python - How to decrypt an AES encrypted data with key and iv already provided -

i trying decrypt aes encrypted data. having key , iv me think key encoded.

here code have used:

import binascii crypto.cipher import aes enckey = '5f35604280b44dd1073f7ee83e346d81' key = binascii.unhexlify(enckey) key32 = "{: <32}".format(key).encode("utf-8") data='692fa1deafad8ad80b98cd6f077899e9be457ac5364c3822aae9457d4912e4829d71cb 8702bd10e1d54f7a0461edba193517b353835480bd174804f586776e623473022548ff098a95 45b608282bf498a36968dd6b858ad631f6eaa79ea1a87c984f4a8da5a9d1cee1b11b32d46c0d 2a670d4e634ecc47c7105387a0a38853c91e10747170de69ebf6f0e1a99f0134ddb0af0cec2c fc70f53c9eab7227460cf1153ef686a5dc5014bd286fb0efdec571327f5a4874bec5fd5c65f0 9f0ed10e906e4199dd8c3cb8340aca1904f486a70b02554581f0e723d22854188e933ed9fce6 0172099bc675b89eba39651bbc0658ae264213217f14ff4f0824494585d8856dfd44e4ce9505 e43762a9f1ea48f9c736603e83c3e10c5740cdf279dc3a914e19eee089160ffa91180d1b4299 38ab1b6a4272d1779f7702f760cbac3f35fc35c16fcf21c7e00183f306e7a18f71ffb3b62b91 250dca7dd627876a6cedbfe83f0f18abbbb7c7650566a7f761844243fe1271cef22b1026a3f1 d37b8e7bd7c068331897680ec101e269ce66c3f129de33d3277c2cc120feb88f77f1bb851d41 b83468128366b7ed92ae07f37675cee07355ebcdfcba90a690e3d4817cd18123a0c9de175ea6 c5049c51170ee73facd5148f6525024116991b0601598a3501e770493dab0653e146981e91d2 ea9c50fbd1e6b8bb38407655c518f30852ce43ed62d1c578e642c4fa92f00bbf102c3418ed52 ed23138c86d327bbc4718ec44440f289e3af6c096c7ad69af5d941768b0f4b2e3decfad5dcfe 6dc491ce4f2f9d86d226b87f19dfb56dc44f6d66820773e6fcfa4fcd7958da2d639037627057 99a414baf93081242c2b594981c93b892f4f28883203875a4010ace9a5eafea51ee406' cipher_text = binascii.unhexlify(data) # decryption decryption_suite = aes.new('key32', aes.mode_cbc, 'hef9batufwuisyo8') plain_text = decryption_suite.decrypt(cipher_text) print plain_text 

and error receiving :

unicodedecodeerror: 'ascii' codec can't decode byte 0x80 in position 4:  ordinal not in range(128) 

i unable figure out problem key , data... , please let me know if have make changes code.

the following code works:

from crypto.cipher import aes  keyascii = '5f35604280b44dd1073f7ee83e346d81' keybinary = bytes(keyascii, 'ascii') ciphertexthex='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' ciphertextbinary = bytes.fromhex(ciphertexthex) ivascii = 'hef9batufwuisyo8' ivbinary = bytes(ivascii, 'ascii') # decryption decrypter = aes.new(keybinary, aes.mode_cbc, ivbinary) plaintextbinary = decrypter.decrypt(ciphertextbinary) plaintext = plaintextbinary.decode('utf-8') print(plaintext) 

and outputs

connection_type=wifi&android_id=863e87fea9a09533&app_name=astronest&app_version=53&app_version_name=2.7.1&device_brand=motorola&device_cpu_type=armv7l&device_model=xt1562&google_aid=ab95a01a-242b-4ac2-ad12-b6189e983a56&google_ad_tracking_disabled=0&insdate=1494826343&installer=com.android.vending&language=en&mac_address=02%3a00%3a00%3a00%3a00%3a00&mat_id=45c0a743-a948-434b-a20d-fe66e870d285&os_version=6.0.1&screen_density=3.0&screen_layout_size=1920x1080&sdk_version=3.11.4&conversion_user_agent=dalvik%2f2.1.0+%28linux%3b+u%3b+android+6.0.1%3b+xt1562+build%2fmpds24.107-70-1-5%29&currency_code=usd&revenue=0.0&system_date=1494826532 

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but it's cryptographically wrong in many ways:

• the key looks 32 character hex string (which encode 128-bit key), need treat ascii encoding 32-byte key. that's wrong, since keys supposed uniformly distributed binary string
• similarly iv supposed uniform binary, it's ascii
• the iv fixed, whole point of iv different (unpredictably random cbc mode) each message.
• cbc mode vulnerable padding oracle attacks, allow active attacker recover plaintext if can execute chosen ciphertext attack learn ciphertext decrypt successfully.

you should use authenticated encryption unique ivs instead.