tpm: Add an implementation of define_space

Add support for this so that the TPM can be set up for use with
Chromium OS verified boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 56eaa65..aa8b651 100644 (file)
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -240,6 +240,7 @@ enum tpm2_command_codes {
        TPM2_CC_CLEAR           = 0x0126,
        TPM2_CC_CLEARCONTROL    = 0x0127,
        TPM2_CC_HIERCHANGEAUTH  = 0x0129,
+       TPM2_CC_NV_DEFINE_SPACE = 0x012a,
        TPM2_CC_PCR_SETAUTHPOL  = 0x012C,
        TPM2_CC_DAM_RESET       = 0x0139,
        TPM2_CC_DAM_PARAMETERS  = 0x013A,
@@ -389,6 +390,23 @@ u32 tpm2_clear(struct udevice *dev, u32 handle, const char *pw,
               const ssize_t pw_sz);
 
 /**
+ * Issue a TPM_NV_DefineSpace command
+ *
+ * This allows a space to be defined with given attributes and policy
+ *
+ * @dev                        TPM device
+ * @space_index                index of the area
+ * @space_size         size of area in bytes
+ * @nv_attributes      TPM_NV_ATTRIBUTES of the area
+ * @nv_policy          policy to use
+ * @nv_policy_size     size of the policy
+ * @return return code of the operation
+ */
+u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
+                        size_t space_size, u32 nv_attributes,
+                        const u8 *nv_policy, size_t nv_policy_size);
+
+/**
  * Issue a TPM2_PCR_Extend command.
  *
  * @dev                TPM device

diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index c4e869e..e9bf401 100644 (file)
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -81,6 +81,53 @@ u32 tpm2_clear(struct udevice *dev, u32 handle, const char *pw,
        return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
 }
 
+u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
+                        size_t space_size, u32 nv_attributes,
+                        const u8 *nv_policy, size_t nv_policy_size)
+{
+       /*
+        * Calculate the offset of the nv_policy piece by adding each of the
+        * chunks below.
+        */
+       uint offset = 10 + 8 + 13 + 14;
+       u8 command_v2[COMMAND_BUFFER_SIZE] = {
+               /* header 10 bytes */
+               tpm_u16(TPM2_ST_SESSIONS),      /* TAG */
+               tpm_u32(offset + nv_policy_size),/* Length */
+               tpm_u32(TPM2_CC_NV_DEFINE_SPACE),/* Command code */
+
+               /* handles 8 bytes */
+               tpm_u32(TPM2_RH_PLATFORM),      /* Primary platform seed */
+
+               /* session header 13 bytes */
+               tpm_u32(9),                     /* Header size */
+               tpm_u32(TPM2_RS_PW),            /* Password authorisation */
+               tpm_u16(0),                     /* nonce_size */
+               0,                              /* session_attrs */
+               tpm_u16(0),                     /* auth_size */
+
+               /* message 14 bytes + policy */
+               tpm_u16(12 + nv_policy_size),   /* size */
+               tpm_u32(space_index),
+               tpm_u16(TPM2_ALG_SHA256),
+               tpm_u32(nv_attributes),
+               tpm_u16(nv_policy_size),
+               /* nv_policy */
+       };
+       int ret;
+
+       /*
+        * Fill the command structure starting from the first buffer:
+        *     - the password (if any)
+        */
+       ret = pack_byte_string(command_v2, sizeof(command_v2), "s",
+                              offset, nv_policy, nv_policy_size);
+       if (ret)
+               return TPM_LIB_ERROR;
+
+       return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+}
+
 u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
                    const u8 *digest, u32 digest_len)
 {