Class: CcipherFactory::DerivedSymKey

Inherits:
Object
  • Object
show all
Includes:
Common, SymKey, TR::CondUtils
Defined in:
lib/ccipher_factory/symkey/derived_symkey.rb

Instance Attribute Summary collapse

Attributes included from SymKey

#key, #keysize, #keytype

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Common

#attach_mode, #cleanup_intOutputBuf, #cleanup_intOutputFile, #detach_mode, #disposeOutput, #intOutputBuf, #intOutputFile, #is_attach_mode?, #is_output_given?, #output, #output_obj, #sanitize_symbol, #write_to_output

Methods included from SymKey

#dispose, #initialize, #is_equals?, #merge_key, #raw_key, #split_key

Methods included from ShamirSharingHelper

#shamir_recover, #shamir_split

Instance Attribute Details

#kdf ⇒ Object

Returns the value of attribute kdf.



53
54
55
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 53

def kdf
  @kdf
end

Class Method Details

.from_encoded(bin, &block) ⇒ Object 



10
11
12
13
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 10

def self.from_encoded(bin, &block)
  ts = BinStruct.instance.struct_from_bin(bin)
  from_tspec(ts, &block)
end

.from_tspec(ts, &block) ⇒ Object

Raises:



15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 15

def self.from_tspec(ts, &block)

  raise SymKeyError, "Block is required" if not block

  pass = block.call(:password)
  raise SymKeyError, "Password to derive symkey is not available" if is_empty?(pass)

  keytype = BTag.value_constant(ts.keytype)
  keysize = ts.keysize
  dsk = DerivedSymKey.new(keytype, keysize) 
  dsk.kdf = KDF.from_encoded(ts.kdf_config)
  dsk.derive(pass)

  kcvBin = ts.kcv

  # default is NOT to generate the KCV flag to beat the recursive test 
  if block
    if not_empty?(kcvBin) and block.call(:pre_verify_password) == true
      kcv = KCV.from_encoded(kcvBin)
      kcv.key = dsk
      raise SymKeyError, "Given password is incorrect" if not kcv.is_matched?
    end
    #else
    #  raise SymKeyError, "Given password is incorrect" if not kcv.is_matched?
  end

  dsk

end

.logger ⇒ Object 



45
46
47
48
49
50
51
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 45

def self.logger
  if @logger.nil?
    @logger = Tlogger.new
    @logger.tag = :derived_symkey
  end
  @logger
end

Instance Method Details

#activate_password_verifier ⇒ Object 



54
55
56
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 54

def activate_password_verifier
  @passVer = true
end

#deactivate_password_verifier ⇒ Object 



57
58
59
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 57

def deactivate_password_verifier
  @passVer = false
end

#derive(pass, eng = :scrypt, &block) ⇒ Object 



61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 61

def derive(pass, eng = :scrypt, &block)

  if is_empty?(@kdf)
    @kdf = KDF.instance(eng) 
    if block
      case eng
      when :scrypt
        @kdf.cost = block.call(:kdf_scrypt_cost)
        @kdf.parallel = block.call(:kdf_scrypt_parallel)
        @kdf.blocksize = block.call(:kdf_scrypt_blocksize)
        @kdf.salt = block.call(:kdf_scrypt_salt)
        @kdf.digestAlgo = block.call(:kdf_scrypt_digestAlgo)
      end
    end

    @kdf.derive_init(@keysize)
  end

  @kdf.derive_update(pass)
  @kdfAsn1 = @kdf.derive_final

  @key = @kdf.derivedVal

  #logger.debug "Derived : #{@key}"

end

#encoded ⇒ Object 



88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 88

def encoded

  ts = BinStruct.instance.struct(:symkey_derived)
  ts.keytype = BTag.constant_value(@keytype)
  ts.keysize = @keysize
  ts.kdf_config = @kdfAsn1
  if @passVer == true
    kcv = KCV.new
    kcv.key = self
    ts.kcv = kcv.encoded
  else
    ts.kcv = ""
  end
  ts.encoded

end

#logger ⇒ Object 



105
106
107
 
# File 'lib/ccipher_factory/symkey/derived_symkey.rb', line 105

def logger
  self.class.logger
end