Key wrapping access control points

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In order to comply with cryptographic standards, including ANSI X9.24 Part 1 and PCI-HSM 2016, CCA provides a set of access control points (ACPs) to ensure that a key is not wrapped with a key weaker than itself. Administrators can use these ACPs to control the wrapping of keys by master and key-encrypting keys in order to meet an installation's individual requirements. These access control points either prohibit the wrapping of a key by a key of weaker strength, or return a warning when a key is wrapped by a weaker key. All of these ACPs are disabled by default.

This subsequent list provides a description of the available access control points, the wrapping they control, and the effect they have on the processing of the affected verbs. These ACPs apply to symmetric and asymmetric keys.

  • When the Prohibit weak wrapping - Transport keys access control point is enabled, any service that attempts to wrap a key with a weaker transport key will fail.
  • When the Prohibit weak wrapping - Master keys access control point is enabled, any service that wraps a key under a master key will fail if the master key is weaker than the key being wrapped.
  • When the Warn when weak wrap - Transport keys access control point is enabled, any service that attempts to wrap a key with a weaker transport key will succeed with a warning reason code.
  • When the Warn when weak wrap - Master keys access control point is enabled, any service that attempts to wrap a key with a weaker master key will succeed with a warning reason code.
  • When the Allow weak wrapping of compliance-tagged keys by DES MK access control point is enabled, any service which attempts to wrap a compliant-tagged key token with a weaker DES master key will succeed.
  • 24-byte DATA keys with a zero control vector can be wrapped with a 16-byte key, the DES master key, or a key-encrypting key, which violates the wrapping requirements. The Prohibit weak wrapping - Transport keys and Prohibit weak wrapping - Master keys access control points do not cause services to fail for this case. The Disallow 24-byte DATA wrapped with 16-byte Key access control point does control this wrapping. When enabled, services will fail. The Warn when weak wrap - Transport keys and Warn when weak wrap - Master keys access control points will cause the warning to be returned when the access control points are enabled.
  • When the Trusted Block Create - Disallow triple-length MAC key access control point is enabled, CSNDRKX will fail to import a triple-length MAC key under a double-length key-encrypting key. CSNDTBC will not wrap a triple-length MAC key under a double-length key-encrypting key. The Prohibit weak wrapping - Transport keys and Prohibit weak wrapping - Master keys access control points do not cause services to fail for this case. The Warn when weak wrap - Transport keys and Warn when weak wrap - Master keys access control points will cause the warning to be returned when the ACPs are enabled.
  • When the Prohibit weak wrapping - ... access control points are enabled, RSA private keys may not be wrapped using a weaker DES key-encrypting key. Enabling the Allow weak DES wrap of RSA access control point will override this restriction.

Additionally, CCA provides a set of access control points in the domain role that prohibit the usage and generation of keys that fall below the minimum key strength requirement of the respective access control point. All of these ACPs are disabled by default in the domain role.

  • When the Disable 56-bit length DES keys access control point is enabled, any verb that attempts to accept or generate a 56-bit length DES key will fail.
  • When the Disable 56-bit effective length DES keys access control point is enabled, any service that attempts to accept or generate a 56-bit effective length DES key (112-bit or 168-bit keys with repeated 56-bit sections) will fail. This will also disallow loading a master key that has a 56-bit effective length.
  • When the Disable RSA keys with less than 1024-bit modulus length access control point is enabled, any service that attempts to accept or generate RSA keys with a modulus length less than 1024 bit will fail.
  • When the Disable RSA keys with less than 2048-bit modulus length access control point is enabled, any service that attempts to accept or generate RSA keys with a modulus length less than 2048 bit will fail.
  • When the Disable ECC keys weaker than 224-bit (P192, BP160, BP192) access control point is enabled, any service that attempts to accept or generate ECC keys weaker than 224 bit (P192, BP160, BP192) will fail.