Domain

public class Domain : CustomStringConvertible, Equatable

A Domain instance contains an elliptic curve domain - either with characteristic 2 or characteristic an odd prime. Please refer [SEC 1] section 3.1.

Constants

OID_P
Prime characteristic domain OID
Declaration
Swift

public static let OID_P: ASN1ObjectIdentifier


                    
                    
                    OID_2

Characteristic 2 domain OID

Declaration

Swift

public static let OID_2: ASN1ObjectIdentifier

Static Methods


                    
                    
                    instance(curve:)

Returns a predefined domain from its curve

Declaration

Swift

public static func instance(curve: ECCurve) -> Domain

Parameters


                                curve

The domain curve

Return Value

The corresponding domain


                    
                    
                    instance(oid:)

Returns a predefined domain from its OID

Throws

An unknownOid exception if oid does not match any domain

Declaration

Swift

public static func instance(oid: ASN1ObjectIdentifier) throws -> Domain

Parameters

oid

The domain OID

Return Value

The corresponding domain


                    
                    
                    instance(pem:)

Constructs a domain from its PEM encoding

Throws

An exception if the PEM contents is wrong

Declaration

Swift

public static func instance(pem: String) throws -> Domain

Parameters

pem

The PEM encoding of the domain

Return Value

The corresponding domain


                    
                    
                    instance(name:p:a:b:gx:gy:order:cofactor:oid:)

Constructs an odd prime characteristic domain based on the curve y^2 = x^3 + a * x + b

Throws

A domainParameter exception if 4 * a^3 + 27 * b^2 = 0 or the generator point is not on the curve

Declaration

Swift

public static func instance(name: String, p: BInt, a: BInt, b: BInt, gx: BInt, gy: BInt, order: BInt, cofactor: Int, oid: ASN1ObjectIdentifier? = nil) throws -> Domain

Parameters

`name`	The domain name
`p`	The field order - a prime greater then 3
`a`	The a coefficient
`b`	The b coefficient
`gx`	The generator point x-coordinate
`gy`	The generator point y-coordinate
`order`	The curve order
`cofactor`	The cofactor
`oid`	An optional domain OID

Return Value

The domain


                    
                    
                    instance(name:rp:a:b:gx:gy:order:cofactor:oid:)

Constructs a characteristic 2 domain based on the curve y^2 + x * y = x^3 + a * x^2 + b

Throws

A domainParameter exception if b = 0 or the generator point is not on the curve

Declaration

Swift

public static func instance(name: String, rp: RP, a: BInt, b: BInt, gx: BInt, gy: BInt, order: BInt, cofactor: Int, oid: ASN1ObjectIdentifier? = nil) throws -> Domain

Parameters

`name`	The domain name
`rp`	The reduction polynomial
`a`	The a coefficient
`b`	The b coefficient
`gx`	The generator point x-coordinate
`gy`	The generator point y-coordinate
`order`	The curve order
`cofactor`	The cofactor
`oid`	An optional domain OID

Return Value

The domain

Stored Properties

name
The domain name
Declaration
Swift

public let name: String
p
The modulus
Declaration
Swift

public let p: BInt
a
The curve a coefficient
Declaration
Swift

public let a: BInt
b
The curve b coefficient
Declaration
Swift

public let b: BInt
g
The generator point
Declaration
Swift

public let g: Point
order
The curve order
Declaration
Swift

public let order: BInt
cofactor
The cofactor
Declaration
Swift

public let cofactor: Int
oid
An optional domain OID
Declaration
Swift

public let oid: ASN1ObjectIdentifier?
characteristic2
Is true if self has characteristic 2, false if it has an odd prime characteristic
Declaration
Swift

public let characteristic2: Bool

Computed Properties

asn1
The ASN1 encoding of self
Declaration
Swift

public var asn1: ASN1 { get }
pem
The PEM encoding of self
Declaration
Swift

public var pem: String { get }
description
A textual representation of the ASN1 encoding of self
Declaration
Swift

public var description: String { get }

Instance Methods


                    
                    
                    ==(_:_:)

Equality of two Domain instances

Declaration

Swift

public static func == (d1: Domain, d2: Domain) -> Bool

Parameters

`d1`	a Domain instance
`d2`	a Domain instance

Return Value

true if d1 and d2 are equal, false otherwise


                    
                    
                    doublePoint(_:)

Doubles a curve Point

Throws

A notOnCurve exception if p is not on the curve

Declaration

Swift

public func doublePoint(_ p: Point) throws -> Point

Parameters

`p`	A curve point

Return Value

p + p


                    
                    
                    addPoints(_:_:)

Adds two curve Points

Throws

A notOnCurve exception if p1 or p2 is not on the curve

Declaration

Swift

public func addPoints(_ p1: Point, _ p2: Point) throws -> Point

Parameters

`p1`	The first curve point
`p2`	The second curve point

Return Value

p1 + p2


                    
                    
                    subtractPoints(_:_:)

Subtracts two curve Points

Throws

A notOnCurve exception if p1 or p2 is not on the curve

Declaration

Swift

public func subtractPoints(_ p1: Point, _ p2: Point) throws -> Point

Parameters

`p1`	The first curve point
`p2`	The second curve point

Return Value

p1 - p2


                    
                    
                    negatePoint(_:)

Negates a curve Point

Throws

A notOnCurve exception if p is not on the curve

Declaration

Swift

public func negatePoint(_ p: Point) throws -> Point

Parameters

`p`	A curve point

Return Value

-p


                    
                    
                    multiplyPoint(_:_:)

Multiplies a curve Point by an integer

Throws

A notOnCurve exception if p is not on the curve

Declaration

Swift

public func multiplyPoint(_ p: Point, _ n: BInt) throws -> Point

Parameters

`p`	The curve point to multiply
`n`	The integer to multiply with

Return Value

n * p


                    
                    
                    contains(_:)

Tests if point is on curve

Declaration

Swift

public func contains(_ p: Point) -> Bool

Parameters

The point

Return Value

true iff p is on the domain curve


                    
                    
                    encodePoint(_:_:)

Encodes a Point to a byte array - please refer [SEC 1] section 2.3.3

Throws

An encodePoint exception if p is not on the curve

Declaration

Swift

public func encodePoint(_ p: Point, _ compress: Bool = false) throws -> Bytes

Parameters

`p`	The point to encode
`compress`	If true use compresssed encoding, if false use uncompressed encoding - false is default

Return Value

Encoding of p


                    
                    
                    decodePoint(_:)

Decodes a Point from a byte array - please refer [SEC 1] section 2.3.4

Throws

An decodePoint exception if bytes contains invalid data

Declaration

Swift

public func decodePoint(_ bytes: Bytes) throws -> Point

Parameters


                                bytes

The byte array to decode

Return Value

The point


                    
                    
                    asn1EncodePoint(_:_:)

Encodes a Point to an ASN1 structure

Throws

An encodePoint exception if p does not lie on the curve

Declaration

Swift

public func asn1EncodePoint(_ p: Point, _ compress: Bool = false) throws -> ASN1

Parameters

`p`	The point to encode
`compress`	If true use compresssed encoding, if false use uncompressed encoding - false is default

Return Value

ASN1 encoding of p


                    
                    
                    asn1DecodePoint(_:)

Decodes a Point from an ASN1 octet string

Throws

An decodePoint exception if the octet string contains invalid data

Declaration

Swift

public func asn1DecodePoint(_ asn1: ASN1OctetString) throws -> Point

Parameters


                                asn1

The ASN1 octet string to decode

Return Value

The point


                    
                    
                    asn1DecodePoint(_:)

Decodes a Point from an ASN1 bit string

Throws

An decodePoint exception if the bit string contains invalid data

Declaration

Swift

public func asn1DecodePoint(_ asn1: ASN1BitString) throws -> Point

Parameters


                                asn1

The ASN1 bit string to decode

Return Value

The point

asn1Explicit()
Explicit ASN1 encoding of self - please refer [SEC 1] appendix C.2
All domain components are included in the encoding - not just the domain OID
Declaration
Swift

public func asn1Explicit() -> ASN1
Return Value

Explicit ASN1 encoding of self
makeKeyPair()
Generates a private- and public key pair for self
Declaration
Swift

public func makeKeyPair() -> (ECPublicKey, ECPrivateKey)
Return Value

(ECPublicKey, ECPrivateKey)