[PATCH v3 09/11] tpm: Add TPM2 support for read/write values
Ilias Apalodimas
ilias.apalodimas at linaro.org
Mon Jan 25 09:37:44 CET 2021
On Sat, Jan 23, 2021 at 10:26:05AM -0700, Simon Glass wrote:
> Implement this API function for TPM2.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> (no changes since v1)
>
> include/tpm-common.h | 3 ++
> include/tpm-v2.h | 38 ++++++++++++++++++++
> lib/tpm-v2.c | 84 ++++++++++++++++++++++++++++++++++++++++++++
> lib/tpm_api.c | 4 +--
> 4 files changed, 127 insertions(+), 2 deletions(-)
>
> diff --git a/include/tpm-common.h b/include/tpm-common.h
> index e29b10b1766..080183779b3 100644
> --- a/include/tpm-common.h
> +++ b/include/tpm-common.h
> @@ -53,6 +53,8 @@ enum tpm_version {
> * @buf: Buffer used during the exchanges with the chip
> * @pcr_count: Number of PCR per bank
> * @pcr_select_min: Minimum size in bytes of the pcrSelect array
> + * @plat_hier_disabled: Platform hierarchy has been disabled (TPM is locked
> + * down until next reboot)
> */
> struct tpm_chip_priv {
> enum tpm_version version;
> @@ -64,6 +66,7 @@ struct tpm_chip_priv {
> /* TPM v2 specific data */
> uint pcr_count;
> uint pcr_select_min;
> + bool plat_hier_disabled;
> };
>
> /**
> diff --git a/include/tpm-v2.h b/include/tpm-v2.h
> index 2766dc72a65..6a400771af1 100644
> --- a/include/tpm-v2.h
> +++ b/include/tpm-v2.h
> @@ -240,6 +240,7 @@ enum tpm2_command_codes {
> TPM2_CC_HIERCHANGEAUTH = 0x0129,
> TPM2_CC_NV_DEFINE_SPACE = 0x012a,
> TPM2_CC_PCR_SETAUTHPOL = 0x012C,
> + TPM2_CC_NV_WRITE = 0x0137,
> TPM2_CC_DAM_RESET = 0x0139,
> TPM2_CC_DAM_PARAMETERS = 0x013A,
> TPM2_CC_NV_READ = 0x014E,
> @@ -354,6 +355,20 @@ enum {
> TPM_MAX_BUF_SIZE = 1260,
> };
>
> +enum {
> + /* Secure storage for firmware settings */
> + TPM_HT_PCR = 0,
> + TPM_HT_NV_INDEX,
> + TPM_HT_HMAC_SESSION,
> + TPM_HT_POLICY_SESSION,
> +
> + HR_SHIFT = 24,
> + HR_PCR = TPM_HT_PCR << HR_SHIFT,
> + HR_HMAC_SESSION = TPM_HT_HMAC_SESSION << HR_SHIFT,
> + HR_POLICY_SESSION = TPM_HT_POLICY_SESSION << HR_SHIFT,
> + HR_NV_INDEX = TPM_HT_NV_INDEX << HR_SHIFT,
> +};
> +
> /**
> * Issue a TPM2_Startup command.
> *
> @@ -418,6 +433,29 @@ u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
> u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
> const u8 *digest, u32 digest_len);
>
> +/**
> + * Read data from the secure storage
> + *
> + * @dev TPM device
> + * @index Index of data to read
> + * @data Place to put data
> + * @count Number of bytes of data
> + * @return code of the operation
> + */
> +u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count);
> +
> +/**
> + * Write data to the secure storage
> + *
> + * @dev TPM device
> + * @index Index of data to write
> + * @data Data to write
> + * @count Number of bytes of data
> + * @return code of the operation
> + */
> +u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data,
> + u32 count);
> +
> /**
> * Issue a TPM2_PCR_Read command.
> *
> diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
> index aea1dfb6ba0..7bf43264ab0 100644
> --- a/lib/tpm-v2.c
> +++ b/lib/tpm-v2.c
> @@ -170,6 +170,90 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
> return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
> }
>
> +u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count)
> +{
> + u8 command_v2[COMMAND_BUFFER_SIZE] = {
> + /* header 10 bytes */
> + tpm_u16(TPM2_ST_SESSIONS), /* TAG */
> + tpm_u32(10 + 8 + 4 + 9 + 4), /* Length */
> + tpm_u32(TPM2_CC_NV_READ), /* Command code */
> +
> + /* handles 8 bytes */
> + tpm_u32(TPM2_RH_PLATFORM), /* Primary platform seed */
> + tpm_u32(HR_NV_INDEX + index), /* Password authorisation */
> +
> + /* 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_u16(count), /* Number of bytes */
> + tpm_u16(0), /* Offset */
> + };
> + size_t response_len = COMMAND_BUFFER_SIZE;
> + u8 response[COMMAND_BUFFER_SIZE];
> + int ret;
> + u16 tag;
> + u32 size, code;
> +
> + ret = tpm_sendrecv_command(dev, command_v2, response, &response_len);
> + if (ret)
> + return log_msg_ret("read", ret);
> + if (unpack_byte_string(response, response_len, "wdds",
> + 0, &tag, 2, &size, 6, &code,
> + 16, data, count))
> + return TPM_LIB_ERROR;
> +
> + return 0;
> +}
> +
> +u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data,
> + u32 count)
> +{
> + struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
> + uint offset = 10 + 8 + 4 + 9 + 2;
> + uint len = offset + count + 2;
> + /* Use empty password auth if platform hierarchy is disabled */
> + u32 auth = priv->plat_hier_disabled ? HR_NV_INDEX + index :
> + TPM2_RH_PLATFORM;
> + u8 command_v2[COMMAND_BUFFER_SIZE] = {
> + /* header 10 bytes */
> + tpm_u16(TPM2_ST_SESSIONS), /* TAG */
> + tpm_u32(len), /* Length */
> + tpm_u32(TPM2_CC_NV_WRITE), /* Command code */
> +
> + /* handles 8 bytes */
> + tpm_u32(auth), /* Primary platform seed */
> + tpm_u32(HR_NV_INDEX + index), /* Password authorisation */
> +
> + /* 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_u16(count),
> + };
> + size_t response_len = COMMAND_BUFFER_SIZE;
> + u8 response[COMMAND_BUFFER_SIZE];
> + int ret;
> +
> + ret = pack_byte_string(command_v2, sizeof(command_v2), "sw",
> + offset, data, count,
> + offset + count, 0);
> + if (ret)
> + return TPM_LIB_ERROR;
> +
> + return tpm_sendrecv_command(dev, command_v2, response, &response_len);
> +}
> +
> u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz,
> void *data, unsigned int *updates)
> {
> diff --git a/lib/tpm_api.c b/lib/tpm_api.c
> index f1553512cc5..687fc8bc7ee 100644
> --- a/lib/tpm_api.c
> +++ b/lib/tpm_api.c
> @@ -118,7 +118,7 @@ u32 tpm_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count)
> if (is_tpm1(dev))
> return tpm1_nv_read_value(dev, index, data, count);
> else if (is_tpm2(dev))
> - return -ENOSYS;
> + return tpm2_nv_read_value(dev, index, data, count);
> else
> return -ENOSYS;
> }
> @@ -129,7 +129,7 @@ u32 tpm_nv_write_value(struct udevice *dev, u32 index, const void *data,
> if (is_tpm1(dev))
> return tpm1_nv_write_value(dev, index, data, count);
> else if (is_tpm2(dev))
> - return -ENOSYS;
> + return tpm2_nv_write_value(dev, index, data, count);
> else
> return -ENOSYS;
> }
> --
> 2.30.0.280.ga3ce27912f-goog
>
Acked-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
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