IO::Socket::SSL::Utils(3)

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

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