Class: XiWechatCorp::AesCrypt

Inherits:
Object
  • Object
show all
Defined in:
lib/xi_wechat_corp/aes_crypt.rb

Constant Summary collapse

PKCS7 = 
PKCS7Encoder.new

Instance Method Summary collapse

Constructor Details

#initialize(aes_key, corp_id) ⇒ AesCrypt

Returns a new instance of AesCrypt.

Raises:

  • (ArgumentError) 


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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 10

def initialize(aes_key, corp_id)
  @aes_key = decode64(aes_key + '=')
  raise ArgumentError if @aes_key.size != 32
  @corp_id = corp_id
end

Instance Method Details

#cipher_decrypt(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 61

def cipher_decrypt(text)
  cipher(:decrypt, text)
end

#cipher_encrypt(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 57

def cipher_encrypt(text)
  cipher(:encrypt, text)
end

#decode64(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 53

def decode64(text)
  Base64.decode64(text)
end

#decrypt(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 20

def decrypt(text)
  unpack unpad cipher_decrypt decode64 text
end

#encode64(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 49

def encode64(text)
  Base64.strict_encode64(text)
end

#encrypt(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 16

def encrypt(text)
  encode64 cipher_encrypt pad pack text
end

#pack(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 24

def pack(text)
  [
    SecureRandom.random_bytes(16),
    [text.bytesize].pack('N'),
    text.force_encoding('ASCII-8BIT'),
    @corp_id
  ].join('')
end

#pad(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 41

def pad(text)
  PKCS7.encode(text)
end

#unpack(text) ⇒ Object

Raises:



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 33

def unpack(text)
  size, corp_id = text.unpack('@16Na*')
  output = corp_id.slice!(0, size)

  raise InvalidCorpIDError.new(corp_id) if corp_id != @corp_id
  output.force_encoding('UTF-8')
end

#unpad(text) ⇒ Object 



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# File 'lib/xi_wechat_corp/aes_crypt.rb', line 45

def unpad(text)
  PKCS7.decode(text)
end