Add ChangeLog entry
diff --git a/ChangeLog b/ChangeLog
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@@ -2,6 +2,12 @@
= mbed TLS 2.16.x branch released xxxx-xx-xx
+Security
+ * Fix side channel vulnerability in ECDSA key generation. Obtaining precise
+ timings on the comparison in the key generation enabled the attacker to
+ learn leading bits of the ephemeral key used during ECDSA signatures and to
+ recover the private key. Reported by Jeremy Dubeuf.
+
Bugfix
* Remove redundant line for getting the bitlen of a bignum, since the variable
holding the returned value is overwritten a line after.