pki --self

pki --self [--in file|--keyid hex] [--type rsa|ecdsa|ed25519|ed448|priv]
            --dn distinguished-name [--san subjectAltName]+
           [--lifetime days] [--not-before datetime] [--not-after datetime] [--dateform form]
           [--serial hex] [--ca] [--pathlen len] [--addrblock addr|subnet|range]+
           [--ocsp uri]+ [--flag serverAuth|clientAuth|crlSign|ocspSigning]+
           [--nc-permitted name] [--nc-excluded name]
           [--policy-map issuer-oid:subject-oid]
           [--policy-explicit len] [--policy-inhibit len] [--policy-any len]
           [--cert-policy oid [--cps-uri uri] [--user-notice text]]+
           [--digest md5|sha1|sha224|sha256|sha384|sha512|sha3_224|sha3_256|sha3_384|sha3_512]
           [--rsa-padding pkcs1|pss] [--outform der|pem]

pki --self --help

--in              (-i)  private key input file, default: stdin
--keyid           (-x)  smartcard or TPM private key object handle
--type            (-t)  type of input key, default: priv
--dn              (-d)  subject and issuer distinguished name
--san             (-a)  subjectAltName to include in certificate
--lifetime        (-l)  days the certificate is valid, default: 1095
--not-before      (-F)  absolute time when the validity of the certificate begins
--not-after       (-T)  absolute time when the validity of the certificate ends
--dateform        (-D)  strptime(3) format for the --not-before and --not-after options, default: %d.%m.%y %T
--serial          (-s)  serial number in hex, default: random
--ca              (-b)  include CA basicConstraint, default: no
--pathlen         (-p)  set path length constraint
--addrblock       (-B)  RFC 3779 addrBlock to include
--nc-permitted    (-n)  add permitted NameConstraint
--nc-excluded     (-N)  add excluded NameConstraint
--cert-policy     (-P)  certificatePolicy OID to include
--cps-uri         (-C)  Certification Practice statement URI for certificatePolicy
--user-notice     (-U)  user notice for certificatePolicy
--policy-mapping  (-M)  policyMapping from issuer to subject OID
--policy-explicit (-E)  requireExplicitPolicy constraint
--policy-inhibit  (-H)  inhibitPolicyMapping constraint
--policy-any      (-A)  inhibitAnyPolicy constraint
--flag            (-e)  include extendedKeyUsage flag
--ocsp            (-o)  OCSP AuthorityInfoAccess URI to include
--digest          (-g)  digest for signature creation, default: key-specific
--rsa-padding     (-R)  padding for RSA signatures, default: pkcs1
--outform         (-f)  encoding of generated cert, default: der
--debug           (-v)  set debug level, default: 1
--options         (-+)  read command line options from file----
--help            (-h)  show usage information

pki --self --in myKey.der --dn "C=CH, O=strongSwan, CN=moon.strongswan.org" > myCert.der

pki --self --in myCaKey.der --ca --dn "C=CH, O=strongSwan, CN=Root CA" --outform pem > myCaCert.pem