Add support for the TPM2_PCR_Extend command.
Change the command file and the help accordingly.
Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com --- cmd/tpm-v2.c | 17 +++++++++++++++++ include/tpm-v2.h | 10 ++++++++++ lib/tpm-v2.c | 38 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 65 insertions(+)
diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c index 9f6a8fc0b6..6e19adbfe6 100644 --- a/cmd/tpm-v2.c +++ b/cmd/tpm-v2.c @@ -74,12 +74,25 @@ static int do_tpm2_clear(cmd_tbl_t *cmdtp, int flag, int argc, return report_return_code(tpm2_clear(handle, pw, pw_sz)); }
+static int do_tpm2_pcr_extend(cmd_tbl_t *cmdtp, int flag, int argc, + char * const argv[]) +{ + u32 index = simple_strtoul(argv[1], NULL, 0); + void *digest = (void *)simple_strtoul(argv[2], NULL, 0); + + if (argc != 3) + return CMD_RET_USAGE; + + return report_return_code(tpm2_pcr_extend(index, digest)); +} + 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, "", ""), U_BOOT_CMD_MKENT(startup, 0, 1, do_tpm2_startup, "", ""), U_BOOT_CMD_MKENT(self_test, 0, 1, do_tpm2_self_test, "", ""), U_BOOT_CMD_MKENT(clear, 0, 1, do_tpm2_clear, "", ""), + U_BOOT_CMD_MKENT(pcr_extend, 0, 1, do_tpm2_pcr_extend, "", ""), };
cmd_tbl_t *get_tpm_commands(unsigned int *size) @@ -111,4 +124,8 @@ U_BOOT_CMD(tpm, 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>: index of the PCR\n" +" <digest_addr>: address of a 32-byte SHA256 digest\n" ); diff --git a/include/tpm-v2.h b/include/tpm-v2.h index 3aac01b2d0..94c1df77b7 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -154,4 +154,14 @@ u32 tpm2_self_test(enum tpm2_yes_no full_test); */ u32 tpm2_clear(u32 handle, const char *pw, const ssize_t pw_sz);
+/** + * Issue a TPM2_PCR_Extend command. + * + * @param index Index of the PCR + * @param digest Value representing the event to be recorded + * + * @return return code of the operation + */ +u32 tpm2_pcr_extend(u32 index, const uint8_t *digest); + #endif /* __TPM_V2_H */ diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index e3bfec5082..2696f8145d 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -77,3 +77,41 @@ u32 tpm2_clear(u32 handle, const char *pw, const ssize_t pw_sz)
return tpm_sendrecv_command(command_v2, NULL, NULL); } + +u32 tpm2_pcr_extend(u32 index, const uint8_t *digest) +{ + u8 command_v2[COMMAND_BUFFER_SIZE] = { + tpm_u16(TPM2_ST_SESSIONS), /* TAG */ + tpm_u32(33 + TPM2_DIGEST_LEN), /* Length */ + tpm_u32(TPM2_CC_PCR_EXTEND), /* Command code */ + + /* HANDLE */ + tpm_u32(index), /* Handle (PCR Index) */ + + /* AUTH_SESSION */ + tpm_u32(9), /* 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(0), /* Size of <hmac/password> */ + /* <hmac/password> (if any) */ + tpm_u32(1), /* Count (number of hashes) */ + tpm_u16(TPM2_ALG_SHA256), /* Algorithm of the hash */ + /* STRING(digest) Digest */ + }; + unsigned int offset = 33; + int ret; + + /* + * Fill the command structure starting from the first buffer: + * - the digest + */ + ret = pack_byte_string(command_v2, sizeof(command_v2), "s", + offset, digest, TPM2_DIGEST_LEN); + offset += TPM2_DIGEST_LEN; + if (ret) + return TPM_LIB_ERROR; + + return tpm_sendrecv_command(command_v2, NULL, NULL); +}