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shr-projectHyunjae Shin
shr-project
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Hyunjae Shin
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python3-cryptography: backport 3 changes to fix CVE-2020-36242
:Release Notes: This is only temporary until https://lists.openembedded.org/g/openembedded-devel/message/97027 is merged in dunfell. :Detailed Notes: backport the actual code change from: pyca/cryptography#5747 without the docs and CI changes (which aren't applicable on old 2.8 version) and backport 2 older changes to make this fix applicable on 2.8. :Testing Performed: Only build tested. :QA Notes: No change to image. :Issues Addressed: [WRO-4101] CCC: Various build fixes Change-Id: Ida324c8dcf8a738372da3ab7a3378c459ed27803
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4 files changed

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‎meta-webos/recipes-devtools/python/python3-cryptography/0001-chunked-update_into-5419.patch

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From 7dee5927eb528f7ddebd62fbab31232d505acc22 Mon Sep 17 00:00:00 2001
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From: Paul Kehrer <[email protected]>
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Date: Sun, 23 Aug 2020 23:41:33 -0500
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Subject: [PATCH] chunked update_into (#5419)
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* chunked update_into
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* all pointer arithmetic all the time
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* review feedback
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Upstream-Status: Backport [https://github.com/pyca/cryptography/commit/f90ba1808ee9bd9a13c5673b776484644f29d7ba]
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Signed-off-by: Martin Jansa <[email protected]>
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---
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.../hazmat/backends/openssl/ciphers.py | 31 +++++++++++++------
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tests/hazmat/primitives/test_ciphers.py | 17 ++++++++++
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2 files changed, 38 insertions(+), 10 deletions(-)
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diff --git a/src/cryptography/hazmat/backends/openssl/ciphers.py b/src/cryptography/hazmat/backends/openssl/ciphers.py
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index 94b48f52..86bc94b3 100644
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--- a/src/cryptography/hazmat/backends/openssl/ciphers.py
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+++ b/src/cryptography/hazmat/backends/openssl/ciphers.py
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@@ -17,6 +17,7 @@ from cryptography.hazmat.primitives.ciphers import modes
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class _CipherContext(object):
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_ENCRYPT = 1
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_DECRYPT = 0
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+ _MAX_CHUNK_SIZE = 2 ** 31
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def __init__(self, backend, cipher, mode, operation):
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self._backend = backend
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@@ -125,22 +126,32 @@ class _CipherContext(object):
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return bytes(buf[:n])
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def update_into(self, data, buf):
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- if len(buf) < (len(data) + self._block_size_bytes - 1):
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+ total_data_len = len(data)
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+ if len(buf) < (total_data_len + self._block_size_bytes - 1):
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raise ValueError(
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"buffer must be at least {} bytes for this "
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"payload".format(len(data) + self._block_size_bytes - 1)
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)
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- buf = self._backend._ffi.cast(
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- "unsigned char *", self._backend._ffi.from_buffer(buf)
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- )
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+ data_processed = 0
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+ total_out = 0
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outlen = self._backend._ffi.new("int *")
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- res = self._backend._lib.EVP_CipherUpdate(
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- self._ctx, buf, outlen,
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- self._backend._ffi.from_buffer(data), len(data)
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- )
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- self._backend.openssl_assert(res != 0)
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- return outlen[0]
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+ baseoutbuf = self._backend._ffi.from_buffer(buf)
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+ baseinbuf = self._backend._ffi.from_buffer(data)
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+
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+ while data_processed != total_data_len:
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+ outbuf = baseoutbuf + total_out
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+ inbuf = baseinbuf + data_processed
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+ inlen = min(self._MAX_CHUNK_SIZE, total_data_len - data_processed)
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+
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+ res = self._backend._lib.EVP_CipherUpdate(
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+ self._ctx, outbuf, outlen, inbuf, inlen
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+ )
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+ self._backend.openssl_assert(res != 0)
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+ data_processed += inlen
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+ total_out += outlen[0]
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+
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+ return total_out
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def finalize(self):
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# OpenSSL 1.0.1 on Ubuntu 12.04 (and possibly other distributions)
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diff --git a/tests/hazmat/primitives/test_ciphers.py b/tests/hazmat/primitives/test_ciphers.py
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index f29ba9a9..b88610e7 100644
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--- a/tests/hazmat/primitives/test_ciphers.py
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+++ b/tests/hazmat/primitives/test_ciphers.py
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@@ -309,3 +309,20 @@ class TestCipherUpdateInto(object):
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buf = bytearray(5)
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with pytest.raises(ValueError):
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encryptor.update_into(b"testing", buf)
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+
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+ def test_update_into_auto_chunking(self, backend, monkeypatch):
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+ key = b"\x00" * 16
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+ c = ciphers.Cipher(AES(key), modes.ECB(), backend)
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+ encryptor = c.encryptor()
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+ # Lower max chunk size so we can test chunking
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+ monkeypatch.setattr(encryptor._ctx, "_MAX_CHUNK_SIZE", 40)
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+ buf = bytearray(527)
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+ pt = b"abcdefghijklmnopqrstuvwxyz012345" * 16 # 512 bytes
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+ processed = encryptor.update_into(pt, buf)
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+ assert processed == 512
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+ decryptor = c.decryptor()
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+ # Change max chunk size to verify alternate boundaries don't matter
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+ monkeypatch.setattr(decryptor._ctx, "_MAX_CHUNK_SIZE", 73)
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+ decbuf = bytearray(527)
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+ decprocessed = decryptor.update_into(buf[:processed], decbuf)
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+ assert decbuf[:decprocessed] == pt

‎meta-webos/recipes-devtools/python/python3-cryptography/0002-chunking-didn-t-actually-work-5499.patch

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From 7c72190620c3ccaeeab53fdd93547ca4d37b2f6b Mon Sep 17 00:00:00 2001
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From: Paul Kehrer <[email protected]>
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Date: Sun, 25 Oct 2020 06:15:18 -0700
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Subject: [PATCH] chunking didn't actually work (#5499)
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Upstream-Status: Backport [https://github.com/pyca/cryptography/commit/836a92a28fbe9df8c37121e340b91ed9cd519ddd]
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Signed-off-by: Martin Jansa <[email protected]>
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---
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src/cryptography/hazmat/backends/openssl/ciphers.py | 2 +-
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tests/hazmat/primitives/test_ciphers.py | 9 +++++++++
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2 files changed, 10 insertions(+), 1 deletion(-)
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diff --git a/src/cryptography/hazmat/backends/openssl/ciphers.py b/src/cryptography/hazmat/backends/openssl/ciphers.py
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index 86bc94b3..2b7da80c 100644
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--- a/src/cryptography/hazmat/backends/openssl/ciphers.py
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+++ b/src/cryptography/hazmat/backends/openssl/ciphers.py
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@@ -17,7 +17,7 @@ from cryptography.hazmat.primitives.ciphers import modes
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class _CipherContext(object):
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_ENCRYPT = 1
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_DECRYPT = 0
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- _MAX_CHUNK_SIZE = 2 ** 31
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+ _MAX_CHUNK_SIZE = 2 ** 31 - 1
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def __init__(self, backend, cipher, mode, operation):
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self._backend = backend
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diff --git a/tests/hazmat/primitives/test_ciphers.py b/tests/hazmat/primitives/test_ciphers.py
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index b88610e7..fd9048b7 100644
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--- a/tests/hazmat/primitives/test_ciphers.py
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+++ b/tests/hazmat/primitives/test_ciphers.py
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@@ -326,3 +326,12 @@ class TestCipherUpdateInto(object):
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decbuf = bytearray(527)
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decprocessed = decryptor.update_into(buf[:processed], decbuf)
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assert decbuf[:decprocessed] == pt
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+
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+ def test_max_chunk_size_fits_in_int32(self, backend):
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+ # max chunk must fit in signed int32 or else a call large enough to
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+ # cause chunking will result in the very OverflowError we want to
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+ # avoid with chunking.
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+ key = b"\x00" * 16
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+ c = ciphers.Cipher(AES(key), modes.ECB(), backend)
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+ encryptor = c.encryptor()
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+ backend._ffi.new("int *", encryptor._ctx._MAX_CHUNK_SIZE)

‎meta-webos/recipes-devtools/python/python3-cryptography/0003-correct-buffer-overflows-cause-by-integer-overflow-i.patch

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From 6d0a76521abe287f5ddb5cd1cfbc799d35f08cf9 Mon Sep 17 00:00:00 2001
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From: Alex Gaynor <[email protected]>
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Date: Sun, 7 Feb 2021 11:36:56 -0500
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Subject: [PATCH] correct buffer overflows cause by integer overflow in openssl
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(#5747)
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* correct buffer overflows cause by integer overflow in openssl
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frustratingly, there is no test for this -- that's because testing this
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requires allocating more memory than is available in CI.
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fixes #5615.
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* backport CI fixes
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* another CI backport
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Upstream-Status: Backport [https://github.com/pyca/cryptography/commit/82b6ce28389f0a317bc55ba2091a74b346db7cae]
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Signed-off-by: Martin Jansa <[email protected]>
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---
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src/cryptography/hazmat/backends/openssl/ciphers.py | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/src/cryptography/hazmat/backends/openssl/ciphers.py b/src/cryptography/hazmat/backends/openssl/ciphers.py
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index 2b7da80c..7ef5f1ea 100644
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--- a/src/cryptography/hazmat/backends/openssl/ciphers.py
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+++ b/src/cryptography/hazmat/backends/openssl/ciphers.py
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@@ -17,7 +17,7 @@ from cryptography.hazmat.primitives.ciphers import modes
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class _CipherContext(object):
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_ENCRYPT = 1
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_DECRYPT = 0
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- _MAX_CHUNK_SIZE = 2 ** 31 - 1
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+ _MAX_CHUNK_SIZE = 2 ** 30 - 1
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def __init__(self, backend, cipher, mode, operation):
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self._backend = backend

‎meta-webos/recipes-devtools/python/python3-cryptography_2.8.bbappend

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# From https://lists.openembedded.org/g/openembedded-devel/message/97027
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FILESEXTRAPATHS:prepend := "${THISDIR}/${BPN}:"
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SRC_URI += " \
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file://0001-chunked-update_into-5419.patch \
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file://0002-chunking-didn-t-actually-work-5499.patch \
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file://0003-correct-buffer-overflows-cause-by-integer-overflow-i.patch \
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"

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