For pcr_read and pcr_extend commands allow the digest algorithm to be
specified by an additional argument. If not specified it will default to
SHA256 for backwards compatibility.
A follow-on to this could be to extend all PCR banks with the detected
algo when the <digest_algo> argument is 'auto'.
Signed-off-by: Tim Harvey <thar...@gateworks.com>
---
v2:
- use tpm2_algorithm_to_len
- use enum tpm2_algorithms
- make function names and parameter names more consistent with existing
tpm-v2 functions
- fix various spelling errors
---
cmd/tpm-v2.c | 49 ++++++++++++++++++++++++++++++++++--------------
include/tpm-v2.h | 18 ++++++++++++++++++
lib/tpm-v2.c | 34 +++++++++++++++++++++++++++++++++
3 files changed, 87 insertions(+), 14 deletions(-)
diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c
index 7e479b9dfe36..2343b4d9cb9e 100644
--- a/cmd/tpm-v2.c
+++ b/cmd/tpm-v2.c
@@ -99,11 +99,19 @@ static int do_tpm2_pcr_extend(struct cmd_tbl *cmdtp, int
flag, int argc,
struct tpm_chip_priv *priv;
u32 index = simple_strtoul(argv[1], NULL, 0);
void *digest = map_sysmem(simple_strtoul(argv[2], NULL, 0), 0);
+ int algo = TPM2_ALG_SHA256;
+ int algo_len;
int ret;
u32 rc;
- if (argc != 3)
+ if (argc < 3 || argc > 4)
return CMD_RET_USAGE;
+ if (argc == 4) {
+ algo = tpm2_name_to_algorithm(argv[3]);
+ if (algo < 0)
+ return CMD_RET_FAILURE;
+ }
+ algo_len = tpm2_algorithm_to_len(algo);
ret = get_tpm(&dev);
if (ret)
@@ -116,8 +124,12 @@ static int do_tpm2_pcr_extend(struct cmd_tbl *cmdtp, int
flag, int argc,
if (index >= priv->pcr_count)
return -EINVAL;
- rc = tpm2_pcr_extend(dev, index, TPM2_ALG_SHA256, digest,
- TPM2_DIGEST_LEN);
+ rc = tpm2_pcr_extend(dev, index, algo, digest, algo_len);
+ if (!rc) {
+ printf("PCR #%u extended with %d byte %s digest\n", index,
+ algo_len, tpm2_algorithm_name(algo));
+ print_byte_string(digest, algo_len);
+ }
unmap_sysmem(digest);
@@ -127,15 +139,23 @@ static int do_tpm2_pcr_extend(struct cmd_tbl *cmdtp, int
flag, int argc,
static int do_tpm_pcr_read(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
+ enum tpm2_algorithms algo = TPM2_ALG_SHA256;
struct udevice *dev;
struct tpm_chip_priv *priv;
u32 index, rc;
+ int algo_len;
unsigned int updates;
void *data;
int ret;
- if (argc != 3)
+ if (argc < 3 || argc > 4)
return CMD_RET_USAGE;
+ if (argc == 4) {
+ algo = tpm2_name_to_algorithm(argv[3]);
+ if (algo < 0)
+ return CMD_RET_FAILURE;
+ }
+ algo_len = tpm2_algorithm_to_len(algo);
ret = get_tpm(&dev);
if (ret)
@@ -151,11 +171,12 @@ 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, TPM2_ALG_SHA256,
- data, TPM2_DIGEST_LEN, &updates);
+ rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, algo,
+ data, algo_len, &updates);
if (!rc) {
- printf("PCR #%u content (%u known updates):\n", index, updates);
- print_byte_string(data, TPM2_DIGEST_LEN);
+ printf("PCR #%u %s %d byte content (%u known updates):\n",
index,
+ tpm2_algorithm_name(algo), algo_len, updates);
+ print_byte_string(data, algo_len);
}
unmap_sysmem(data);
@@ -415,14 +436,14 @@ U_BOOT_CMD(tpm2, CONFIG_SYS_MAXARGS, 1, do_tpm, "Issue a
TPMv2.x command",
" <hierarchy> is one of:\n"
" * TPM2_RH_LOCKOUT\n"
" * TPM2_RH_PLATFORM\n"
-"pcr_extend <pcr> <digest_addr>\n"
-" Extend PCR #<pcr> with digest at <digest_addr>.\n"
+"pcr_extend <pcr> <digest_addr> [<digest_algo>]\n"
+" Extend PCR #<pcr> with digest at <digest_addr> with digest_algo.\n"
" <pcr>: index of the PCR\n"
-" <digest_addr>: address of a 32-byte SHA256 digest\n"
-"pcr_read <pcr> <digest_addr>\n"
-" Read PCR #<pcr> to memory address <digest_addr>.\n"
+" <digest_addr>: address of digest of digest_algo type (defaults to
SHA256)\n"
+"pcr_read <pcr> <digest_addr> [<digest_algo>]\n"
+" Read PCR #<pcr> to memory address <digest_addr> with <digest_algo>.\n"
" <pcr>: index of the PCR\n"
-" <digest_addr>: address to store the a 32-byte SHA256 digest\n"
+" <digest_addr>: address of digest of digest_algo type (defaults to
SHA256)\n"
"get_capability <capability> <property> <addr> <count>\n"
" Read and display <count> entries indexed by <capability>/<property>.\n"
" Values are 4 bytes long and are written at <addr>.\n"
diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 33dd103767c4..933882fcbf97 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -965,4 +965,22 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint
vendor_cmd,
*/
u32 tpm2_auto_start(struct udevice *dev);
+/**
+ * tpm2_name_to_algorithm() - Return an algorithm id given a supported
+ * algorithm name
+ *
+ * @name: algorithm name
+ * Return: enum tpm2_algorithms or -EINVAL
+ */
+enum tpm2_algorithms tpm2_name_to_algorithm(const char *name);
+
+/**
+ * tpm2_algorithm_name() - Return an algorithm name string for a
+ * supported algorithm id
+ *
+ * @algorithm_id: algorithm defined in enum tpm2_algorithms
+ * Return: algorithm name string or ""
+ */
+const char *tpm2_algorithm_name(enum tpm2_algorithms);
+
#endif /* __TPM_V2_H */
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 68eaaa639f89..19b2535682e1 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -29,6 +29,13 @@ const enum tpm2_algorithms tpm2_supported_algorithms[4] = {
TPM2_ALG_SHA512,
};
+const char *tpm2_supported_algorithm_names[4] = {
+ "sha1",
+ "sha256",
+ "sha384",
+ "sha512",
+};
+
int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks)
{
u32 supported = 0;
@@ -1555,3 +1562,30 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint
vendor_cmd,
return 0;
}
+
+enum tpm2_algorithms tpm2_name_to_algorithm(const char *name)
+{
+ enum tpm2_algorithms algo;
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
+ algo = tpm2_supported_algorithms[i];
+ if (!strcasecmp(name, tpm2_supported_algorithm_names[i]))
+ return algo;
+ }
+ printf("%s: unsupported algorithm %s\n", __func__, name);
+
+ return -EINVAL;
+}
+
+const char *tpm2_algorithm_name(enum tpm2_algorithms algo)
+{
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
+ if (tpm2_supported_algorithms[i] == algo)
+ return tpm2_supported_algorithm_names[i];
+ }
+
+ return "";
+}
--
2.25.1
