Re: [PATCH 2/3] KEYS: trusted: use encode_OID for OID encoding

["Jarkko Sakkinen" <jarkko@kernel.org>]

On Fri May 24, 2024 at 3:59 PM EEST, James Bottomley wrote:
> The new routine takes the OID enum instead of needing the u32 OID
> array explicitly which reduces duplication and the potential for
> mistakes.
>
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> ---
>  security/keys/trusted-keys/trusted_tpm2.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> index 9c7ac2e423d3..b6f34ff0ca5c 100644
> --- a/security/keys/trusted-keys/trusted_tpm2.c
> +++ b/security/keys/trusted-keys/trusted_tpm2.c
> @@ -19,8 +19,6 @@
>  #include "tpm2key.asn1.h"
>  #include "tpm2-policy.h"
>  
> -static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
> -
>  static int tpm2_key_encode(struct trusted_key_payload *payload,
>  			   struct trusted_key_options *options,
>  			   u8 *src, u32 len)
> @@ -31,6 +29,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
>  	u8 *end_work = scratch + SCRATCH_SIZE;
>  	u8 *priv, *pub;
>  	u16 priv_len, pub_len;
> +	int ret;
>  
>  	priv_len = get_unaligned_be16(src) + 2;
>  	priv = src;
> @@ -43,8 +42,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
>  	if (!scratch)
>  		return -ENOMEM;
>  
> -	work = asn1_encode_oid(work, end_work, tpm2key_oid,
> -			       asn1_oid_len(tpm2key_oid));
> +	ret = encode_OID(OID_TPMSealedData, work, end_work - work);
> +	if (ret < 0)
> +		return ret;
> +	work += ret;
>  
>  	if (options->blobauth_len == 0) {
>  		unsigned char bool[3], *w = bool;

Yupe, it's better this way.

BR, Jarkko