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configure.ac: link to all mbed TLS libs during library detection

PATCH In review Steffan Karger 2 participants 5 messages May 1, 2016 – May 5, 2016

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Steffan Karger

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#0 lore raw

PATCH 1/1 configure.ac: link to all mbed TLS libs during library detection

When for some reason the dependencies of the compiled mbed TLS libaries (libmbedtls, libmbedcrypto and libmbedx509) are not correct, the configure script will fail to link against libmbedcrypto and/or libmbedx509. This is reported to happen after using 'make install' to install mbedtls.

This patch makes sure the configure tests link to all three. The build process itself already did.

Signed-off-by Steffan Karger <[email protected]...>
---
 configure.ac | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
configure.ac +2 -1
index 3b8bf96..f1dc8af 100644
@@ -843,7 +843,8 @@ elif test "${with_crypto_library}" = "mbedtls"; then
 	saved_LIBS="${LIBS}"
 
 	if test -z "${MBEDTLS_CFLAGS}" -a -z "${MBEDTLS_LIBS}"; then
-	# if the user did not explicitly specify flags, try to autodetect
+		# if the user did not explicitly specify flags, try to autodetect
+		LIBS="${LIBS} -lmbedtls -lmbedcrypto -lmbedx509"
 		AC_CHECK_LIB(
 			[mbedtls],
 			[mbedtls_ssl_init],
Signature · 1 line
2.7.4
#1 lore raw

ACK. Tested on ubuntu 14.04 with "default Makefile"-installed mbedtls (it works if you have cmake build your Makefile first...)

Your patch has been applied to the master branch.

gmane archive lookup is broken right now, so no URL: below - but the message ID is there.

commit e860059baa912ced7acf00f9b1e85a3d80dc0b1f

Author: Steffan Karger
Date:   Sun May 1 20:23:06 2016 +0200
     configure.ac: link to all mbed TLS libs during library detection

     Signed-off-by: Steffan Karger <[email protected]...>
     Acked-by: Gert Doering <[email protected]...>
     Message-Id: <[email protected]...>
     Signed-off-by: Gert Doering <[email protected]...>

--
kind regards,

Gert Doering

#2 lore raw
In reply to Steffan Karger

Hi,

Quoted 7 lines · Steffan Karger

When for some reason the dependencies of the compiled mbed TLS libaries (libmbedtls, libmbedcrypto and libmbedx509) are not correct, the configure script will fail to link against libmbedcrypto and/or libmbedx509. This is reported to happen after using 'make install' to install mbedtls.

This patch makes sure the configure tests link to all three. The build process itself already did.

It originally looked good on my test systems, but I found more caveats - when you have static libraries, dependency resolving only happens left-to-right, and libmbedx509.a wants stuff from libmbedcrypto.a - so we end up with

configure:28582: gcc -o conftest -g -O2 conftest.c -lmbedtls
-lresolv -lmbedtls -lmbedcrypto -lmbedx509 >&5
Undefined first referenced

 symbol                             in file
mbedtls_pk_load_file                /usr/lib/libmbedx509.a(x509_crt.o)
mbedtls_pk_parse_subpubkey          /usr/lib/libmbedx509.a(x509_crt.o)

ld: fatal: symbol referencing errors. No output written to conftest

... unless we change the ordering. Patch below.

(Linking the final openvpn seems to work no matter what library order, because some .o "further to the left" already uses these functions, so when the linker looks at libmedx509.a unresolved symbols, it already knows where to find them. Still changing both places to be consistent)

gert

author
#3 lore raw
Quoted 6 lines · Gert Doering
configure.ac +0 -0
@@ -844,11 +844,11 @@ elif test "${with_crypto_library}" = "mbedtls"; then
 
        if test -z "${MBEDTLS_CFLAGS}" -a -z "${MBEDTLS_LIBS}"; then
                # if the user did not explicitly specify flags, try to autodetect

configure.ac elif test "${with_crypto_library}" = "mbedtls"; then · line 854

Quoted 10 lines
configure.ac +2 -2
-               LIBS="${LIBS} -lmbedtls -lmbedcrypto -lmbedx509"
+               LIBS="${LIBS} -lmbedtls -lmbedx509 -lmbedcrypto"
                AC_CHECK_LIB(
                        [mbedtls],
                        [mbedtls_ssl_init],
-                       [MBEDTLS_LIBS="-lmbedtls -lmbedcrypto -lmbedx509"],
+                       [MBEDTLS_LIBS="-lmbedtls -lmbedx509 -lmbedcrypto"],
                        [AC_MSG_ERROR([Could not find mbed TLS.])],
                        [${PKCS11_HELPER_LIBS}]
                )

Yes, makes sense. ACK.

-Steffan

#4 lore raw

[Openvpn-devel] [PATCH applied] Re: Fix library order in -lmbedtls test.

In reply to Gert Doering

Patch has been applied to the master branch.

commit 1ae17b7e97881ab57352b0bd525f15e6e9b60011

Author: Gert Doering
Date:   Thu May 5 13:48:16 2016 +0200
     Fix library order in -lmbedtls test.

     Signed-off-by: Gert Doering <[email protected]...>
     Acked-by: Steffan Karger <[email protected]...>
     Message-Id: <[email protected]...>
     URL: http://article.gmane.org/gmane.network.openvpn.devel/11605
     Signed-off-by: Gert Doering <[email protected]...>

--
kind regards,

Gert Doering