Sat, 26 Apr 2025 12:34:32 +0200
MicroPython
- Added a configuration option to disable the support for the no longer produced Pimoroni Pico Wireless Pack.
<!DOCTYPE html> <html><head> <title>eric7.EricUtilities.crypto.py3AES</title> <meta charset="UTF-8"> <link rel="stylesheet" href="styles.css"> </head> <body> <a NAME="top" ID="top"></a> <h1>eric7.EricUtilities.crypto.py3AES</h1> <p> Module implementing classes for encryption according Advanced Encryption Standard. </p> <h3>Global Attributes</h3> <table> <tr><td>None</td></tr> </table> <h3>Classes</h3> <table> <tr> <td><a href="#AES">AES</a></td> <td>Class implementing the Advanced Encryption Standard algorithm.</td> </tr> <tr> <td><a href="#AESModeOfOperation">AESModeOfOperation</a></td> <td>Class implementing the different AES mode of operations.</td> </tr> </table> <h3>Functions</h3> <table> <tr> <td><a href="#append_PKCS7_padding">append_PKCS7_padding</a></td> <td>Function to pad the given data to a multiple of 16-bytes by PKCS7 padding.</td> </tr> <tr> <td><a href="#decryptData">decryptData</a></td> <td>Module function to decrypt the given data with the given key.</td> </tr> <tr> <td><a href="#encryptData">encryptData</a></td> <td>Module function to encrypt the given data with the given key.</td> </tr> <tr> <td><a href="#strip_PKCS7_padding">strip_PKCS7_padding</a></td> <td>Function to strip off PKCS7 padding.</td> </tr> </table> <hr /> <hr /> <a NAME="AES" ID="AES"></a> <h2>AES</h2> <p> Class implementing the Advanced Encryption Standard algorithm. </p> <h3>Derived from</h3> None <h3>Class Attributes</h3> <table> <tr><td>KeySize</td></tr> <tr><td>Rcon</td></tr> <tr><td>rsbox</td></tr> <tr><td>sbox</td></tr> </table> <h3>Class Methods</h3> <table> <tr><td>None</td></tr> </table> <h3>Methods</h3> <table> <tr> <td><a href="#AES.__addRoundKey">__addRoundKey</a></td> <td>Private method to add (XORs) the round key to the state.</td> </tr> <tr> <td><a href="#AES.__aes_invMain">__aes_invMain</a></td> <td>Private method to do the inverse AES encryption for one round.</td> </tr> <tr> <td><a href="#AES.__aes_invRound">__aes_invRound</a></td> <td>Private method to apply the 4 operations of the inverse round in sequence.</td> </tr> <tr> <td><a href="#AES.__aes_main">__aes_main</a></td> <td>Private method to do the AES encryption for one round.</td> </tr> <tr> <td><a href="#AES.__aes_round">__aes_round</a></td> <td>Private method to apply the 4 operations of the forward round in sequence.</td> </tr> <tr> <td><a href="#AES.__core">__core</a></td> <td>Private method performing the key schedule core operation.</td> </tr> <tr> <td><a href="#AES.__createRoundKey">__createRoundKey</a></td> <td>Private method to create a round key.</td> </tr> <tr> <td><a href="#AES.__expandKey">__expandKey</a></td> <td>Private method performing Rijndael's key expansion.</td> </tr> <tr> <td><a href="#AES.__galois_multiplication">__galois_multiplication</a></td> <td>Private method to perform a Galois multiplication of 8 bit characters a and b.</td> </tr> <tr> <td><a href="#AES.__getRconValue">__getRconValue</a></td> <td>Private method to retrieve a given Rcon value.</td> </tr> <tr> <td><a href="#AES.__getSBoxInvert">__getSBoxInvert</a></td> <td>Private method to retrieve a given Inverted S-Box value.</td> </tr> <tr> <td><a href="#AES.__getSBoxValue">__getSBoxValue</a></td> <td>Private method to retrieve a given S-Box value.</td> </tr> <tr> <td><a href="#AES.__mixColumn">__mixColumn</a></td> <td>Private method to perform a galois multiplication of 1 column the 4x4 matrix.</td> </tr> <tr> <td><a href="#AES.__mixColumns">__mixColumns</a></td> <td>Private method to perform a galois multiplication of the 4x4 matrix.</td> </tr> <tr> <td><a href="#AES.__rotate">__rotate</a></td> <td>Private method performing Rijndael's key schedule rotate operation.</td> </tr> <tr> <td><a href="#AES.__shiftRow">__shiftRow</a></td> <td>Private method to shift the bytes of a row to the left.</td> </tr> <tr> <td><a href="#AES.__shiftRows">__shiftRows</a></td> <td>Private method to iterate over the 4 rows and call __shiftRow() with that row.</td> </tr> <tr> <td><a href="#AES.__subBytes">__subBytes</a></td> <td>Private method to substitute all the values from the state with the value in the SBox using the state value as index for the SBox.</td> </tr> <tr> <td><a href="#AES.decrypt">decrypt</a></td> <td>Public method to decrypt a 128 bit input block against the given key of size specified.</td> </tr> <tr> <td><a href="#AES.encrypt">encrypt</a></td> <td>Public method to encrypt a 128 bit input block against the given key of size specified.</td> </tr> </table> <h3>Static Methods</h3> <table> <tr><td>None</td></tr> </table> <a NAME="AES.__addRoundKey" ID="AES.__addRoundKey"></a> <h4>AES.__addRoundKey</h4> <b>__addRoundKey</b>(<i>state, roundKey</i>) <p> Private method to add (XORs) the round key to the state. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be changed </dd> <dt><i>roundKey</i> (bytearray)</dt> <dd> key to be used for the modification </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__aes_invMain" ID="AES.__aes_invMain"></a> <h4>AES.__aes_invMain</h4> <b>__aes_invMain</b>(<i>state, expandedKey, nbrRounds</i>) <p> Private method to do the inverse AES encryption for one round. </p> <p> Perform the initial operations, the standard round, and the final operations of the inverse AES, creating a round key for each round. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>expandedKey</i> (bytearray)</dt> <dd> expanded key to be used </dd> <dt><i>nbrRounds</i> (int)</dt> <dd> number of rounds to be done </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__aes_invRound" ID="AES.__aes_invRound"></a> <h4>AES.__aes_invRound</h4> <b>__aes_invRound</b>(<i>state, roundKey</i>) <p> Private method to apply the 4 operations of the inverse round in sequence. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>roundKey</i> (bytearray)</dt> <dd> round key to be used </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__aes_main" ID="AES.__aes_main"></a> <h4>AES.__aes_main</h4> <b>__aes_main</b>(<i>state, expandedKey, nbrRounds</i>) <p> Private method to do the AES encryption for one round. </p> <p> Perform the initial operations, the standard round, and the final operations of the forward AES, creating a round key for each round. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>expandedKey</i> (bytearray)</dt> <dd> expanded key to be used </dd> <dt><i>nbrRounds</i> (int)</dt> <dd> number of rounds to be done </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__aes_round" ID="AES.__aes_round"></a> <h4>AES.__aes_round</h4> <b>__aes_round</b>(<i>state, roundKey</i>) <p> Private method to apply the 4 operations of the forward round in sequence. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>roundKey</i> (bytearray)</dt> <dd> round key to be used </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__core" ID="AES.__core"></a> <h4>AES.__core</h4> <b>__core</b>(<i>data, iteration</i>) <p> Private method performing the key schedule core operation. </p> <dl> <dt><i>data</i> (bytearray)</dt> <dd> data to operate on </dd> <dt><i>iteration</i> (int)</dt> <dd> iteration counter </dd> </dl> <dl> <dt>Return:</dt> <dd> modified data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__createRoundKey" ID="AES.__createRoundKey"></a> <h4>AES.__createRoundKey</h4> <b>__createRoundKey</b>(<i>expandedKey, roundKeyPointer</i>) <p> Private method to create a round key. </p> <dl> <dt><i>expandedKey</i> (bytearray)</dt> <dd> expanded key to be used </dd> <dt><i>roundKeyPointer</i> (int)</dt> <dd> position within the expanded key </dd> </dl> <dl> <dt>Return:</dt> <dd> round key </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__expandKey" ID="AES.__expandKey"></a> <h4>AES.__expandKey</h4> <b>__expandKey</b>(<i>key, size, expandedKeySize</i>) <p> Private method performing Rijndael's key expansion. </p> <p> Expands a 128, 192 or 256 bit key into a 176, 208 or 240 bit key. </p> <dl> <dt><i>key</i> (bytes or bytearray)</dt> <dd> key to be expanded </dd> <dt><i>size</i> (int)</dt> <dd> size of the key in bytes (16, 24 or 32) </dd> <dt><i>expandedKeySize</i> (int)</dt> <dd> size of the expanded key </dd> </dl> <dl> <dt>Return:</dt> <dd> expanded key </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__galois_multiplication" ID="AES.__galois_multiplication"></a> <h4>AES.__galois_multiplication</h4> <b>__galois_multiplication</b>(<i>a, b</i>) <p> Private method to perform a Galois multiplication of 8 bit characters a and b. </p> <dl> <dt><i>a</i> (bytes)</dt> <dd> first factor </dd> <dt><i>b</i> (bytes)</dt> <dd> second factor </dd> </dl> <dl> <dt>Return:</dt> <dd> result </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <a NAME="AES.__getRconValue" ID="AES.__getRconValue"></a> <h4>AES.__getRconValue</h4> <b>__getRconValue</b>(<i>num</i>) <p> Private method to retrieve a given Rcon value. </p> <dl> <dt><i>num</i> (int)</dt> <dd> position of the value </dd> </dl> <dl> <dt>Return:</dt> <dd> Rcon value </dd> </dl> <dl> <dt>Return Type:</dt> <dd> int </dd> </dl> <a NAME="AES.__getSBoxInvert" ID="AES.__getSBoxInvert"></a> <h4>AES.__getSBoxInvert</h4> <b>__getSBoxInvert</b>(<i>num</i>) <p> Private method to retrieve a given Inverted S-Box value. </p> <dl> <dt><i>num</i> (int)</dt> <dd> position of the value </dd> </dl> <dl> <dt>Return:</dt> <dd> value of the Inverted S-Box </dd> </dl> <dl> <dt>Return Type:</dt> <dd> int </dd> </dl> <a NAME="AES.__getSBoxValue" ID="AES.__getSBoxValue"></a> <h4>AES.__getSBoxValue</h4> <b>__getSBoxValue</b>(<i>num</i>) <p> Private method to retrieve a given S-Box value. </p> <dl> <dt><i>num</i> (int)</dt> <dd> position of the value </dd> </dl> <dl> <dt>Return:</dt> <dd> value of the S-Box </dd> </dl> <dl> <dt>Return Type:</dt> <dd> int </dd> </dl> <a NAME="AES.__mixColumn" ID="AES.__mixColumn"></a> <h4>AES.__mixColumn</h4> <b>__mixColumn</b>(<i>column, isInv</i>) <p> Private method to perform a galois multiplication of 1 column the 4x4 matrix. </p> <dl> <dt><i>column</i> (bytearray)</dt> <dd> column to be worked on </dd> <dt><i>isInv</i> (bool)</dt> <dd> flag indicating an inverse operation </dd> </dl> <dl> <dt>Return:</dt> <dd> modified column </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__mixColumns" ID="AES.__mixColumns"></a> <h4>AES.__mixColumns</h4> <b>__mixColumns</b>(<i>state, isInv</i>) <p> Private method to perform a galois multiplication of the 4x4 matrix. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>isInv</i> (bool)</dt> <dd> flag indicating an inverse operation </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__rotate" ID="AES.__rotate"></a> <h4>AES.__rotate</h4> <b>__rotate</b>(<i>data</i>) <p> Private method performing Rijndael's key schedule rotate operation. </p> <p> Rotate the data word eight bits to the left: eg, rotate(1d2c3a4f) == 2c3a4f1d. </p> <dl> <dt><i>data</i> (bytearray)</dt> <dd> data of size 4 </dd> </dl> <dl> <dt>Return:</dt> <dd> rotated data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__shiftRow" ID="AES.__shiftRow"></a> <h4>AES.__shiftRow</h4> <b>__shiftRow</b>(<i>state, statePointer, nbr, isInv</i>) <p> Private method to shift the bytes of a row to the left. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>statePointer</i> (int)</dt> <dd> index into the state </dd> <dt><i>nbr</i> (int)</dt> <dd> number of positions to shift </dd> <dt><i>isInv</i> (bool)</dt> <dd> flag indicating an inverse operation </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__shiftRows" ID="AES.__shiftRows"></a> <h4>AES.__shiftRows</h4> <b>__shiftRows</b>(<i>state, isInv</i>) <p> Private method to iterate over the 4 rows and call __shiftRow() with that row. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>isInv</i> (bool)</dt> <dd> flag indicating an inverse operation </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.__subBytes" ID="AES.__subBytes"></a> <h4>AES.__subBytes</h4> <b>__subBytes</b>(<i>state, isInv</i>) <p> Private method to substitute all the values from the state with the value in the SBox using the state value as index for the SBox. </p> <dl> <dt><i>state</i> (bytearray)</dt> <dd> state to be worked on </dd> <dt><i>isInv</i> (bool)</dt> <dd> flag indicating an inverse operation </dd> </dl> <dl> <dt>Return:</dt> <dd> modified state </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AES.decrypt" ID="AES.decrypt"></a> <h4>AES.decrypt</h4> <b>decrypt</b>(<i>iput, key, size</i>) <p> Public method to decrypt a 128 bit input block against the given key of size specified. </p> <dl> <dt><i>iput</i> (bytearray)</dt> <dd> input data </dd> <dt><i>key</i> (bytes or bytearray)</dt> <dd> key to be used </dd> <dt><i>size</i> (int)</dt> <dd> key size (16, 24 or 32) </dd> </dl> <dl> <dt>Return:</dt> <dd> decrypted data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> key size is invalid </dd> </dl> <a NAME="AES.encrypt" ID="AES.encrypt"></a> <h4>AES.encrypt</h4> <b>encrypt</b>(<i>iput, key, size</i>) <p> Public method to encrypt a 128 bit input block against the given key of size specified. </p> <dl> <dt><i>iput</i> (bytearray)</dt> <dd> input data </dd> <dt><i>key</i> (bytes or bytearray)</dt> <dd> key to be used </dd> <dt><i>size</i> (int)</dt> <dd> key size (16, 24 or 32) </dd> </dl> <dl> <dt>Return:</dt> <dd> encrypted data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> key size is invalid </dd> </dl> <div align="right"><a href="#top">Up</a></div> <hr /> <hr /> <a NAME="AESModeOfOperation" ID="AESModeOfOperation"></a> <h2>AESModeOfOperation</h2> <p> Class implementing the different AES mode of operations. </p> <h3>Derived from</h3> None <h3>Class Attributes</h3> <table> <tr><td>ModeOfOperation</td></tr> <tr><td>aes</td></tr> </table> <h3>Class Methods</h3> <table> <tr><td>None</td></tr> </table> <h3>Methods</h3> <table> <tr> <td><a href="#AESModeOfOperation.__extractBytes">__extractBytes</a></td> <td>Private method to extract a range of bytes from the input.</td> </tr> <tr> <td><a href="#AESModeOfOperation.decrypt">decrypt</a></td> <td>Public method to perform the decryption operation.</td> </tr> <tr> <td><a href="#AESModeOfOperation.encrypt">encrypt</a></td> <td>Public method to perform the encryption operation.</td> </tr> </table> <h3>Static Methods</h3> <table> <tr><td>None</td></tr> </table> <a NAME="AESModeOfOperation.__extractBytes" ID="AESModeOfOperation.__extractBytes"></a> <h4>AESModeOfOperation.__extractBytes</h4> <b>__extractBytes</b>(<i>inputData, start, end, mode</i>) <p> Private method to extract a range of bytes from the input. </p> <dl> <dt><i>inputData</i> (bytes)</dt> <dd> input data </dd> <dt><i>start</i> (int)</dt> <dd> start index </dd> <dt><i>end</i> (int)</dt> <dd> end index </dd> <dt><i>mode</i> (int)</dt> <dd> mode of operation (0, 1, 2) </dd> </dl> <dl> <dt>Return:</dt> <dd> extracted bytes </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytearray </dd> </dl> <a NAME="AESModeOfOperation.decrypt" ID="AESModeOfOperation.decrypt"></a> <h4>AESModeOfOperation.decrypt</h4> <b>decrypt</b>(<i>cipherIn, originalsize, mode, key, size, IV</i>) <p> Public method to perform the decryption operation. </p> <dl> <dt><i>cipherIn</i> (bytes)</dt> <dd> data to be decrypted </dd> <dt><i>originalsize</i> (int)</dt> <dd> unencrypted string length (required for CBC) </dd> <dt><i>mode</i> (int)</dt> <dd> mode of operation (0, 1 or 2) </dd> <dt><i>key</i> (bytes)</dt> <dd> key to be used </dd> <dt><i>size</i> (int)</dt> <dd> length of the key (16, 24 or 32) </dd> <dt><i>IV</i> (bytearray)</dt> <dd> initialisation vector </dd> </dl> <dl> <dt>Return:</dt> <dd> decrypted data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> key size is invalid or decrypted data is invalid </dd> </dl> <a NAME="AESModeOfOperation.encrypt" ID="AESModeOfOperation.encrypt"></a> <h4>AESModeOfOperation.encrypt</h4> <b>encrypt</b>(<i>inputData, mode, key, size, IV</i>) <p> Public method to perform the encryption operation. </p> <dl> <dt><i>inputData</i> (bytes)</dt> <dd> data to be encrypted </dd> <dt><i>mode</i> (int)</dt> <dd> mode of operation (0, 1 or 2) </dd> <dt><i>key</i> (bytes)</dt> <dd> key to be used </dd> <dt><i>size</i> (int)</dt> <dd> length of the key (16, 24 or 32) </dd> <dt><i>IV</i> (bytearray)</dt> <dd> initialisation vector </dd> </dl> <dl> <dt>Return:</dt> <dd> tuple with mode of operation, length of the input data and the encrypted data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> tuple of (int, int, bytes) </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> key size is invalid or decrypted data is invalid </dd> </dl> <div align="right"><a href="#top">Up</a></div> <hr /> <hr /> <a NAME="append_PKCS7_padding" ID="append_PKCS7_padding"></a> <h2>append_PKCS7_padding</h2> <b>append_PKCS7_padding</b>(<i>b</i>) <p> Function to pad the given data to a multiple of 16-bytes by PKCS7 padding. </p> <dl> <dt><i>b</i> (bytes)</dt> <dd> data to be padded </dd> </dl> <dl> <dt>Return:</dt> <dd> padded data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <div align="right"><a href="#top">Up</a></div> <hr /> <hr /> <a NAME="decryptData" ID="decryptData"></a> <h2>decryptData</h2> <b>decryptData</b>(<i>key, data, mode=AESModeOfOperation.ModeOfOperation["CBC"]</i>) <p> Module function to decrypt the given data with the given key. </p> <dl> <dt><i>key</i> (bytes)</dt> <dd> key to be used for decryption </dd> <dt><i>data</i> (bytes)</dt> <dd> data to be decrypted (with initialization vector prepended) </dd> <dt><i>mode</i> (int)</dt> <dd> mode of operations (0, 1 or 2) </dd> </dl> <dl> <dt>Return:</dt> <dd> decrypted data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> raised to indicate an invalid key size </dd> </dl> <div align="right"><a href="#top">Up</a></div> <hr /> <hr /> <a NAME="encryptData" ID="encryptData"></a> <h2>encryptData</h2> <b>encryptData</b>(<i>key, data, mode=AESModeOfOperation.ModeOfOperation["CBC"]</i>) <p> Module function to encrypt the given data with the given key. </p> <dl> <dt><i>key</i> (bytes)</dt> <dd> key to be used for encryption </dd> <dt><i>data</i> (bytes)</dt> <dd> data to be encrypted </dd> <dt><i>mode</i> (int)</dt> <dd> mode of operations (0, 1 or 2) </dd> </dl> <dl> <dt>Return:</dt> <dd> encrypted data prepended with the initialization vector </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> raised to indicate an invalid key size </dd> </dl> <div align="right"><a href="#top">Up</a></div> <hr /> <hr /> <a NAME="strip_PKCS7_padding" ID="strip_PKCS7_padding"></a> <h2>strip_PKCS7_padding</h2> <b>strip_PKCS7_padding</b>(<i>b</i>) <p> Function to strip off PKCS7 padding. </p> <dl> <dt><i>b</i> (bytes)</dt> <dd> data to be stripped </dd> </dl> <dl> <dt>Return:</dt> <dd> stripped data </dd> </dl> <dl> <dt>Return Type:</dt> <dd> bytes </dd> </dl> <dl> <dt>Raises <b>ValueError</b>:</dt> <dd> data padding is invalid </dd> </dl> <div align="right"><a href="#top">Up</a></div> <hr /> </body></html>