generation apps to use 2048 bits by default.
[Kurt Roeckx]
+ *) Prevent over long nonces in ChaCha20-Poly1305.
+
+ ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input
+ for every encryption operation. RFC 7539 specifies that the nonce value
+ (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length
+ and front pads the nonce with 0 bytes if it is less than 12
+ bytes. However it also incorrectly allows a nonce to be set of up to 16
+ bytes. In this case only the last 12 bytes are significant and any
+ additional leading bytes are ignored.
+
+ It is a requirement of using this cipher that nonce values are
+ unique. Messages encrypted using a reused nonce value are susceptible to
+ serious confidentiality and integrity attacks. If an application changes
+ the default nonce length to be longer than 12 bytes and then makes a
+ change to the leading bytes of the nonce expecting the new value to be a
+ new unique nonce then such an application could inadvertently encrypt
+ messages with a reused nonce.
+
+ Additionally the ignored bytes in a long nonce are not covered by the
+ integrity guarantee of this cipher. Any application that relies on the
+ integrity of these ignored leading bytes of a long nonce may be further
+ affected. Any OpenSSL internal use of this cipher, including in SSL/TLS,
+ is safe because no such use sets such a long nonce value. However user
+ applications that use this cipher directly and set a non-default nonce
+ length to be longer than 12 bytes may be vulnerable.
+
+ This issue was reported to OpenSSL on 16th of March 2019 by Joran Dirk
+ Greef of Ronomon.
+ (CVE-2019-1543)
+ [Matt Caswell]
+
*) Added SCA hardening for modular field inversion in EC_GROUP through
a new dedicated field_inv() pointer in EC_METHOD.
This also addresses a leakage affecting conversions from projective