On Fri, Jun 05, 2020 at 10:39:31AM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> CRYPTO_CTR no longer selects CRYPTO_SEQIV, which breaks IPsec for users
> who need any of the algorithms that use seqiv. These users now would
> need to explicitly enable CRYPTO_SEQIV.
>
> There doesn't seem to be a clear rule on what algorithms the IPsec
> options (INET_ESP and INET6_ESP) actually select, as apparently none is
> *always* required. They currently select just a particular subset,
> along with CRYPTO_ECHAINIV which is the other IV generator template.
>
> As a compromise between too many and too few selections, select
> CRYPTO_SEQIV if either CRYPTO_CTR or CRYPTO_CHACHA20POLY1305 is enabled.
> These are the algorithms that can use seqiv for IPsec. (Note: GCM and
> CCM can too, but those both use CTR.)
>
> Fixes: f23efcbcc523 ("crypto: ctr - no longer needs CRYPTO_SEQIV")
> Cc: Corentin Labbe <clabbe@xxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
>
> v2: added the 'if' condition and updated commit message
>
> net/ipv4/Kconfig | 1 +
> net/ipv6/Kconfig | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
> index 23ba5045e3d3..6520b30883cf 100644
> --- a/net/ipv4/Kconfig
> +++ b/net/ipv4/Kconfig
> @@ -361,6 +361,7 @@ config INET_ESP
> select CRYPTO_SHA1
> select CRYPTO_DES
> select CRYPTO_ECHAINIV
> + select CRYPTO_SEQIV if CRYPTO_CTR || CRYPTO_CHACHA20POLY1305
> ---help---
> Support for IPsec ESP.
>
Oops, this doesn't actually work:
scripts/kconfig/conf --olddefconfig Kconfig
crypto/Kconfig:1799:error: recursive dependency detected!
crypto/Kconfig:1799: symbol CRYPTO_DRBG_MENU is selected by CRYPTO_RNG_DEFAULT
crypto/Kconfig:83: symbol CRYPTO_RNG_DEFAULT is selected by CRYPTO_SEQIV
crypto/Kconfig:330: symbol CRYPTO_SEQIV is selected by CRYPTO_CTR
crypto/Kconfig:370: symbol CRYPTO_CTR is selected by CRYPTO_DRBG_CTR
crypto/Kconfig:1819: symbol CRYPTO_DRBG_CTR depends on CRYPTO_DRBG_MENU
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"
I guess we need to go with v1 (which just had 'select CRYPTO_SEQIV'),
or else make users explicitly select CRYPTO_SEQIV?
- Eric
