| Message ID | 20211124075625.197449-2-ruchika.gupta@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3,1/3] efi_loader: Add check for event log passed from firmware | expand |
On Wed, Nov 24, 2021 at 01:26:24PM +0530, Ruchika Gupta wrote: > The current tpm2_pcr_read is hardcoded using SHA256. Make the > actual command to TPM configurable to use wider range of algorithms. > The current command line is kept as is i.e limited to SHA-256 only. > > Signed-off-by: Ruchika Gupta <ruchika.gupta@linaro.org> > --- > v3: No change > > v2: > Change algorithm from u32 to u16 > Add parameter description in function declaration > > cmd/tpm-v2.c | 3 ++- > include/tpm-v2.h | 5 ++++- > lib/tpm-v2.c | 12 ++++++++---- > 3 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c > index daae91100a..4ea5f9f094 100644 > --- a/cmd/tpm-v2.c > +++ b/cmd/tpm-v2.c > @@ -151,7 +151,8 @@ static int do_tpm_pcr_read(struct cmd_tbl *cmdtp, int flag, int argc, > > data = map_sysmem(simple_strtoul(argv[2], NULL, 0), 0); > > - rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, data, &updates); > + rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, TPM2_ALG_SHA256, > + data, TPM2_DIGEST_LEN, &updates); > if (!rc) { > printf("PCR #%u content (%u known updates):\n", index, updates); > print_byte_string(data, TPM2_DIGEST_LEN); > diff --git a/include/tpm-v2.h b/include/tpm-v2.h > index ceff7d245e..4e9dd52cb6 100644 > --- a/include/tpm-v2.h > +++ b/include/tpm-v2.h > @@ -512,13 +512,16 @@ u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data, > * @dev TPM device > * @idx Index of the PCR > * @idx_min_sz Minimum size in bytes of the pcrSelect array > + * @algorithm Algorithm used, defined in 'enum tpm2_algorithms' > * @data Output buffer for contents of the named PCR > + * @digest_len len of the data > * @updates Optional out parameter: number of updates for this PCR > * > * @return code of the operation > */ > u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, > - void *data, unsigned int *updates); > + u16 algorithm, void *data, u32 digest_len, > + unsigned int *updates); > > /** > * Issue a TPM2_GetCapability command. This implementation is limited > diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c > index 2e7b27bd6b..1bf627853a 100644 > --- a/lib/tpm-v2.c > +++ b/lib/tpm-v2.c > @@ -254,7 +254,8 @@ u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data, > } > > u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, > - void *data, unsigned int *updates) > + u16 algorithm, void *data, u32 digest_len, > + unsigned int *updates) > { > u8 idx_array_sz = max(idx_min_sz, DIV_ROUND_UP(idx, 8)); > u8 command_v2[COMMAND_BUFFER_SIZE] = { > @@ -264,7 +265,7 @@ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, > > /* TPML_PCR_SELECTION */ > tpm_u32(1), /* Number of selections */ > - tpm_u16(TPM2_ALG_SHA256), /* Algorithm of the hash */ > + tpm_u16(algorithm), /* Algorithm of the hash */ > idx_array_sz, /* Array size for selection */ > /* bitmap(idx) Selected PCR bitmap */ > }; > @@ -283,10 +284,13 @@ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, > if (ret) > return ret; > > + if (digest_len > response_len) > + return TPM_LIB_ERROR; > + > if (unpack_byte_string(response, response_len, "ds", > 10, &counter, > - response_len - TPM2_DIGEST_LEN, data, > - TPM2_DIGEST_LEN)) > + response_len - digest_len, data, > + digest_len)) > return TPM_LIB_ERROR; > > if (updates) > -- > 2.25.1 > Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c index daae91100a..4ea5f9f094 100644 --- a/cmd/tpm-v2.c +++ b/cmd/tpm-v2.c @@ -151,7 +151,8 @@ static int do_tpm_pcr_read(struct cmd_tbl *cmdtp, int flag, int argc, data = map_sysmem(simple_strtoul(argv[2], NULL, 0), 0); - rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, data, &updates); + rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, TPM2_ALG_SHA256, + data, TPM2_DIGEST_LEN, &updates); if (!rc) { printf("PCR #%u content (%u known updates):\n", index, updates); print_byte_string(data, TPM2_DIGEST_LEN); diff --git a/include/tpm-v2.h b/include/tpm-v2.h index ceff7d245e..4e9dd52cb6 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -512,13 +512,16 @@ u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data, * @dev TPM device * @idx Index of the PCR * @idx_min_sz Minimum size in bytes of the pcrSelect array + * @algorithm Algorithm used, defined in 'enum tpm2_algorithms' * @data Output buffer for contents of the named PCR + * @digest_len len of the data * @updates Optional out parameter: number of updates for this PCR * * @return code of the operation */ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, - void *data, unsigned int *updates); + u16 algorithm, void *data, u32 digest_len, + unsigned int *updates); /** * Issue a TPM2_GetCapability command. This implementation is limited diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 2e7b27bd6b..1bf627853a 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -254,7 +254,8 @@ u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data, } u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, - void *data, unsigned int *updates) + u16 algorithm, void *data, u32 digest_len, + unsigned int *updates) { u8 idx_array_sz = max(idx_min_sz, DIV_ROUND_UP(idx, 8)); u8 command_v2[COMMAND_BUFFER_SIZE] = { @@ -264,7 +265,7 @@ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, /* TPML_PCR_SELECTION */ tpm_u32(1), /* Number of selections */ - tpm_u16(TPM2_ALG_SHA256), /* Algorithm of the hash */ + tpm_u16(algorithm), /* Algorithm of the hash */ idx_array_sz, /* Array size for selection */ /* bitmap(idx) Selected PCR bitmap */ }; @@ -283,10 +284,13 @@ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, if (ret) return ret; + if (digest_len > response_len) + return TPM_LIB_ERROR; + if (unpack_byte_string(response, response_len, "ds", 10, &counter, - response_len - TPM2_DIGEST_LEN, data, - TPM2_DIGEST_LEN)) + response_len - digest_len, data, + digest_len)) return TPM_LIB_ERROR; if (updates)
The current tpm2_pcr_read is hardcoded using SHA256. Make the actual command to TPM configurable to use wider range of algorithms. The current command line is kept as is i.e limited to SHA-256 only. Signed-off-by: Ruchika Gupta <ruchika.gupta@linaro.org> --- v3: No change v2: Change algorithm from u32 to u16 Add parameter description in function declaration cmd/tpm-v2.c | 3 ++- include/tpm-v2.h | 5 ++++- lib/tpm-v2.c | 12 ++++++++---- 3 files changed, 14 insertions(+), 6 deletions(-)