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dns: fix max_name overflow and test invalid names read/write
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@pinheadmz
pinheadmz committed Mar 1, 2022
1 parent 5d846f9 commit e61eb76
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Showing 3 changed files with 136 additions and 45 deletions.
10 changes: 10 additions & 0 deletions src/dns.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2142,6 +2142,10 @@ hsk_dns_name_parse(

// Only occurs at end of name (zero-length label aka ".")
if (c == 0x00) {
// Almost made it! Last byte exceeds max.
if (noff + 1 > HSK_DNS_MAX_NAME)
return -1;

if (name)
name[noff] = 0x00;

Expand Down Expand Up @@ -2249,6 +2253,12 @@ hsk_dns_name_serialize(

// End of name "."
if (label == 0x00) {
// Almost made it! Last byte exceeds max
if (1 + noff > HSK_DNS_MAX_NAME) {
*len = off;
return false;
}

if (data)
data[off] = 0x00;

Expand Down
128 changes: 94 additions & 34 deletions test/data/record_read_vectors.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,10 +14,17 @@ typedef struct record_read_vector {
uint16_t type;
char name1[HSK_DNS_MAX_NAME_STRING];
char name2[HSK_DNS_MAX_NAME_STRING];
uint8_t data[HSK_DNS_MAX_NAME];
uint8_t data[HSK_DNS_MAX_NAME + 1]; // extended to fit invalid data
size_t data_len;
bool valid;
uint8_t invalidname[HSK_DNS_MAX_NAME + 1]; // extended to fit invalid data
size_t invalidname_len;
} record_read_vector_t;

typedef struct {
uint8_t target[HSK_DNS_MAX_NAME_STRING]; // extended to fit invalid data
} hsk_dns_invalid_cname_rd_t;

/*
* Vectors
*/
Expand All @@ -38,14 +45,19 @@ static char *record_read_msg_qname = "xxxx.rec.test.";

// Currently we only test for reading/writing names,
// other data in records is ignored (commented out for future tests).
static const record_read_vector_t record_read_vectors_valid[] = {
static const record_read_vector_t record_read_vectors[] = {
/*
* VALID
*/

// local nameserver
{
HSK_DNS_NS,
"ns.rec.test.",
"",
"\x02ns\xc0\x11",
5
5,
true
},

// non-local nameserver
Expand All @@ -54,7 +66,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"ns.example.com.",
"",
"\x02ns\x07""example\x03""com\x00",
16
16,
true
},

// local alias
Expand All @@ -63,7 +76,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"name.rec.test.",
"",
"\x04name\xc0\x11",
7
7,
true
},

// non-local alias
Expand All @@ -72,7 +86,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"name.example.com.",
"",
"\x04name\x07""example\x03""com\x00",
18
18,
true
},

// max label length (63)
Expand All @@ -81,7 +96,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"123456789012345678901234567890123456789012345678901234567890123.example.com.",
"",
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x07""example\x03""com\x00",
77
77,
true
},

// local max name length (255)
Expand All @@ -90,7 +106,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.1234567890123456789012345678901234567890123456789012.rec.test.",
"",
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x34""1234567890123456789012345678901234567890123456789012\xc0\x11",
247
247,
true
},

// non-local max name length (255)
Expand All @@ -99,7 +116,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.1234567890123456789012345678901234567890123456789012345678901.",
"",
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3d""1234567890123456789012345678901234567890123456789012345678901\x00",
255
255,
true
},

// local names
Expand All @@ -109,7 +127,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"hostmaster.test.rec.",
/*2013051201 3600 3600 604800 120*/
"\x02ns\xc0\x11\x0ahostmaster\x04test\x03rec\x00\x77\xfc\xb9\x41\x00\x00\x0e\x10\x00\x00\x0e\x10\x00\x09\x3a\x80\x00\x00\x00\x78",
46
46,
true
},

// non-local names
Expand All @@ -119,7 +138,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"hostmaster.example.com.",
/*2013051201 3600 3600 604800 120*/
"\x02ns\x07""example\x03""com\x00\x0ahostmaster\xc0\x28\x77\xfc\xb9\x41\x00\x00\x0e\x10\x00\x00\x0e\x10\x00\x09\x3a\x80\x00\x00\x00\x78",
49
49,
true
},

// local name
Expand All @@ -128,7 +148,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"ptr.rec.test.",
"",
"\x03ptr\xc0\x11",
6
6,
true
},

// non-local name
Expand All @@ -137,7 +158,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"ptr.example.com.",
"",
"\x03ptr\x07""example\x03""com\x00",
17
17,
true

},

Expand All @@ -148,7 +170,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"mx.rec.test.",
"",
"\x00\x0a\x02mx\xc0\x11",
7
7,
true
},

// non-local name
Expand All @@ -158,7 +181,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"mx.example.com.",
"",
"\x00\x14\x02mx\x07""example\x03""com\x00",
18
18,
true
},

// root label
Expand All @@ -168,7 +192,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
".",
"",
"\x00\x14\x00",
3
3,
true
},

// local name
Expand All @@ -177,7 +202,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"admin.rec.test.",
"admin-info.rec.test.",
"\x05""admin\x03rec\x04test\x00\x0a""admin-info\x03rec\x04test\x00",
37
37,
true
},

// non-local name
Expand All @@ -186,7 +212,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"admin.example.com.",
"admin-info.example.com.",
"\x05""admin\x07""example\x03""com\x00\x0a""admin-info\x07""example\x03""com\x00",
43
43,
true
},

// local name
Expand All @@ -196,7 +223,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"sip.rec.test.",
"",
"\x00\x0a\x00\x0a\x13\xc4\x03sip\x03rec\x04test\x00",
20
20,
true
},

// non-local name
Expand All @@ -206,7 +234,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"sip.example.com.",
"",
"\x00\x0a\x00\x0a\x13\xc4\x03sip\x07""example\x03""com\x00",
24
24,
true
},

// root name
Expand All @@ -216,7 +245,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
".",
"",
"\x00\x0a\x00\x0a\x13\xc4\x00",
7
7,
true
},

{
Expand All @@ -226,7 +256,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
"",
/*ecWKD/OsdAiXpbM/sgPT82KVD/WiQnnqcxoJgiH3ixHa+LOAcYU7FG7V4BRRJxLriY1e0rB2gAs3kCel9D4bzfK6wAqG4Di/eHUgHptRlaR2ycELJ4t1pjzrnuGiIzA1wM2izRmeE+Xoy1367Qu0pOz5DLzTfQITWFsB2iUzN4Y=*/
"\x00\x06\x08\x03\x00\x00\x01\x2c\x51\x9d\x5c\x00\x51\x8a\xe7\x00\xd3\xc8\x03\x72\x65\x63\x04\x74\x65\x73\x74\x00\x79\xc5\x8a\x0f\xf3\xac\x74\x08\x97\xa5\xb3\x3f\xb2\x03\xd3\xf3\x62\x95\x0f\xf5\xa2\x42\x79\xea\x73\x1a\x09\x82\x21\xf7\x8b\x11\xda\xf8\xb3\x80\x71\x85\x3b\x14\x6e\xd5\xe0\x14\x51\x27\x12\xeb\x89\x8d\x5e\xd2\xb0\x76\x80\x0b\x37\x90\x27\xa5\xf4\x3e\x1b\xcd\xf2\xba\xc0\x0a\x86\xe0\x38\xbf\x78\x75\x20\x1e\x9b\x51\x95\xa4\x76\xc9\xc1\x0b\x27\x8b\x75\xa6\x3c\xeb\x9e\xe1\xa2\x23\x30\x35\xc0\xcd\xa2\xcd\x19\x9e\x13\xe5\xe8\xcb\x5d\xfa\xed\x0b\xb4\xa4\xec\xf9\x0c\xbc\xd3\x7d\x02\x13\x58\x5b\x01\xda\x25\x33\x37\x86",
156
156,
true
},

{
Expand All @@ -235,7 +266,8 @@ static const record_read_vector_t record_read_vectors_valid[] = {
/*A NS SOA MX AAAA RRSIG NSEC DNSKEY*/
"",
"\x01""a\x03rec\x04test\x00\x00\x07\x62\x01\x00\x08\x00\x03\x80",
21
21,
true
},

// TODO: Fix the 255-byte limit on URI record tarets
Expand All @@ -253,15 +285,43 @@ static const record_read_vector_t record_read_vectors_valid[] = {
// "",
// "\x00\x0a\x00\x01\x66\x74\x70\x3a\x2f\x2f\x66\x74\x70\x31\x2e\x65\x78\x61\x6d\x70\x6c\x65\x2e\x63\x6f\x6d\x2f\x70\x75\x62\x6c\x69\x63\x2f\x77\x69\x74\x68\x2f\x61\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x76\x65\x72\x79\x2f\x6c\x6f\x6e\x67\x2f\x75\x72\x6c"
// }
};

// static const record_read_vector_t record_read_vectors_invalid[] = {
// // empty label, must be broken. No serilization exists for reverse test so use dummy
// {HSK_DNS_CNAME, "name..example.com.", "", "\xff.dummy"},
// // overly large label (64), must be broken
// {HSK_DNS_CNAME, "1234567890123456789012345678901234567890123456789012345678901234.example.com.", "", "\x40""1234567890123456789012345678901234567890123456789012345678901234\x07""example\x03""com\x00"},
// // local overly large name (256), must be broken
// {HSK_DNS_CNAME, "123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.12345678901234567890123456789012345678901234567890123.rec.test.", "", "\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x35""12345678901234567890123456789012345678901234567890123\xc0\x11"},
// // non-local overly large name (256), must be broken
// {HSK_DNS_CNAME, "123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.12345678901234567890123456789012345678901234567890123456789012.", "", "\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3e""12345678901234567890123456789012345678901234567890123456789012\x00"}
// };
/*
* INVALID
*/

// overly large label (64), must be broken
{
HSK_DNS_CNAME,
"1234567890123456789012345678901234567890123456789012345678901234.example.com.",
"",
"\x40""1234567890123456789012345678901234567890123456789012345678901234\x07""example\x03""com\x00",
78,
false,
"\x40""1234567890123456789012345678901234567890123456789012345678901234\x07""example\x03""com\x00",
78
},

// local overly large name (256), must be broken
{
HSK_DNS_CNAME,
"123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.12345678901234567890123456789012345678901234567890123.rec.test.",
"",
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x35""12345678901234567890123456789012345678901234567890123\xc0\x11",
238,
false,
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x35""12345678901234567890123456789012345678901234567890123\x03rec\x04test\x00",
256
},
// non-local overly large name (256), must be broken
{
HSK_DNS_CNAME,
"123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.12345678901234567890123456789012345678901234567890123456789012.",
"",
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3e""12345678901234567890123456789012345678901234567890123456789012\x00",
256,
false,
"\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3f""123456789012345678901234567890123456789012345678901234567890123\x3e""12345678901234567890123456789012345678901234567890123456789012\x00",
256
}
};
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