包装和发送消息

gss-client 应用程序必须首先包装（即加密）数据，然后才能将其发送。应用程序通过执行以下步骤来包装消息：

• 确定包装大小限制，此过程可确保协议提供经过包装的消息。

• 获取源和目标的名称。将名称从对象标识符转换为字符串。

• 获取机制名称的列表。将名称从对象标识符转换为字符串。

• 将消息插入到缓冲区中并对其进行包装。

• 将消息发送到服务器。

以下源代码可用于包装消息。

此示例的源代码也可以通过 Sun 下载中心获取。请访问 http://www.sun.com/download/products.xml?id=41912db5

示例 5–6 gss-client 示例：call_server()－包装消息

/* Test gss_wrap_size_limit */

maj_stat = gss_wrap_size_limit(&min_stat, context, conf_req_flag, 

    GSS_C_QOP_DEFAULT, req_output_size, &max_input_size);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("wrap_size_limit call", maj_stat, min_stat);

} else

    fprintf (stderr, "gss_wrap_size_limit returned "

        "max input size = %d \n"

        "for req_output_size = %d with Integrity only\n",

         max_input_size , req_output_size , conf_req_flag);



conf_req_flag = 1;

maj_stat = gss_wrap_size_limit(&min_stat, context, conf_req_flag,

    GSS_C_QOP_DEFAULT, req_output_size, &max_input_size);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("wrap_size_limit call", maj_stat, min_stat);

} else

    fprintf (stderr, "gss_wrap_size_limit returned "

        " max input size = %d \n" "for req_output_size = %d with "

        "Integrity & Privacy \n", max_input_size , req_output_size );



maj_stat = gss_display_name(&min_stat, src_name, &sname, &name_type);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("displaying source name", maj_stat, min_stat);

    return -1;

}



maj_stat = gss_display_name(&min_stat, targ_name, &tname, 

    (gss_OID *) NULL);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("displaying target name", maj_stat, min_stat);

    return -1;

 }

fprintf(stderr, "\"%.*s\" to \"%.*s\", lifetime %u, flags %x, %s, %s\n",

    (int) sname.length, (char *) sname.value, (int) tname.length, 

    (char *) tname.value, lifetime, context_flags,

    (is_local) ? "locally initiated" : "remotely initiated",

    (is_open) ? "open" : "closed");



(void) gss_release_name(&min_stat, &src_name);

(void) gss_release_name(&min_stat, &targ_name);

(void) gss_release_buffer(&min_stat, &sname);

(void) gss_release_buffer(&min_stat, &tname);



maj_stat = gss_oid_to_str(&min_stat, name_type, &oid_name);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("converting oid->string", maj_stat, min_stat);

    return -1;

}

fprintf(stderr, "Name type of source name is %.*s.\n", (int) oid_name.length,

    (char *) oid_name.value);

(void) gss_release_buffer(&min_stat, &oid_name);



/* Now get the names supported by the mechanism */

maj_stat = gss_inquire_names_for_mech(&min_stat, mechanism, &mech_names);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("inquiring mech names", maj_stat, min_stat);

    return -1;

}



maj_stat = gss_oid_to_str(&min_stat, mechanism, &oid_name);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("converting oid->string", maj_stat, min_stat);

    return -1;

}

mechStr = (char *)__gss_oid_to_mech(mechanism);

fprintf(stderr, "Mechanism %.*s (%s) supports %d names\n", (int) oid_name.length, 

    (char *) oid_name.value, (mechStr == NULL ? "NULL" : mechStr),

    mech_names->count);

(void) gss_release_buffer(&min_stat, &oid_name);



for (i=0; i < mech_names->count; i++) {

    maj_stat = gss_oid_to_str(&min_stat, &mech_names->elements[i], &oid_name);

    if (maj_stat != GSS_S_COMPLETE) {

        display_status("converting oid->string", maj_stat, min_stat);

        return -1;

    }

    fprintf(stderr, "  %d: %.*s\n", i, (int) oid_name.length, (

    char *) oid_name.value);



    (void) gss_release_buffer(&min_stat, &oid_name);

    }

(void) gss_release_oid_set(&min_stat, &mech_names);



if (use_file) {

    read_file(msg, &in_buf);

} else {

    /* Wrap the message */

    in_buf.value = msg;

    in_buf.length = strlen(msg) + 1;

}



if (ret_flag & GSS_C_CONF_FLAG) {

    state = 1;

else

    state = 0;

}

maj_stat = gss_wrap(&min_stat, context, 1, GSS_C_QOP_DEFAULT, &in_buf, 

    &state, &out_buf);

if (maj_stat != GSS_S_COMPLETE) {

    display_status("wrapping message", maj_stat, min_stat);

    (void) close(s);

    (void) gss_delete_sec_context(&min_stat, &context, GSS_C_NO_BUFFER);

    return -1;

} else if (! state) {

    fprintf(stderr, "Warning!  Message not encrypted.\n");

}



/* Send to server */

if (send_token(s, &out_buf) < 0) {

    (void) close(s);

    (void) gss_delete_sec_context(&min_stat, &context, GSS_C_NO_BUFFER);

    return -1;

}

(void) gss_release_buffer(&min_stat, &out_buf);