X.509: Remove red'n bounds checks and zeroiz'n in OtherName parsing
- ASN.1 parsing functions check that length don't exceed buffer bounds,
so checks `p + len > end` are redundant.
- If `p + len == end`, this is erroneous because we expect further fields,
which is automatically caught by the next ASN.1 parsing call.
Hence, the two branches handling `p + len >= end` in x509_get_other_name()
can be removed.
Further, zeroization of the `other_name` structure isn't necessary
because it's not confidential (and it's also not performed on other
error conditions in this function).
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 289f0c5..3b6b54b 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1733,12 +1733,6 @@
return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
}
- if( p + len >= end )
- {
- mbedtls_platform_zeroize( other_name, sizeof( *other_name ) );
- return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
- MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
- }
p += len;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
@@ -1755,12 +1749,6 @@
other_name->value.hardware_module_name.oid.p = p;
other_name->value.hardware_module_name.oid.len = len;
- if( p + len >= end )
- {
- mbedtls_platform_zeroize( other_name, sizeof( *other_name ) );
- return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
- MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
- }
p += len;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
@@ -1772,8 +1760,6 @@
p += len;
if( p != end )
{
- mbedtls_platform_zeroize( other_name,
- sizeof( *other_name ) );
return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ) );
}