Ë
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¬`i : ã ó d Z dgZddlZddlmZ ddlmZmZmZ ddl m
|
Z
|
ddl m Z ddl mZmZ dd lmZmZ dd
|
lmZ G d de« Zd Zy) z
|
EAX mode.
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ÚEaxModeé N)Ú unhexlify)Ú byte_stringÚbordÚ _copy_bytes)Ú is_buffer)Ústrxor)Ú long_to_bytesÚ bytes_to_long)ÚCMACÚBLAKE2s)Úget_random_bytesc óT e Zd ZdZd Zd Zd dZd dZd Zd Z d Z
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d
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Z d d Z d d Z y)r aç *EAX* mode.
|
|
This is an Authenticated Encryption with Associated Data
|
(`AEAD`_) mode. It provides both confidentiality and authenticity.
|
|
The header of the message may be left in the clear, if needed,
|
and it will still be subject to authentication.
|
|
The decryption step tells the receiver if the message comes
|
from a source that really knowns the secret key.
|
Additionally, decryption detects if any part of the message -
|
including the header - has been modified or corrupted.
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|
This mode requires a *nonce*.
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|
This mode is only available for ciphers that operate on 64 or
|
128 bits blocks.
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|
There are no official standards defining EAX.
|
The implementation is based on `a proposal`__ that
|
was presented to NIST.
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.. _AEAD: http://blog.cryptographyengineering.com/2012/05/how-to-choose-authenticated-encryption.html
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.. __: http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/eax/eax-spec.pdf
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|
:undocumented: __init__
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c ó4 |j | _ t dd|« | _ || _ d| _ g d¢| _ d| j cxk r| j k sn t d| j z « t | j « dk( r t d« t |« s t d« t dd« D cg c]B }t j |d | j d
|
z
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z t j d |« z ||¬ « D c}| _ | j d j! | j « | j d
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| _ t% | j d j' « « } |j ||j( f|d d|¤| _ yc c}w )zEAX cipher modeN©ÚupdateÚencryptÚdecryptÚdigestÚverifyé z3'mac_len' must be at least 2 and not larger than %dr z!Nonce cannot be empty in EAX modez,nonce must be bytes, bytearray or memoryviewé ó é ÚB)Ú ciphermodÚ cipher_paramsó )Ú initial_valueÚnonce)Ú
|
block_sizer r Ú_mac_lenÚ_mac_tagÚ_nextÚ
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ValueErrorÚlenr Ú TypeErrorÚranger ÚnewÚstructÚpackÚ_omacr Ú_signerr r ÚMODE_CTRÚ_cipher)ÚselfÚfactoryÚkeyr Úmac_lenr ÚiÚ counter_ints õj H:\项ç®\archive\æµè¯ç»\èæ¬\Change_password\venv_build\Lib\site-packages\Crypto/Cipher/_mode_eax.pyÚ__init__zEaxMode.__init__P sx ð "×,Ñ,Ø@ä t¨UÓ3
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Ø=à Ø ò*
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ð T]]Ô5 d§o¡oÔ5Ü Ð RØ #ñ /ó 0ð 0ô tzz?aÒ Ü Ð @ÓAÐ AÜÔ ÜÐ JÓKÐ Kô q !ö ð
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ô Ø D§O¡O°aÑ$7Ñ8¼6¿;¹;ÀsÈAÓ;NÑNØ#*Ø'4ö6ò
|
ð
|
|
1 × Ñ TZZÔ(Øzz !} ô $ D§J¡J¨q¡M×$8Ñ$8Ó$:Ó; Ø"w{{ 3Ø#*×#3Ñ#3ð4à1<Ø),ñ4ð &3ñ 4 ùò s Â=AFc ó d| j vr t d« g d¢| _ | j j |« | S )a Protect associated data
|
|
If there is any associated data, the caller has to invoke
|
this function one or more times, before using
|
``decrypt`` or ``encrypt``.
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By *associated data* it is meant any data (e.g. packet headers) that
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will not be encrypted and will be transmitted in the clear.
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However, the receiver is still able to detect any modification to it.
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If there is no associated data, this method must not be called.
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|
The caller may split associated data in segments of any size, and
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invoke this method multiple times, each time with the next segment.
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:Parameters:
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assoc_data : bytes/bytearray/memoryview
|
A piece of associated data. There are no restrictions on its size.
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r z<update() can only be called immediately after initializationr )r$ r' r- r )r0 Ú
|
assoc_datas r6 r zEaxMode.update sG ð* 4::Ñ %Üð Dó Eð Eò*
|
ð ×ÑJÔ'Ø r Nc ó d| j vr t d« ddg| _ | j j ||¬« }| | j d j |« |S | j d j |« |S )aé Encrypt data with the key and the parameters set at initialization.
|
|
A cipher object is stateful: once you have encrypted a message
|
you cannot encrypt (or decrypt) another message using the same
|
object.
|
|
The data to encrypt can be broken up in two or
|
more pieces and `encrypt` can be called multiple times.
|
|
That is, the statement:
|
|
>>> c.encrypt(a) + c.encrypt(b)
|
|
is equivalent to:
|
|
>>> c.encrypt(a+b)
|
|
This function does not add any padding to the plaintext.
|
|
:Parameters:
|
plaintext : bytes/bytearray/memoryview
|
The piece of data to encrypt.
|
It can be of any length.
|
:Keywords:
|
output : bytearray/memoryview
|
The location where the ciphertext must be written to.
|
If ``None``, the ciphertext is returned.
|
:Return:
|
If ``output`` is ``None``, the ciphertext as ``bytes``.
|
Otherwise, ``None``.
|
r z@encrypt() can only be called after initialization or an update()r ©Úoutputr )r$ r' r/ r r, r )r0 Ú plaintextr< Úcts r6 r zEaxMode.encrypt s ðB DJJÑ &Üð =ó >ð >à Ð*
|
Ø \\× !Ñ ! )°FÐ !Ó ;Ø >Ø JJqM× Ñ Ô $ð ð JJqM× Ñ Ô (Ø r c ó¼ d| j vr t d« ddg| _ | j d j |« | j j ||¬« S )aë Decrypt data with the key and the parameters set at initialization.
|
|
A cipher object is stateful: once you have decrypted a message
|
you cannot decrypt (or encrypt) another message with the same
|
object.
|
|
The data to decrypt can be broken up in two or
|
more pieces and `decrypt` can be called multiple times.
|
|
That is, the statement:
|
|
>>> c.decrypt(a) + c.decrypt(b)
|
|
is equivalent to:
|
|
>>> c.decrypt(a+b)
|
|
This function does not remove any padding from the plaintext.
|
|
:Parameters:
|
ciphertext : bytes/bytearray/memoryview
|
The piece of data to decrypt.
|
It can be of any length.
|
:Keywords:
|
output : bytearray/memoryview
|
The location where the plaintext must be written to.
|
If ``None``, the plaintext is returned.
|
:Return:
|
If ``output`` is ``None``, the plaintext as ``bytes``.
|
Otherwise, ``None``.
|
r z@decrypt() can only be called after initialization or an update()r r r; )r$ r' r, r r/ r )r0 Ú
|
ciphertextr< s r6 r zEaxMode.decryptÊ sb ðB DJJÑ &Üð Có Dð Dà Ð*
|
Ø
|
|
1 × Ñ ZÔ(Ø||×#Ñ# J°vÐ#Ó>Ð>r c ó( d| j vr t d« dg| _ | j sZd| j z }t d« D ]) }t || j | j « « }+ |d| j | _ | j S )zýCompute the *binary* MAC tag.
|
|
The caller invokes this function at the very end.
|
|
This method returns the MAC that shall be sent to the receiver,
|
together with the ciphertext.
|
|
:Return: the MAC, as a byte string.
|
r zAdigest() cannot be called when decrypting or validating a messager r N) r$ r' r# r! r( r r, r r" )r0 Útagr4 s r6 r zEaxMode.digestò s ð 4::Ñ %Üð ;ó <ð <à Z
|
à}}ØDOOÑ+CÜ1Xò :Ü S $§*¡*¨Q¡-×"6Ñ"6Ó"8Ó9ð :à § ¡ Ð /DMà}}Ð r c ó~ dj | j « D cg c] }dt |« z c}« S c c}w )zCompute the *printable* MAC tag.
|
|
This method is like `digest`.
|
|
:Return: the MAC, as a hexadecimal string.
|
Ú z%02x)Újoinr r )r0 Úxs r6 Ú hexdigestzEaxMode.hexdigest
|
s0 ð ww°$·+±+³-Ö@¨Q¤ a£Ó(Ò@ÓAÐAùÒ@s :c óô d| j vr t d« dg| _ | j sZd| j z }t d« D ]) }t || j | j « « }+ |d| j | _ t d« }t j d|| j ¬« }t j d||¬« }|j « |j « k7 r t d « y)
|
a. Validate the *binary* MAC tag.
|
|
The caller invokes this function at the very end.
|
|
This method checks if the decrypted message is indeed valid
|
(that is, if the key is correct) and it has not been
|
tampered with while in transit.
|
|
:Parameters:
|
received_mac_tag : bytes/bytearray/memoryview
|
This is the *binary* MAC, as received from the sender.
|
:Raises MacMismatchError:
|
if the MAC does not match. The message has been tampered with
|
or the key is incorrect.
|
r z3verify() cannot be called when encrypting a messager r Né é )Ú digest_bitsr2 ÚdatazMAC check failed) r$ r' r# r! r( r r, r r" r r r) r% )r0 Úreceived_mac_tagrB r4 ÚsecretÚmac1Úmac2s r6 r zEaxMode.verify sÚ ð" 4::Ñ %Üð =ó >ð >à Z
|
à}}ØDOOÑ+CÜ1Xò :Ü S $§*¡*¨Q¡-×"6Ñ"6Ó"8Ó9ð :à § ¡ Ð /DMä! "Ó%ä{{ s°¸T¿]¹]ÔKÜ{{ s°Ð=MÔNà ;;=DKKMÒ )Ü Ð /Ó0Ð 0ð *r c ó8 | j t |« « y)a] Validate the *printable* MAC tag.
|
|
This method is like `verify`.
|
|
:Parameters:
|
hex_mac_tag : string
|
This is the *printable* MAC, as received from the sender.
|
:Raises MacMismatchError:
|
if the MAC does not match. The message has been tampered with
|
or the key is incorrect.
|
N)r r )r0 Ú hex_mac_tags r6 Ú hexverifyzEaxMode.hexverify7 s ð IkÓ*Õ+r c óH | j ||¬« | j « fS )a\ Perform encrypt() and digest() in one step.
|
|
:Parameters:
|
plaintext : bytes/bytearray/memoryview
|
The piece of data to encrypt.
|
:Keywords:
|
output : bytearray/memoryview
|
The location where the ciphertext must be written to.
|
If ``None``, the ciphertext is returned.
|
:Return:
|
a tuple with two items:
|
|
- the ciphertext, as ``bytes``
|
- the MAC tag, as ``bytes``
|
|
The first item becomes ``None`` when the ``output`` parameter
|
specified a location for the result.
|
r; )r r )r0 r= r< s r6 Úencrypt_and_digestzEaxMode.encrypt_and_digestF s" ð( ||I¨f|Ó5°t·{±{³}ÐDÐDr c óN | j ||¬« }| j |« |S )aé Perform decrypt() and verify() in one step.
|
|
:Parameters:
|
ciphertext : bytes/bytearray/memoryview
|
The piece of data to decrypt.
|
received_mac_tag : bytes/bytearray/memoryview
|
This is the *binary* MAC, as received from the sender.
|
:Keywords:
|
output : bytearray/memoryview
|
The location where the plaintext must be written to.
|
If ``None``, the plaintext is returned.
|
:Return: the plaintext as ``bytes`` or ``None`` when the ``output``
|
parameter specified a location for the result.
|
:Raises MacMismatchError:
|
if the MAC does not match. The message has been tampered with
|
or the key is incorrect.
|
r; )r r )r0 r@ rM r< Úpts r6 Údecrypt_and_verifyzEaxMode.decrypt_and_verify\ s( ð& \\*¨V\Ó 4Ø Ð$Ô%Ø r )N)Ú__name__Ú
|
__module__Ú __qualname__Ú__doc__r7 r r r r rG r rS rU rX © r r6 r r 3 s? ñò8-4ò^ ó>*óX&?òP ò0Bò"1òH ,ó Eô,r c ó
|
|j d« }|j dd« }| t d« }|j d| j « }t | ||||« S # t $ r }t dt |« z « d}~ww xY w)aY Create a new block cipher, configured in EAX mode.
|
|
:Parameters:
|
factory : module
|
A symmetric cipher module from `Crypto.Cipher` (like
|
`Crypto.Cipher.AES`).
|
|
:Keywords:
|
key : bytes/bytearray/memoryview
|
The secret key to use in the symmetric cipher.
|
|
nonce : bytes/bytearray/memoryview
|
A value that must never be reused for any other encryption.
|
There are no restrictions on its length, but it is recommended to use
|
at least 16 bytes.
|
|
The nonce shall never repeat for two different messages encrypted with
|
the same key, but it does not need to be random.
|
|
If not specified, a 16 byte long random string is used.
|
|
mac_len : integer
|
Length of the MAC, in bytes. It must be no larger than the cipher
|
block bytes (which is the default).
|
r2 r NrI r3 zMissing parameter: )Úpopr r! ÚKeyErrorr' Ústrr )r1 Úkwargsr2 r r3 Úes r6 Ú_create_eax_cipherrd t s ð68ØjjÓ Ø
|
|
7 DÓ)Ø =Ü$ RÓ(EØ**Y¨×(:Ñ(:Ó;ô 7C ¨°Ó 8Ð8øô ò 8ÜÐ-´°A³Ñ6Ó7Ð7ûð8ús A A Á BÁ&A=Á=B)r\ Ú__all__r* Úbinasciir ÚCrypto.Util.py3compatr r r ÚCrypto.Util._raw_apir ÚCrypto.Util.strxorr ÚCrypto.Util.numberr
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r Ú Crypto.Hashr r Ú Crypto.Randomr Úobjectr rd r] r r6 ú<module>rn sB ðñ>ð +ã Ý ç @Ñ @å *å %ß ;ç %Ý *ô~fô ~óB
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