Module: AesShared

Included in:
AesAlg
Defined in:
lib/ruby-aes/aes_shared.rb

Overview

This file is a part of ruby-aes <rubyforge.org/projects/ruby-aes>

Written by Alex Boussinet <[email protected]>

It contains the code shared by all the implementations

Instance Method Summary collapse

Instance Method Details

#decrypt_blocks(buffer) ⇒ Object 



23
24
25
26
27
28
29
30
31
32
33
34
35
 
# File 'lib/ruby-aes/aes_shared.rb', line 23

def decrypt_blocks(buffer)
    raise "Bad block length" unless (buffer.length % 16).zero?
    pt = ""
    block = ""
    buffer.each_byte do |char|
        block << char
        if block.length == 16
            pt << decrypt_block(block)
            block = ""
        end
    end
    pt
end

#decrypt_buffer(buffer) ⇒ Object 



55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
 
# File 'lib/ruby-aes/aes_shared.rb', line 55

def decrypt_buffer(buffer)
    pt = ""
    block = ""
    buffer.each_byte do |char|
        block << char
        if block.length == 16
            pt << decrypt_block(block)
            block = ""
        end
    end
    if block.length != 1
        raise 'Bad Block Padding'
    elsif (c = block[-1]).zero?
        pt
    else
        if block * c == pt[-c..-1]
            pt[0..-c-1]
        else
            raise "Bad Block Padding"
        end
    end
end

#encrypt_blocks(buffer) ⇒ Object 



9
10
11
12
13
14
15
16
17
18
19
20
21
 
# File 'lib/ruby-aes/aes_shared.rb', line 9

def encrypt_blocks(buffer)
    raise "Bad block length" unless (buffer.length % 16).zero?
    ct = ""
    block = ""
    buffer.each_byte do |char|
        block << char
        if block.length == 16
            ct << encrypt_block(block)
            block = ""
        end
    end
    ct
end

#encrypt_buffer(buffer) ⇒ Object 



37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 
# File 'lib/ruby-aes/aes_shared.rb', line 37

def encrypt_buffer(buffer)
    ct = ""
    block = ""
    buffer.each_byte do |char|
        block << char
        if block.length == 16
            ct << encrypt_block(block)
            block = ""
        end
    end
    c = "\000"
    if (m = 16 - block.length % 16) != 16
        c = m.chr
        ct << encrypt_block(block << c * m)
    end
    ct << c
end