Re: [PATCH v2 09/22] crypto: move storage for grub_crypto_pk_* to crypto.c

[Stefan Berger <stefanb@linux.ibm.com>]

On 6/30/21 4:40 AM, Daniel Axtens wrote:
> The way gcry_rsa and friends (the asymmetric ciphers) are loaded for the
> pgp module is a bit quirky.
>
> include/grub/crypto.h contains:
>    extern struct gcry_pk_spec *grub_crypto_pk_rsa;
>
> commands/pgp.c contains the actual storage:
>    struct gcry_pk_spec *grub_crypto_pk_rsa;
>
> And the module itself saves to the storage in pgp.c:
>    GRUB_MOD_INIT(gcry_rsa)
>    {
>      grub_crypto_pk_rsa = &_gcry_pubkey_spec_rsa;
>    }
>
> This is annoying: gcry_rsa now has a dependency on pgp!
>
> We want to be able to bring in gcry_rsa without bringing in PGP,
> so move the storage to crypto.c.
>
> Previously, gcry_rsa depended on pgp and mpi. Now it depends on
> crypto and mpi. As pgp depends on crypto, this doesn't add any new
> module dependencies using the PGP verfier.
>
> [FWIW, the story is different for the symmetric ciphers. cryptodisk
> and friends (zfs encryption etc) use grub_crypto_lookup_cipher_by_name()
> to get a cipher handle. That depends on grub_ciphers being populated
> by people calling grub_cipher_register. import_gcry.py ensures that the
> symmetric ciphers call it.]
>
> Signed-off-by: Daniel Axtens <dja@axtens.net>

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>


> ---
>   grub-core/commands/pgp.c | 4 ----
>   grub-core/lib/crypto.c   | 4 ++++
>   2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/grub-core/commands/pgp.c b/grub-core/commands/pgp.c
> index 2408db4994f6..355a43844acc 100644
> --- a/grub-core/commands/pgp.c
> +++ b/grub-core/commands/pgp.c
> @@ -147,10 +147,6 @@ const char *hashes[] = {
>     [0x0b] = "sha224"
>   };
>   
> -struct gcry_pk_spec *grub_crypto_pk_dsa;
> -struct gcry_pk_spec *grub_crypto_pk_ecdsa;
> -struct gcry_pk_spec *grub_crypto_pk_rsa;
> -
>   static int
>   dsa_pad (gcry_mpi_t *hmpi, grub_uint8_t *hval,
>   	 const gcry_md_spec_t *hash, struct grub_public_subkey *sk);
> diff --git a/grub-core/lib/crypto.c b/grub-core/lib/crypto.c
> index ca334d5a40e0..c578128a59db 100644
> --- a/grub-core/lib/crypto.c
> +++ b/grub-core/lib/crypto.c
> @@ -121,6 +121,10 @@ grub_md_unregister (gcry_md_spec_t *cipher)
>         }
>   }
>   
> +struct gcry_pk_spec *grub_crypto_pk_dsa;
> +struct gcry_pk_spec *grub_crypto_pk_ecdsa;
> +struct gcry_pk_spec *grub_crypto_pk_rsa;
> +
>   void
>   grub_crypto_hash (const gcry_md_spec_t *hash, void *out, const void *in,
>   		  grub_size_t inlen)