Hi On 2017-01-03 11:05:40, Sebastian Ramacher wrote: > On 2017-01-01 20:55:40, Sebastian Ramacher wrote: > > Control: tags -1 - moreinfo > > > > Hi > > > > On 2016-12-31 17:03:32, Adam D. Barratt wrote: > > > Control: tags -1 + moreinfo > > > > > > On Thu, 2016-12-29 at 23:15 +0100, Sebastian Ramacher wrote: > > > > I'd like to fix CVE-2013-7459 (#849495) in jessie via the next point release. > > > > The issue was marked as no-dsa. > > > > > > > > The proposed debdiff is attached. The same patch was applied to the package in > > > > unstable. > > > > > > + * Throw exception when IV is used with ECB or CTR (CVE-2013-7459) > > > > > > Do we know if any packages currently in Debian misuse the functions in > > > that way? (I realise that any that do are broken, but I'd prefer to find > > > that out /before/ releasing an point release that makes them explode if > > > possible.) > > Seems like python-paramiko broke in wheezy-lts (#850025). I will come back to > you once I've checked if stable is affected as well. New debdiff is attached. Instead of throwing an exception the IV is simply ignored and a warning is displayed. Cheers -- Sebastian Ramacher
diff --git a/debian/changelog b/debian/changelog index ecee2bf..57a5a16 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,3 +1,12 @@ +python-crypto (2.6.1-5+deb8u1) jessie; urgency=high + + * debian/patches/CVE-2013-7459.patch: Raise a warning when IV is used with + ECB or CTR and ignored the IV in that case. Thanks to Salvatore Bonaccorso + for the initial patch. (CVE-2013-7459) (Closes: + #849495) + + -- Sebastian Ramacher <sramacher@debian.org> Tue, 03 Jan 2017 13:56:09 +0100 + python-crypto (2.6.1-5) unstable; urgency=medium * debian/patches/asn1-decoding.patch: Fix TypeError in ASN1 implementation. diff --git a/debian/patches/CVE-2013-7459.patch b/debian/patches/CVE-2013-7459.patch new file mode 100644 index 0000000..cb9d982 --- /dev/null +++ b/debian/patches/CVE-2013-7459.patch @@ -0,0 +1,86 @@ +From 8dbe0dc3eea5c689d4f76b37b93fe216cf1f00d4 Mon Sep 17 00:00:00 2001 +From: Legrandin <helderijs@gmail.com> +Date: Sun, 22 Dec 2013 22:24:46 +0100 +Subject: [PATCH] Throw exception when IV is used with ECB or CTR + +The IV parameter is currently ignored when initializing +a cipher in ECB or CTR mode. + +For CTR mode, it is confusing: it takes some time to see +that a different parameter is needed (the counter). + +For ECB mode, it is outright dangerous. + +This patch forces an exception to be raised. + +[sramacher@debian.org]: Raise a warning instead of an exception and ignore IV. +--- + lib/Crypto/SelfTest/Cipher/common.py | 31 +++++++++++++++++++++++-------- + src/block_template.c | 11 +++++++++++ + 2 files changed, 34 insertions(+), 8 deletions(-) + +--- a/lib/Crypto/SelfTest/Cipher/common.py ++++ b/lib/Crypto/SelfTest/Cipher/common.py +@@ -239,19 +239,34 @@ + return """%s .decrypt() output of .encrypt() should not be garbled""" % (self.module_name,) + + def runTest(self): +- for mode in (self.module.MODE_ECB, self.module.MODE_CBC, self.module.MODE_CFB, self.module.MODE_OFB, self.module.MODE_OPENPGP): ++ ++ ## ECB mode ++ mode = self.module.MODE_ECB ++ encryption_cipher = self.module.new(a2b_hex(self.key), mode) ++ ciphertext = encryption_cipher.encrypt(self.plaintext) ++ decryption_cipher = self.module.new(a2b_hex(self.key), mode) ++ decrypted_plaintext = decryption_cipher.decrypt(ciphertext) ++ self.assertEqual(self.plaintext, decrypted_plaintext) ++ ++ ## OPENPGP mode ++ mode = self.module.MODE_OPENPGP ++ encryption_cipher = self.module.new(a2b_hex(self.key), mode, self.iv) ++ eiv_ciphertext = encryption_cipher.encrypt(self.plaintext) ++ eiv = eiv_ciphertext[:self.module.block_size+2] ++ ciphertext = eiv_ciphertext[self.module.block_size+2:] ++ decryption_cipher = self.module.new(a2b_hex(self.key), mode, eiv) ++ decrypted_plaintext = decryption_cipher.decrypt(ciphertext) ++ self.assertEqual(self.plaintext, decrypted_plaintext) ++ ++ ## All other non-AEAD modes (but CTR) ++ for mode in (self.module.MODE_CBC, self.module.MODE_CFB, self.module.MODE_OFB): + encryption_cipher = self.module.new(a2b_hex(self.key), mode, self.iv) + ciphertext = encryption_cipher.encrypt(self.plaintext) +- +- if mode != self.module.MODE_OPENPGP: +- decryption_cipher = self.module.new(a2b_hex(self.key), mode, self.iv) +- else: +- eiv = ciphertext[:self.module.block_size+2] +- ciphertext = ciphertext[self.module.block_size+2:] +- decryption_cipher = self.module.new(a2b_hex(self.key), mode, eiv) ++ decryption_cipher = self.module.new(a2b_hex(self.key), mode, self.iv) + decrypted_plaintext = decryption_cipher.decrypt(ciphertext) + self.assertEqual(self.plaintext, decrypted_plaintext) + ++ + class PGPTest(unittest.TestCase): + def __init__(self, module, params): + unittest.TestCase.__init__(self) +--- a/src/block_template.c ++++ b/src/block_template.c +@@ -170,6 +170,17 @@ + "Key cannot be the null string"); + return NULL; + } ++ if (IVlen != 0 && mode == MODE_ECB) ++ { ++ PyErr_WarnEx(PyExc_FutureWarning, "ECB mode does not use IV", 1); ++ IVlen = 0; ++ } ++ if (IVlen != 0 && mode == MODE_CTR) ++ { ++ PyErr_WarnEx(PyExc_FutureWarning, ++ "CTR mode needs counter parameter, not IV", 1); ++ IVlen = 0; ++ } + if (IVlen != BLOCK_SIZE && mode != MODE_ECB && mode != MODE_CTR) + { + PyErr_Format(PyExc_ValueError, diff --git a/debian/patches/series b/debian/patches/series index e077da9..191ab43 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -9,3 +9,4 @@ multiprocessing-test.patch unittest-stream.patch deprecated-test-methods.patch asn1-decoding.patch +CVE-2013-7459.patch
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