[PATCH] tpm-v2: allow algo name to be conigured for pcr_read and pcr_extend
Tim Harvey
tharvey at gateworks.com
Wed Mar 27 23:37:04 CET 2024
For pcr_read and pcr_extend commands allow the digest algo 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 <tharvey at gateworks.com>
---
cmd/tpm-v2.c | 51 +++++++++++++++++++++++++++++++++++-------------
include/tpm-v2.h | 17 ++++++++++++++++
lib/tpm-v2.c | 46 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 100 insertions(+), 14 deletions(-)
diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c
index 7e479b9dfe36..52d232c3ea7d 100644
--- a/cmd/tpm-v2.c
+++ b/cmd/tpm-v2.c
@@ -99,11 +99,20 @@ 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_len = TPM2_SHA256_DIGEST_SIZE;
+ int algo = TPM2_ALG_SHA256;
int ret;
u32 rc;
- if (argc != 3)
+ if (argc < 3 || argc > 4)
return CMD_RET_USAGE;
+ if (argc == 4) {
+ algo = tpm2_algo_len(argv[3], &algo_len);
+ if (algo < 0) {
+ printf("Error: invalid algo\n");
+ return CMD_RET_USAGE;
+ }
+ }
ret = get_tpm(&dev);
if (ret)
@@ -116,8 +125,12 @@ 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_algo_name(algo));
+ print_byte_string(digest, algo_len);
+ }
unmap_sysmem(digest);
@@ -127,6 +140,8 @@ 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[])
{
+ int algo_len = TPM2_SHA256_DIGEST_SIZE;
+ int algo = TPM2_ALG_SHA256;
struct udevice *dev;
struct tpm_chip_priv *priv;
u32 index, rc;
@@ -134,8 +149,15 @@ static int do_tpm_pcr_read(struct cmd_tbl *cmdtp, int flag, int argc,
void *data;
int ret;
- if (argc != 3)
+ if (argc < 3 || argc > 4)
return CMD_RET_USAGE;
+ if (argc == 4) {
+ algo = tpm2_algo_len(argv[3], &algo_len);
+ if (algo < 0) {
+ printf("Error: invalid algo\n");
+ return CMD_RET_USAGE;
+ }
+ }
ret = get_tpm(&dev);
if (ret)
@@ -151,11 +173,12 @@ 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_algo_name(algo), algo_len, updates);
+ print_byte_string(data, algo_len);
}
unmap_sysmem(data);
@@ -415,14 +438,14 @@ 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..07d3ca5e6c83 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -965,4 +965,21 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd,
*/
u32 tpm2_auto_start(struct udevice *dev);
+/**
+ * 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;
+}
+
+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
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