[SeaBIOS] Re: [PATCH 1/3] tcgbios: Only write logs for PCRs that are in active PCR banks

[Marc-André Lureau]

On Sat, Mar 28, 2020 at 5:02 AM Stefan Berger
 wrote:
> Only write the logs for those PCRs that are in active PCR banks.
> A PCR banks is assumed to be active if any of the BIOS relevant
> PCRs 0 -  7 is enabled, thus pcrSelect[0] != 0.
>
> Signed-off-by: Stefan Berger

Reviewed-by: Marc-André Lureau
> src/tcgbios.c | 30 ++++++++++++++++++++++--------
>  1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/src/tcgbios.c b/src/tcgbios.c
> index 95c1e94..997da87 100644
> --- a/src/tcgbios.c
> +++ b/src/tcgbios.c
> @@ -265,7 +265,7 @@ tpm20_write_EfiSpecIdEventStruct(void)
>      struct tpms_pcr_selection *sel = tpm20_pcr_selection->selections;
>      void *nsel, *end = (void*)tpm20_pcr_selection + tpm20_pcr_selection_size;
> u32 count;
> u32 count, numAlgs = 0;
> for (count = 0; count < be32_to_cpu(tpm20_pcr_selection->count); count++) {
>     u8 sizeOfSelect = sel->sizeOfSelect;
>
> @@ -273,6 +273,11 @@ tpm20_write_EfiSpecIdEventStruct(void)
>          if (nsel > end)
>              break;
>    if (sel->pcrSelect[0] == 0) {
>        sel = nsel;
>        continue;
>    }
>    int hsize = tpm20_get_hash_buffersize(be16_to_cpu(sel->hashAlg));
>    if (hsize < 0) {
>        dprintf(DEBUG_tcg, "TPM is using an unsupported hash: %d\n",
>
> @@ -287,8 +292,9 @@ tpm20_write_EfiSpecIdEventStruct(void)
>              return -1;
>          }
>    event.hdr.digestSizes[count].algorithmId = be16_to_cpu(sel->hashAlg);
>    event.hdr.digestSizes[count].digestSize = hsize;
>    event.hdr.digestSizes[numAlgs].algorithmId = be16_to_cpu(sel->hashAlg);
>    event.hdr.digestSizes[numAlgs].digestSize = hsize;
>    numAlgs++;
>
>    sel = nsel;
>
> }
>
> @@ -298,9 +304,9 @@ tpm20_write_EfiSpecIdEventStruct(void)
>          return -1;
>      }
> event.hdr.numberOfAlgorithms = count;
> event.hdr.numberOfAlgorithms = numAlgs;
> int event_size = offsetof(struct TCG_EfiSpecIdEventStruct
>                          , digestSizes[count]);
>                          , digestSizes[numAlgs]);
> u32 *vendorInfoSize = (void*)&event + event_size;
>    *vendorInfoSize = 0;
>    event_size += sizeof(*vendorInfoSize);
>
> @@ -336,7 +342,7 @@ tpm20_build_digest(struct tpm_log_entry *le, const u8 *sha1, int bigEndian)
>      void *nsel, *end = (void*)tpm20_pcr_selection + tpm20_pcr_selection_size;
>      void *dest = le->hdr.digest + sizeof(struct tpm2_digest_values);
> u32 count;
> u32 count, numAlgs = 0;
> for (count = 0; count < be32_to_cpu(tpm20_pcr_selection->count); count++) {
>     u8 sizeOfSelect = sel->sizeOfSelect;
>
> @@ -344,6 +350,12 @@ tpm20_build_digest(struct tpm_log_entry *le, const u8 *sha1, int bigEndian)
>          if (nsel > end)
>              break;
>    /* PCR 0-7 unused? -- skip */
>    if (sel->pcrSelect[0] == 0) {
>        sel = nsel;
>        continue;
>    }
>    int hsize = tpm20_get_hash_buffersize(be16_to_cpu(sel->hashAlg));
>    if (hsize < 0) {
>        dprintf(DEBUG_tcg, "TPM is using an unsupported hash: %d\n",
>
> @@ -368,6 +380,8 @@ tpm20_build_digest(struct tpm_log_entry *le, const u8 *sha1, int bigEndian)
>      dest += sizeof(*v) + hsize;
>      sel = nsel;
>    numAlgs++;
>
> }
>
> if (sel != end) {
>
> @@ -377,9 +391,9 @@ tpm20_build_digest(struct tpm_log_entry *le, const u8 *sha1, int bigEndian)
>  struct tpm2_digest_values *v = (void*)le->hdr.digest;
>  if (bigEndian)
>    v->count = cpu_to_be32(count);
>    v->count = cpu_to_be32(numAlgs);
> else
>    v->count = count;
>    v->count = numAlgs;
>
> return dest - (void*)le->hdr.digest;
> }
>
> 2.24.1
> _______________________________________________
> SeaBIOS mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]