Compile OpenSSL from source for macOS, creating a universal xcframework that works for Intel (x86_64) and Apple Silicon (arm64)

build_apple.sh

#!/usr/bin/env zsh

set -e

# This script compiles OpenSSL from source for macOS, creating a universal xcframework that works for Intel (x86_64) and Apple Silicon (arm64).
# How to use it: download or clone OpenSSL. Put this script in the root of the repository and run it.

CROSS_COMPILE=`xcode-select --print-path`/Toolchains/XcodeDefault.xctoolchain/usr/bin/
CROSS_TOP=`xcode-select --print-path`/Platforms/MacOSX.platform/Developer
CROSS_SDK=MacOSX.sdk
ARCH="x86_64" # The x86_64 architecture preset also includes the ARM64 architecture.

# Set up a build directory
BUILD_ROOT="/private/tmp/openssl-macos";
rm -rf $BUILD_ROOT;
mkdir -p $BUILD_ROOT;

# Compile OpenSSL
perl "./Configure" no-asm no-apps no-docs no-shared no-dso no-quic darwin64-$ARCH --prefix="$BUILD_ROOT"
make -j8
make install

# Merge libssl and libcrypto into a single static library
libtool -static -o "$BUILD_ROOT/lib/openssl.a" "$BUILD_ROOT/lib/libssl.a" "$BUILD_ROOT/lib/libcrypto.a"

# Create the xcframework
OUTPUT_FRAMEWORK="$BUILD_ROOT/openssl.xcframework"
rm -rf $OUTPUT_FRAMEWORK
xcodebuild -create-xcframework \
    -library $BUILD_ROOT/lib/openssl.a \
    -headers $BUILD_ROOT/include \
    -output $OUTPUT_FRAMEWORK

echo "Success! The OpenSSL xcframework is located at $OUTPUT_FRAMEWORK"