[PATCH v3] tpm-v2: allow algoirthm name to be configured for pcr_read and pcr_extend
Tim Harvey
tharvey at gateworks.com
Fri Apr 5 02:17:22 CEST 2024
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 <tharvey at gateworks.com>
---
v3:
- replace tpm2_supported_algorithms with struct and use this to relate hash algoirthm
details
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 | 67 ++++++++++++++++++++++++++++++++++++++-
lib/efi_loader/efi_tcg2.c | 4 +--
lib/tpm-v2.c | 62 +++++++++++++++++++++++-------------
4 files changed, 143 insertions(+), 39 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..263f9529e55d 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -386,7 +386,54 @@ enum tpm2_algorithms {
TPM2_ALG_SM3_256 = 0x12,
};
-extern const enum tpm2_algorithms tpm2_supported_algorithms[4];
+/**
+ * struct digest_info - details of supported digests
+ *
+ * @hash_name: hash name
+ * @hash_alg: hash algorithm id
+ * @hash_mask: hash registry mask
+ * @hash_len: hash digest length
+ */
+struct digest_info {
+ const char *hash_name;
+ u16 hash_alg;
+ u32 hash_mask;
+ u16 hash_len;
+};
+
+/* Algorithm Registry */
+#define TCG2_BOOT_HASH_ALG_SHA1 0x00000001
+#define TCG2_BOOT_HASH_ALG_SHA256 0x00000002
+#define TCG2_BOOT_HASH_ALG_SHA384 0x00000004
+#define TCG2_BOOT_HASH_ALG_SHA512 0x00000008
+#define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
+
+static const struct digest_info hash_algo_list[] = {
+ {
+ "sha1",
+ TPM2_ALG_SHA1,
+ TCG2_BOOT_HASH_ALG_SHA1,
+ TPM2_SHA1_DIGEST_SIZE,
+ },
+ {
+ "sha256",
+ TPM2_ALG_SHA256,
+ TCG2_BOOT_HASH_ALG_SHA256,
+ TPM2_SHA256_DIGEST_SIZE,
+ },
+ {
+ "sha384",
+ TPM2_ALG_SHA384,
+ TCG2_BOOT_HASH_ALG_SHA384,
+ TPM2_SHA384_DIGEST_SIZE,
+ },
+ {
+ "sha512",
+ TPM2_ALG_SHA512,
+ TCG2_BOOT_HASH_ALG_SHA512,
+ TPM2_SHA512_DIGEST_SIZE,
+ },
+};
static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a)
{
@@ -965,4 +1012,22 @@ 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/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index b07e0099c27e..cf5d8de018a7 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -414,8 +414,8 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
}
digest_list->count = 0;
- for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); i++) {
- u16 hash_alg = tpm2_supported_algorithms[i];
+ for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
+ u16 hash_alg = hash_algo_list[i].hash_alg;
if (!(active & tpm2_algorithm_to_mask(hash_alg)))
continue;
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 68eaaa639f89..83f490c82541 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -22,13 +22,6 @@
#include "tpm-utils.h"
-const enum tpm2_algorithms tpm2_supported_algorithms[4] = {
- TPM2_ALG_SHA1,
- TPM2_ALG_SHA256,
- TPM2_ALG_SHA384,
- TPM2_ALG_SHA512,
-};
-
int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks)
{
u32 supported = 0;
@@ -82,14 +75,14 @@ int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
return rc;
digest_list->count = 0;
- for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
+ for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
u32 mask =
- tpm2_algorithm_to_mask(tpm2_supported_algorithms[i]);
+ tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg);
if (!(active & mask))
continue;
- switch (tpm2_supported_algorithms[i]) {
+ switch (hash_algo_list[i].hash_alg) {
case TPM2_ALG_SHA1:
sha1_starts(&ctx);
sha1_update(&ctx, input, length);
@@ -116,12 +109,12 @@ int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
break;
default:
printf("%s: unsupported algorithm %x\n", __func__,
- tpm2_supported_algorithms[i]);
+ hash_algo_list[i].hash_alg);
continue;
}
digest_list->digests[digest_list->count].hash_alg =
- tpm2_supported_algorithms[i];
+ hash_algo_list[i].hash_alg;
memcpy(&digest_list->digests[digest_list->count].digest, final,
len);
digest_list->count++;
@@ -208,13 +201,13 @@ static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog)
return rc;
event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes);
- for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
- mask = tpm2_algorithm_to_mask(tpm2_supported_algorithms[i]);
+ for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+ mask = tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg);
if (!(active & mask))
continue;
- switch (tpm2_supported_algorithms[i]) {
+ switch (hash_algo_list[i].hash_alg) {
case TPM2_ALG_SHA1:
case TPM2_ALG_SHA256:
case TPM2_ALG_SHA384:
@@ -253,17 +246,17 @@ static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog)
put_unaligned_le32(count, &ev->number_of_algorithms);
count = 0;
- for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
- mask = tpm2_algorithm_to_mask(tpm2_supported_algorithms[i]);
+ for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+ mask = tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg);
if (!(active & mask))
continue;
- len = tpm2_algorithm_to_len(tpm2_supported_algorithms[i]);
+ len = hash_algo_list[i].hash_len;
if (!len)
continue;
- put_unaligned_le16(tpm2_supported_algorithms[i],
+ put_unaligned_le16(hash_algo_list[i].hash_alg,
&ev->digest_sizes[count].algorithm_id);
put_unaligned_le16(len, &ev->digest_sizes[count].digest_size);
count++;
@@ -304,7 +297,7 @@ static int tcg2_replay_eventlog(struct tcg2_event_log *elog,
pos = offsetof(struct tcg_pcr_event2, digests) +
offsetof(struct tpml_digest_values, count);
count = get_unaligned_le32(log + pos);
- if (count > ARRAY_SIZE(tpm2_supported_algorithms) ||
+ if (count > ARRAY_SIZE(hash_algo_list) ||
(digest_list->count && digest_list->count != count))
return 0;
@@ -407,7 +400,7 @@ static int tcg2_log_parse(struct udevice *dev, struct tcg2_event_log *elog)
return 0;
count = get_unaligned_le32(&event->number_of_algorithms);
- if (count > ARRAY_SIZE(tpm2_supported_algorithms))
+ if (count > ARRAY_SIZE(hash_algo_list))
return 0;
calc_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
@@ -1110,7 +1103,7 @@ int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr,
* We only support 5 algorithms for now so check against that
* instead of TPM2_NUM_PCR_BANKS
*/
- if (pcrs.count > ARRAY_SIZE(tpm2_supported_algorithms) ||
+ if (pcrs.count > ARRAY_SIZE(hash_algo_list) ||
pcrs.count < 1) {
printf("%s: too many pcrs: %u\n", __func__, pcrs.count);
return -EMSGSIZE;
@@ -1555,3 +1548,28 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd,
return 0;
}
+
+enum tpm2_algorithms tpm2_name_to_algorithm(const char *name)
+{
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
+ if (!strcasecmp(name, hash_algo_list[i].hash_name))
+ return hash_algo_list[i].hash_alg;
+ }
+ 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(hash_algo_list); ++i) {
+ if (hash_algo_list[i].hash_alg == algo)
+ return hash_algo_list[i].hash_name;
+ }
+
+ return "";
+}
--
2.25.1
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