismatch");
        return SASL_BADVERS;
    }

    *out_version = SASL_SERVER_PLUG_VERSION;
    *pluglist = login_server_plugins;
    *plugcount = 1;

    return SASL_OK;
}

/*****************************  Client Section  *****************************/

typedef struct client_context {
    int state;

#ifdef _INTEGRATED_SOLARIS_
    void *h;
#endif /* _INTEGRATED_SOLARIS_ */
    sasl_secret_t *password;
    unsigned int free_password; /* set if we need to free password */
} client_context_t;

static int login_client_mech_new(void *glob_context __attribute__((unused)),
                                 sasl_client_params_t *params,
                                 void **conn_context)
{
    client_context_t *text;

    /* holds state are in */
    text = params->utils->malloc(sizeof(client_context_t));
    if (text == NULL) {
        MEMERROR(params->utils);
        return SASL_NOMEM;
    }

    memset(text, 0, sizeof(client_context_t));

    text->state = 1;

    *conn_context = text;

    return SASL_OK;
}

static int login_client_mech_step(void *conn_context,
                                  sasl_client_params_t *params,
                                  const char *serverin __attribute__((unused)),
                                  unsigned serverinlen __attribute__((unused)),
                                  sasl_interact_t **prompt_need,
                                  const char **clientout,
                                  unsigned *clientoutlen,
                                  sasl_out_params_t *oparams)
{
    client_context_t *text = (client_context_t *) conn_context;

    *clientout = NULL;
    *clientoutlen = 0;

    switch (text->state) {

    case 1: {
        const char *user;
        int auth_result = SASL_OK;
        int pass_result = SASL_OK;
        int result;

        /* check if sec layer strong enough */
        if (params->props.min_ssf > params->external_ssf) {
#ifdef _INTEGRATED_SOLARIS_
            params->utils->log(params->utils->conn, SASL_LOG_ERR,
                gettext("SSF requested of LOGIN plugin"));
#else
            SETERROR( params->utils, "SSF requested of LOGIN plugin");
#endif /* _INTEGRATED_SOLARIS_ */
            return SASL_TOOWEAK;
        }

        /* try to get the userid */
        /* Note: we want to grab the authname and not the userid, which is
         *       who we AUTHORIZE as, and will be the same as the authname
         *       for the LOGIN mech.
         */
        if (oparams->user == NULL) {
            auth_result = _plug_get_authid(params->utils, &user, prompt_need);

            if ((auth_result != SASL_OK) && (auth_result != SASL_INTERACT))
                return auth_result;
        }

        /* try to get the password */
        if (text->password == NULL) {
            pass_result = _plug_get_password(params->utils, &text->password,
                                             &text->free_password, prompt_need);

            if ((pass_result != SASL_OK) && (pass_result != SASL_INTERACT))
                return pass_result;
        }

        /* free prompts we got */
        if (prompt_need && *prompt_need) {
            params->utils->free(*prompt_need);
            *prompt_need = NULL;
        }

        /* if there are prompts not filled in */
        if ((auth_result == SASL_INTERACT) || (pass_result == SASL_INTERACT)) {
            /* make the prompt list */
            result =
#ifdef _INTEGRATED_SOLARIS_
                _plug_make_prompts(params->utils, &text->h, prompt_need,
                    NULL, NULL,
                    auth_result == SASL_INTERACT ?
                    gettext("Please enter your authentication name") : NULL,
                    NULL,
                    pass_result == SASL_INTERACT ?
                    gettext("Please enter your password") : NULL, NULL,
                    NULL, NULL, NULL,
                    NULL, NULL, NULL);
#else
                _plug_make_prompts(params->utils, prompt_need,
                                   NULL, NULL,
                                   auth_result == SASL_INTERACT ?
                                   "Please enter your authentication name" : NULL,
                                   NULL,
                                   pass_result == SASL_INTERACT ?
                                   "Please enter your password" : NULL, NULL,
                                   NULL, NULL, NULL,
                                   NULL, NULL, NULL);
#endif /* _INTEGRATED_SOLARIS_ */
            if (result != SASL_OK) return result;

            return SASL_INTERACT;
        }

        if (!text->password) {
            PARAMERROR(params->utils);
            return SASL_BADPARAM;
        }

        result = params->canon_user(params->utils->conn, user, 0,
                                    SASL_CU_AUTHID | SASL_CU_AUTHZID, oparams);
        if (result != SASL_OK) return result;

        /* server should have sent request for username - we ignore it */
        if (!serverin) {
#ifdef _SUN_SDK_
            params->utils->log(params->utils->conn, SASL_LOG_ERR,
                      "Server didn't issue challenge for USERNAME");
#else
            SETERROR( params->utils,
                      "Server didn't issue challenge for USERNAME");
#endif /* _SUN_SDK_ */
            return SASL_BADPROT;
        }

        if (!clientout) {
            PARAMERROR( params->utils );
            return SASL_BADPARAM;
        }

        if (clientoutlen) *clientoutlen = oparams->alen;
        *clientout = oparams->authid;

        text->state = 2;

        return SASL_CONTINUE;
    }

    case 2:
        /* server should have sent request for password - we ignore it */
        if (!serverin) {
#ifdef _SUN_SDK_
            params->utils->log(params->utils->conn, SASL_LOG_ERR,
                      "Server didn't issue challenge for PASSWORD");
#else
            SETERROR( params->utils,
                      "Server didn't issue challenge for PASSWORD");
#endif /* _SUN_SDK_ */
            return SASL_BADPROT;
        }

        if (!clientout) {
            PARAMERROR(params->utils);
            return SASL_BADPARAM;
        }

        if (clientoutlen) *clientoutlen = text->password->len;
        *clientout = (char *)text->password->data;

        /* set oparams */
        oparams->doneflag = 1;
        oparams->mech_ssf = 0;
        oparams->maxoutbuf = 0;
        oparams->encode_context = NULL;
        oparams->encode = NULL;
        oparams->decode_context = NULL;
        oparams->decode = NULL;
        oparams->param_version = 0;

        return SASL_OK;

    default:
        params->utils->log(NULL, SASL_LOG_ERR,
                           "Invalid LOGIN client step %d\n", text->state);
        return SASL_FAIL;
    }

    return SASL_FAIL; /* should never get here */
}

static void login_client_mech_dispose(void *conn_context,
                                      const sasl_utils_t *utils)
{
    client_context_t *text = (client_context_t *) conn_context;

    if (!text) return;

    /* free sensitive info */
    if (text->free_password) _plug_free_secret(utils, &(text->password));
#ifdef _INTEGRATED_SOLARIS_
    convert_prompt(utils, &text->h, NULL);
#endif /* _INTEGRATED_SOLARIS_ */

    utils->free(text);
}

static sasl_client_plug_t login_client_plugins[] =
{
    {
        "LOGIN",                        /* mech_name */
        0,                              /* max_ssf */
        SASL_SEC_NOANONYMOUS,           /* security_flags */
        SASL_FEAT_SERVER_FIRST,         /* features */
        NULL,                           /* required_prompts */
        NULL,                           /* glob_context */
        &login_client_mech_new,         /* mech_new */
        &login_client_mech_step,        /* mech_step */
        &login_client_mech_dispose,     /* mech_dispose */
        NULL,                           /* mech_free */
        NULL,                           /* idle */
        NULL,                           /* spare */
        NULL                            /* spare */
    }
};

int login_client_plug_init(sasl_utils_t *utils,
                           int maxversion,
                           int *out_version,
                           sasl_client_plug_t **pluglist,
                           int *plugcount)
{
    if (maxversion < SASL_CLIENT_PLUG_VERSION) {
        SETERROR(utils, "Version mismatch in LOGIN");
        return SASL_BADVERS;
    }

    *out_version = SASL_CLIENT_PLUG_VERSION;
    *pluglist = login_client_plugins;
    *plugcount = 1;

    return SASL_OK;
}