| Message ID | 20210615144115.2113484-2-stefanb@linux.ibm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tcgbios: Use the proper hashes for the TPM 2 PCR banks | expand |
On 6/16/21 00:41, Stefan Berger wrote: > Change the format of the S_CRTM_VERSION string to ucs-2 since this > is what seems to be commonly used by other firmwares following > insight from a TCG work group member. > > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> > --- > lib/libtpm/tcgbios.c | 45 ++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 37 insertions(+), 8 deletions(-) > > diff --git a/lib/libtpm/tcgbios.c b/lib/libtpm/tcgbios.c > index d3deccb..6ba4873 100644 > --- a/lib/libtpm/tcgbios.c > +++ b/lib/libtpm/tcgbios.c > @@ -1091,6 +1091,29 @@ uint32_t tpm_measure_gpt(void) > (const uint8_t *)uefi_gpt_data, sz); > } > > +/* convert a normal string of given length into a ucs-2 string */ > +static char *string2ucs2(const char *str, size_t str_length, > + size_t *ucs2_length) > +{ > + char *ucs2; > + size_t i; > + > + if (str_length > 0) { > + *ucs2_length = str_length * 2; > + if (str[str_length - 1] != 0) > + *ucs2_length += 2; If the source string was not null terminated, you add 2 bytes for the 0 in the destination string but you do not seem to write the actual 0 at the end. > + } else { > + *ucs2_length = 2; > + } > + ucs2 = SLOF_alloc_mem(*ucs2_length); > + if (ucs2) { > + memset(ucs2, 0, *ucs2_length); > + for (i = 0; i < str_length; i++) > + ucs2[i * 2] = str[i]; (a nit) may be "ucs2[i * 2 + 1] = 0" and drop the memset? > + } if ucs2==NULL, *ucs2_length won't be 0 but it should. > + return ucs2; > +} > + > uint32_t tpm_measure_scrtm(void) > { > uint32_t rc; > @@ -1100,19 +1123,25 @@ uint32_t tpm_measure_scrtm(void) > char *slof_text_start = (char *)&_slof_text; > uint32_t slof_text_length = (long)&_slof_text_end - (long)&_slof_text; > const char *scrtm = "S-CRTM Contents"; > + char *ucs2_version; > + size_t ucs2_length; > > version_end = strchr(version_start, '\r'); > version_length = version_end - version_start; > I am looking at this version_start/end and thinking can we just use the RELEASE macro instead (this is what board-qemu/slof/version.S uses anyway)? And then L##RELEASE (or whatever the preprocessor syntax is for gluing "L" and a macro). > - dprintf("Measure S-CRTM Version: addr = %p, length = %d\n", > - version_start, version_length); > + ucs2_version = string2ucs2(version_start, version_length, &ucs2_length); > + if (ucs2_version) { > + dprintf("Measure S-CRTM Version: addr = %p, length = %d\n", > + ucs2_version, ucs2_length); > > - rc = tpm_add_measurement_to_log(0, EV_S_CRTM_VERSION, > - version_start, version_length, > - (uint8_t *)version_start, > - version_length); > - if (rc) > - return rc; > + rc = tpm_add_measurement_to_log(0, EV_S_CRTM_VERSION, > + ucs2_version, ucs2_length, > + (uint8_t *)ucs2_version, > + ucs2_length); > + SLOF_free_mem(ucs2_version, ucs2_length); > + if (rc) > + return rc; > + } > > dprintf("Measure S-CRTM Content (text): start = %p, length = %d\n", > slof_text_start, slof_text_length); >
diff --git a/lib/libtpm/tcgbios.c b/lib/libtpm/tcgbios.c index d3deccb..6ba4873 100644 --- a/lib/libtpm/tcgbios.c +++ b/lib/libtpm/tcgbios.c @@ -1091,6 +1091,29 @@ uint32_t tpm_measure_gpt(void) (const uint8_t *)uefi_gpt_data, sz); } +/* convert a normal string of given length into a ucs-2 string */ +static char *string2ucs2(const char *str, size_t str_length, + size_t *ucs2_length) +{ + char *ucs2; + size_t i; + + if (str_length > 0) { + *ucs2_length = str_length * 2; + if (str[str_length - 1] != 0) + *ucs2_length += 2; + } else { + *ucs2_length = 2; + } + ucs2 = SLOF_alloc_mem(*ucs2_length); + if (ucs2) { + memset(ucs2, 0, *ucs2_length); + for (i = 0; i < str_length; i++) + ucs2[i * 2] = str[i]; + } + return ucs2; +} + uint32_t tpm_measure_scrtm(void) { uint32_t rc; @@ -1100,19 +1123,25 @@ uint32_t tpm_measure_scrtm(void) char *slof_text_start = (char *)&_slof_text; uint32_t slof_text_length = (long)&_slof_text_end - (long)&_slof_text; const char *scrtm = "S-CRTM Contents"; + char *ucs2_version; + size_t ucs2_length; version_end = strchr(version_start, '\r'); version_length = version_end - version_start; - dprintf("Measure S-CRTM Version: addr = %p, length = %d\n", - version_start, version_length); + ucs2_version = string2ucs2(version_start, version_length, &ucs2_length); + if (ucs2_version) { + dprintf("Measure S-CRTM Version: addr = %p, length = %d\n", + ucs2_version, ucs2_length); - rc = tpm_add_measurement_to_log(0, EV_S_CRTM_VERSION, - version_start, version_length, - (uint8_t *)version_start, - version_length); - if (rc) - return rc; + rc = tpm_add_measurement_to_log(0, EV_S_CRTM_VERSION, + ucs2_version, ucs2_length, + (uint8_t *)ucs2_version, + ucs2_length); + SLOF_free_mem(ucs2_version, ucs2_length); + if (rc) + return rc; + } dprintf("Measure S-CRTM Content (text): start = %p, length = %d\n", slof_text_start, slof_text_length);
Change the format of the S_CRTM_VERSION string to ucs-2 since this is what seems to be commonly used by other firmwares following insight from a TCG work group member. Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> --- lib/libtpm/tcgbios.c | 45 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-)