diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c
index c245440f9d330ebb348c21f32f80be0487fc11cd..38add4f4622c46946dbf313159dac877715dffd3 100644
--- a/cmd/tpm-v2.c
+++ b/cmd/tpm-v2.c
@@ -264,6 +264,43 @@ static int do_tpm_change_auth(cmd_tbl_t *cmdtp, int flag, int argc,
oldpw, oldpw_sz));
}
+static int do_tpm_pcr_setauthpolicy(cmd_tbl_t *cmdtp, int flag, int argc,
+ char * const argv[])
+{
+ u32 index = simple_strtoul(argv[1], NULL, 0);
+ char *key = argv[2];
+ const char *pw = (argc < 4) ? NULL : argv[3];
+ const ssize_t pw_sz = pw ? strlen(pw) : 0;
+
+ if (strlen(key) != TPM2_DIGEST_LEN)
+ return -EINVAL;
+
+ if (argc < 3 || argc > 4)
+ return CMD_RET_USAGE;
+
+ return report_return_code(tpm2_pcr_setauthpolicy(pw, pw_sz, index,
+ key));
+}
+
+static int do_tpm_pcr_setauthvalue(cmd_tbl_t *cmdtp, int flag,
+ int argc, char * const argv[])
+{
+ u32 index = simple_strtoul(argv[1], NULL, 0);
+ char *key = argv[2];
+ const ssize_t key_sz = strlen(key);
+ const char *pw = (argc < 4) ? NULL : argv[3];
+ const ssize_t pw_sz = pw ? strlen(pw) : 0;
+
+ if (strlen(key) != TPM2_DIGEST_LEN)
+ return -EINVAL;
+
+ if (argc < 3 || argc > 4)
+ return CMD_RET_USAGE;
+
+ return report_return_code(tpm2_pcr_setauthvalue(pw, pw_sz, index,
+ key, key_sz));
+}
+
static cmd_tbl_t tpm2_commands[] = {
U_BOOT_CMD_MKENT(info, 0, 1, do_tpm_info, "", ""),
U_BOOT_CMD_MKENT(init, 0, 1, do_tpm_init, "", ""),
@@ -276,6 +313,10 @@ static cmd_tbl_t tpm2_commands[] = {
U_BOOT_CMD_MKENT(dam_reset, 0, 1, do_tpm_dam_reset, "", ""),
U_BOOT_CMD_MKENT(dam_parameters, 0, 1, do_tpm_dam_parameters, "", ""),
U_BOOT_CMD_MKENT(change_auth, 0, 1, do_tpm_change_auth, "", ""),
+ U_BOOT_CMD_MKENT(pcr_setauthpolicy, 0, 1,
+ do_tpm_pcr_setauthpolicy, "", ""),
+ U_BOOT_CMD_MKENT(pcr_setauthvalue, 0, 1,
+ do_tpm_pcr_setauthvalue, "", ""),
};
cmd_tbl_t *get_tpm_commands(unsigned int *size)
@@ -338,4 +379,11 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm, "Issue a TPMv2.x command",
" <hierarchy>: the hierarchy\n"
" <new_pw>: new password for <hierarchy>\n"
" <old_pw>: optional previous password of <hierarchy>\n"
+"pcr_setauthpolicy|pcr_setauthvalue <pcr> <key> [<password>]\n"
+" Change the <key> to access PCR #<pcr>.\n"
+" hierarchy and may be empty.\n"
+" /!\\WARNING: untested function, use at your own risks !\n"
+" <pcr>: index of the PCR\n"
+" <key>: secret to protect the access of PCR #<pcr>\n"
+" <password>: optional password of the PLATFORM hierarchy\n"
);
diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index be1aa2c705bbb3716ddad75582139e7c33df9d82..780e0619750cef4c6c8ea6c2144b2de9196b1e3b 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -80,11 +80,13 @@ enum tpm2_command_codes {
TPM2_CC_CLEAR = 0x0126,
TPM2_CC_CLEARCONTROL = 0x0127,
TPM2_CC_HIERCHANGEAUTH = 0x0129,
+ TPM2_CC_PCR_SETAUTHPOL = 0x012C,
TPM2_CC_DAM_RESET = 0x0139,
TPM2_CC_DAM_PARAMETERS = 0x013A,
TPM2_CC_GET_CAPABILITY = 0x017A,
TPM2_CC_PCR_READ = 0x017E,
TPM2_CC_PCR_EXTEND = 0x0182,
+ TPM2_CC_PCR_SETAUTHVAL = 0x0183,
};
/**
@@ -230,4 +232,31 @@ u32 tpm2_dam_parameters(const char *pw, const ssize_t pw_sz,
int tpm2_change_auth(u32 handle, const char *newpw, const ssize_t newpw_sz,
const char *oldpw, const ssize_t oldpw_sz);
+/**
+ * Issue a TPM_PCR_SetAuthPolicy command.
+ *
+ * @pw Platform password
+ * @pw_sz Length of the password
+ * @index Index of the PCR
+ * @digest New key to access the PCR
+ *
+ * @return code of the operation
+ */
+u32 tpm2_pcr_setauthpolicy(const char *pw, const ssize_t pw_sz, u32 index,
+ const char *key);
+
+/**
+ * Issue a TPM_PCR_SetAuthValue command.
+ *
+ * @pw Platform password
+ * @pw_sz Length of the password
+ * @index Index of the PCR
+ * @digest New key to access the PCR
+ * @key_sz Length of the new key
+ *
+ * @return code of the operation
+ */
+u32 tpm2_pcr_setauthvalue(const char *pw, const ssize_t pw_sz, u32 index,
+ const char *key, const ssize_t key_sz);
+
#endif /* __TPM_V2_H */
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index ffe8613edc349ca1c41bff3c9b226caae244135f..f1bbca8e7aa51e06806fa5914404605d64bc0d8f 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -317,3 +317,103 @@ int tpm2_change_auth(u32 handle, const char *newpw, const ssize_t newpw_sz,
return tpm_sendrecv_command(command_v2, NULL, NULL);
}
+
+u32 tpm2_pcr_setauthpolicy(const char *pw, const ssize_t pw_sz, u32 index,
+ const char *key)
+{
+ u8 command_v2[COMMAND_BUFFER_SIZE] = {
+ tpm_u16(TPM2_ST_SESSIONS), /* TAG */
+ tpm_u32(35 + pw_sz + TPM2_DIGEST_LEN), /* Length */
+ tpm_u32(TPM2_CC_PCR_SETAUTHPOL), /* Command code */
+
+ /* HANDLE */
+ tpm_u32(TPM2_RH_PLATFORM), /* TPM resource handle */
+
+ /* AUTH_SESSION */
+ tpm_u32(9 + pw_sz), /* Authorization size */
+ tpm_u32(TPM2_RS_PW), /* session handle */
+ tpm_u16(0), /* Size of <nonce> */
+ /* <nonce> (if any) */
+ 0, /* Attributes: Cont/Excl/Rst */
+ tpm_u16(pw_sz) /* Size of <hmac/password> */
+ /* STRING(pw) <hmac/password> (if any) */
+
+ /* TPM2B_AUTH (TPM2B_DIGEST) */
+ /* tpm_u16(TPM2_DIGEST_LEN) Digest size length */
+ /* STRING(key) Digest buffer (PCR key) */
+
+ /* TPMI_ALG_HASH */
+ /* tpm_u16(TPM2_ALG_SHA256) Algorithm of the hash */
+
+ /* TPMI_DH_PCR */
+ /* tpm_u32(index), PCR Index */
+ };
+ unsigned int offset = 27;
+ int ret;
+
+ /*
+ * Fill the command structure starting from the first buffer:
+ * - the password (if any)
+ * - the PCR key length
+ * - the PCR key
+ * - the hash algorithm
+ * - the PCR index
+ */
+ ret = pack_byte_string(command_v2, sizeof(command_v2), "swswd",
+ offset, pw, pw_sz,
+ offset + pw_sz, TPM2_DIGEST_LEN,
+ offset + pw_sz + 2, key, TPM2_DIGEST_LEN,
+ offset + pw_sz + 2 + TPM2_DIGEST_LEN,
+ TPM2_ALG_SHA256,
+ offset + pw_sz + 4 + TPM2_DIGEST_LEN, index);
+ offset += pw_sz + 2 + TPM2_DIGEST_LEN + 2 + 4;
+ if (ret)
+ return TPM_LIB_ERROR;
+
+ return tpm_sendrecv_command(command_v2, NULL, NULL);
+}
+
+u32 tpm2_pcr_setauthvalue(const char *pw, const ssize_t pw_sz, u32 index,
+ const char *key, const ssize_t key_sz)
+{
+ u8 command_v2[COMMAND_BUFFER_SIZE] = {
+ tpm_u16(TPM2_ST_SESSIONS), /* TAG */
+ tpm_u32(33 + pw_sz + TPM2_DIGEST_LEN), /* Length */
+ tpm_u32(TPM2_CC_PCR_SETAUTHVAL), /* Command code */
+
+ /* HANDLE */
+ tpm_u32(index), /* Handle (PCR Index) */
+
+ /* AUTH_SESSION */
+ tpm_u32(9 + pw_sz), /* Authorization size */
+ tpm_u32(TPM2_RS_PW), /* session handle */
+ tpm_u16(0), /* Size of <nonce> */
+ /* <nonce> (if any) */
+ 0, /* Attributes: Cont/Excl/Rst */
+ tpm_u16(pw_sz), /* Size of <hmac/password> */
+ /* STRING(pw) <hmac/password> (if any) */
+
+ /* TPM2B_DIGEST */
+ /* tpm_u16(key_sz) Key length */
+ /* STRING(key) Key */
+ };
+ unsigned int offset = 27;
+ int ret;
+
+ /*
+ * Fill the command structure starting from the first buffer:
+ * - the password (if any)
+ * - the number of digests, 1 in our case
+ * - the algorithm, sha256 in our case
+ * - the digest (64 bytes)
+ */
+ ret = pack_byte_string(command_v2, sizeof(command_v2), "sws",
+ offset, pw, pw_sz,
+ offset + pw_sz, key_sz,
+ offset + pw_sz + 2, key, key_sz);
+ offset += pw_sz + 2 + key_sz;
+ if (ret)
+ return TPM_LIB_ERROR;
+
+ return tpm_sendrecv_command(command_v2, NULL, NULL);
+}