--***************************************************************************--
--                         IEEE Std 1609.2.1: ACPC                           --
--***************************************************************************--

/** 
 * @brief NOTE: Section references in this file are to clauses in IEEE Std
 * 1609.2.1 unless indicated otherwise. Full forms of acronyms and
 * abbreviations used in this file are specified in 3.2.
 */

Ieee1609Dot2Dot1Acpc {iso(1) identified-organization(3) ieee(111)
  standards-association-numbered-series-standards(2) wave-stds(1609) dot2(2)
  extension-standards(255) dot1(1) interfaces(1) acpc(18) major-version-1(1)
  minor-version-2(2)
}

DEFINITIONS AUTOMATIC TAGS ::= BEGIN

EXPORTS ALL;

IMPORTS
  HashAlgorithm,
  IValue,
  Psid,
  Time32,
  Uint8
FROM Ieee1609Dot2BaseTypes {iso(1) identified-organization(3) ieee(111)
  standards-association-numbered-series-standards(2) wave-stds(1609)
  dot2(2) base(1) base-types(2) major-version-2(2) minor-version-2(2)}

  Ieee1609Dot2Data-Unsecured,
  Ieee1609Dot2Data-Signed
FROM Ieee1609Dot2Dot1Protocol {iso(1) identified-organization(3) ieee(111)
  standards-association-numbered-series-standards(2) wave-stds(1609) dot2(2)
  extension-standards(255) dot1(1) interfaces(1) protocol(17) 
  major-version-2(2)  minor-version-2(2)}
;

/**
 * @class AcpcPdu
 *
 * @brief This structure contains an APrV structure produced by the CAM. An
 * overview of this structure is as follows:
 *
 * @param tree contains an AprvBinaryTree.
 *
 * @param aprv contains a single IndividualAprv.
 */
  AcpcPdu ::= CHOICE {
    tree  AprvBinaryTree,
    aprv  IndividualAprv,
    ...
  }

/**
 * @class AprvBinaryTree
 *
 * @brief This structure encodes a binary tree. An overview of this structure
 * is as follows:
 *
 * @param version contains the current version of the structure.
 *
 * @param generationTime contains the generation time of AprvBinaryTree.
 *
 * @param currentI contains the i-value associated with the batch of
 * certificates.
 *
 * @param acpcTreeId contains an identifier for the CAM creating this binary
 * tree.
 *
 * @param hashAlgorithmId contains the identifier of the hash algorithm used
 * inside the binary tree.
 *
 * @param tree contains a bit string indicating which nodes of the tree are 
 * present. It is calculated as specified in 9.5.4.2, and can be used by the
 * EE to determine which entry in nodeValueList to use to derive that EE's
 * APrV as specified in 9.5.2.
 *
 * @param nodeValueList contains the values of the nodes that are present in 
 * the order indicated by tree.
 */
  AprvBinaryTree ::= SEQUENCE {
    version          Uint8 (2), 
    generationTime   Time32,
    currentI         IValue, 
    acpcTreeId       AcpcTreeId,
    hashAlgorithmId  HashAlgorithm,
    tree             BIT STRING,
    nodeValueList    SEQUENCE (SIZE (1..MAX)) OF AcpcNodeValue,
    ...
  }

/**
 * @class AcpcPsid
 *
 * @brief This is the PSID used to indicate activities in ACPC as specified in
 * this document.
 */
  AcpcPsid ::= Psid(2113696)

/**
 * @class UnsecuredAprvBinaryTree
 *
 * @brief This is used to wrap an AprvBinaryTree in an Ieee1609Dot2Data for
 * transmission if the policy is that the AprvBinaryTree need not be signed.
 * See 9.5.6 for discussion.
 */
  UnsecuredAprvBinaryTree ::= Ieee1609Dot2Data-Unsecured {
	AcpcPdu (WITH COMPONENTS {tree})
  }

/**
 * @class SignedAprvBinaryTree
 *
 * @brief This is used to wrap an AprvBinaryTree in an Ieee1609Dot2Data for
 * transmission if the policy is that the AprvBinaryTree be signed. See 9.5.6
 * for discussion.
 */
  SignedAprvBinaryTree ::= Ieee1609Dot2Data-Signed {
    AcpcPdu (WITH COMPONENTS {tree}), AcpcPsid
  }

/**
 * @class IndividualAprv
 *
 * @brief This structure contains an individual APrV. An overview of this
 * structure is as follows:
 *
 * @param version contains the current version of the structure.
 *
 * @param generationTime contains the generation time of IndividualAprv.
 *
 * @param currentI contains the i-value associated with the batch of
 * certificates.
 *
 * @param acpcTreeId contains an identifier for the CAM creating this binary
 * tree.
 *
 * @param nodeId contains the identifier of the node.
 *
 * @param nodeValue contains the value of the node.
 */
  IndividualAprv ::= SEQUENCE {
    version         Uint8 (2),
    generationTime  Time32,
    currentI        IValue,
    acpcTreeId      AcpcTreeId,
    nodeId          BIT STRING,
    nodeValue       AcpcNodeValue,
    ...
  }

/**
 * @class SignedIndividualAprv
 *
 * @brief This is used to wrap an IndividualAprv in an Ieee1609Dot2Data for
 * transmission if the policy is that the IndividualAprv be signed. See 9.5.6
 * for discussion.
 */
  SignedIndividualAprv ::= Ieee1609Dot2Data-Signed {
    AcpcPdu (WITH COMPONENTS {aprv}), AcpcPsid
  }

/**
 * @class AcpcTreeId
 *
 * @brief This is an 8 byte string that identifies an ACPC tree series. It is
 * required to be globally unique within the system and is the same for all
 * ACPC tree instances within the ACPC tree series. Registration of AcpcTreeId
 * values is managed by the IEEE RA; see http://standards.ieee.org/regauth. A
 * list of assigned AcpcTreeId values is provided in L.2.
 */
  AcpcTreeId ::= OCTET STRING (SIZE(8))

/**
 * @class AcpcNodeValue
 *
 * @brief This is a 16 byte string that represents the value of a node in the
 * ACPC tree.
 */
  AcpcNodeValue ::= OCTET STRING (SIZE(16))

/**
 * @class AprvHashCalculationInput
 *
 * @brief This structure, C-OER encoded, is the input to the hash function to
 * calculate child node values from a parent node. By including the ID fields
 * it "firewalls" the hash function so that an attacker who inverts the hash
 * has only found the hash preimage for a specific node, in a specific tree,
 * for a specific time period. An overview of this structure is as follows:
 *
 * @param version contains the current version of the structure.
 *
 * @param acpcTreeId contains an identifier for this ACPC tree series.
 *
 * @param acpcPeriod contains an identifier for the time period for this tree.
 * If the certificates for which this set of APrVs are intended have an IValue
 * field, acpcPeriod in this structure shall be equal to the IValue field in
 * the certificates. How the RA and the CAM synchronize on this value is
 * outside the scope of this document.
 *
 * @param childNodeId contains a bit string of length l encoding the node
 * location within the l'th level. 
 *
 * @param parentNodeValue contains the value of the parent node.
 */
  AprvHashCalculationInput ::= SEQUENCE {
    version          Uint8 (2),
    acpcTreeId       AcpcTreeId,
    acpcPeriod       IValue,
    childNodeId      BIT STRING,
    parentNodeValue  OCTET STRING (SIZE(16)),
    ...
  }

END