grub/grub-core/loader/i386/verity-hash.h
Matthew Garrett e5ee3e8fa5 Add verity hash passthrough
Read the verity hash from the kernel binary and pass it to the running
system via the kernel command line
2015-06-23 13:15:53 -07:00

25 lines
746 B
C

#define VERITY_ARG " verity.usrhash="
#define VERITY_HASH_OFFSET 0x40
#define VERITY_HASH_LENGTH 64
static inline void grub_pass_verity_hash(struct linux_kernel_header *lh,
char *cmdline)
{
char *buf = (char *)lh;
grub_size_t cmdline_len;
int i;
for (i=VERITY_HASH_OFFSET; i<VERITY_HASH_OFFSET + VERITY_HASH_LENGTH; i++)
{
if (buf[i] < '0' || buf[i] > '9') // Not a number
if (buf[i] < 'a' || buf[i] > 'f') // Not a hex letter
return;
}
grub_memcpy (cmdline + grub_strlen(cmdline), VERITY_ARG,
sizeof (VERITY_ARG));
cmdline_len = grub_strlen(cmdline);
grub_memcpy (cmdline + cmdline_len, buf + VERITY_HASH_OFFSET,
VERITY_HASH_LENGTH);
cmdline[cmdline_len + VERITY_HASH_LENGTH] = '\0';
}