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Diffstat (limited to 'lib/digsig.c')
-rw-r--r--lib/digsig.c52
1 files changed, 23 insertions, 29 deletions
diff --git a/lib/digsig.c b/lib/digsig.c
index fd2402f67f8..286d558033e 100644
--- a/lib/digsig.c
+++ b/lib/digsig.c
@@ -34,14 +34,9 @@ static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
unsigned long msglen,
unsigned long modulus_bitlen,
unsigned char *out,
- unsigned long *outlen,
- int *is_valid)
+ unsigned long *outlen)
{
unsigned long modulus_len, ps_len, i;
- int result;
-
- /* default to invalid packet */
- *is_valid = 0;
modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0);
@@ -50,39 +45,30 @@ static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
return -EINVAL;
/* separate encoded message */
- if ((msg[0] != 0x00) || (msg[1] != (unsigned char)1)) {
- result = -EINVAL;
- goto bail;
- }
+ if ((msg[0] != 0x00) || (msg[1] != (unsigned char)1))
+ return -EINVAL;
for (i = 2; i < modulus_len - 1; i++)
if (msg[i] != 0xFF)
break;
/* separator check */
- if (msg[i] != 0) {
+ if (msg[i] != 0)
/* There was no octet with hexadecimal value 0x00
to separate ps from m. */
- result = -EINVAL;
- goto bail;
- }
+ return -EINVAL;
ps_len = i - 2;
if (*outlen < (msglen - (2 + ps_len + 1))) {
*outlen = msglen - (2 + ps_len + 1);
- result = -EOVERFLOW;
- goto bail;
+ return -EOVERFLOW;
}
*outlen = (msglen - (2 + ps_len + 1));
memcpy(out, &msg[2 + ps_len + 1], *outlen);
- /* valid packet */
- *is_valid = 1;
- result = 0;
-bail:
- return result;
+ return 0;
}
/*
@@ -96,7 +82,7 @@ static int digsig_verify_rsa(struct key *key,
unsigned long len;
unsigned long mlen, mblen;
unsigned nret, l;
- int valid, head, i;
+ int head, i;
unsigned char *out1 = NULL, *out2 = NULL;
MPI in = NULL, res = NULL, pkey[2];
uint8_t *p, *datap, *endp;
@@ -105,6 +91,10 @@ static int digsig_verify_rsa(struct key *key,
down_read(&key->sem);
ukp = key->payload.data;
+
+ if (ukp->datalen < sizeof(*pkh))
+ goto err1;
+
pkh = (struct pubkey_hdr *)ukp->data;
if (pkh->version != 1)
@@ -117,18 +107,23 @@ static int digsig_verify_rsa(struct key *key,
goto err1;
datap = pkh->mpi;
- endp = datap + ukp->datalen;
+ endp = ukp->data + ukp->datalen;
+
+ err = -ENOMEM;
for (i = 0; i < pkh->nmpi; i++) {
unsigned int remaining = endp - datap;
pkey[i] = mpi_read_from_buffer(datap, &remaining);
+ if (!pkey[i])
+ goto err;
datap += remaining;
}
mblen = mpi_get_nbits(pkey[0]);
mlen = (mblen + 7)/8;
- err = -ENOMEM;
+ if (mlen == 0)
+ goto err;
out1 = kzalloc(mlen, GFP_KERNEL);
if (!out1)
@@ -167,10 +162,9 @@ static int digsig_verify_rsa(struct key *key,
memset(out1, 0, head);
memcpy(out1 + head, p, l);
- err = -EINVAL;
- pkcs_1_v1_5_decode_emsa(out1, len, mblen, out2, &len, &valid);
+ err = pkcs_1_v1_5_decode_emsa(out1, len, mblen, out2, &len);
- if (valid && len == hlen)
+ if (!err && len == hlen)
err = memcmp(out2, h, hlen);
err:
@@ -178,8 +172,8 @@ err:
mpi_free(res);
kfree(out1);
kfree(out2);
- mpi_free(pkey[0]);
- mpi_free(pkey[1]);
+ while (--i >= 0)
+ mpi_free(pkey[i]);
err1:
up_read(&key->sem);