[PATCH] tpm-v2: allow algo name to be conigured for pcr_read and pcr_extend

[Ilias Apalodimas]

Hi Tim,

[...]

>
> +/**
> + * tpm2_algo_len() - Return an algo value and length given a algorithm name
> + *
> + * @name: algorithm name
> + * @rwlen: pointer to integer to populate with algorithm length if non-null
> + * Return: algorithm value
> + */
> +int tpm2_algo_len(const char *name, int *rwlen);
> +
> +/**
> + * tpm2_algo_len() - Return an algoithm name string
> + *
> + * @algo: algorithm value
> + * Return: algorithm string
> + */
> +const char *tpm2_algo_name(int algo);
> +
>  #endif /* __TPM_V2_H */
> diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
> index 68eaaa639f89..6a090ce5810c 100644
> --- a/lib/tpm-v2.c
> +++ b/lib/tpm-v2.c
> @@ -1555,3 +1555,49 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd,
>
>         return 0;
>  }
> +
> +int tpm2_algo_len(const char *name, int *rwlen)
> +{
> +       int algo = -EINVAL;
> +       int len = 0;
> +
> +       if (!strcasecmp("sha1", name)) {
> +               algo = TPM2_ALG_SHA1;
> +               len = TPM2_SHA1_DIGEST_SIZE;
> +       } else if (!strcasecmp("sha256", name)) {
> +               algo = TPM2_ALG_SHA256;
> +               len = TPM2_SHA256_DIGEST_SIZE;
> +       } else if (!strcasecmp("sha384", name)) {
> +               algo = TPM2_ALG_SHA384;
> +               len = TPM2_SHA384_DIGEST_SIZE;
> +       } else if (!strcasecmp("sha512", name)) {
> +               algo = TPM2_ALG_SHA512;
> +               len = TPM2_SHA512_DIGEST_SIZE;
> +       } else if (!strcasecmp("sm3_256", name)) {
> +               algo = TPM2_ALG_SM3_256;
> +               len = TPM2_SM3_256_DIGEST_SIZE;
> +       }
> +
> +       if (*rwlen)
> +               *rwlen = len;
> +
> +       return algo;
> +}
> +

We already have tpm2_algorithm_to_len(). Instead of defining a new
function, can we convert strings to 'enum tpm2_algorithms'? We can
then reuse the existing function.

> +const char *tpm2_algo_name(int algo)
> +{
> +       switch (algo) {
> +       case TPM2_ALG_SHA1:
> +               return "sha1";
> +       case TPM2_ALG_SHA256:
> +               return "sha256";
> +       case TPM2_ALG_SHA384:
> +               return "sha384";
> +       case TPM2_ALG_SHA512:
> +               return "sha512";
> +       case TPM2_ALG_SM3_256:
> +               return "sm3_256";
> +       }
> +
> +       return "";
> +}
> --
> 2.25.1
>

Thanks
/Ilias