Class: H2C::Suite

Inherits:
Object
  • Object
show all
Defined in:
lib/h2c/suite.rb

Overview

Hash to curve suites

Constant Summary collapse

SECP256K1_XMDSHA256_SSWU_NU_ = 
"secp256k1_XMD:SHA-256_SSWU_NU_"
SECP256K1_XMDSHA256_SSWU_RO_ = 
"secp256k1_XMD:SHA-256_SSWU_RO_"
BLS12381G1_XMDSHA256_SSWU_NU_ = 
"BLS12381G1_XMD:SHA-256_SSWU_NU_"
BLS12381G1_XMDSHA256_SSWU_RO_ = 
"BLS12381G1_XMD:SHA-256_SSWU_RO_"
P256_XMDSHA256_SSWU_NU_ = 
"P256_XMD:SHA-256_SSWU_NU_"
P256_XMDSHA256_SSWU_RO_ = 
"P256_XMD:SHA-256_SSWU_RO_"
P384_XMDSHA384_SSWU_NU_ = 
"P384_XMD:SHA-384_SSWU_NU_"
P384_XMDSHA384_SSWU_RO_ = 
"P384_XMD:SHA-384_SSWU_RO_"
P521_XMDSHA512_SSWU_NU_ = 
"P521_XMD:SHA-512_SSWU_NU_"
P521_XMDSHA512_SSWU_RO_ = 
"P521_XMD:SHA-512_SSWU_RO_"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(id, dst) ⇒ Suite

Initialize suite



21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
 
# File 'lib/h2c/suite.rb', line 21

def initialize(id, dst)
  @id = id
  @k = 128
  @m = 1
  case id
  when SECP256K1_XMDSHA256_SSWU_NU_, SECP256K1_XMDSHA256_SSWU_RO_
    @curve = ECDSA::Group::Secp256k1
    @exp = Expander.get(HashFunc::SHA256, dst, @k)
    @l = 48
    @map = M2C::SSWUAB0.new(H2C::M2C::ISOGeny::Secp256k1.new, -11)
    @ro = (id == SECP256K1_XMDSHA256_SSWU_RO_)
  when BLS12381G1_XMDSHA256_SSWU_NU_, BLS12381G1_XMDSHA256_SSWU_RO_
    @curve = BLS::Group::BLS12381G1
    @exp = Expander.get(HashFunc::SHA256, dst, @k)
    @l = 64
    @map = M2C::SSWUAB0.new(H2C::M2C::ISOGeny::BLS12381G1.new, 11)
    @ro = (id == BLS12381G1_XMDSHA256_SSWU_RO_)
  when P256_XMDSHA256_SSWU_NU_, P256_XMDSHA256_SSWU_RO_
    @curve = ECDSA::Group::Nistp256
    @exp = Expander.get(HashFunc::SHA256, dst, @k)
    @l = 48
    @map = M2C::SSWU.new(ECDSA::Group::Nistp256, -10)
    @ro = (id == P256_XMDSHA256_SSWU_RO_)
  when P384_XMDSHA384_SSWU_NU_, P384_XMDSHA384_SSWU_RO_
    @k = 192
    @curve = ECDSA::Group::Nistp384
    @exp = Expander.get(HashFunc::SHA384, dst, @k)
    @l = 72
    @map = M2C::SSWU.new(ECDSA::Group::Nistp384, -12)
    @ro = (id == P384_XMDSHA384_SSWU_RO_)
  when P521_XMDSHA512_SSWU_NU_, P521_XMDSHA512_SSWU_RO_
    @k = 256
    @curve = ECDSA::Group::Nistp521
    @exp = Expander.get(HashFunc::SHA512, dst, @k)
    @l = 98
    @map = M2C::SSWU.new(ECDSA::Group::Nistp521, -4)
    @ro = (id == P521_XMDSHA512_SSWU_RO_)
  else
    raise H2C::Error, "suite #{curve} unsupported."
  end
end

Instance Attribute Details

#curve ⇒ Object (readonly)

Returns the value of attribute curve.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def curve
  @curve
end

#exp ⇒ Object (readonly)

Returns the value of attribute exp.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def exp
  @exp
end

#id ⇒ Object (readonly)

Returns the value of attribute id.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def id
  @id
end

#k ⇒ Object (readonly)

Returns the value of attribute k.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def k
  @k
end

#l ⇒ Object (readonly)

Returns the value of attribute l.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def l
  @l
end

#m ⇒ Object (readonly)

Returns the value of attribute m.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def m
  @m
end

#map ⇒ Object (readonly)

Returns the value of attribute map.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def map
  @map
end

#ro ⇒ Object (readonly)

Returns the value of attribute ro.



5
6
7
 
# File 'lib/h2c/suite.rb', line 5

def ro
  @ro
end