Module: K3CloudWebapiSdk::Util::Base64Util

Defined in:
lib/k3cloud_webapi_sdk/util/base64_util.rb

Constant Summary collapse

CHARSET = 
('A'..'Z').to_a.join + ('a'..'z').to_a.join + ('0'..'9').to_a.join + '+/'

Class Method Summary collapse

Class Method Details

.decode(base64_str) ⇒ Object

Custom base64 decode



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# File 'lib/k3cloud_webapi_sdk/util/base64_util.rb', line 41

def self.decode(base64_str)
  return [] if !valid_base64_str(base64_str)
  
  # Remove padding for processing
  chars_to_process = base64_str.gsub('=', '')
  
  # Convert to 6-bit chunks
  base64_bytes = chars_to_process.chars.map do |c|
    CHARSET.index(c).to_s(2).rjust(6, '0')
  end
  
  resp = []
  nums = base64_bytes.length / 4
  remain = base64_bytes.length % 4
  
  # Process complete 4-chunk units
  (0...nums).each do |i|
    tmp_unit = base64_bytes[i*4..i*4+3].join('')
    [0, 8, 16].each do |offset|
      value = tmp_unit[offset, 8].to_i(2)
      resp << value
    end
  end
  
  # Handle remaining chunks
  if remain > 0
    remain_part = base64_bytes[nums*4..-1].join('')
    (0...remain-1).each do |i|
      value = remain_part[i*8, 8].to_i(2)
      resp << value
    end
  end
  
  resp
end

.encode(origin_bytes) ⇒ Object

Custom base64 encode (Ruby equivalent of Python’s base64_util.py)



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# File 'lib/k3cloud_webapi_sdk/util/base64_util.rb', line 7

def self.encode(origin_bytes)
  return '' if origin_bytes.nil? || origin_bytes.empty?
  
  # Convert to binary string
  base64_bytes = origin_bytes.bytes.map { |b| b.to_s(2).rjust(8, '0') }
  
  resp = ''
  nums = base64_bytes.length / 3
  remain = base64_bytes.length % 3
  
  # Process complete 3-byte chunks
  (0...nums).each do |i|
    tmp_unit = base64_bytes[i*3..i*3+2].join('')
    [0, 6, 12, 18].each do |offset|
      value = tmp_unit[offset, 6].to_i(2)
      resp << CHARSET[value]
    end
  end
  
  # Handle remaining bytes
  if remain > 0
    remain_part = base64_bytes[nums*3..-1].join('').ljust((3-remain)*8, '0')
    [0, 6, 12, 18].each_with_index do |offset, idx|
      break if idx >= remain + 1
      value = remain_part[offset, 6].to_i(2)
      resp << CHARSET[value]
    end
    resp << '=' * (3 - remain)
  end
  
  resp
end

.valid_base64_str(b_str) ⇒ Object

Validate base64 string



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# File 'lib/k3cloud_webapi_sdk/util/base64_util.rb', line 78

def self.valid_base64_str(b_str)
  return false if b_str.length % 4 != 0
  b_str.each_char.all? { |m| CHARSET.include?(m) }
end