IO::Socket::SSL::Utils -- loading, storing, creating certificates and keys

1. SYNOPSIS
2. DESCRIPTION
3. FUNCTIONS
4. AUTHOR

SYNOPSIS

use IO::Socket::SSL::Utils;

$cert = PEM_file2cert('cert.pem');     # load certificate from file
my $hash = CERT_asHash($cert);         # get details from certificate
PEM_cert2file($cert,'cert.pem');       # write certificate to file
CERT_free($cert);                      # free memory within OpenSSL

@certs = PEM_file2certs('chain.pem');  # load multiple certificates from file
PEM_certs2file('chain.pem', @certs);   # write multiple certificates to file
CERT_free(@certs);                     # free memory for all within OpenSSL

my $cert = PEM_string2cert($pem);      # load certificate from PEM string
$pem = PEM_cert2string($cert);         # convert certificate to PEM string

$key = KEY_create_rsa(2048);           # create new 2048-bit RSA key
PEM_key2file($key,"key.pem");          # and write it to file
KEY_free($key);                        # free memory within OpenSSL

DESCRIPTION

This module provides various utility functions to work with certificates and private keys, shielding some of the complexity of the underlying Net::SSLeay and OpenSSL.

FUNCTIONS

• Functions converting between string or file and certificates and keys. They croak if the operation cannot be completed.

  PEM_file2cert(file) -> cert

  PEM_cert2file(cert,file)

  PEM_file2certs(file) -> @certs

  PEM_certs2file(file,@certs)

  PEM_string2cert(string) -> cert

  PEM_cert2string(cert) -> string

  PEM_file2key(file) -> key

  PEM_key2file(key,file)

  PEM_string2key(string) -> key

  PEM_key2string(key) -> string

• Functions for cleaning up. Each loaded or created cert and key must be freed to not leak memory.

  CERT_free(@certs)

  KEY_free(@keys)

• KEY_create_rsa(bits) -> key

  Creates an RSA key pair, bits defaults to 2048.

• KEY_create_ec(curve) -> key

  Creates an EC key, curve defaults to prime256v1.

• CERT_asHash(cert,[digest_algo]) -> hash

  Extracts the information from the certificate into a hash and uses the given digest_algo (default: SHA-256) to determine digest of pubkey and cert. The resulting hash contains:

  subject

  Hash with the parts of the subject, e.g. commonName, countryName, organizationName, stateOrProvinceName, localityName. If there are multiple values for any of these parts the hash value will be an array ref with the values in order instead of just a scalar.

  subjectAltNames

  Array with list of alternative names. Each entry in the list is of [type,value], where type can be OTHERNAME, EMAIL, DNS, X400, DIRNAME, EDIPARTY, URI, IP or RID.

  issuer

  Hash with the parts of the issuer, e.g. commonName, countryName, organizationName, stateOrProvinceName, localityName. If there are multiple values for any of these parts the hash value will be an array ref with the values in order instead of just a scalar.

  not_before, not_after

  The time frame, where the certificate is valid, as time_t, e.g. can be converted with localtime or similar functions.

  serial

  The serial number

  crl_uri

  List of URIs for CRL distribution.

  ocsp_uri

  List of URIs for revocation checking using OCSP.

  keyusage

  List of keyUsage information in the certificate.

  extkeyusage

  List of extended key usage information from the certificate. Each entry in this list consists of a hash with oid, nid, ln and sn.

  pubkey_digest_xxx

  Binary digest of the pubkey using the given digest algorithm, e.g. pubkey_digest_sha256 if (the default) SHA-256 was used.

  x509_digest_xxx

  Binary digest of the X.509 certificate using the given digest algorithm, e.g. x509_digest_sha256 if (the default) SHA-256 was used.

  fingerprint_xxx

  Fingerprint of the certificate using the given digest algorithm, e.g. fingerprint_sha256 if (the default) SHA-256 was used. Contrary to digest_* this is an ASCII string with a list if hexadecimal numbers, e.g. "73:59:75:5C:6D...".

  signature_alg

  Algorithm used to sign certificate, e.g. sha256WithRSAEncryption.

  ext

  List of extensions. Each entry in the list is a hash with oid, nid, sn, critical flag (boolean) and data (string representation given by X509V3_EXT_print).

  version

  Certificate version, usually 2 (x509v3)

• CERT_create(hash) -> (cert,key)

  Creates a certificate based on the given hash. If the issuer is not specified the certificate will be self-signed. The following keys can be given:

  subject

  Hash with the parts of the subject, e.g. commonName, countryName, ... as described in CERT_asHash. Default points to IO::Socket::SSL.

  not_before

  A time_t value when the certificate starts to be valid. Defaults to current time.

  not_after

  A time_t value when the certificate ends to be valid. Defaults to current time plus one 365 days.

  serial

  The serial number. If not given a random number will be used.

  version

  The version of the certificate, default 2 (x509v3).

  CA true|false

  If true declare certificate as CA, defaults to false.

  purpose string|array|hash

  Set the purpose of the certificate. The different purposes can be given as a string separated by non-word character, as array or hash. With string or array each purpose can be prefixed with '+' (enable) or '-' (disable) and same can be done with the value when given as a hash. By default enabling the purpose is assumed.

  If the CA option is given and true the defaults "ca,sslca,emailca,objca" are assumed, but can be overridden with explicit purpose. If the CA option is given and false the defaults "server,client" are assumed. If no CA option and no purpose is given it defaults to "server,client".

  Purpose affects basicConstraints, keyUsage, extKeyUsage and netscapeCertType. The following purposes are defined (case is not important):

  client
  server
  email
  objsign
  
  CA
  sslCA
  emailCA
  objCA
  
  emailProtection
  codeSigning
  timeStamping
  
  digitalSignature
  nonRepudiation
  keyEncipherment
  dataEncipherment
  keyAgreement
  keyCertSign
  cRLSign
  encipherOnly
  decipherOnly

  Examples:

  # root-CA for SSL certificates
  purpose => 'sslCA'   # or CA => 1
  
  # server certificate and CA (typically self-signed)
  purpose => 'sslCA,server'
  
  # client certificate
  purpose => 'client',

  ext [{ sn => .., data => ... }, ... ]

  List of extensions. The type of the extension can be specified as name with sn or as NID with nid and the data with data. These data must be in the same syntax as expected within openssl.cnf, e.g. something like OCSP;URI=http://.... Additionally the critical flag can be set with critical = 1>.

  key key

  use given key as key for certificate, otherwise a new one will be generated and returned

  issuer_cert cert

  set issuer for new certificate

  issuer_key key

  sign new certificate with given key

  issuer [ cert, key ]

  Instead of giving issuer_key and issuer_cert as separate arguments they can be given both together.

  digest algorithm

  specify the algorithm used to sign the certificate, default SHA-256.

  ignore_invalid_args

  ignore any unknown arguments which might be in the argument list (which might be in the arguments for example as result from CERT_asHash)

AUTHOR

Steffen Ullrich