[Caml-list] ocamlnet and missing SRP functions in gnutls

[Sebastien Ferre <Sebastien.Ferre@irisa.fr>]

Hi,

when trying to use gnutls for TLS-secured
connections with ocamlnet, I encounter a
problem with SRP functions.

When linking with package nettls-gnutls of
ocamlnet, I get the following linking errors
(excerpt here, full log at the end).

/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `abs_gnutls_srp_client_credentials_t_finalize':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:1841: 
undefined reference to `gnutls_srp_free_client_credentials'
[...]

All undefined functions start with 'gnutls_srp_'. After
some web search, I found that those functions are excluded
in some Linux distributions (mine is a Fedora) because of
patent issues.

Are those functions really necessary for TLS connections ?
If not, is there a patch of the package 'nettls-gnutls' that
avoids them ? If yes, is there a workaround ? Has anybody else
encounter the same problem.

My global objective is to provide a secure authentication
for a Web application.

Thanks,
---
Sébastien Ferré

==============================================================
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `abs_gnutls_srp_client_credentials_t_finalize':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:1841: 
undefined reference to `gnutls_srp_free_client_credentials'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `abs_gnutls_srp_server_credentials_t_finalize':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:1770: 
undefined reference to `gnutls_srp_free_server_credentials'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_allocate_client_credentials':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5431: 
undefined reference to `gnutls_srp_allocate_client_credentials'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_set_client_credentials':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5446: 
undefined reference to `gnutls_srp_set_client_credentials'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_allocate_server_credentials':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5456: 
undefined reference to `gnutls_srp_allocate_server_credentials'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_set_server_credentials_file':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5471: 
undefined reference to `gnutls_srp_set_server_credentials_file'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_server_get_username':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5482: 
undefined reference to `gnutls_srp_server_get_username'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_set_prime_bits':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5493: 
undefined reference to `gnutls_srp_set_prime_bits'
/local/ferre/.opam/system/lib/nettls-gnutls/libnettls-gnutls.a(nettls_gnutls_bindings_stubs.o): 
In function `net_gnutls_srp_verifier':
/home/ferre/.opam/system/build/ocamlnet.4.0.2/src/nettls-gnutls/nettls_gnutls_bindings_stubs.c:5512: 
undefined reference to `gnutls_srp_verifier'
collect2: error: ld returned 1 exit status
File "caml_startup", line 1:
Error: Error during linking