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Re: [PATCH] verify: search keyid in hashed signature subpackets
From: |
Ignat Korchagin |
Subject: |
Re: [PATCH] verify: search keyid in hashed signature subpackets |
Date: |
Thu, 28 Apr 2016 22:32:13 +0100 |
Is this going to 2.02? I think it should, because it is a bug.
On Thu, Apr 21, 2016 at 5:54 PM, Ignat Korchagin <address@hidden> wrote:
> Best of both worlds: I left the READBUF_SIZE as is for the rest of the code,
> but rather reallocate the buffer with appropriate length for subpackets
> specifically. Hashing is outside of the keyid search function, so the name is
> good this time.
>
> Still did not get your response about PGP private test key. If it is not
> available, I can regenerate it and resign all test files for future use.
>
> diff --git a/grub-core/commands/verify.c b/grub-core/commands/verify.c
> index 4268eaa..91e1da6 100644
> --- a/grub-core/commands/verify.c
> +++ b/grub-core/commands/verify.c
> @@ -445,6 +445,38 @@
> return ret;
> }
>
> +static grub_uint64_t
> +grub_subpacket_keyid_search (const grub_uint8_t * sub, grub_ssize_t sub_len)
> +{
> + const grub_uint8_t *ptr;
> + grub_uint32_t l;
> + grub_uint64_t keyid = 0;
> +
> + for (ptr = sub; ptr < sub + sub_len; ptr += l)
> + {
> + if (*ptr < 192)
> + l = *ptr++;
> + else if (*ptr < 255)
> + {
> + if (ptr + 1 >= sub + sub_len)
> + break;
> + l = (((ptr[0] & ~192) << GRUB_CHAR_BIT) | ptr[1]) + 192;
> + ptr += 2;
> + }
> + else
> + {
> + if (ptr + 5 >= sub + sub_len)
> + break;
> + l = grub_be_to_cpu32 (grub_get_unaligned32 (ptr + 1));
> + ptr += 5;
> + }
> + if (*ptr == 0x10 && l >= 8)
> + keyid = grub_get_unaligned64 (ptr + 1);
> + }
> +
> + return keyid;
> +}
> +
> static grub_err_t
> grub_verify_signature_real (char *buf, grub_size_t size,
> grub_file_t f, grub_file_t sig,
> @@ -529,20 +561,31 @@
> break;
> hash->write (context, readbuf, r);
> }
> + grub_free (readbuf);
> +
> + readbuf = grub_malloc (rem);
> + if (!readbuf)
> + goto fail;
>
> hash->write (context, &v, sizeof (v));
> hash->write (context, &v4, sizeof (v4));
> - while (rem)
> +
> + r = 0;
> + while (r < rem)
> {
> - r = grub_file_read (sig, readbuf,
> - rem < READBUF_SIZE ? rem : READBUF_SIZE);
> - if (r < 0)
> + grub_ssize_t rr = grub_file_read (sig, readbuf + r, rem - r);
> + if (rr < 0)
> goto fail;
> - if (r == 0)
> + if (rr == 0)
> break;
> - hash->write (context, readbuf, r);
> - rem -= r;
> + r += rr;
> }
> + if (r != rem)
> + goto fail;
> + hash->write (context, readbuf, rem);
> + keyid = grub_subpacket_keyid_search (readbuf, rem);
> + grub_free (readbuf);
> +
> hash->write (context, &v, sizeof (v));
> s = 0xff;
> hash->write (context, &s, sizeof (s));
> @@ -550,40 +593,34 @@
> r = grub_file_read (sig, &unhashed_sub, sizeof (unhashed_sub));
> if (r != sizeof (unhashed_sub))
> goto fail;
> - {
> - grub_uint8_t *ptr;
> - grub_uint32_t l;
> - rem = grub_be_to_cpu16 (unhashed_sub);
> - if (rem > READBUF_SIZE)
> - goto fail;
> - r = grub_file_read (sig, readbuf, rem);
> - if (r != rem)
> - goto fail;
> - for (ptr = readbuf; ptr < readbuf + rem; ptr += l)
> - {
> - if (*ptr < 192)
> - l = *ptr++;
> - else if (*ptr < 255)
> - {
> - if (ptr + 1 >= readbuf + rem)
> - break;
> - l = (((ptr[0] & ~192) << GRUB_CHAR_BIT) | ptr[1]) + 192;
> - ptr += 2;
> - }
> - else
> - {
> - if (ptr + 5 >= readbuf + rem)
> - break;
> - l = grub_be_to_cpu32 (grub_get_unaligned32 (ptr + 1));
> - ptr += 5;
> - }
> - if (*ptr == 0x10 && l >= 8)
> - keyid = grub_get_unaligned64 (ptr + 1);
> - }
> - }
> + rem = grub_be_to_cpu16 (unhashed_sub);
> + readbuf = grub_malloc (rem);
> + if (!readbuf)
> + goto fail;
> +
> + r = 0;
> + while (r < rem)
> + {
> + grub_ssize_t rr = grub_file_read (sig, readbuf + r, rem - r);
> + if (rr < 0)
> + goto fail;
> + if (rr == 0)
> + break;
> + r += rr;
> + }
> + if (r != rem)
> + goto fail;
> +
> + if (keyid == 0)
> + keyid = grub_subpacket_keyid_search (readbuf, rem);
> + grub_free (readbuf);
>
> hash->final (context);
>
> + readbuf = grub_zalloc (READBUF_SIZE);
> + if (!readbuf)
> + goto fail;
> +
> grub_dprintf ("crypt", "alive\n");
>
> hval = hash->read (context);
>