/*
 * Copyright (c) 2003 - 2005 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 "test_locl.h"
#include <gssapi/gssapi.h>
#include <gssapi/gssapi_krb5.h>
#include <gssapi/gssapi_spnego.h>
#include "gss_common.h"
#include <base64.h>

RCSID("$Id$");

/*
 * A simplistic client implementing draft-brezak-spnego-http-04.txt
 */

static int
do_connect (const char *hostname, const char *port)
{
    struct addrinfo *ai, *a;
    struct addrinfo hints;
    int error;
    int s = -1;

    memset (&hints, 0, sizeof(hints));
    hints.ai_family = PF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = 0;

    error = getaddrinfo (hostname, port, &hints, &ai);
    if (error)
        errx (1, "getaddrinfo(%s): %s", hostname, gai_strerror(error));

    for (a = ai; a != NULL; a = a->ai_next) {
        s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
        if (s < 0)
            continue;
        if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
            warn ("connect(%s)", hostname);
            close (s);
            continue;
        }
        break;
    }
    freeaddrinfo (ai);
    if (a == NULL)
        errx (1, "failed to contact %s", hostname);

    return s;
}

static void
fdprintf(int s, const char *fmt, ...)
{
    size_t len;
    ssize_t ret;
    va_list ap;
    char *str, *buf;

    va_start(ap, fmt);
    vasprintf(&str, fmt, ap);
    va_end(ap);

    if (str == NULL)
        errx(1, "vasprintf");

    buf = str;
    len = strlen(buf);
    while (len) {
        ret = write(s, buf, len);
        if (ret == 0)
            err(1, "connection closed");
        else if (ret < 0)
            err(1, "error");
        len -= ret;
        buf += ret;
    }
    free(str);
}

static int help_flag;
static int version_flag;
static int verbose_flag;
static int mutual_flag = 1;
static int delegate_flag;
static char *port_str = "http";
static char *gss_service = "HTTP";

static struct getargs http_args[] = {
    { "verbose", 'v', arg_flag, &verbose_flag, "verbose logging", },
    { "port", 'p', arg_string, &port_str, "port to connect to", "port" },
    { "delegate", 0, arg_flag, &delegate_flag, "gssapi delegate credential" },
    { "gss-service", 's', arg_string, &gss_service, "gssapi service to use",
      "service" },
    { "mech", 'm', arg_string, &mech, "gssapi mech to use", "mech" },
    { "mutual", 0, arg_negative_flag, &mutual_flag, "no gssapi mutual auth" },
    { "help", 'h', arg_flag, &help_flag },
    { "version", 0, arg_flag, &version_flag }
};

static int num_http_args = sizeof(http_args) / sizeof(http_args[0]);

static void
usage(int code)
{
    arg_printusage(http_args, num_http_args, NULL, "host [page]");
    exit(code);
}

/*
 *
 */

struct http_req {
    char *response;
    char **headers;
    int num_headers;
    void *body;
    size_t body_size;
};


static void
http_req_zero(struct http_req *req)
{
    req->response = NULL;
    req->headers = NULL;
    req->num_headers = 0;
    req->body = NULL;
    req->body_size = 0;
}

static void
http_req_free(struct http_req *req)
{
    int i;

    free(req->response);
    for (i = 0; i < req->num_headers; i++)
        free(req->headers[i]);
    free(req->headers);
    free(req->body);
    http_req_zero(req);
}

static const char *
http_find_header(struct http_req *req, const char *header)
{
    int i, len = strlen(header);

    for (i = 0; i < req->num_headers; i++) {
        if (strncasecmp(header, req->headers[i], len) == 0) {
            return req->headers[i] + len + 1;
        }
    }
    return NULL;
}


static int
http_query(const char *host, const char *page,
           char **headers, int num_headers, struct http_req *req)
{
    enum { RESPONSE, HEADER, BODY } state;
    ssize_t ret;
    char in_buf[1024], *in_ptr = in_buf;
    size_t in_len = 0;
    int s, i;

    http_req_zero(req);

    s = do_connect(host, port_str);
    if (s < 0)
        errx(1, "connection failed");

    fdprintf(s, "GET %s HTTP/1.0\r\n", page);
    for (i = 0; i < num_headers; i++)
        fdprintf(s, "%s\r\n", headers[i]);
    fdprintf(s, "Host: %s\r\n\r\n", host);

    state = RESPONSE;

    while (1) {
        ret = read (s, in_ptr, sizeof(in_buf) - in_len - 1);
        if (ret == 0)
            break;
        else if (ret < 0)
            err (1, "read: %lu", (unsigned long)ret);

        in_buf[ret + in_len] = '\0';

        if (state == HEADER || state == RESPONSE) {
            char *p;

            in_len += ret;
            in_ptr += ret;

            while (1) {
                p = strstr(in_buf, "\r\n");

                if (p == NULL) {
                    break;
                } else if (p == in_buf) {
                    memmove(in_buf, in_buf + 2, sizeof(in_buf) - 2);
                    state = BODY;
                    in_len -= 2;
                    in_ptr -= 2;
                    break;
                } else if (state == RESPONSE) {
                    req->response = emalloc(p - in_buf + 1);
                    memcpy(req->response, in_buf, p - in_buf);
                    req->response[p - in_buf] = '\0';
                    state = HEADER;
                } else {
                    req->headers = realloc(req->headers,
                                           (req->num_headers + 1) * sizeof(req->headers[0]));
                    req->headers[req->num_headers] = emalloc(p - in_buf + 1);
                    memcpy(req->headers[req->num_headers], in_buf, p - in_buf);
                    req->headers[req->num_headers][p - in_buf] = '\0';
                    if (req->headers[req->num_headers] == NULL)
                        errx(1, "strdup");
                    req->num_headers++;
                }
                memmove(in_buf, p + 2, sizeof(in_buf) - (p - in_buf) - 2);
                in_len -= (p - in_buf) + 2;
                in_ptr -= (p - in_buf) + 2;
            }
        }

        if (state == BODY) {

            req->body = erealloc(req->body, req->body_size + ret + 1);

            memcpy((char *)req->body + req->body_size, in_buf, ret);
            req->body_size += ret;
            ((char *)req->body)[req->body_size] = '\0';

            in_ptr = in_buf;
            in_len = 0;
        } else
            abort();
    }

    if (verbose_flag) {
        int i;
        printf("response: %s\n", req->response);
        for (i = 0; i < req->num_headers; i++)
            printf("header[%d] %s\n", i, req->headers[i]);
        printf("body: %.*s\n", (int)req->body_size, (char *)req->body);
    }

    close(s);
    return 0;
}


int
main(int argc, char **argv)
{
    struct http_req req;
    const char *host, *page;
    int i, done, print_body, gssapi_done, gssapi_started;
    char *headers[10]; /* XXX */
    int num_headers;
    gss_ctx_id_t context_hdl = GSS_C_NO_CONTEXT;
    gss_name_t server = GSS_C_NO_NAME;
    int optind = 0;
    gss_OID mech_oid;
    OM_uint32 flags;

    setprogname(argv[0]);

    if(getarg(http_args, num_http_args, argc, argv, &optind))
        usage(1);

    if (help_flag)
        usage (0);

    if(version_flag) {
        print_version(NULL);
        exit(0);
    }

    argc -= optind;
    argv += optind;

    mech_oid = select_mech(mech);

    if (argc != 1 && argc != 2)
        errx(1, "usage: %s host [page]", getprogname());
    host = argv[0];
    if (argc == 2)
        page = argv[1];
    else
        page = "/";

    flags = 0;
    if (delegate_flag)
        flags |= GSS_C_DELEG_FLAG;
    if (mutual_flag)
        flags |= GSS_C_MUTUAL_FLAG;

    done = 0;
    num_headers = 0;
    gssapi_done = 1;
    gssapi_started = 0;
    do {
        print_body = 0;

        http_query(host, page, headers, num_headers, &req);
        for (i = 0 ; i < num_headers; i++)
            free(headers[i]);
        num_headers = 0;

        if (strstr(req.response, " 200 ") != NULL) {
            print_body = 1;
            done = 1;
        } else if (strstr(req.response, " 401 ") != NULL) {
            if (http_find_header(&req, "WWW-Authenticate:") == NULL)
                errx(1, "Got %s but missed `WWW-Authenticate'", req.response);
            gssapi_done = 0;
        }

        if (!gssapi_done) {
            const char *h = http_find_header(&req, "WWW-Authenticate:");
            if (h == NULL)
                errx(1, "Got %s but missed `WWW-Authenticate'", req.response);

            if (strncasecmp(h, "Negotiate", 9) == 0) {
                OM_uint32 maj_stat, min_stat;
                gss_buffer_desc input_token, output_token;

                if (verbose_flag)
                    printf("Negotiate found\n");

                if (server == GSS_C_NO_NAME) {
                    char *name;
                    asprintf(&name, "%s@%s", gss_service, host);
                    input_token.length = strlen(name);
                    input_token.value = name;

                    maj_stat = gss_import_name(&min_stat,
                                               &input_token,
                                               GSS_C_NT_HOSTBASED_SERVICE,
                                               &server);
                    if (GSS_ERROR(maj_stat))
                        gss_err (1, min_stat, "gss_inport_name");
                    free(name);
                    input_token.length = 0;
                    input_token.value = NULL;
                }

                i = 9;
                while(h[i] && isspace((unsigned char)h[i]))
                    i++;
                if (h[i] != '\0') {
                    int len = strlen(&h[i]);
                    if (len == 0)
                        errx(1, "invalid Negotiate token");
                    input_token.value = emalloc(len);
                    len = base64_decode(&h[i], input_token.value);
                    if (len < 0)
                        errx(1, "invalid base64 Negotiate token %s", &h[i]);
                    input_token.length = len;
                } else {
                    if (gssapi_started)
                        errx(1, "Negotiate already started");
                    gssapi_started = 1;

                    input_token.length = 0;
                    input_token.value = NULL;
                }

                maj_stat =
                    gss_init_sec_context(&min_stat,
                                         GSS_C_NO_CREDENTIAL,
                                         &context_hdl,
                                         server,
                                         mech_oid,
                                         flags,
                                         0,
                                         GSS_C_NO_CHANNEL_BINDINGS,
                                         &input_token,
                                         NULL,
                                         &output_token,
                                         NULL,
                                         NULL);
                if (GSS_ERROR(maj_stat))
                    gss_err (1, min_stat, "gss_init_sec_context");
                else if (maj_stat & GSS_S_CONTINUE_NEEDED)
                    gssapi_done = 0;
                else {
                    gss_name_t targ_name, src_name;
                    gss_buffer_desc name_buffer;
                    gss_OID mech_type;

                    gssapi_done = 1;

                    printf("Negotiate done: %s\n", mech);

                    maj_stat = gss_inquire_context(&min_stat,
                                                   context_hdl,
                                                   &src_name,
                                                   &targ_name,
                                                   NULL,
                                                   &mech_type,
                                                   NULL,
                                                   NULL,
                                                   NULL);
                    if (GSS_ERROR(maj_stat))
                        gss_err (1, min_stat, "gss_inquire_context");

                    maj_stat = gss_display_name(&min_stat,
                                                src_name,
                                                &name_buffer,
                                                NULL);
                    if (GSS_ERROR(maj_stat))
                        gss_err (1, min_stat, "gss_display_name");

                    printf("Source: %.*s\n",
                           (int)name_buffer.length,
                           (char *)name_buffer.value);

                    gss_release_buffer(&min_stat, &name_buffer);

                    maj_stat = gss_display_name(&min_stat,
                                                targ_name,
                                                &name_buffer,
                                                NULL);
                    if (GSS_ERROR(maj_stat))
                        gss_err (1, min_stat, "gss_display_name");

                    printf("Target: %.*s\n",
                           (int)name_buffer.length,
                           (char *)name_buffer.value);

                    gss_release_name(&min_stat, &targ_name);
                    gss_release_buffer(&min_stat, &name_buffer);
                }

                if (output_token.length) {
                    char *neg_token;

                    base64_encode(output_token.value,
                                  output_token.length,
                                  &neg_token);

                    asprintf(&headers[0], "Authorization: Negotiate %s",
                             neg_token);

                    num_headers = 1;
                    free(neg_token);
                    gss_release_buffer(&min_stat, &output_token);
                }
                if (input_token.length)
                    free(input_token.value);

            } else
                done = 1;
        } else
            done = 1;

        if (verbose_flag) {
            printf("%s\n\n", req.response);

            for (i = 0; i < req.num_headers; i++)
                printf("%s\n", req.headers[i]);
            printf("\n");
        }
        if (print_body || verbose_flag)
            printf("%.*s\n", (int)req.body_size, (char *)req.body);

        http_req_free(&req);
    } while (!done);

    if (gssapi_done == 0)
        errx(1, "gssapi not done but http dance done");

    return 0;
}