diff options
Diffstat (limited to 'firmware/2lib/include/2api.h')
| -rw-r--r-- | firmware/2lib/include/2api.h | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/firmware/2lib/include/2api.h b/firmware/2lib/include/2api.h index 03e49fe0..869d2361 100644 --- a/firmware/2lib/include/2api.h +++ b/firmware/2lib/include/2api.h @@ -150,19 +150,37 @@ enum vb2_pcr_digest { * Verify the hash of each section of code/data you need to boot the RW * firmware. For each section: * - * Call vb2_init_hash() to see if the hash exists. + * 1) Normal verification: * - * Load the data for the section. Call vb2_extend_hash() on the + * Call vb2api_init_hash() to see if the hash exists. + * + * Load the data for the section. Call vb2api_extend_hash() on the * data as you load it. You can load it all at once and make one * call, or load and hash-extend a block at a time. * - * Call vb2_check_hash() to see if the hash is valid. + * Call vb2api_check_hash() to see if the hash is valid. * * If it is valid, you may use the data and/or execute * code from that section. * * If the hash was invalid, you must reboot. * + * 2) Verification with CBFS integration: + * + * Call vb2api_get_metadata_hash() to get hash of CBFS metadata. + * + * Initialize CBFS using stored hash as correct metadata hash. + * + * If CBFS initialization fails because of metadata hash + * mismatch, you must reboot. + * + * If CBFS initialization succeeds, you may use the data + * and/or execute code from that section. + * IMPORTANT: Be aware, that to have full section + * verification, the CBFS_VERIFICATION has to be enabled. + * Initialization of CBFS volume only checks hash of files + * metadata, not their contents! + * * At this point, firmware verification is done, and vb2_context contains the * kernel key needed to verify the kernel. That context should be preserved * and passed on to kernel selection. The kernel selection process may be @@ -442,6 +460,9 @@ vb2_error_t vb2api_fw_phase3(struct vb2_context *ctx); /** * Initialize hashing data for the specified tag. + * This function is not legal when running from a coreboot image that has + * CONFIG_VBOOT_CBFS_INTEGRATION=y set. In that case, vb2api_get_metadata_hash() + * must be used instead. * * @param ctx Vboot context * @param tag Tag to start hashing (enum vb2_hash_tag) @@ -484,6 +505,23 @@ vb2_error_t vb2api_check_hash_get_digest(struct vb2_context *ctx, uint32_t digest_out_size); /** + * Get pointer to metadata hash from body signature in preamble. + * Body signature data size has to be zero to indicate that it contains + * metadata hash. This is only legal to call after vb2api_fw_phase3() has + * returned successfully, and will return with error otherwise. + * This function is only legal to call from coreboot with + * CONFIG_VBOOT_CBFS_INTEGRATION=y. `futility sign` will automatically detect + * the presence of that option in an image and prepare the correct kind + * of signature. + * + * @param ctx Vboot context + * @param hash_ptr_out pointer to output hash to + * @return VB2_SUCCESS, or error code on error. + */ +vb2_error_t vb2api_get_metadata_hash(struct vb2_context *ctx, + struct vb2_hash **hash_ptr_out); + +/** * Get a PCR digest * * @param ctx Vboot context @@ -726,6 +764,8 @@ vb2_gbb_flags_t vb2api_gbb_get_flags(struct vb2_context *ctx); /** * Get the size of the signed firmware body. This is only legal to call after * vb2api_fw_phase3() has returned successfully, and will return 0 otherwise. + * It will also return 0 when body signature contains metadata hash instead + * of body hash. * * @param ctx Vboot context * |