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|
! Copyright (c) 2020 Jeffrey Armstrong <jeff@rainbow-100.com>
!
! Permission is hereby granted, free of charge, to any person obtaining a copy
! of this software and associated documentation files (the "Software"), to deal
! in the Software without restriction, including without limitation the rights
! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
! copies of the Software, and to permit persons to whom the Software is
! furnished to do so, subject to the following conditions:
!
! The above copyright notice and this permission notice shall be included in
! all copies or substantial portions of the Software.
!
! The Software shall be used for Good, not Evil.
!
! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
! SOFTWARE.
program gnc
use jessl
use iso_c_binding
use iso_fortran_env
implicit none
! For our TLS connection
type(c_ptr)::ctx
type(c_ptr)::method
type(c_ptr)::ssl
integer(kind=c_long)::res
! Cert stuff
character(512)::cert_public, cert_private
! Requested file
character(1024)::request
character(512)::mimetype
integer::request_unit
! Argument handling
integer::i
character(512)::arg
! Logfile
integer, parameter::logunit = 1097
character(512)::logfile
! root serving dir
character(512), target::rootdir
logfile = "/tmp/gnc.log"
rootdir = " "
if(command_argument_count() < 4) then
call usage()
close(logunit)
stop
end if
i = 1
do while(i < command_argument_count())
call get_command_argument(i, arg)
if(trim(arg) == "-pub") then
i = i + 1
call get_command_argument(i, cert_public)
else if(trim(arg) == "-priv") then
i = i + 1
call get_command_argument(i, cert_private)
else if(trim(arg) == "-l") then
i = i + 1
call get_command_argument(i, logfile)
else if(trim(arg) == "-root") then
i = i + 1
call get_command_argument(i, rootdir)
end if
i = i + 1
end do
open(unit=logunit, file=trim(logfile), action="write", status="unknown", position="append")
call write_log("Initiating program")
call random_seed()
call library_init()
method = tls_server_method()
ctx = ctx_new(method)
if(.not. C_ASSOCIATED(ctx)) then
call write_log("Context failed")
close(logunit)
stop
end if
! Seems to be a dummy now...
!res = ctx_set_ecdh_auto(ctx, 1)
if(.not. ctx_use_certificate_file(ctx, trim(cert_public), SSL_FILETYPE_PEM)) then
call write_log("Cert file failed")
call write_log("Public: "//trim(cert_public))
!call print_error()
close(logunit)
stop
end if
if(.not. ctx_use_private_key_file(ctx, trim(cert_private), SSL_FILETYPE_PEM)) then
call write_log("Cert file failed")
call write_log("Private: "//trim(cert_private))
!call print_error()
close(logunit)
stop
end if
ssl = ssl_new(ctx)
call write_log("Initiating connection")
! So this is a GNU Extension...
res = set_read_fd(ssl, fnum(input_unit))
if(res /= 1) then
call write_log("set rfd failed")
!call print_error()
close(logunit)
stop
end if
res = set_write_fd(ssl, fnum(output_unit))
if(res /= 1) then
call write_log("set wfd failed")
!call print_error()
close(logunit)
stop
end if
res = ssl_accept(ssl)
if(res <= 0) then
call write_log("ssl_accept failed")
!call print_error()
close(logunit)
stop
end if
call write_log("Handling read_request")
! Do the actual protocol nonsense
call read_request(ssl, request)
call write_log("Request is "//trim(request))
! If it ends in a slash, let's manually and silently add "index.gmi"
if(request(len_trim(request):len_trim(request)) == "/") then
request = trim(request)//"index.gmi"
end if
res = process_request(trim(request), trim(rootdir), request_unit, mimetype)
call write_log("Request processed")
select case(res)
case(2) ! Success
call write_log("Delivering")
call write_file(ssl, request_unit, mimetype)
close(request_unit)
case(3) ! Redirect
call write_log("Redirecting")
call write_redirect(ssl, request)
case(5) ! Not Found
call write_log("Notfound")
call write_notfound(ssl)
end select
call write_log("Shutdown")
res = ssl_shutdown(ssl)
res = ssl_free(ssl)
res = ctx_free(ctx)
close(logunit)
contains
subroutine write_string(ssl, string)
use jessl, only: ssl_write
use iso_c_binding, only: c_ptr
implicit none
type(c_ptr)::ssl
character(*)::string
character, dimension(:), allocatable::buf
integer::i
allocate(buf(len(string)))
do i = 1, len(string)
buf(i) = string(i:i)
end do
i = ssl_write(ssl, buf)
deallocate(buf)
end subroutine write_string
subroutine write_notfound(ssl)
use iso_c_binding, only: c_ptr, c_carriage_return, c_new_line
implicit none
type(c_ptr)::ssl
character(*), parameter::notfound_response = "50 Not Found"
call write_string(ssl, notfound_response//c_carriage_return//c_new_line)
end subroutine write_notfound
function read_into_buffer(unit_number, buffer)
implicit none
integer, intent(in)::unit_number
character, dimension(*), intent(out)::buffer
integer::read_into_buffer
integer::i, ierr
ierr = 0
i = 0
do while(ierr == 0 .and. i < len(buffer))
i = i + 1
read(unit_number, iostat=ierr) buffer(i)
end do
if(ierr /= 0) then
i = i - 1
end if
read_into_buffer = i
end function read_into_buffer
subroutine write_file(ssl, unit_number, mimetype)
use iso_c_binding, only: c_ptr, c_carriage_return, c_new_line
use jessl, only: ssl_write
implicit none
type(c_ptr)::ssl
integer, intent(in)::unit_number
character(*), intent(in)::mimetype
character, dimension(64)::buf
integer::buflen, written
call write_string(ssl, "20 "//trim(mimetype)//c_carriage_return//c_new_line)
buflen = read_into_buffer(unit_number, buf)
do while(buflen > 0)
written = ssl_write(ssl, buf(1:buflen))
buflen = read_into_buffer(unit_number, buf)
end do
end subroutine write_file
subroutine write_redirect(ssl, req)
use iso_c_binding, only: c_ptr, c_carriage_return, c_new_line
implicit none
type(c_ptr)::ssl
character(*), intent(in)::req
integer::i
character(*), parameter::index_file = "index.gmi"
i = len_trim(req)
if(req(i:i) == '/') then
call write_string(ssl, "30 "//trim(req)//index_file//c_carriage_return//c_new_line)
else
call write_string(ssl, "30 "//trim(req)//"/"//index_file//c_carriage_return//c_new_line)
end if
end subroutine write_redirect
function requires_redirect(req)
implicit none
character(*), intent(in)::req
logical::requires_redirect
integer::i
requires_redirect = .false.
i = len_trim(req)
if(req(i:i) == '/') then
requires_redirect = .true.
else
! The root url without any further slashes also requires redirect
i = index(req, "://")
if(i > 0) then
requires_redirect = (index(req(i+3:len_trim(req)), "/") <= 0)
end if
end if
end function requires_redirect
subroutine determine_mimetype(filename, mimetype)
implicit none
character(*), intent(in)::filename
character(*), intent(out)::mimetype
character(256)::tmpfile
character(1024)::cmdline
character, dimension(5)::rand_string
real, dimension(5)::rand_values
integer::i, readback_unit
i = index(filename, ".gmi")
if(i == (len_trim(filename)-3)) then
mimetype = "text/gemini"
else
call random_number(rand_values)
rand_string = char(ichar('A') + int(25*rand_values))
tmpfile = "/tmp/gemini_"
do i = 1, 5
tmpfile = trim(tmpfile)//rand_string(i)
end do
cmdline = "file -b --mime-type "//trim(filename)//" > "//trim(tmpfile)
call write_log("Executing: "//trim(cmdline))
call execute_command_line(cmdline, wait=.true.)
open(newunit=readback_unit, file=tmpfile, action="read", status="old")
read(readback_unit, *) mimetype
close(readback_unit)
! I saw this happen once...
if(trim(mimetype) == "text") then
mimetype = "text/plain"
end if
! GNU Extenstion... :(
call unlink(tmpfile)
end if
end subroutine determine_mimetype
function process_request(request, rootdir, request_unit, mimetype) result(status_code)
implicit none
character(*), intent(in)::request
character(*), intent(in)::rootdir
integer, intent(out)::request_unit
character(*), intent(out)::mimetype
integer::status_code
character(1024)::filename
integer::i, j, ioerror
if(requires_redirect(request)) then
status_code = 3
else
! Get the file of interest
i = index(request, "://")
if(i <= 0) then
filename = request
else
j = index(request(i+3:len_trim(request)), "/")
filename = request((i+j+2):len_trim(request))
end if
if(len_trim(rootdir) > 0) then
filename = rootdir//"/"//trim(filename)
call write_log("Canonicalize: "//trim(filename))
! Here we'll get rid of any dots or whatever and
if(.not. canonicalize_path(filename) .or. index(filename, rootdir) /= 1) then
call write_log("File outside root requested: "//trim(filename))
status_code = 5
return
end if
end if
call write_log("Opening: "//trim(filename))
! First, check if exists by opening
open(newunit=request_unit, file=trim(filename), status="old", &
form="unformatted", iostat=ioerror, access="stream")
if(ioerror /= 0) then
status_code = 5
else
call determine_mimetype(filename, mimetype)
status_code = 2
end if
end if
end function process_request
subroutine read_request(ssl, req)
use jessl, only: ssl_read
use iso_c_binding, only: c_ptr
implicit none
type(c_ptr)::ssl
character(*), intent(out)::req
character, dimension(64)::buf
integer::bufread
integer::i, j
req = " "
i = 1
bufread = ssl_read(ssl, buf)
do while(bufread > 0)
do j = 1, bufread
if(buf(j) == c_new_line) then
exit
end if
if(buf(j) /= c_carriage_return) then
req(i:i) = buf(j)
i = i + 1
end if
end do
if(buf(j) == c_new_line) then
exit
end if
bufread = ssl_read(ssl, buf)
end do
end subroutine read_request
function canonicalize_path(path)
use iso_c_binding, only: c_char, c_null_char
implicit none
character(*), intent(inout)::path
character(kind=c_char), allocatable, dimension(:), target::srcpath
logical::canonicalize_path
type(c_ptr)::cdst
character(kind=c_char), dimension(:), pointer::dstpath
character(256)::errr
integer::pathlen, i
interface
function realpath(src, dst) bind(c)
use iso_c_binding
type(c_ptr)::realpath
type(c_ptr), value::src, dst
end function realpath
end interface
interface
subroutine c_free(p) bind(c, name="free")
use iso_c_binding
type(c_ptr), value::p
end subroutine c_free
end interface
pathlen = (len_trim(path)+1)
allocate(srcpath(len(path)))
srcpath = c_null_char
do i = 1, pathlen-1
srcpath(i) = path(i:i)
end do
srcpath(pathlen) = c_null_char
cdst = realpath(c_loc(srcpath), c_null_ptr)
if(c_associated(cdst)) then
path = " "
call c_f_pointer(cdst, dstpath, [1])
i = 1
do while(dstpath(i) /= c_null_char)
path(i:i) = dstpath(i)
i = i + 1
end do
dstpath => null()
call c_free(cdst)
canonicalize_path = .true.
else
write(errr, *) "realpath error: ", ierrno()
call write_log(trim(errr))
canonicalize_path = .false.
end if
deallocate(srcpath)
end function canonicalize_path
subroutine usage()
implicit none
character(256)::exe
call get_command_argument(0, exe)
Print *, "Usage: "//trim(exe)//" -pub <public cert> -priv <private cert> [-l <logfile>] [-root <rootdir>]"
end subroutine usage
subroutine write_log(string)
implicit none
character(*), intent(in)::string
! GNU Extension... :(
write(logunit, *) fdate()//" :: "//string
call flush(logunit)
end subroutine write_log
end program gnc
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