/* Copyright (C) 2011 the GSS-PROXY contributors, see COPYING for license */

#include "config.h"
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include <netinet/in.h>
#include <pthread.h>
#include <gssapi/gssapi.h>
#include <gssapi/gssapi_krb5.h>
#include "src/gp_proxy.h"
#include "src/gp_rpc_process.h"
#include "src/gp_conv.h"
#include "src/gp_debug.h"
#include "src/client/gssapi_gpm.h"
#include "popt.h"

#define DEBUG(...) do { \
    char msg[4096]; \
    snprintf(msg, 4096, __VA_ARGS__); \
    fprintf(stderr, "%s:%d: %s", __FUNCTION__, __LINE__, msg); \
    fflush(stderr); \
} while(0);


int gp_send_buffer(int fd, char *buf, uint32_t len)
{
    uint32_t size;
    size_t wn;
    size_t pos;

    size = htonl(len);

    wn = write(fd, &size, sizeof(uint32_t));
    if (wn != 4) {
        return EIO;
    }

    pos = 0;
    while (len > pos) {
        wn = write(fd, buf + pos, len - pos);
        if (wn == -1) {
            if (errno == EINTR) {
                continue;
            }
            return errno;
        }
        pos += wn;
    }

    return 0;
}

int gp_recv_buffer(int fd, char *buf, uint32_t *len)
{
    uint32_t size;
    size_t rn;
    size_t pos;

    rn = read(fd, &size, sizeof(uint32_t));
    if (rn != 4) {
        return EIO;
    }

    *len = ntohl(size);

    if (*len > MAX_RPC_SIZE) {
        return EINVAL;
    }

    pos = 0;
    while (*len > pos) {
        rn = read(fd, buf + pos, *len - pos);
        if (rn == -1) {
            if (errno == EINTR) {
                continue;
            }
            return errno;
        }
        if (rn == 0) {
            return EIO;
        }
        pos += rn;
    }

    return 0;
}

int gp_send_accept_sec_context(int fd,
                               gssx_arg_accept_sec_context *arg,
                               gssx_res_accept_sec_context *res)
{
    XDR xdr_call_ctx;
    XDR xdr_reply_ctx;
    gp_rpc_msg msg;
    char buffer[MAX_RPC_SIZE];
    uint32_t length;
    bool xdrok;
    int ret;

    memset(&msg, 0, sizeof(gp_rpc_msg));

    xdrmem_create(&xdr_call_ctx, buffer, MAX_RPC_SIZE, XDR_ENCODE);
    xdrmem_create(&xdr_reply_ctx, buffer, MAX_RPC_SIZE, XDR_DECODE);

    msg.xid = 1;
    msg.header.type = GP_RPC_CALL;
    msg.header.gp_rpc_msg_union_u.chdr.rpcvers = 2;
    msg.header.gp_rpc_msg_union_u.chdr.prog = GSSPROXY;
    msg.header.gp_rpc_msg_union_u.chdr.vers = GSSPROXYVERS;
    msg.header.gp_rpc_msg_union_u.chdr.proc = GSSX_ACCEPT_SEC_CONTEXT;
    msg.header.gp_rpc_msg_union_u.chdr.cred.flavor = GP_RPC_AUTH_NONE;
    msg.header.gp_rpc_msg_union_u.chdr.cred.body.body_len = 0;
    msg.header.gp_rpc_msg_union_u.chdr.cred.body.body_val = NULL;
    msg.header.gp_rpc_msg_union_u.chdr.verf.flavor = GP_RPC_AUTH_NONE;
    msg.header.gp_rpc_msg_union_u.chdr.verf.body.body_len = 0;
    msg.header.gp_rpc_msg_union_u.chdr.verf.body.body_val = NULL;

    /* encode header */
    xdrok = xdr_gp_rpc_msg(&xdr_call_ctx, &msg);
    if (!xdrok) {
        return EFAULT;
    }

    /* encode data */
    xdrok = xdr_gssx_arg_accept_sec_context(&xdr_call_ctx, arg);
    if (!xdrok) {
        return EFAULT;
    }

    /* send to proxy */
    ret = gp_send_buffer(fd, buffer, xdr_getpos(&xdr_call_ctx));
    if (ret) {
        return EIO;
    }

    /* receive answer */
    ret = gp_recv_buffer(fd, buffer, &length);
    if (ret) {
        return EIO;
    }

    /* decode header */
    xdrok = xdr_gp_rpc_msg(&xdr_reply_ctx, &msg);
    if (!xdrok) {
        return EFAULT;
    }

    if (msg.xid != 1 ||
        msg.header.type != GP_RPC_REPLY ||
        msg.header.gp_rpc_msg_union_u.rhdr.status != GP_RPC_MSG_ACCEPTED ||
        msg.header.gp_rpc_msg_union_u.rhdr.gp_rpc_reply_header_u.accepted.reply_data.status != GP_RPC_SUCCESS) {
        return EINVAL;
    }

    /* decode answer */
    xdrok = xdr_gssx_res_accept_sec_context(&xdr_reply_ctx, res);
    if (!xdrok) {
        return EFAULT;
    }

    xdr_free((xdrproc_t)xdr_gp_rpc_msg, (char *)&msg);
    xdr_destroy(&xdr_call_ctx);
    xdr_destroy(&xdr_reply_ctx);
    return 0;
}

struct athread {
    pthread_t tid;
    int *cli_pipe;
    int *srv_pipe;
    char *target;
};

#define CLI_MSG "I am the buffer"

void *client_thread(void *pvt)
{
    struct athread *data;
    uint32_t ret_maj;
    uint32_t ret_min;
    char buffer[MAX_RPC_SIZE];
    uint32_t buflen;
    gss_buffer_desc target_buf;
    gss_buffer_desc in_token = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc out_token = GSS_C_EMPTY_BUFFER;
    struct gssx_name *name = NULL;
    struct gssx_ctx *ctx = NULL;
    struct gssx_cred *cred_handle = NULL;
    int ret = 0;
    gss_buffer_desc msg_buf = GSS_C_EMPTY_BUFFER;
    int conf_state;
    uint32_t max_size;

    data = (struct athread *)pvt;

    target_buf.value = (void *)data->target;
    target_buf.length = strlen(data->target) + 1;

    ret_maj = gpm_import_name(&ret_min, &target_buf,
                              GSS_C_NT_HOSTBASED_SERVICE, &name);
    if (ret_maj) {
        goto done;
    }

    do {
        ret_maj = gpm_init_sec_context(&ret_min,
                                       cred_handle,
                                       &ctx,
                                       name,
                                       GSS_C_NO_OID,
                                       GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG,
                                       0,
                                       GSS_C_NO_CHANNEL_BINDINGS,
                                       &in_token,
                                       NULL,
                                       &out_token,
                                       NULL,
                                       NULL);
        if (ret_maj != GSS_S_COMPLETE &&
            ret_maj != GSS_S_CONTINUE_NEEDED) {
            DEBUG("gss_init_sec_context() failed with: %d\n", ret_maj);
            goto done;
        }
        if (out_token.length != 0) {
            /* send to server */
            ret = gp_send_buffer(data->srv_pipe[1],
                                 out_token.value, out_token.length);
            if (ret) {
                goto done;
            }

            gss_release_buffer(&ret_min, &out_token);
        }

        if (!ctx) {
            goto done;
        }

        if (ret_maj == GSS_S_CONTINUE_NEEDED) {
            /* and wait for reply */
            ret = gp_recv_buffer(data->cli_pipe[0], buffer, &buflen);
            if (ret) {
                goto done;
            }

            in_token.value = buffer;
            in_token.length = buflen;
        }

    } while (ret_maj == GSS_S_CONTINUE_NEEDED);

    memcpy(buffer, CLI_MSG, sizeof(CLI_MSG));
    msg_buf.value = (void *)buffer;
    msg_buf.length = sizeof(CLI_MSG);

    ret_maj = gpm_get_mic(&ret_min, ctx,
                          GSS_C_QOP_DEFAULT,
                          &msg_buf, &out_token);
    if (ret_maj) {
        DEBUG("gpm_get_mic failed: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    /* send msg to server */
    ret = gp_send_buffer(data->srv_pipe[1],
                         msg_buf.value, msg_buf.length);
    if (ret) {
        goto done;
    }

    /* send signature to server */
    ret = gp_send_buffer(data->srv_pipe[1],
                         out_token.value, out_token.length);
    if (ret) {
        goto done;
    }

    gss_release_buffer(&ret_min, &out_token);

    in_token.value = CLI_MSG;
    in_token.length = strlen(in_token.value) + 1;

    ret_maj = gpm_wrap(&ret_min,
                       ctx,
                       1, /* conf_req_flag */
                       GSS_C_QOP_DEFAULT, /* qop_req */
                       &in_token,
                       &conf_state,
                       &out_token);
    if (ret_maj) {
        DEBUG("gpm_wrap failed: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    /* send to server */
    ret = gp_send_buffer(data->srv_pipe[1],
                         out_token.value,
                         out_token.length);
    if (ret) {
        goto done;
    }

    ret_maj = gpm_wrap_size_limit(&ret_min,
                                  ctx,
                                  1, /* conf_req */
                                  GSS_C_QOP_DEFAULT, /* qop_req */
                                  4096, /* size_req */
                                  &max_size);
    if (ret_maj) {
        DEBUG("gpm_wrap_size_limit failed: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    DEBUG("client: Success!\n");

done:
    gpm_release_name(&ret_min, &name);
    gss_release_buffer(&ret_min, &out_token);
    close(data->cli_pipe[0]);
    close(data->srv_pipe[1]);
    pthread_exit(NULL);
}

void *server_thread(void *pvt)
{
    struct athread *data;
    char buffer[MAX_RPC_SIZE];
    uint32_t buflen;
    gss_buffer_desc in_token = GSS_C_EMPTY_BUFFER;
    uint32_t ret_maj;
    uint32_t ret_min;
    struct gssx_ctx *context_handle = NULL;
    struct gssx_cred *cred_handle = NULL;
    struct gssx_name *src_name = NULL;
    gss_buffer_desc out_token = GSS_C_EMPTY_BUFFER;
    struct gssx_cred *deleg_cred = NULL;
    gss_OID_set mech_set = GSS_C_NO_OID_SET;
    gss_OID_set mech_names = GSS_C_NO_OID_SET;
    gss_OID_set mech_types = GSS_C_NO_OID_SET;
    gss_OID_set mech_attrs = GSS_C_NO_OID_SET;
    gss_OID_set known_mech_attrs = GSS_C_NO_OID_SET;
    gss_buffer_desc sasl_mech_name = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc mech_name = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc mech_description = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc name = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc short_desc = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc long_desc = GSS_C_EMPTY_BUFFER;
    gss_OID_set mechs = GSS_C_NO_OID_SET;
    gss_buffer_desc target_buf;
    struct gssx_name *target_name = NULL;
    struct gssx_name *canon_name = NULL;
    gss_buffer_desc out_name_buf = GSS_C_EMPTY_BUFFER;
    gss_OID out_name_type = GSS_C_NO_OID;
    gss_buffer_desc msg_token = GSS_C_EMPTY_BUFFER;
    int ret;
    gss_buffer_desc input_message_buffer = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc output_message_buffer = GSS_C_EMPTY_BUFFER;
    gss_qop_t qop_state;
    int conf_state;

    data = (struct athread *)pvt;

    target_buf.value = (void *)data->target;
    target_buf.length = strlen(data->target) + 1;

    /* import name family functions tests */
    ret_maj = gpm_import_name(&ret_min, &target_buf,
                              GSS_C_NT_HOSTBASED_SERVICE, &target_name);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_canonicalize_name(&ret_min, target_name,
                                    gss_mech_krb5, &canon_name);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_display_name(&ret_min, canon_name,
                               &out_name_buf, &out_name_type);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }
    DEBUG("Acquiring for: %s\n", (char *)out_name_buf.value);

    /* indicate mechs family functions tests */
    ret_maj = gpm_indicate_mechs(&ret_min, &mech_set);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    ret_maj = gpm_inquire_names_for_mech(&ret_min,
                                         &mech_set->elements[0],
                                         &mech_names);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(&mech_set->elements[0], ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_inquire_attrs_for_mech(&ret_min,
                                         &mech_set->elements[0],
                                         &mech_attrs,
                                         &known_mech_attrs);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(&mech_set->elements[0], ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_inquire_saslname_for_mech(&ret_min,
                                            &mech_set->elements[0],
                                            &sasl_mech_name,
                                            &mech_name,
                                            &mech_description);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(&mech_set->elements[0], ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_display_mech_attr(&ret_min,
                                    &mech_attrs->elements[0],
                                    &name, &short_desc, &long_desc);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_indicate_mechs_by_attrs(&ret_min,
                                          GSS_C_NO_OID_SET,
                                          GSS_C_NO_OID_SET,
                                          GSS_C_NO_OID_SET,
                                          &mechs);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }
    ret_maj = gpm_inquire_mechs_for_name(&ret_min, target_name, &mech_types);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    ret_maj = gpm_acquire_cred(&ret_min,
                               NULL, NULL,
                               GSS_C_INDEFINITE,
                               mech_set,
                               GSS_C_ACCEPT,
                               false,
                               &cred_handle,
                               NULL,
                               NULL);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    ret = gp_recv_buffer(data->srv_pipe[0], buffer, &buflen);
    if (ret) {
        DEBUG("Failed to get data from client!\n");
        goto done;
    }

    in_token.value = buffer;
    in_token.length = buflen;

    ret_maj = gpm_accept_sec_context(&ret_min,
                                     &context_handle,
                                     cred_handle,
                                     &in_token,
                                     GSS_C_NO_CHANNEL_BINDINGS,
                                     &src_name,
                                     NULL,
                                     &out_token,
                                     NULL,
                                     NULL,
                                     &deleg_cred);
    if (ret_maj) {
        DEBUG("gssproxy returned an error: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    if (out_token.length) {
        ret = gp_send_buffer(data->cli_pipe[1],
                             out_token.value, out_token.length);
        if (ret) {
            DEBUG("Failed to send data to client!\n");
            goto done;
        }
    }

    /* receive message from client */
    ret = gp_recv_buffer(data->srv_pipe[0], buffer, &buflen);
    if (ret) {
        DEBUG("Failed to get data from client!\n");
        goto done;
    }
    in_token.value = buffer;
    in_token.length = buflen;

    /* receive signature from client */
    ret = gp_recv_buffer(data->srv_pipe[0],
                         &buffer[in_token.length], &buflen);
    if (ret) {
        DEBUG("Failed to get data from client!\n");
        goto done;
    }
    msg_token.value = &buffer[in_token.length];
    msg_token.length = buflen;

    ret_maj = gpm_verify_mic(&ret_min, context_handle,
                             &in_token, &msg_token, NULL);
    if (ret_maj) {
        DEBUG("gpm_verify_mic failed: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    DEBUG("Received valid msg from client: [%s]\n", buffer);

    ret = gp_recv_buffer(data->srv_pipe[0], buffer, &buflen);
    if (ret) {
        DEBUG("Failed to get data from client!\n");
        goto done;
    }

    input_message_buffer.value = buffer;
    input_message_buffer.length = buflen;

    ret_maj = gpm_unwrap(&ret_min,
                         context_handle,
                         &input_message_buffer,
                         &output_message_buffer,
                         &conf_state,
                         &qop_state);
    if (ret_maj) {
        DEBUG("gpm_unwrap failed: %d\n", ret_maj);
        gp_log_failure(GSS_C_NO_OID, ret_maj, ret_min);
        goto done;
    }

    DEBUG("Received valid msg from client: [%s]\n",
        (char *)output_message_buffer.value);

done:
    gpm_release_name(&ret_min, &src_name);
    gpm_release_buffer(&ret_min, &out_token);
    gpm_release_buffer(&ret_min, &output_message_buffer);
    gpm_release_cred(&ret_min, &deleg_cred);
    gpm_delete_sec_context(&ret_min, &context_handle, GSS_C_NO_BUFFER);
    gss_release_oid_set(&ret_min, &mech_set);
    gss_release_oid_set(&ret_min, &mech_names);
    gss_release_oid_set(&ret_min, &mech_types);
    gss_release_oid_set(&ret_min, &mech_attrs);
    gss_release_oid_set(&ret_min, &known_mech_attrs);
    gss_release_buffer(&ret_min, &sasl_mech_name);
    gss_release_buffer(&ret_min, &mech_name);
    gss_release_buffer(&ret_min, &mech_description);
    gss_release_buffer(&ret_min, &name);
    gss_release_buffer(&ret_min, &short_desc);
    gss_release_buffer(&ret_min, &long_desc);
    gss_release_oid_set(&ret_min, &mechs);
    gpm_release_name(&ret_min, &target_name);
    gpm_release_name(&ret_min, &canon_name);
    gss_release_buffer(&ret_min, &out_name_buf);
    gss_release_oid(&ret_min, &out_name_type);
    close(data->srv_pipe[0]);
    close(data->cli_pipe[1]);
    pthread_exit(NULL);
}

int main(int argc, const char *argv[])
{
    int opt;
    poptContext pc;
    int opt_version = 0;
    char *opt_target = NULL;
    int srv_pipe[2];
    int cli_pipe[2];
    pthread_attr_t attr;
    struct athread server;
    struct athread client;
    void *retval;
    int ret;

    struct poptOption long_options[] = {
        POPT_AUTOHELP
        {"target", 't', POPT_ARG_STRING, &opt_target, 0, \
         _("Specify the target name used for the tests"), NULL}, \
        {"version", '\0', POPT_ARG_NONE, &opt_version, 0, \
         _("Print version number and exit"), NULL }, \
        POPT_TABLEEND
    };

    pc = poptGetContext(argv[0], argc, argv, long_options, 0);
    while((opt = poptGetNextOpt(pc)) != -1) {
        switch(opt) {
        default:
            fprintf(stderr, "\nInvalid option %s: %s\n\n",
                    poptBadOption(pc, 0), poptStrerror(opt));
            poptPrintUsage(pc, stderr, 0);
            return 1;
        }
    }

    if (opt_version) {
        puts(VERSION""DISTRO_VERSION""PRERELEASE_VERSION);
        return 0;
    }

    if (opt_target == NULL) {
        fprintf(stderr, "Missing target!\n");
        poptPrintUsage(pc, stderr, 0);
        return 1;
    }

    ret = pipe(srv_pipe);
    if (ret) {
        return -1;
    }
    ret = pipe(cli_pipe);
    if (ret) {
        return -1;
    }

    /* make thread joinable (portability) */
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);

    server.srv_pipe = srv_pipe;
    server.cli_pipe = cli_pipe;
    server.target = opt_target;

    ret = pthread_create(&server.tid, &attr, server_thread, &server);
    if (ret) {
        return -1;
    }

    client.srv_pipe = srv_pipe;
    client.cli_pipe = cli_pipe;
    client.target = opt_target;

    ret = pthread_create(&client.tid, &attr, client_thread, &client);
    if (ret) {
        return -1;
    }

    pthread_join(server.tid, &retval);
    pthread_join(client.tid, &retval);

    return 0;
}