crypto: Permit variable-sized IVs for ciphers with a reinit hook.

[jhb]

Summary

Add a 'len' argument to the reinit hook in 'struct enc_xform' to
permit support for AEAD ciphers such as AES-CCM and Chacha20-Poly1305
which support different nonce lengths.

Sponsored by: Chelsio Communications, The FreeBSD Foundation

[markj]

sys/opencrypto/xform_aes_icm.c

117

I think it'd be a bit nicer to call it ivlen here and below.

sys/opencrypto/xform_aes_xts.c

90

Perhaps assert that AES_XTS_IVSIZE == len? Here and elsewhere where we don't actually handle a variable length IV. (I know that CCM gets updated in a follow-up commit.)

[jhb]

sys/opencrypto/xform_aes_xts.c

90

I've actually added assertions to all of the reinit routines.

[jhb]

• Rename 'len' to 'ivlen' in a few places.
• Add assertions for IV / nonce lengths.

[markj]

sys/crypto/chacha20/chacha-sw.c

21

Still len here, would be nice to be consistent.

sys/opencrypto/xform_aes_xts.c

80

Ditto.

sys/opencrypto/xform_chacha20_poly1305.c

53

And here.