FPC320 lib for SSL

[mm7]

There are know issues with libssl v1.1 in FPC304.
I've decided to work it around by building my little library in FPC320 and then use it from program in FPC304.

Code: Pascal  [Select][+][-]

1. library freehttpslib;
2. {$mode objfpc}{$H+}
3.  
4. uses
5.   Classes, SysUtils,
6.   fphttpclient, fpopenssl, OpenSSL, ssockets, opensslsockets,
7.   strutils;
8.  
9. function https_get(url:string):RawByteString; cdecl;
10. var Client: TFPHttpClient;
11. begin
12.    Result := '';
13.    InitSSLInterface;
14.    Client := TFPHttpClient.Create(nil);
15.    try
16.      Client.AddHeader('User-Agent','Mozilla/5.0 (compatible; fpweb)');
17.      Client.AllowRedirect := true;
18.      //URL:='https://google.com/';
19.      Result := Client.Get(URL);
20.    finally
21.      Client.Free;
22.    end;
23. end;
24.  
25. const
26.   Prefix = {$if defined(unix)}'lib'
27.            {$elseif freebsd}'lib'
28.            {$else}''
29.            {$endif};
30. exports
31.   https_get name Prefix+'https_get';
32. end.
33.  

The library is built fine.

Program

Code: Pascal  [Select][+][-]

1. program project1;
2. {$mode objfpc}{$H+}
3.  
4. {$IF FPC_FULLVERSION < 32000}
5. function libhttps_get(url:string):RawByteString; cdecl; external 'libfreehttpslib.so';
6. {$endif}
7.  
8. var R: RawByteString;
9. begin
10.   R := libhttps_get('https://google.com');
11.   writeln(R);
12. end.
13.  

The program is built fine.

But it fails when I run it

Code: Pascal  [Select][+][-]

1. mark@ustudio:~/MyProjects/fpc/https32$ ldd project1
2.         linux-vdso.so.1 (0x00007fff2a71e000)
3.         libfreehttpslib.so => /usr/local/lib/libfreehttpslib.so (0x00007f43b6fe6000)
4.         /lib64/ld-linux-x86-64.so.2 (0x00007f43b6f3f000)
5.         libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f43b6d3b000)
6.         libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f43b694a000)
7. mark@ustudio:~/MyProjects/fpc/https32$ ./project1
8. Inconsistency detected by ld.so: dl-minimal.c: 126: realloc: Assertion `ptr == alloc_last_block' failed!
9.  

why?

[Cyrax]

Use PChar type instead of String type.

[mm7]

just tryed. Same error
Inconsistency detected by ld.so: dl-minimal.c: 126: realloc: Assertion `ptr == alloc_last_block' failed!

[Cyrax]

Run your program under strace utility and see what your program really doing when its running.

[Cyrax]

See this stackoverflow post : https://stackoverflow.com/questions/59956996/problem-loading-a-library-with-ffi-in-php-7-4/59994038#59994038

[mm7]

After the program found all required libs, and even has opened connection to google, it has failed.

Code: Pascal  [Select][+][-]

1. ......
2. connect(3, {sa_family=AF_INET, sin_port=htons(443), sin_addr=inet_addr("172.217.165.14")}, 16) = -1 EINPROGRESS (Operation now in progress)
3. select(4, NULL, [3], NULL, {tv_sec=3, tv_usec=0}) = 1 (out [3], left {tv_sec=2, tv_usec=989744})
4. getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
5. fcntl(3, F_GETFL)                       = 0x802 (flags O_RDWR|O_NONBLOCK)
6. fcntl(3, F_SETFL, O_RDWR)               = 0
7. futex(0x7f2075956810, FUTEX_WAKE_PRIVATE, 2147483647) = 0
8. futex(0x7f2075956804, FUTEX_WAKE_PRIVATE, 2147483647) = 0
9. futex(0x7f20759568d8, FUTEX_WAKE_PRIVATE, 2147483647) = 0
10. mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2075ff5000
11. writev(2, [{iov_base="Inconsistency detected by ld.so:"..., iov_len=33}, {iov_base="dl-minimal.c", iov_len=12}, {iov_base=": ", iov_len=2}, {iov_base="126", iov_len=3}, {iov_base=": ", iov_len=2}, {iov_base="realloc", iov_len=7}, {iov_base=": ", iov_len=2}, {iov_base="Assertion `", iov_len=11}, {iov_base="ptr == alloc_last_block", iov_len=23}, {iov_base="' failed!\n", iov_len=10}], 10Inconsistency detected by ld.so: dl-minimal.c: 126: realloc: Assertion `ptr == alloc_last_block' failed!
12. ) = 105
13. exit_group(127)                         = ?
14. +++ exited with 127 +++
15.  

I suspect something is wrong with memory/stack etc...
But I am not sure how to fix it.

the library was compiled with 0 No optimization, Relocatable -WR, Heap size 0, Stack size 0, All checks and assertions, and debug info.

[Fred vS]

Hello.

Using cmem + cthreads is working here:

The library:

Code: Pascal  [Select][+][-]

1. library freehttpslib;
2. {$mode objfpc}{$H+}
3.  
4. uses
5.  cmem,
6.  {$ifdef unix}
7.   cthreads, {$endif}
8.   Classes, SysUtils,
9.   fphttpclient, fpopenssl, OpenSSL, ssockets, opensslsockets,
10.   strutils;
11.  
12. function https_get(url:string):RawByteString; cdecl;
13. var Client: TFPHttpClient;
14. begin
15.    Result := '';
16.    InitSSLInterface;
17.    Client := TFPHttpClient.Create(nil);
18.    try
19.      Client.AddHeader('User-Agent','Mozilla/5.0 (compatible; fpweb)');
20.      Client.AllowRedirect := true;
21.      //URL:='https://google.com/';
22.      Result := Client.Get(URL);
23.    finally
24.      Client.Free;
25.    end;
26. end;
27.  
28. const
29.   Prefix = {$if defined(unix)}'lib'
30.            {$else}''
31.            {$endif};
32. exports
33.   https_get name Prefix+'https_get';
34. end.

The program:

Code: Pascal  [Select][+][-]

1. program project1;
2. {$mode objfpc}{$H+}
3.  
4.   uses
5.   cmem
6.   {$ifdef unix}
7.   ,cthreads {$endif}
8.   ;
9.  
10. {$IF FPC_FULLVERSION < 32000}
11. function libhttps_get(url:string):RawByteString; cdecl; external 'libfreehttpslib.so';
12. {$endif}
13.  
14. var R: RawByteString;
15. begin
16.   R := libhttps_get('https://google.com');
17.   writeln(R);
18. end.

Result:

Code: Pascal  [Select][+][-]

1. fred@fiens ~/freehttps> ./project1

<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage" lang="es"><head><meta content="Google.es permite acceder a la información mundial en castellano, catalán, gallego, euskara e inglés." name="description"><meta content="noodp" name="robots"><meta content="text/html; charset=UTF-8" http-equiv="Content-Type"><meta content="/images/branding/googleg/1x/googleg_standard_color_128dp.png" itemprop="image"><title>Google</title><script nonce="UXEocwoZoPbp5q2TG2qhrA==">(function()

... // too much char for Lazarus forum...

\x22,\x22psrl\x22:\x22Eliminar\x22,\x22sbit\x22:\x22Buscar por imagen\x22,\x22srch\x22:\x22Buscar con Google\x22},\x22ovr\x22:{},\x22pq\x22:\x22\x22,\x22refpd\x22:true,\x22rfs\x22:[],\x22sbpl\x22:16,\x22sbpr\x22:16,\x22scd\x22:10,\x22stok\x22:\x22lawobTB0fafCFjQoIvT26wfgiaw\x22,\x22uhde\x22:false}}';google.pmc=JSON.parse(pmc);})();</script>        </body></html>

[mm7]

Thanks Cyrax!

after I've added -Cn to Custom options, then edited link.res
moving INPUT(/lib64/ld-linux-x86-64.so.2) after all other INPUTs, I was able to run program successfully.
It is quite a hacky way, but it does the trick.

Code: Pascal  [Select][+][-]

1. )
2. INPUT(
3. -ldl
4. )
5. GROUP(
6. -lc
7. )
8. INPUT(
9. /usr/lib/gcc/x86_64-linux-gnu/9/crtendS.o
10. /usr/lib/x86_64-linux-gnu/crtn.o
11. )
12. INPUT(
13. /lib64/ld-linux-x86-64.so.2
14. )
15. SECTIONS
16. {
17.   .fpcdata           :
18.   {
19.     KEEP (*(.fpc .fpc.n_version .fpc.n_links))
20.   }
21.   .threadvar : { *(.threadvar .threadvar.* .gnu.linkonce.tv.*) }
22. }
23. INSERT AFTER .data;
24.  

Thanks Fred!
I like your approach more because it does not require to hack into the build process. Excellent!
Also it can use String.

[Fred vS]

Re-hello.

You even dont need to use cmem but cthreads is needed in Unix OS.

[argb32]

Did you know that there is a pascal implementation of TLS? I.e. without the need of openssl or other external library:
https://github.com/fundamentalslib/fundamentals5/tree/master/Source/TLS