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ecc-sos: Fix gpg-agent for SOS handling.

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* agent/cvt-openpgp.c (scan_pgp_format): New.
(do_unprotect): Fix NBITS in SOS.  Use scan_pgp_format.
(convert_from_openpgp_main): Always use opaque MPI.
Use GCRYMPI_FLAG_USER1 for encrypted data.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
This commit is contained in:
NIIBE Yutaka 2020-05-18 15:45:31 +09:00
parent 1e079f4601
commit 37aa23c55c
1 changed files with 63 additions and 25 deletions
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88
agent/cvt-openpgp.c
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@ -374,6 +374,38 @@ prepare_unprotect (int pubkey_algo, gcry_mpi_t *skey, size_t skeysize,
}
/* Scan octet string in the PGP format (length-in-two-octet octets) */
static int
scan_pgp_format (gcry_mpi_t *r_mpi, int pubkey_algo,
const unsigned char *buffer,
size_t buflen, size_t *r_nbytes)
{
/* Using gcry_mpi_scan with GCRYMPI_FLAG_PGP can be used if it is
MPI, but it will be "normalized" removing leading zeros. */
unsigned int nbits, nbytes;
if (pubkey_algo != GCRY_PK_ECC)
return gcry_mpi_scan (r_mpi, GCRYMPI_FMT_PGP, buffer, buflen, r_nbytes);
/* It's ECC, where we use "simply, octet string" */
if (buflen < 2)
return GPG_ERR_INV_OBJ;
nbits = (buffer[0] << 8) | buffer[1];
if (nbits >= 16384)
return GPG_ERR_INV_OBJ;
nbytes = (nbits + 7) / 8;
if (buflen < nbytes + 2)
return GPG_ERR_INV_OBJ;
*r_nbytes = nbytes + 2;
*r_mpi = gcry_mpi_set_opaque_copy (NULL, buffer+2, nbits);
return 0;
}
/* Note that this function modifies SKEY. SKEYSIZE is the allocated
size of the array including the NULL item; this is used for a
bounds check. On success a converted key is stored at R_KEY. */
@ -407,29 +439,42 @@ do_unprotect (const char *passphrase,
actual_csum = 0;
for (i=npkey; i < nskey; i++)
{
unsigned char *buffer;
if (!skey[i] || gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_USER1))
return gpg_error (GPG_ERR_BAD_SECKEY);
if (gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_OPAQUE))
{
unsigned int nbits;
const unsigned char *buffer;
buffer = gcry_mpi_get_opaque (skey[i], &nbits);
nbytes = (nbits+7)/8;
nbits = nbytes * 8;
if (nbits >= 8 && !(*buffer & 0x80))
if (--nbits >= 7 && !(*buffer & 0x40))
if (--nbits >= 6 && !(*buffer & 0x20))
if (--nbits >= 5 && !(*buffer & 0x10))
if (--nbits >= 4 && !(*buffer & 0x08))
if (--nbits >= 3 && !(*buffer & 0x04))
if (--nbits >= 2 && !(*buffer & 0x02))
if (--nbits >= 1 && !(*buffer & 0x01))
--nbits;
actual_csum += (nbits >> 8);
actual_csum += (nbits & 0xff);
actual_csum += checksum (buffer, nbytes);
}
else
{
unsigned char *buffer;
err = gcry_mpi_aprint (GCRYMPI_FMT_PGP, &buffer, &nbytes,
skey[i]);
if (!err)
actual_csum += checksum (buffer, nbytes);
if (err)
return err;
actual_csum += checksum (buffer, nbytes);
xfree (buffer);
}
if (err)
return err;
}
if (actual_csum != desired_csum)
@ -487,7 +532,7 @@ do_unprotect (const char *passphrase,
unsigned char *data;
u16 csum_pgp7 = 0;
if (!gcry_mpi_get_flag (skey[npkey], GCRYMPI_FLAG_OPAQUE ))
if (!gcry_mpi_get_flag (skey[npkey], GCRYMPI_FLAG_USER1))
{
gcry_cipher_close (cipher_hd);
return gpg_error (GPG_ERR_BAD_SECKEY);
@ -556,7 +601,7 @@ do_unprotect (const char *passphrase,
{
for (i=npkey; i < nskey; i++ )
{
if (gcry_mpi_scan (&tmpmpi, GCRYMPI_FMT_PGP, p, ndata, &nbytes))
if (scan_pgp_format (&tmpmpi, pubkey_algo, p, ndata, &nbytes))
{
/* Checksum was okay, but not correctly decrypted. */
desired_csum = 0;
@ -587,7 +632,7 @@ do_unprotect (const char *passphrase,
size_t ndata;
unsigned int ndatabits;
if (!skey[i] || !gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_OPAQUE))
if (!skey[i] || !gcry_mpi_get_flag (skey[i], GCRYMPI_FLAG_USER1))
{
gcry_cipher_close (cipher_hd);
return gpg_error (GPG_ERR_BAD_SECKEY);
@ -614,7 +659,7 @@ do_unprotect (const char *passphrase,
buffer[1] = p[1];
gcry_cipher_decrypt (cipher_hd, buffer+2, ndata-2, p+2, ndata-2);
actual_csum += checksum (buffer, ndata);
err = gcry_mpi_scan (&tmpmpi, GCRYMPI_FMT_PGP, buffer, ndata, &ndata);
err = scan_pgp_format (&tmpmpi, pubkey_algo, buffer, ndata, &nbytes);
xfree (buffer);
if (err)
{
@ -837,20 +882,12 @@ convert_from_openpgp_main (ctrl_t ctrl, gcry_sexp_t s_pgp, int dontcare_exist,
value = gcry_sexp_nth_data (list, ++idx, &valuelen);
if (!value || !valuelen)
goto bad_seckey;
skey[skeyidx] = gcry_mpi_set_opaque_copy (NULL, value, valuelen*8);
if (!skey[skeyidx])
goto outofmem;
if (is_enc)
{
/* Encrypted parameters need to be stored as opaque. */
skey[skeyidx] = gcry_mpi_set_opaque_copy (NULL, value, valuelen*8);
if (!skey[skeyidx])
goto outofmem;
gcry_mpi_set_flag (skey[skeyidx], GCRYMPI_FLAG_USER1);
}
else
{
if (gcry_mpi_scan (skey + skeyidx, GCRYMPI_FMT_STD,
value, valuelen, NULL))
goto bad_seckey;
}
/* Encrypted parameters need to have a USER1 flag. */
gcry_mpi_set_flag (skey[skeyidx], GCRYMPI_FLAG_USER1);
skeyidx++;
}
skey[skeyidx++] = NULL;
@ -1171,6 +1208,7 @@ apply_protection (gcry_mpi_t *array, int npkey, int nskey,
array[i] = NULL;
}
array[npkey] = gcry_mpi_set_opaque (NULL, data, ndata*8);
gcry_mpi_set_flag (array[npkey], GCRYMPI_FLAG_USER1);
return 0;
}
@ -1366,7 +1404,7 @@ convert_to_openpgp (ctrl_t ctrl, gcry_sexp_t s_key, const char *passphrase,
put_membuf_str (&mbuf, "(skey");
for (i=j=0; i < npkey; i++)
{
if (gcry_mpi_get_flag (array[i], GCRYMPI_FLAG_OPAQUE))
if (gcry_mpi_get_flag (array[i], GCRYMPI_FLAG_USER1))
put_membuf_str (&mbuf, " e %m");
else
put_membuf_str (&mbuf, " _ %m");