Build: modernize crypto library detection

Use package config instead of checking headers.
Package config is faster because it does not invoke compiler
and guarantees proper linking flags because these are provided
by package maintainer instead of hardcoded into build system.

Reviewed-By: Martin Basti <mbasti@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

daemons/configure.ac

@@ -125,12 +125,7 @@ AC_SUBST(LDAP_LIBS)
 dnl ---------------------------------------------------------------------------
 dnl - Check for OpenSSL Crypto library
 dnl ---------------------------------------------------------------------------
-dnl This is a very simple check, we should probably check also for MD4_Init and
-dnl probably also the version we are using is recent enough
-SSL_LIBS=
-AC_CHECK_HEADER(openssl/md4.h, [], [AC_MSG_ERROR([openssl/md4.h not found])])
-AC_CHECK_LIB(crypto, MD4_Init, [SSL_LIBS="-lcrypto"])
-AC_SUBST(SSL_LIBS)
+PKG_CHECK_MODULES([CRYPTO], [libcrypto], [], [AC_MSG_ERROR([libcrypto not found])])
 
 dnl ---------------------------------------------------------------------------
 dnl - Check for UUID library
@@ -381,6 +376,6 @@ echo "
         LDAP libs:                ${LDAP_LIBS}
         KRB5 libs:                ${KRB5_LIBS}
         KRAD libs:                ${KRAD_LIBS}
-        OpenSSL libs:             ${SSL_LIBS}
+        OpenSSL crypto libs:      ${CRYPTO_LIBS}
         Maintainer mode:          ${USE_MAINTAINER_MODE}
 "

daemons/ipa-sam/Makefile.am

@@ -23,6 +23,7 @@ AM_CPPFLAGS =						\
 	-DLDAPIDIR=\""$(localstatedir)/run"\"		\
 	-DHAVE_LDAP					\
 	-I $(KRB5_UTIL_DIR)				\
+	$(CRYPTO_CFLAGS)				\
 	$(LDAP_CFLAGS)					\
 	$(KRB5_CFLAGS)					\
 	$(WARN_CFLAGS)					\
@@ -48,10 +49,10 @@ ipasam_la_LDFLAGS = 		\
 	$(NULL)
 
 ipasam_la_LIBADD = 		\
+	$(CRYPTO_LIBS)		\
 	$(LDAP_LIBS)		\
 	$(KRB5_LIBS)		\
 	$(TALLOC_LIBS)		\
-	$(SSL_LIBS)		\
 	$(SAMBAUTIL_LIBS)	\
 	$(NDR_LIBS)		\
 	$(SAMBA40EXTRA_LIBS)	\

daemons/ipa-slapi-plugins/ipa-pwd-extop/Makefile.am

@@ -19,16 +19,16 @@ AM_CPPFLAGS =							\
 	-DLIBDIR=\""$(libdir)"\" 				\
 	-DLIBEXECDIR=\""$(libexecdir)"\"			\
 	-DDATADIR=\""$(datadir)"\"				\
+	$(CRYPTO_CFLAGS)					\
 	$(LDAP_CFLAGS)					\
 	$(KRB5_CFLAGS)						\
-	$(SSL_CFLAGS)						\
 	$(NSS_CFLAGS)						\
 	$(WARN_CFLAGS)						\
 	$(NULL)
 
 AM_LDFLAGS = \
+	$(CRYPTO_LIBS)	\
 	$(KRB5_LIBS)	\
-	$(SSL_LIBS)	\
 	$(LDAP_LIBS)	\
 	$(NSPR_LIBS)	\
 	$(NSS_LIBS)	\