vbatts/grub
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Add verity hash passthrough

Browse source 
Read the verity hash from the kernel binary and pass it to the running
system via the kernel command line
This commit is contained in:
Matthew Garrett 2015-05-28 11:15:30 -07:00
parent 2755ecd157
commit e5ee3e8fa5
3 changed files with 30 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

25
grub-core/loader/i386/verity-hash.h Normal file
View file

@ -0,0 +1,25 @@
#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';
}