[PATCH v4 9/9] Makefile: discuss SHAttered in *_SHA{1,256} discussion

From

Ævar Arnfjörð Bjarmason <avarab@gmail.com>

Date

Oct 26, 2022, 14:56 UTC

Message-ID

<patch-v4-9.9-9045ff9c4ed-20221026T145255Z-avarab@gmail.com>

In-Reply-To

<cover-v4-0.9-00000000000-20221026T145255Z-avarab@gmail.com>

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 Makefile | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Makefile b/Makefile
index a0ca6456b85..805e88ed5fd 100644
--- a/Makefile
+++ b/Makefile
@@ -481,6 +481,16 @@ include shared.mak
 #
 # === SHA-1 backend ===
 #
+# ==== Security ====
+#
+# Due to the SHAttered (https://shattered.io) attack vector on SHA-1
+# it's strongly recommended to use the sha1collisiondetection
+# counter-cryptanalysis library for SHA-1 hashing (DC_SHA1).
+#
+# If you know that you can trust the repository contents, or where
+# potential SHA-1 attacks are otherwise mitigated the backends listed
+# in "Other SHA-1 implementations" are faster than DC_SHA1.
+#
 # ==== Default SHA-1 backend ====
 #
 # If no *_SHA1 backend is picked we'll fall back on using the default.
@@ -525,6 +535,11 @@ include shared.mak
 #
 # === SHA-256 backend ===
 #
+# ==== Security ====
+#
+# Unlike SHA-1 the SHA-256 algorithm does not suffer from any known
+# vulnerabilities, so any implementation will do.
+#
 # ==== Default SHA-256 backend ====
 #
 # If no *_SHA256 backend is picked we'll fall fall back on using the

-- 
2.38.0.1251.g3eefdfb5e7a