diff --git a/crypto/openssl/BSDmakefile b/crypto/openssl/BSDmakefile
new file mode 100644
--- /dev/null
+++ b/crypto/openssl/BSDmakefile
@@ -0,0 +1,32 @@
+NO_OBJ=
+
+vendor-import: .PHONY
+	cd ${SRCTOP}/crypto/openssl && \
+	    perl ./Configure \
+	    disable-aria \
+	    disable-idea \
+	    disable-mdc2 \
+	    disable-sm2 \
+	    disable-sm3 \
+	    disable-sm4 \
+	    enable-ktls \
+	    enable-sctp \
+	    --openssldir=etc \
+	    --prefix=/usr
+	# Spam arch-specific overrides to config file.
+	cat ${.CURDIR}/dynamic_freebsd_configuration.h >> \
+	    ${SRCTOP}/crypto/openssl/include/openssl/configuration.h
+	cd ${SRCTOP}/secure/lib/libcrypto && \
+	    ${MAKE} cleanasm && \
+	    ${MAKE} buildasm
+	# Passing `-j ${.MAKE.JOBS}` doesn't work here for some reason.
+	cd ${SRCTOP}/crypto/openssl && \
+	    gmake build_man_docs
+	rsync -av --delete \
+	    --exclude 'Makefile*' --exclude '*.1' \
+	    ${SRCTOP}/crypto/openssl/doc/man/ \
+	    ${SRCTOP}/secure/lib/libcrypto/man
+	rsync -av --delete \
+	    --exclude 'Makefile*' --exclude '*.[357]' \
+	    ${SRCTOP}/crypto/openssl/doc/man/man1/ \
+	    ${SRCTOP}/secure/usr.bin/openssl/man
diff --git a/crypto/openssl/dynamic_freebsd_configuration.h b/crypto/openssl/dynamic_freebsd_configuration.h
new file mode 100644
--- /dev/null
+++ b/crypto/openssl/dynamic_freebsd_configuration.h
@@ -0,0 +1,40 @@
+
+/**
+ * OpenSSL's Configure script generates these values automatically for the host
+ * architecture, but FreeBSD provides values which are universal for all
+ * supported target architectures.
+ */
+
+#ifndef	__DYNAMIC_FREEBSD_CONFIGURATION_H__
+#define	__DYNAMIC_FREEBSD_CONFIGURATION_H__
+
+# undef OPENSSL_NO_EC_NISTP_64_GCC_128
+# if !defined(__LP64__) || __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
+#  ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
+#   define OPENSSL_NO_EC_NISTP_64_GCC_128
+#  endif
+# endif
+
+# undef BN_LLONG
+# undef	SIXTY_FOUR_BIT_LONG
+# undef SIXTY_FOUR_BIT
+# undef	THIRTY_TWO_BIT
+# if !defined(OPENSSL_SYS_UEFI)
+#  if __SIZEOF_LONG__ == 8
+#   undef BN_LLONG
+/* Only one for the following should be defined */
+#   define SIXTY_FOUR_BIT_LONG
+#   undef SIXTY_FOUR_BIT
+#   undef THIRTY_TWO_BIT
+#  elif __SIZEOF_LONG__ == 4
+#   define BN_LLONG
+/* Only one for the following should be defined */
+#   undef SIXTY_FOUR_BIT_LONG
+#   undef SIXTY_FOUR_BIT
+#   define THIRTY_TWO_BIT
+#  else
+#   error Unsupported size of long
+#  endif
+# endif
+
+#endif  /* __DYNAMIC_FREEBSD_CONFIGURATION_H__ */