configure: split out each TLS library detector into its own function

... and put those functions in separate m4 files per TLS library.

1 files changed, 165 insertions, 0 deletions

diff --git a/m4/curl-gnutls.m4 b/m4/curl-gnutls.m4
new file mode 100644
index 000000000..f0b80abe8
--- /dev/null
+++ b/m4/curl-gnutls.m4
@@ -0,0 +1,165 @@
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at https://curl.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+#***************************************************************************
+
+dnl ----------------------------------------------------
+dnl check for GnuTLS
+dnl ----------------------------------------------------
+
+AC_DEFUN([CURL_WITH_GNUTLS], [
+if test "x$OPT_GNUTLS" != xno; then
+  ssl_msg=
+
+  if test X"$OPT_GNUTLS" != Xno; then
+
+    addld=""
+    addlib=""
+    gtlslib=""
+    version=""
+    addcflags=""
+
+    if test "x$OPT_GNUTLS" = "xyes"; then
+      dnl this is with no partiular path given
+      CURL_CHECK_PKGCONFIG(gnutls)
+
+      if test "$PKGCONFIG" != "no" ; then
+        addlib=`$PKGCONFIG --libs-only-l gnutls`
+        addld=`$PKGCONFIG --libs-only-L gnutls`
+        addcflags=`$PKGCONFIG --cflags-only-I gnutls`
+        version=`$PKGCONFIG --modversion gnutls`
+        gtlslib=`echo $addld | $SED -e 's/^-L//'`
+      else
+        dnl without pkg-config, we try libgnutls-config as that was how it
+        dnl used to be done
+        check=`libgnutls-config --version 2>/dev/null`
+        if test -n "$check"; then
+          addlib=`libgnutls-config --libs`
+          addcflags=`libgnutls-config --cflags`
+          version=`libgnutls-config --version`
+          gtlslib=`libgnutls-config --prefix`/lib$libsuff
+        fi
+      fi
+    else
+      dnl this is with a given path, first check if there's a libgnutls-config
+      dnl there and if not, make an educated guess
+      cfg=$OPT_GNUTLS/bin/libgnutls-config
+      check=`$cfg --version 2>/dev/null`
+      if test -n "$check"; then
+        addlib=`$cfg --libs`
+        addcflags=`$cfg --cflags`
+        version=`$cfg --version`
+        gtlslib=`$cfg --prefix`/lib$libsuff
+      else
+        dnl without pkg-config and libgnutls-config, we guess a lot!
+        addlib=-lgnutls
+        addld=-L$OPT_GNUTLS/lib$libsuff
+        addcflags=-I$OPT_GNUTLS/include
+        version="" # we just don't know
+        gtlslib=$OPT_GNUTLS/lib$libsuff
+      fi
+    fi
+
+    if test -z "$version"; then
+      dnl lots of efforts, still no go
+      version="unknown"
+    fi
+
+    if test -n "$addlib"; then
+
+      CLEANLIBS="$LIBS"
+      CLEANCPPFLAGS="$CPPFLAGS"
+      CLEANLDFLAGS="$LDFLAGS"
+
+      LIBS="$addlib $LIBS"
+      LDFLAGS="$LDFLAGS $addld"
+      if test "$addcflags" != "-I/usr/include"; then
+         CPPFLAGS="$CPPFLAGS $addcflags"
+      fi
+
+      dnl this function is selected since it was introduced in 3.1.10
+      AC_CHECK_LIB(gnutls, gnutls_x509_crt_get_dn2,
+       [
+       AC_DEFINE(USE_GNUTLS, 1, [if GnuTLS is enabled])
+       AC_SUBST(USE_GNUTLS, [1])
+       GNUTLS_ENABLED=1
+       USE_GNUTLS="yes"
+       ssl_msg="GnuTLS"
+       test gnutls != "$DEFAULT_SSL_BACKEND" || VALID_DEFAULT_SSL_BACKEND=yes
+       ],
+       [
+         LIBS="$CLEANLIBS"
+         CPPFLAGS="$CLEANCPPFLAGS"
+       ])
+
+      if test "x$USE_GNUTLS" = "xyes"; then
+        AC_MSG_NOTICE([detected GnuTLS version $version])
+        check_for_ca_bundle=1
+        if test -n "$gtlslib"; then
+          dnl when shared libs were found in a path that the run-time
+          dnl linker doesn't search through, we need to add it to
+          dnl CURL_LIBRARY_PATH to prevent further configure tests to fail
+          dnl due to this
+          if test "x$cross_compiling" != "xyes"; then
+            CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$gtlslib"
+            export CURL_LIBRARY_PATH
+            AC_MSG_NOTICE([Added $gtlslib to CURL_LIBRARY_PATH])
+          fi
+        fi
+      fi
+
+    fi
+
+  fi dnl GNUTLS not disabled
+
+  test -z "$ssl_msg" || ssl_backends="${ssl_backends:+$ssl_backends, }$ssl_msg"
+fi
+
+dnl ---
+dnl Check which crypto backend GnuTLS uses
+dnl ---
+
+if test "$GNUTLS_ENABLED" = "1"; then
+  USE_GNUTLS_NETTLE=
+  # First check if we can detect either crypto library via transitive linking
+  AC_CHECK_LIB(gnutls, nettle_MD5Init, [ USE_GNUTLS_NETTLE=1 ])
+
+  # If not, try linking directly to both of them to see if they are available
+  if test "$USE_GNUTLS_NETTLE" = ""; then
+    AC_CHECK_LIB(nettle, nettle_MD5Init, [ USE_GNUTLS_NETTLE=1 ])
+  fi
+  if test "$USE_GNUTLS_NETTLE" = ""; then
+    AC_MSG_ERROR([GnuTLS found, but nettle was not found])
+  fi
+  LIBS="-lnettle $LIBS"
+fi
+
+dnl ---
+dnl We require GnuTLS with SRP support.
+dnl ---
+if test "$GNUTLS_ENABLED" = "1"; then
+  AC_CHECK_LIB(gnutls, gnutls_srp_verifier,
+   [
+     AC_DEFINE(HAVE_GNUTLS_SRP, 1, [if you have the function gnutls_srp_verifier])
+     AC_SUBST(HAVE_GNUTLS_SRP, [1])
+   ])
+fi
+
+])