Dockerfile: Replace ADD with wget

According to Docker's best practices ([1]), wget is in favor of ADD

[1] = https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#add-or-copy

Signed-off-by: Julien Hachenberger <julien.hachenberger@sit.fraunhofer.de>

diff --git a/Dockerfile b/Dockerfile
index 7639f8f..566658e 100644
--- a/Dockerfile
+++ b/Dockerfile

@@ -16,8 +16,9 @@
 # OpenSSL
 ARG openssl_name=openssl-1.1.0h
 WORKDIR /tmp
-ADD https://www.openssl.org/source/$openssl_name.tar.gz .
-RUN tar xvf $openssl_name.tar.gz
+RUN wget --quiet --show-progress --progress=dot:giga https://www.openssl.org/source/$openssl_name.tar.gz \
+	&& tar xvf $openssl_name.tar.gz \
+	&& rm /tmp/$openssl_name.tar.gz
 WORKDIR $openssl_name
 RUN ./config --prefix=/usr/local/openssl --openssldir=/usr/local/openssl
 RUN make -j$(nproc)
@@ -27,10 +28,11 @@
 # IBM's Software TPM 2.0
 ARG ibmtpm_name=ibmtpm1119
 WORKDIR /tmp
-ADD "https://downloads.sourceforge.net/project/ibmswtpm2/$ibmtpm_name.tar.gz" .
-RUN sha256sum $ibmtpm_name.tar.gz | grep ^b9eef79904e276aeaed2a6b9e4021442ef4d7dfae4adde2473bef1a6a4cd10fb
-RUN mkdir -p $ibmtpm_name
-RUN tar xvf $ibmtpm_name.tar.gz -C $ibmtpm_name
+RUN wget --quiet --show-progress --progress=dot:giga "https://downloads.sourceforge.net/project/ibmswtpm2/$ibmtpm_name.tar.gz" \
+	&& sha256sum $ibmtpm_name.tar.gz | grep ^b9eef79904e276aeaed2a6b9e4021442ef4d7dfae4adde2473bef1a6a4cd10fb \
+	&& mkdir -p $ibmtpm_name \
+	&& tar xvf $ibmtpm_name.tar.gz -C $ibmtpm_name \
+	&& rm $ibmtpm_name.tar.gz
 WORKDIR $ibmtpm_name/src
 RUN CFLAGS="-I/usr/local/openssl/include" make -j$(nproc)
 RUN cp tpm_server /usr/local/bin