build armv7l images (ansible#669)

* build armv7l images

* Update build-docker-images.yml

* Don't use `enable-ec_nistp_64_gcc_128` on armv7l

* hack?

* We are an armv4 build

(cherry picked from commit 519b16bd0803ea22dbd0a4525c641060581c0215)

Author: alex

build-scripts/manylinux-container-image/install_openssl.sh

@@ -18,7 +18,13 @@ pushd openssl-${OPENSSL_VERSION}
 if [[ "$1" =~ '^manylinux1_.*$' ]]; then
   PATH=/opt/perl/bin:$PATH
 fi
-./config $OPENSSL_BUILD_FLAGS --prefix=/opt/pyca/cryptography/openssl --openssldir=/opt/pyca/cryptography/openssl
+BUILD_FLAGS="$OPENSSL_BUILD_FLAGS"
+# Can't use `$(uname -m) = "armv7l"` because that returns what kernel we're
+# using, and we build for armv7l with an ARM64 host.
+if [ "$(readelf -h /proc/self/exe | grep -o 'Machine:.* ARM')" ]; then
+    BUILD_FLAGS="$OPENSSL_BUILD_FLAGS_ARMV7L"
+fi
+./config $BUILD_FLAGS --prefix=/opt/pyca/cryptography/openssl --openssldir=/opt/pyca/cryptography/openssl
 make depend
 make -j4
 # avoid installing the docs

build-scripts/manylinux-container-image/openssl-version.sh

@@ -3,4 +3,5 @@ export OPENSSL_SHA256="892a0875b9872acd04a9fde79b1f943075d5ea162415de3047c327df3
 # We need a base set of flags because on Windows using MSVC
 # enable-ec_nistp_64_gcc_128 doesn't work since there's no 128-bit type
 export OPENSSL_BUILD_FLAGS_WINDOWS="no-ssl3 no-ssl3-method no-zlib no-shared no-comp no-dynamic-engine"
+export OPENSSL_BUILD_FLAGS_ARMV7L="linux-armv4 ${OPENSSL_BUILD_FLAGS_WINDOWS}"
 export OPENSSL_BUILD_FLAGS="${OPENSSL_BUILD_FLAGS_WINDOWS} enable-ec_nistp_64_gcc_128"