If the length of the plaintext is zero, there's no need to waste cycles
on encryption and decryption. Using the chacha20poly1305 construction
for zero-length plaintexts is a common way of using a shared encryption
key for AAD authentication.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As architecture specific drivers need a software fallback, export Poly1305
init/update/final functions together with some helpers in a header file.
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As architecture specific drivers need a software fallback, export a
ChaCha20 en-/decryption function together with some helpers in a header
file.
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch converts rfc7539 and rfc7539esp to the new AEAD interface.
The test vectors for rfc7539esp have also been updated to include
the IV.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Martin Willi <martin@strongswan.org>
The Poly1305 authenticator requires a unique key for each generated tag. This
implies that we can't set the key per tfm, as multiple users set individual
keys. Instead we pass a desc specific key as the first two blocks of the
message to authenticate in update().
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
draft-ietf-ipsecme-chacha20-poly1305 defines the use of ChaCha20/Poly1305 in
ESP. It uses additional four byte key material as a salt, which is then used
with an 8 byte IV to form the ChaCha20 nonce as defined in the RFC7539.
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This AEAD uses a chacha20 ablkcipher and a poly1305 ahash to construct the
ChaCha20-Poly1305 AEAD as defined in RFC7539. It supports both synchronous and
asynchronous operations, even if we currently have no async chacha20 or poly1305
drivers.
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Jason A. Donenfeld