openssl does not generate certificate with PKCS#1 key format in RHEL 9

Issue

• We are experiencing issues converting from PKCS8 to PKCS1 on RHEL 9 servers.

• We are using the following command:

  [root@localhost ~]# openssl rsa -in input.key -out output.rsa.key
  

• The input file looks like this:

  [root@localhost ~]# cat input.key
  -----BEGIN PRIVATE KEY-----
  MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCflwydaSdwbKWa
  [...]
  teLV0p8/NVJdaNM2XMisR+Xt
  -----END PRIVATE KEY-----
  

• The resulting output file looks like this:

  [root@localhost ~]# cat output.rsa.key
  -----BEGIN PRIVATE KEY-----
  MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCflwydaSdwbKWa
  [...]
  teLV0p8/NVJdaNM2XMisR+Xt
  -----END PRIVATE KEY-----
  

• The output file does not match the expected headers:

  -----BEGIN RSA PRIVATE KEY-----
  [...]
  -----END RSA PRIVATE KEY-----
  

• We tested the same command in RHEL 7 and there we have the RSA PRIVATE KEY headers.