diff --git a/0001-Fix-CVE-2020-13757.patch b/0001-Fix-CVE-2020-13757.patch deleted file mode 100644 index ef10bfe..0000000 --- a/0001-Fix-CVE-2020-13757.patch +++ /dev/null @@ -1,47 +0,0 @@ -From 93af6f2f89a9bf28361e67716c4240e691520f30 Mon Sep 17 00:00:00 2001 -From: =?UTF-8?q?Sybren=20A=2E=20St=C3=BCvel?= -Date: Wed, 3 Jun 2020 14:39:23 +0200 -Subject: [PATCH] Fix CVE-2020-13757: detect cyphertext modifications by - prepending zero bytes - -Reject cyphertexts that have been modified by prepending zero bytes, by -checking the cyphertext length against the expected size (given the -decryption key). This resolves CVE-2020-13757. - -The same approach is used when verifying a signature. - -Thanks Carnil for pointing this out on https://github.com/sybrenstuvel/python-rsa/issues/146 ---- - rsa/pkcs1.py | 9 +++++++++ - 1 files changed, 9 insertions(+) - -diff --git a/rsa/pkcs1.py b/rsa/pkcs1.py -index 28f0dc5..cdf830b 100644 ---- a/rsa/pkcs1.py -+++ b/rsa/pkcs1.py -@@ -232,6 +232,12 @@ def decrypt(crypto, priv_key): - decrypted = priv_key.blinded_decrypt(encrypted) - cleartext = transform.int2bytes(decrypted, blocksize) - -+ # Detect leading zeroes in the crypto. These are not reflected in the -+ # encrypted value (as leading zeroes do not influence the value of an -+ # integer). This fixes CVE-2020-13757. -+ if len(crypto) > blocksize: -+ raise DecryptionError('Decryption failed') -+ - # If we can't find the cleartext marker, decryption failed. - if cleartext[0:2] != b('\x00\x02'): - raise DecryptionError('Decryption failed') -@@ -310,6 +316,9 @@ def verify(message, signature, pub_key): - cleartext = HASH_ASN1[method_name] + message_hash - expected = _pad_for_signing(cleartext, keylength) - -+ if len(signature) != keylength: -+ raise VerificationError('Verification failed') -+ - # Compare with the signed one - if expected != clearsig: - raise VerificationError('Verification failed') - --- -1.8.3.1