Allow non-versioned library soname.

Signed-off-by: Mansour Moufid <mansourmoufid@gmail.com>
diff --git a/library/Makefile b/library/Makefile
index 3c4c7ea..2f58f66 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -47,9 +47,9 @@
 endif
 endif
 
-SOEXT_TLS=so.18
-SOEXT_X509=so.4
-SOEXT_CRYPTO=so.12
+SOEXT_TLS?=so.18
+SOEXT_X509?=so.4
+SOEXT_CRYPTO?=so.12
 
 # Set AR_DASH= (empty string) to use an ar implementation that does not accept
 # the - prefix for command line options (e.g. llvm-ar)
@@ -219,9 +219,11 @@
 	echo "  LD    $@"
 	$(CC) -shared -Wl,-soname,$@ -o $@ $(OBJS_TLS) -L. -lmbedx509 -lmbedcrypto $(LOCAL_LDFLAGS) $(LDFLAGS)
 
+ifneq ($(SOEXT_TLS),so)
 libmbedtls.so: libmbedtls.$(SOEXT_TLS)
 	echo "  LN    $@ -> $<"
 	ln -sf $< $@
+endif
 
 libmbedtls.dylib: $(OBJS_TLS) libmbedx509.dylib
 	echo "  LD    $@"
@@ -246,9 +248,11 @@
 	echo "  LD    $@"
 	$(CC) -shared -Wl,-soname,$@ -o $@ $(OBJS_X509) -L. -lmbedcrypto $(LOCAL_LDFLAGS) $(LDFLAGS)
 
+ifneq ($(SOEXT_X509),so)
 libmbedx509.so: libmbedx509.$(SOEXT_X509)
 	echo "  LN    $@ -> $<"
 	ln -sf $< $@
+endif
 
 libmbedx509.dylib: $(OBJS_X509) libmbedcrypto.dylib
 	echo "  LD    $@"
@@ -273,9 +277,11 @@
 	echo "  LD    $@"
 	$(CC) -shared -Wl,-soname,$@ -o $@ $(OBJS_CRYPTO) $(LOCAL_LDFLAGS) $(LDFLAGS)
 
+ifneq ($(SOEXT_CRYPTO),so)
 libmbedcrypto.so: libmbedcrypto.$(SOEXT_CRYPTO)
 	echo "  LN    $@ -> $<"
 	ln -sf $< $@
+endif
 
 libmbedcrypto.dylib: $(OBJS_CRYPTO)
 	echo "  LD    $@"