Creating a CA and certificates: Difference between revisions

Latest revision as of 14:00, 6 November 2021

Create the CA Key and Certificate[edit]

openssl req -x509 -newkey rsa:2048 -nodes -days 9999 -subj /O=WilliamsNet/C=US/CN=<CA name>/ -keyout <CA file>.key -out <CA file>.crt

Create the Certificate Signing Request[edit]

openssl req -newkey rsa:2048 -nodes -subj /O=WilliamsNet/C=US/CN=<cert CN>/ -keyout <cert file>.key -out <cert file>.csr

Create the Certificate[edit]

If just a simple certificated is needed, this can be done in one step:

openssl x509 -req -in <cert file>.csr -CA <CA cert> -CAkey <CA key> -CAcreateserial -out <cert file>.crt -days 9999 -sha256

Create a Certificate with SAN[edit]

If a certificate with SAN entries is needed, a configuration file is needed to specify the SAN items required. The CN itself (specified when creating the certificate request) should be included as one of the SAN entries, as some newer applications actually ignore the CN:

authorityKeyIdentifier=keyid,issuer
basicConstraints=CA:FALSE
keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
subjectAltName = @alt_names

[alt_names]
DNS.1 = 10.0.0.61
DNS.2 = compute1.williams.localnet
DNS.3 = compute1

Create the certificate:

openssl x509 -req -in <cert file>.csr -CA <CA cert> -CAkey <CA key> -CAcreateserial -out <cert file>.crt -days 9999 -sha256 \
  -extfile <cert file>.cnf

Convert Key to PKCS8 Format[edit]

Some applications (OpenSearch included) require all keys to be in PKCS8 format:

openssl pkcs8 -inform PEM -outform PEM -in <cert file>.key -topk8 -nocrypt -v1 PBE-SHA1-3DES -out <cert files>-pkcs8.key

Create PKCS12 Keystore[edit]

openssl pkcs12 -export -in <cert file> -inkey <key file> \
               -out <cert name>.p12 -name [<cert.name>] \
               -CAfile <CAcert> -caname root

Validating that a key/crt is correct[edit]

openssl pkey -pubout -outform pem -in privateKey.key | sha256sum
openssl x509 -pubkey -noout -outform pem -in certificate.crt | sha256sum
openssl req -pubkey -noout -outform pem -in CSR.csr | sha256sum

Helper Scripts[edit]

Helper scripts are in the repository (and in /work/bin):

cert-create-ca <CA name> <CA file> 
cert-create <CN> <CAcert> <CAkey> <cert file>
cert-create-san <hostname> <CAcert> <CAkey> <cert file>
cert-import-keystore <cert file> <key file> <CAcert> <base name>

@@ Line 31: / Line 31: @@
 === Create PKCS12 Keystore ===
-  openssl pkcs12 -export -in server.crt -inkey server.key \
+  openssl pkcs12 -export -in <cert file> -inkey <key file> \
-                 -out server.p12 -name [some-alias] \
+                 -out <cert name>.p12 -name [<cert.name>] \
-                 -CAfile ca.crt -caname root
+                 -CAfile <CAcert> -caname root
-'''Note:''' Make sure you put a password on the pkcs12 file - otherwise you'll get a null pointer exception when you try to import it.
 === Validating that a key/crt is correct ===
@@ Line 47: / Line 45: @@
   cert-create <CN> <CAcert> <CAkey> <cert file>
   cert-create-san <hostname> <CAcert> <CAkey> <cert file>
+ cert-import-keystore <cert file> <key file> <CAcert> <base name>