helpers: Helper functions for key vault objects
In cloudyr/AzureKeyVault: Key and Secret Management in 'Azure'

Helper functions for key vault objects

cert_key_properties(
  type = c("RSA", "EC"),
  hardware = FALSE,
  ec_curve = NULL,
  rsa_key_size = NULL,
  key_exportable = TRUE,
  reuse_key = FALSE
)

cert_x509_properties(
  dns_names = character(),
  emails = character(),
  upns = character(),
  key_usages = c("digitalSignature", "keyEncipherment"),
  enhanced_key_usages = c("1.3.6.1.5.5.7.3.1", "1.3.6.1.5.5.7.3.2"),
  validity_months = NULL
)

cert_issuer_properties(issuer = "self", cert_type = NULL, transparent = NULL)

cert_expiry_action(remaining = 0.1, action = c("AutoRenew", "EmailContacts"))

vault_object_attrs(
  enabled = TRUE,
  expiry_date = NULL,
  activation_date = NULL,
  recovery_level = NULL
)

`type`	For `cert_key_properties`, the type of key to create: RSA or elliptic curve (EC). Note that for keys backing a certificate, only RSA is allowed.
`hardware`	For `cert_key_properties`, whether to use a hardware key or software key. The former requires a premium key vault.
`ec_curve`	For an EC key, the type of elliptic curve.
`rsa_key_size`	For an RSA key, the key size, either 2048, 3072 or 4096.
`key_exportable`	For a key used in a certificate, whether it should be exportable.
`reuse_key`	For a key used in a certificate, whether it should be reused when renewing the certificate.
`dns_names, emails, upns`	For `cert_x509_properties`, the possible subject alternative names (SANs) for a certificate. These should be character vectors.
`key_usages`	For `cert_x509_properties`, a character vector of key usages.
`enhanced_key_usages`	For `cert_x509_properties`, a character vector of enhanced key usages (EKUs).
`validity_months`	For `cert_x509_properties`, the number of months the certificate should be valid for.
`issuer`	For `cert_issuer_properties`, the name of the issuer. Defaults to "self" for a self-signed certificate.
`cert_type`	For `cert_issuer_properties`, the type of certificate to issue, eg "OV-SSL", "DV-SSL" or "EV-SSL".
`transparent`	For `cert_issuer_properties`, whether the certificate should be transparent.
`remaining`	For `cert_expiry_action`, The remaining certificate lifetime at which to take action. If this is a number between 0 and 1, it is interpreted as the percentage of life remaining; otherwise, the number of days remaining. To disable expiry actions, set this to NULL.
`action`	For `cert_expiry_action`, what action to take when a certificate is about to expire. Can be either "AutoRenew" or "EmailContacts". Ignored if `remaining == NULL`.
`enabled`	For `vault_object_attrs`, whether this stored object (key, secret, certificate, storage account) is enabled.
`expiry_date, activation_date`	For `vault_object_attrs`, the optional expiry date and activation date of the stored object. Can be any R object that can be coerced to POSIXct format.
`recovery_level`	For `vault_object_attrs`, the recovery level for the stored object.