module Wechat::Cipher
Constants
- BLOCK_SIZE
- CIPHER
Public Instance Methods
decrypt(msg, encoding_aes_key)
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# File lib/wechat/cipher.rb, line 20 def decrypt(msg, encoding_aes_key) cipher = OpenSSL::Cipher.new(CIPHER) cipher.decrypt cipher.padding = 0 key_data = Base64.decode64("#{encoding_aes_key}=") cipher.key = key_data cipher.iv = [key_data].pack('H*') plain = cipher.update(msg) + cipher.final decode_padding(plain) end
encrypt(plain, encoding_aes_key)
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# File lib/wechat/cipher.rb, line 8 def encrypt(plain, encoding_aes_key) cipher = OpenSSL::Cipher.new(CIPHER) cipher.encrypt cipher.padding = 0 key_data = Base64.decode64("#{encoding_aes_key}=") cipher.key = key_data cipher.iv = [key_data].pack('H*') cipher.update(plain) + cipher.final end
pack(content, app_id)
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app_id or corp_id
# File lib/wechat/cipher.rb, line 34 def pack(content, app_id) random = SecureRandom.hex(8) text = content.dup.force_encoding('ASCII-8BIT') msg_len = [text.length].pack('N') encode_padding("#{random}#{msg_len}#{text}#{app_id}") end
unpack(msg)
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# File lib/wechat/cipher.rb, line 42 def unpack(msg) msg = decode_padding(msg) msg_len = msg[16, 4].reverse.unpack1('V') content = msg[20, msg_len] app_id = msg[(msg_len + 20)..-1] [content, app_id] end
Private Instance Methods
decode_padding(plain)
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# File lib/wechat/cipher.rb, line 61 def decode_padding(plain) pad = plain.bytes[-1] # no padding pad = 0 if pad < 1 || pad > BLOCK_SIZE plain[0...(plain.length - pad)] end
encode_padding(data)
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# File lib/wechat/cipher.rb, line 53 def encode_padding(data) length = data.bytes.length amount_to_pad = BLOCK_SIZE - (length % BLOCK_SIZE) amount_to_pad = BLOCK_SIZE if amount_to_pad.zero? padding = ([amount_to_pad].pack('c') * amount_to_pad) data + padding end