From 2909e565636dd10eb322a3b2bd3296b8292240f9 Mon Sep 17 00:00:00 2001 From: Jonas Gunz Date: Sun, 19 Sep 2021 23:00:28 +0200 Subject: dns.c: add character range check + test --- src/dns.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'src/dns.c') diff --git a/src/dns.c b/src/dns.c index 9bdcd9b..50db12c 100644 --- a/src/dns.c +++ b/src/dns.c @@ -210,8 +210,10 @@ int fqdn_to_qname( char* _source, int _sourcelen, char* _sink ,int _sinklen ) _sink[i+1] = _source[i]; } - if( _source[i] ) /* _source not terminated, thus no valid string */ + if( _source[i] ) { + _sink[0] = 0; /* ensure _sink is terminated */ return -1; + } for (o = 0; o < i; o++) { if( _sink[o] == '.') { @@ -239,6 +241,7 @@ int qname_to_fqdn( char* _source, int _sourcelen, char* _sink, int _sinklen ) for(i = 1; i < (unsigned)_sourcelen; i++) { if( i > (unsigned)_sinklen){ /* Output too small. Not >= bc sink[i-1] is used */ + _sink[0] = 0; /* ensure _sink is terminated */ return -1; } if ( !_source[i] ) { @@ -263,9 +266,7 @@ int qname_check( char* _source, int _sourcelen ) if (!_sourcelen) return -1; - /* TODO questionable control flow */ - /* TODO add ASCII prrintable check */ for (i = 0; i < _sourcelen; i++) { if ( i == next_dot ) { if (_source[i]) { /* Not last dot */ @@ -275,6 +276,13 @@ int qname_check( char* _source, int _sourcelen ) } } else if (!_source[i]) { /* Unexpected \0 */ return -1; + } else if ( + !(_source[i]>='0' && _source[i]<='9') && + !(_source[i]>='A' && _source[i]<='Z') && + !(_source[i]>='a' && _source[i]<='z') && + !(_source[i]== '-') && !(_source[i]=='_') + ) { + return -1; } } -- cgit v1.2.3