1 | Bletchley provides a variety of tools that make black box |
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2 | cryptanalysis easier by taking care of some of the more tedious |
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3 | engineering challenges. Bletchley is maintained by <a href="http://vsecurity.com/">VSR</a>. |
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4 | Bletchley is currently in the early stages of development, which means |
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5 | documentation may be lacking. Contributions are welcome. |
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6 | |
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7 | *Contents* |
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8 | <wiki:toc max_depth="2" /> |
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9 | |
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10 | = Installation = |
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11 | See: <a href="http://code.google.com/p/bletchley/source/browse/trunk/INSTALL">INSTALL</a> |
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12 | |
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13 | = Command Line Tools = |
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14 | |
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15 | == bletchley-analyze == |
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16 | |
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17 | Analyzes samples of encrypted data in an attempt to decode samples to |
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18 | binary and identify patterns useful in cryptanalysis. The purpose of |
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19 | the tool is to provide an cryptanalyst with a variety of information |
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20 | that is useful in determining how a token is encoded, encrypted and |
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21 | formatted. |
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22 | <br /> |
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23 | bletchley-analyze currently performs two primary functions: iterative |
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24 | encoding detection and ciphertext-only block analysis. Encrypted tokens |
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25 | are processed in multiple rounds. Within each round, the following |
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26 | occurs: |
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27 | <ul> |
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28 | <li>Token length analysis is performed to attempt to determine possible |
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29 | ciphertext block sizes, where applicable</li> |
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30 | <li>The tokens are analyzed for blocks of data that are repeated |
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31 | throughout any of the tokens</li> |
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32 | <li>A hexadecimal dump and escaped binary/ascii string is printed for |
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33 | each token with repeated blocks highlighted</li> |
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34 | <li>The full set of all known and possible data encodings is |
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35 | determined<sup>1</sup></li> |
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36 | <li>An educated guess is made as to the most likely encoding is</li> |
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37 | <li>All tokens are decoded using the most likely encoding, and then the |
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38 | process is repeated until no further encodings are detected</li> |
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39 | </ul> |
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40 | |
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41 | `bletchley-analyze` can read from stdin or from a file. Tokens are |
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42 | delimited with newlines. Various options are provided to give the |
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43 | analyst control over the block sizes and encoding used during analysis. |
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44 | See the tool's usage statement for more information. |
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45 | |
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46 | As an example, several tokens were encrypted using ECB mode and encoded |
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47 | using base64, and then percent (URL) encoded: |
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48 | {{{ |
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49 | zRW5bHxcRYHHqi0nriqOzg%3D%3D |
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50 | meU8SyxVHE3Hqi0nriqOzg%3D%3D |
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51 | vTA9eA4hhbFlktsbYI4hIg%3D%3D |
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52 | meU8SyxVHE1lktsbYI4hIg%3D%3D |
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53 | }}} |
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54 | |
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55 | These tokens were then fed to `bletchley-analyze`: |
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56 | <img src="http://bletchley.googlecode.com/svn/wiki/images/bletchley-analyze.png" /> |
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57 | |
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58 | 1. <i>Bletchley's blobtools module currently supports 33 encoding variants, |
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59 | including various forms of hexadecimal, base32, base64, and percent |
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60 | encodings. Try '`-e ?`' to list them.</i> |
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61 | |
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62 | |
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63 | == bletchley-encode == |
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64 | A simple tool to encode arbitrary data using a specified encoding chain. |
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65 | See the usage statement for more information. A quick example: |
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66 | {{{ |
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67 | $ echo 'Mallory Is My Friend.' | bletchley-encode -e percent/upper-plus,base64/rfc3548 |
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68 | TWFsbG9yeSBJcyBNeSBGcmllbmQuCg%3D%3D |
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69 | }}} |
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70 | |
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71 | NOTE: The encoding chain is applied from right to left in order to be consistent with other tools. |
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72 | That is, one can use the same encoding chain ordering for |
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73 | `bletchley-encode`, `bletchley-decode`, and `bletchley-analyze`. |
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74 | |
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75 | |
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76 | == bletchley-decode == |
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77 | A simple tool to decode data using a specified encoding chain. See the |
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78 | usage statement for more information. A quick example: |
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79 | {{{ |
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80 | $ echo 'TWFsbG9yeSBJcyBNeSBGcmllbmQuCg%3D%3D' | bletchley-decode -e percent/upper-plus,base64/rfc3548 |
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81 | Mallory Is My Friend. |
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82 | }}} |
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83 | |
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84 | == bletchley-http2py == |
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85 | This script parses an HTTP request (provided via stdin or as a text |
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86 | file) and generates a Python script that sends (approximately) the same |
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87 | request. This is useful when one wants to repeatedly send variations of |
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88 | a request that was observed to be sent by an application or web |
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89 | browser. For more information, see the script's usage statement. |
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90 | |
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91 | == bletchley-nextrand == |
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92 | A simple program which computes the state of a Java Random class |
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93 | instance given two sequential outputs of |
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94 | <a href="http://docs.oracle.com/javase/6/docs/api/java/util/Random.html#nextInt()">`nextInt()`</a>. |
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95 | For more information, see the usage statement. |
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96 | |
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97 | |
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98 | = Libraries = |
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99 | |
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100 | Hint: start with '`pydoc bletchley`'? |
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101 | TODO |
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102 | |
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103 | == blobtools == |
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104 | TODO |
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105 | |
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106 | == CBC == |
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107 | TODO |
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108 | |
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109 | |
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110 | = Support = |
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111 | |
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112 | Having trouble? Submit an issue <a href="http://code.google.com/p/bletchley/issues/list">here</a>. |
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113 | |
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114 | |
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115 | = Contributing = |
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116 | |
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117 | We welcome any kind of help with the project, from new tools to bug |
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118 | fixes and documentation. You might want to start with our |
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119 | <a href="http://code.google.com/p/bletchley/source/browse/trunk/doc/TODO">TODO</a> |
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120 | list. To submit a patch, just check out a copy of our Subversion |
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121 | repository, make your changes, and submit the output of `svn diff` to one of the project leaders. |
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