In most OpenSSL versions (1.0.2 or earlier), SHA256 is NOT an available hashing

algorithm (according to the documentation) and OpenSSL ignores the field and
uses the default, which is MD5. Setting the default hash to SHA1.

ssl-ca

@@ -12,7 +12,7 @@ dir = $PWD
 certs = \$dir/certs
 certificate = \$dir/CA.crt
 private_key = \$dir/CA.key
-default_md = sha256
+default_md = sha1
 default_days = 365
 email_in_dn = no
 RANDFILE = /dev/urandom
@@ -22,7 +22,7 @@ database = /dev/null
 distinguished_name = req_distinguished_name
 prompt = no
 encrypt_key = no
-default_md = sha256
+default_md = sha1
 default_bits = 2048
 RANDFILE = /dev/urandom