Fix stack buffer overflow in ECDSA signature format conversions
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/psa_util.c b/library/psa_util.c
index 4ccc5b0..679d00e 100644
--- a/library/psa_util.c
+++ b/library/psa_util.c
@@ -443,6 +443,9 @@
if (raw_len != (2 * coordinate_len)) {
return MBEDTLS_ERR_ASN1_INVALID_DATA;
}
+ if (coordinate_len > sizeof(r)) {
+ return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
+ }
/* Since raw and der buffers might overlap, dump r and s before starting
* the conversion. */
@@ -561,6 +564,9 @@
if (raw_size < coordinate_size * 2) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
+ if (2 * coordinate_size > sizeof(raw_tmp)) {
+ return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
+ }
/* Check that the provided input DER buffer has the right header. */
ret = mbedtls_asn1_get_tag(&p, der + der_len, &data_len,