--with-gnutls --with-openssl enables USE_TLS_SRP, even when OpenSSL/LibreSSL doesn't support it; build fails

[steils]

./configure --with-ssl --with-nettle --with-gnutls --with-openssl

configure.log

checking for SRP_Calc_client_key in -lcrypto... no
checking for gnutls_srp_verifier in -lgnutls... yes
checking whether to enable TLS-SRP authentication... yes

Then make...

/bin/sh ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H   -I../include -I../lib -I../lib  -DBUILDING_LIBCURL  -DCURL_HIDDEN_SYMBOLS   -fvisibility=hidden -Werror-implicit-function-declaration -O2 -Wno-system-headers -pthread  -MT vtls/libcurl_la-openssl.lo -MD -MP -MF vtls/.deps/libcurl_la-openssl.Tpo -c -o vtls/libcurl_la-openssl.lo `test -f 'vtls/openssl.c' || echo './'`vtls/openssl.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I../include -I../lib -I../lib -DBUILDING_LIBCURL -DCURL_HIDDEN_SYMBOLS -fvisibility=hidden -Werror-implicit-function-declaration -O2 -Wno-system-headers -pthread -MT vtls/libcurl_la-openssl.lo -MD -MP -MF vtls/.deps/libcurl_la-openssl.Tpo -c vtls/openssl.c  -fPIC -DPIC -o vtls/.libs/libcurl_la-openssl.o
vtls/openssl.c: In function ‘ossl_connect_step1’:
vtls/openssl.c:2802:9: error: implicit declaration of function ‘SSL_CTX_set_srp_username’; did you mean ‘SSL_CTX_set_ssl_version’? [-Werror=implicit-function-declaration]
 2802 |     if(!SSL_CTX_set_srp_username(backend->ctx, ssl_username)) {
      |         ^~~~~~~~~~~~~~~~~~~~~~~~
      |         SSL_CTX_set_ssl_version
vtls/openssl.c:2806:9: error: implicit declaration of function ‘SSL_CTX_set_srp_password’; did you mean ‘SSL_CTX_set_ssl_version’? [-Werror=implicit-function-declaration]
 2806 |     if(!SSL_CTX_set_srp_password(backend->ctx, SSL_SET_OPTION(password))) {
      |         ^~~~~~~~~~~~~~~~~~~~~~~~
      |         SSL_CTX_set_ssl_version
cc1: some warnings being treated as errors
make[2]: *** [Makefile:2611: vtls/libcurl_la-openssl.lo] Error 1

It's LibreSSL 3.2.1, but the version is irrelevant, because SRP was removed from LibreSSL in 2014.

[cvengler]

I'm curious why two TLS back ends are even allowed, it would make no sense

[steils]

@emilengler it should make sense, see #2665

[bagder]

@emilengler to allow the application to select the specific TLS backend in run-time rather than just one at build time. Supported since libcurl 7.56.0. See curl_global_sslset().

[bagder]

@steils please try #5870 and see if that fixes this issue for you!

[ghost]

Hello @bagder, I really appreciate you taking your time to fix this, but I'm trying to compile curl on Gentoo (from the official repository) with libressl as the ssl provider and I'm experiencing the same issue (extract from the build log after compilation failed):

 * SSL provided by gnutls
 * SSL provided by openssl
 * Default SSL provided by LibreSSL
[...]
checking whether to enable TLS-SRP authentication... yes
[...]
/var/tmp/portage/net-misc/curl-7.72.0/work/curl-7.72.0/lib/vtls/openssl.c:2802:9: error: implicit declaration of function ‘SSL_CTX_set_srp_username’; did you mean ‘SSL_CTX_set_ssl_version’? [-Werror=implicit-function-declaration]
 2802 |     if(!SSL_CTX_set_srp_username(backend->ctx, ssl_username)) {
      |         ^~~~~~~~~~~~~~~~~~~~~~~~
      |         SSL_CTX_set_ssl_version
/var/tmp/portage/net-misc/curl-7.72.0/work/curl-7.72.0/lib/vtls/openssl.c:2806:9: error: implicit declaration of function ‘SSL_CTX_set_srp_password’; did you mean ‘SSL_CTX_set_ssl_version’? [-Werror=implicit-function-declaration]
 2806 |     if(!SSL_CTX_set_srp_password(backend->ctx, SSL_SET_OPTION(password))) {
      |         ^~~~~~~~~~~~~~~~~~~~~~~~
      |         SSL_CTX_set_ssl_version
cc1: some warnings being treated as errors
make[2]: *** [Makefile:2615: vtls/libcurl_la-openssl.lo] Error 1

I saw that the PR you opened hasn't been merged. Was this intentional? Are these changes going to make it into production anytime?

[bagder]

See above. This was fixed in commit 68a5132 which is not part of 7.72.0 but is part of 7.73.0...

[jzakrzewski]

I saw that the PR you opened hasn't been merged.

You saw wrong.

bagder closed this in 68a5132 on Aug 28