
Bifroest	Mr. Tines	CTC Home	CTClib	MacCTC	CTCjava	Manual

Global Constants

This page describes a number of constants defined in CTC that are not associated with any single module. They appear in a number of separate header files.

abstract.h

This header file is abstract type definitions file. It provides incomplete definitions of most CTC datatypes. See the appropriate modules for documentation these.

These are adequate for prototype definitions and manipulation of pointers to the types, but providing no details of the internals of the structures.

Many of these structures are used only quite locally. However as we are leaking no information about their internals there is no danger in making their names widely available. Indeed it has the effect of globally reserving the name, preventing accidently clashes.

In addition abstract.h, holds the definitions of types accessMode and fileType which are defined for, and documented with, port_io.

Abstract.h requires the definitions from basic.h

Constant Values

KEYFRAGSIZE: Number of bytes in Key Id.
KEYPRINTFRAGSIZE: Number of bytes of key Id. normally printed.
SIZEOF_TIMESTAMP: Size in bytes of timestamp
SIZEOF_VALIDITY: Size in bytes of validity period
MAX_DEPTH: max. value of max_cert_depth
MAXHASHSIZE: largest digest size in use (bytes)
MAXCVALGS: Maximum number of levels of conventional encryption
MAXBLOCKSIZE: largest block size in use (bytes)
MAXKEYSIZE: largest key size in use (bytes)

Enumeration Types

continue_action: This data-type represents the result of decision on continuing the current operation. Typically taken during decryption operations. The valid values are:-

basic.h

This defines a number of very simple and universal types and constants.

Most of these values and types very standard and are defined by many compilers or standard include files. Accordingly basic.h only defines these when not predefined by the C development system.

Constant Values

VERSIONNO: version number of package (as a character string)
VOID: Void data type
TRUE: Boolean true value
FALSE: Boolean false value

Macros

max: Returns the maximum of two arguments. Note that this macro evaluates the selected value twice. Substituting an expression with side-effects (e.g. anything including '++' or '--') is likely to have unexpected results.
min: Returns the minimum of two arguments. Implemented in the same way as max().
NAMESPACE_CTCLIB: Used to declare the start of CTC's Namespace, for compilers that support Namespace directives.
END_NAMESPACE: Used to mark the end of CTC's Namespace.

DataTypes

This file defines a number of general purpose datatypes:-

boolean: Boolean value.
byte: Single 8-bit byte; usually implemented as unsigned char
ushort: Obsolete alternative to uint16_t; no longer defined
ulong: Obsolete alternative to uint32_t; no longer defined
uint8_t: Unsigned short (8-bit) integer (not used by most of CTClib which uses byte but is used in some of the ciphers.
uint16_t: Unsigned short (16-bit) integer
uint32_t: Unsigned long (32-bit) integer
common_error: This datatype is used in a number of modules as a common return code type.

keyconst.h

This header file defines a number of constants associated with PKE keys, and encryption algorith selection.

Constants

MAXBUFFERSIZE

Cipher Type Byte (CTB)

fields: These constants define the bit fields within a Cipher Type Byte, the first byte of a PGP binary file block.
Block Types: The following types:-
Signature type: These constants are used to indicate the significance of a signature.
Sub-Packet Type: This is the definition of the constants for the type field of Signature sub-packets. See OpenPGP documentation of details on the use of each of these. (This is now more or less finalised as RFC2440.)
Trust Byte fields: This is the definition of the constants for manipulating Trust bytes. CTC does not take Trust bytes seriously as they are in plain and unauthenticated hence wide open to forgery.
PKE algorithm bytes: This is may change. Arguably here should probably be separate selectors for key exchange and authentication algorithm. However at present algorithm and whether it is usable of key-exchange or authentication or both is encoded in a single value. Note that CTC does not enforce these restrictions. It is up to the application to enforce this, if this is required.
Symmetric algorithm selector bytes: Note that there are wide range of different ciphers in use by different PGP implementations. We tried to at least correctly identify all the cipher bytes, albeit we do not implement all ciphers. Hence this has a large number of values not processed by CTC and more are understood but never written by CTC.
Symmetric Mode-of-Operation selector bytes
Message digest algorithm selector
Compression algorithm: Defines the method of
Version byte: for data structures created by this version of PGP