OpenSSL Makefile configuration example for CentOS Linux 7

Get the default configuration file Makefile for OpenSSL, optimized for CentOS Linux 7. This example configuration ensures optimal compatibility and performance for OpenSSL, making it easy to set up and adjust to meet your needs.

Find and download the configuration file here: /etc/pki/tls/certs/Makefile.

For more configurations and setup guides, visit our related files section to further customize your system.

    UTF8 := $(shell locale -c LC_CTYPE -k | grep -q charmap.*UTF-8 && echo -utf8)
DAYS=365
KEYLEN=2048
TYPE=rsa:$(KEYLEN)
EXTRA_FLAGS=
ifdef SERIAL
	EXTRA_FLAGS+=-set_serial $(SERIAL)
endif

.PHONY: usage
.SUFFIXES: .key .csr .crt .pem
.PRECIOUS: %.key %.csr %.crt %.pem

usage:
	@echo "This makefile allows you to create:"
	@echo "  o public/private key pairs"
	@echo "  o SSL certificate signing requests (CSRs)"
	@echo "  o self-signed SSL test certificates"
	@echo
	@echo "To create a key pair, run \"make SOMETHING.key\"."
	@echo "To create a CSR, run \"make SOMETHING.csr\"."
	@echo "To create a test certificate, run \"make SOMETHING.crt\"."
	@echo "To create a key and a test certificate in one file, run \"make SOMETHING.pem\"."
	@echo
	@echo "To create a key for use with Apache, run \"make genkey\"."
	@echo "To create a CSR for use with Apache, run \"make certreq\"."
	@echo "To create a test certificate for use with Apache, run \"make testcert\"."
	@echo
	@echo "To create a test certificate with serial number other than random, add SERIAL=num"
	@echo "You can also specify key length with KEYLEN=n and expiration in days with DAYS=n"
	@echo "Any additional options can be passed to openssl req via EXTRA_FLAGS"
	@echo
	@echo Examples:
	@echo "  make server.key"
	@echo "  make server.csr"
	@echo "  make server.crt"
	@echo "  make stunnel.pem"
	@echo "  make genkey"
	@echo "  make certreq"
	@echo "  make testcert"
	@echo "  make server.crt SERIAL=1"
	@echo "  make stunnel.pem EXTRA_FLAGS=-sha384"
	@echo "  make testcert DAYS=600"

%.pem:
	umask 77 ; \
	PEM1=`/bin/mktemp /tmp/openssl.XXXXXX` ; \
	PEM2=`/bin/mktemp /tmp/openssl.XXXXXX` ; \
	/usr/bin/openssl req $(UTF8) -newkey $(TYPE) -keyout $$PEM1 -nodes -x509 -days $(DAYS) -out $$PEM2 $(EXTRA_FLAGS) ; \
	cat $$PEM1 >  $@ ; \
	echo ""    >> $@ ; \
	cat $$PEM2 >> $@ ; \
	$(RM) $$PEM1 $$PEM2

%.key:
	umask 77 ; \
	/usr/bin/openssl genrsa -aes128 $(KEYLEN) > $@

%.csr: %.key
	umask 77 ; \
	/usr/bin/openssl req $(UTF8) -new -key $^ -out $@

%.crt: %.key
	umask 77 ; \
	/usr/bin/openssl req $(UTF8) -new -key $^ -x509 -days $(DAYS) -out $@ $(EXTRA_FLAGS)

TLSROOT=/etc/pki/tls
KEY=$(TLSROOT)/private/localhost.key
CSR=$(TLSROOT)/certs/localhost.csr
CRT=$(TLSROOT)/certs/localhost.crt

genkey: $(KEY)
certreq: $(CSR)
testcert: $(CRT)

$(CSR): $(KEY)
	umask 77 ; \
	/usr/bin/openssl req $(UTF8) -new -key $(KEY) -out $(CSR)

$(CRT): $(KEY)
	umask 77 ; \
	/usr/bin/openssl req $(UTF8) -new -key $(KEY) -x509 -days $(DAYS) -out $(CRT) $(EXTRA_FLAGS)

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