dtls_utils: skip over DTLSCiphertext from DTLS 1.3
where we can not extract any message_seq for piggybacking.
BUG=webrtc:367395350
Change-Id: I2e42d3b1304b5cf204c34bc8a136f17c363e011c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/372881
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Jonas Oreland <jonaso@webrtc.org>
Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43731}
diff --git a/p2p/dtls/dtls_utils.cc b/p2p/dtls/dtls_utils.cc
index 050ecd9..e341431 100644
--- a/p2p/dtls/dtls_utils.cc
+++ b/p2p/dtls/dtls_utils.cc
@@ -20,8 +20,14 @@
namespace {
// https://datatracker.ietf.org/doc/html/rfc5246#appendix-A.1
-const uint8_t kDtlsHandshakeRecord = 22;
const uint8_t kDtlsChangeCipherSpecRecord = 20;
+const uint8_t kDtlsHandshakeRecord = 22;
+
+// https://www.rfc-editor.org/rfc/rfc9147.html#section-4
+const uint8_t kFixedBitmask = 0b00100000;
+const uint8_t kConnectionBitmask = 0b00010000;
+const uint8_t kSequenceNumberBitmask = 0b00001000;
+const uint8_t kLengthPresentBitmask = 0b00000100;
} // namespace
namespace cricket {
@@ -61,10 +67,38 @@
uint8_t content_type;
uint64_t epoch_and_seq;
uint16_t len;
- // Read content_type(1), skip version(2), read epoch+seq(2+6),
- // read len(2)
- if (!(record_buf.ReadUInt8(&content_type) && record_buf.Consume(2) &&
- record_buf.ReadUInt64(&epoch_and_seq) &&
+ // Read content_type(1).
+ if (!record_buf.ReadUInt8(&content_type)) {
+ return std::nullopt;
+ }
+
+ // DTLS 1.3 rules:
+ // https://www.rfc-editor.org/rfc/rfc9147.html#section-4.1
+ if ((content_type & kFixedBitmask) == kFixedBitmask) {
+ // Interpret as DTLSCipherText:
+ // https://www.rfc-editor.org/rfc/rfc9147.html#appendix-A.1
+ // We assume no connection id is used so C must be 0.
+ if ((content_type & kConnectionBitmask) != 0) {
+ return std::nullopt;
+ }
+ // Skip sequence_number(1 or 2 bytes depending on S bit).
+ if (!record_buf.Consume((content_type & kSequenceNumberBitmask) ==
+ kSequenceNumberBitmask
+ ? 2
+ : 1)) {
+ return std::nullopt;
+ }
+ // If the L bit is set, consume the 16 bit length field.
+ if ((content_type & kLengthPresentBitmask) == kLengthPresentBitmask) {
+ if (!(record_buf.ReadUInt16(&len) && record_buf.Consume(len))) {
+ return std::nullopt;
+ }
+ }
+ // DTLSCipherText is encrypted so we can not read it.
+ continue;
+ }
+ // Skip version(2), read epoch+seq(2+6), read len(2)
+ if (!(record_buf.Consume(2) && record_buf.ReadUInt64(&epoch_and_seq) &&
record_buf.ReadUInt16(&len) && record_buf.Length() >= len)) {
return std::nullopt;
}
diff --git a/p2p/dtls/dtls_utils_unittest.cc b/p2p/dtls/dtls_utils_unittest.cc
index 9f3e25b..410e3b1 100644
--- a/p2p/dtls/dtls_utils_unittest.cc
+++ b/p2p/dtls/dtls_utils_unittest.cc
@@ -128,50 +128,54 @@
0x40, 0x29, 0x30, 0x58, 0x37, 0x26, 0x0d, 0xe8, 0xc0, 0x2b, 0x00, 0x00,
0x18, 0x00, 0x17, 0x00, 0x00, 0xff, 0x01, 0x00, 0x01, 0x00, 0x00, 0x0b,
0x00, 0x02, 0x01, 0x00, 0x00, 0x0e, 0x00, 0x05, 0x00, 0x02, 0x00, 0x01,
- 0x00, 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
- 0x01, 0x28, 0x0b, 0x00, 0x01, 0x1c, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
- 0x01, 0x1c, 0x00, 0x01, 0x19, 0x00, 0x01, 0x16, 0x30, 0x82, 0x01, 0x12,
- 0x30, 0x81, 0xb8, 0xa0, 0x03, 0x02, 0x01, 0x02, 0x02, 0x08, 0x15, 0xc9,
- 0xcc, 0xd0, 0x55, 0x57, 0xa2, 0x32, 0x30, 0x0a, 0x06, 0x08, 0x2a, 0x86,
- 0x48, 0xce, 0x3d, 0x04, 0x03, 0x02, 0x30, 0x0f, 0x31, 0x0d, 0x30, 0x0b,
+ 0x00, //
+ 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01,
+ 0x28, 0x0b, 0x00, 0x01, 0x1c, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x01,
+ 0x1c, 0x00, 0x01, 0x19, 0x00, 0x01, 0x16, 0x30, 0x82, 0x01, 0x12, 0x30,
+ 0x81, 0xb8, 0xa0, 0x03, 0x02, 0x01, 0x02, 0x02, 0x08, 0x15, 0xc9, 0xcc,
+ 0xd0, 0x55, 0x57, 0xa2, 0x32, 0x30, 0x0a, 0x06, 0x08, 0x2a, 0x86, 0x48,
+ 0xce, 0x3d, 0x04, 0x03, 0x02, 0x30, 0x0f, 0x31, 0x0d, 0x30, 0x0b, 0x06,
+ 0x03, 0x55, 0x04, 0x03, 0x0c, 0x04, 0x74, 0x65, 0x73, 0x74, 0x30, 0x1e,
+ 0x17, 0x0d, 0x32, 0x34, 0x31, 0x31, 0x30, 0x35, 0x32, 0x30, 0x35, 0x33,
+ 0x34, 0x38, 0x5a, 0x17, 0x0d, 0x32, 0x34, 0x31, 0x32, 0x30, 0x36, 0x32,
+ 0x30, 0x35, 0x33, 0x34, 0x38, 0x5a, 0x30, 0x0f, 0x31, 0x0d, 0x30, 0x0b,
0x06, 0x03, 0x55, 0x04, 0x03, 0x0c, 0x04, 0x74, 0x65, 0x73, 0x74, 0x30,
- 0x1e, 0x17, 0x0d, 0x32, 0x34, 0x31, 0x31, 0x30, 0x35, 0x32, 0x30, 0x35,
- 0x33, 0x34, 0x38, 0x5a, 0x17, 0x0d, 0x32, 0x34, 0x31, 0x32, 0x30, 0x36,
- 0x32, 0x30, 0x35, 0x33, 0x34, 0x38, 0x5a, 0x30, 0x0f, 0x31, 0x0d, 0x30,
- 0x0b, 0x06, 0x03, 0x55, 0x04, 0x03, 0x0c, 0x04, 0x74, 0x65, 0x73, 0x74,
- 0x30, 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02,
- 0x01, 0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03,
- 0x42, 0x00, 0x04, 0x8f, 0x43, 0xeb, 0x7b, 0x88, 0x73, 0x4f, 0xe7, 0x69,
- 0x06, 0x81, 0xb6, 0xb9, 0xf3, 0xca, 0x73, 0x32, 0x69, 0xb2, 0xc5, 0xe6,
- 0x4e, 0xf0, 0x8c, 0xf4, 0xdd, 0x4e, 0x5b, 0xea, 0x06, 0x52, 0x94, 0x9a,
- 0x12, 0x77, 0x11, 0xde, 0xf9, 0x12, 0x9a, 0xeb, 0x3c, 0x7c, 0xe4, 0xcf,
- 0x58, 0x4c, 0x74, 0x44, 0x84, 0x0a, 0x84, 0xeb, 0xe6, 0xa4, 0xd5, 0xd3,
- 0x06, 0xca, 0x52, 0x15, 0x7e, 0xeb, 0x19, 0x30, 0x0a, 0x06, 0x08, 0x2a,
- 0x86, 0x48, 0xce, 0x3d, 0x04, 0x03, 0x02, 0x03, 0x49, 0x00, 0x30, 0x46,
- 0x02, 0x21, 0x00, 0xab, 0xc7, 0x06, 0x7e, 0x36, 0x9b, 0xad, 0xe0, 0x26,
- 0x61, 0x6b, 0x59, 0xa0, 0x1c, 0x70, 0x0c, 0xa6, 0xd3, 0xff, 0x8a, 0xc7,
- 0xba, 0xe4, 0x23, 0x0a, 0x8b, 0x22, 0x82, 0xcd, 0x5a, 0x5c, 0x56, 0x02,
- 0x21, 0x00, 0xc7, 0xe8, 0x57, 0x04, 0xb5, 0x44, 0x69, 0x42, 0xa2, 0xa2,
- 0x1e, 0xde, 0x7f, 0xc4, 0x44, 0x98, 0xa4, 0x5c, 0x84, 0x41, 0xa1, 0x31,
- 0x38, 0x3c, 0xe5, 0x4f, 0xf5, 0xc0, 0xa9, 0xa8, 0xbc, 0x16, 0x16, 0xfe,
- 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x7a, 0x0c,
- 0x00, 0x00, 0x6e, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x6e, 0x03,
- 0x00, 0x1d, 0x20, 0x89, 0xb9, 0xeb, 0x39, 0x29, 0xa0, 0x31, 0x08, 0x9a,
- 0xbf, 0xc3, 0xc0, 0x20, 0x60, 0xbb, 0xea, 0x73, 0x19, 0xcf, 0x63, 0xe4,
- 0x5a, 0xa8, 0xa9, 0x56, 0x77, 0xe8, 0x81, 0x48, 0xae, 0x9f, 0x34, 0x04,
- 0x03, 0x00, 0x46, 0x30, 0x44, 0x02, 0x20, 0x23, 0x34, 0xc6, 0x39, 0x94,
- 0x84, 0xcc, 0x67, 0xeb, 0x44, 0xf9, 0xc3, 0x5c, 0x52, 0xb3, 0x99, 0x52,
- 0xf7, 0x4f, 0xff, 0x8b, 0xc5, 0xea, 0xb5, 0xd0, 0xf9, 0x36, 0xb3, 0xe6,
- 0xfc, 0x37, 0x50, 0x02, 0x20, 0x4c, 0xe2, 0x29, 0xf5, 0x4a, 0x4c, 0x7a,
- 0x01, 0x37, 0xce, 0xc1, 0xb0, 0x15, 0x23, 0xfd, 0xa5, 0xd9, 0xac, 0x75,
- 0xcb, 0x55, 0x56, 0x99, 0x97, 0xe3, 0x13, 0xbd, 0x5b, 0xcc, 0x5d, 0x0c,
- 0xa8, 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
- 0x00, 0x25, 0x0d, 0x00, 0x00, 0x19, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x19, 0x02, 0x01, 0x40, 0x00, 0x12, 0x04, 0x03, 0x08, 0x04, 0x04,
- 0x01, 0x05, 0x03, 0x08, 0x05, 0x05, 0x01, 0x08, 0x06, 0x06, 0x01, 0x02,
- 0x01, 0x00, 0x00, 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x04, 0x00, 0x0c, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00};
+ 0x59, 0x30, 0x13, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01,
+ 0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07, 0x03, 0x42,
+ 0x00, 0x04, 0x8f, 0x43, 0xeb, 0x7b, 0x88, 0x73, 0x4f, 0xe7, 0x69, 0x06,
+ 0x81, 0xb6, 0xb9, 0xf3, 0xca, 0x73, 0x32, 0x69, 0xb2, 0xc5, 0xe6, 0x4e,
+ 0xf0, 0x8c, 0xf4, 0xdd, 0x4e, 0x5b, 0xea, 0x06, 0x52, 0x94, 0x9a, 0x12,
+ 0x77, 0x11, 0xde, 0xf9, 0x12, 0x9a, 0xeb, 0x3c, 0x7c, 0xe4, 0xcf, 0x58,
+ 0x4c, 0x74, 0x44, 0x84, 0x0a, 0x84, 0xeb, 0xe6, 0xa4, 0xd5, 0xd3, 0x06,
+ 0xca, 0x52, 0x15, 0x7e, 0xeb, 0x19, 0x30, 0x0a, 0x06, 0x08, 0x2a, 0x86,
+ 0x48, 0xce, 0x3d, 0x04, 0x03, 0x02, 0x03, 0x49, 0x00, 0x30, 0x46, 0x02,
+ 0x21, 0x00, 0xab, 0xc7, 0x06, 0x7e, 0x36, 0x9b, 0xad, 0xe0, 0x26, 0x61,
+ 0x6b, 0x59, 0xa0, 0x1c, 0x70, 0x0c, 0xa6, 0xd3, 0xff, 0x8a, 0xc7, 0xba,
+ 0xe4, 0x23, 0x0a, 0x8b, 0x22, 0x82, 0xcd, 0x5a, 0x5c, 0x56, 0x02, 0x21,
+ 0x00, 0xc7, 0xe8, 0x57, 0x04, 0xb5, 0x44, 0x69, 0x42, 0xa2, 0xa2, 0x1e,
+ 0xde, 0x7f, 0xc4, 0x44, 0x98, 0xa4, 0x5c, 0x84, 0x41, 0xa1, 0x31, 0x38,
+ 0x3c, 0xe5, 0x4f, 0xf5, 0xc0, 0xa9, 0xa8, 0xbc, 0x16, //
+ 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00,
+ 0x7a, 0x0c, 0x00, 0x00, 0x6e, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x6e, 0x03, 0x00, 0x1d, 0x20, 0x89, 0xb9, 0xeb, 0x39, 0x29, 0xa0, 0x31,
+ 0x08, 0x9a, 0xbf, 0xc3, 0xc0, 0x20, 0x60, 0xbb, 0xea, 0x73, 0x19, 0xcf,
+ 0x63, 0xe4, 0x5a, 0xa8, 0xa9, 0x56, 0x77, 0xe8, 0x81, 0x48, 0xae, 0x9f,
+ 0x34, 0x04, 0x03, 0x00, 0x46, 0x30, 0x44, 0x02, 0x20, 0x23, 0x34, 0xc6,
+ 0x39, 0x94, 0x84, 0xcc, 0x67, 0xeb, 0x44, 0xf9, 0xc3, 0x5c, 0x52, 0xb3,
+ 0x99, 0x52, 0xf7, 0x4f, 0xff, 0x8b, 0xc5, 0xea, 0xb5, 0xd0, 0xf9, 0x36,
+ 0xb3, 0xe6, 0xfc, 0x37, 0x50, 0x02, 0x20, 0x4c, 0xe2, 0x29, 0xf5, 0x4a,
+ 0x4c, 0x7a, 0x01, 0x37, 0xce, 0xc1, 0xb0, 0x15, 0x23, 0xfd, 0xa5, 0xd9,
+ 0xac, 0x75, 0xcb, 0x55, 0x56, 0x99, 0x97, 0xe3, 0x13, 0xbd, 0x5b, 0xcc,
+ 0x5d, 0x0c,
+ 0xa8, //
+ 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00,
+ 0x25, 0x0d, 0x00, 0x00, 0x19, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x19, 0x02, 0x01, 0x40, 0x00, 0x12, 0x04, 0x03, 0x08, 0x04, 0x04, 0x01,
+ 0x05, 0x03, 0x08, 0x05, 0x05, 0x01, 0x08, 0x06, 0x06, 0x01, 0x02, 0x01,
+ 0x00, 0x00, //
+ 0x16, 0xfe, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00,
+ 0x0c, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00};
std::optional<std::vector<uint16_t>> acks2 = GetDtlsHandshakeAcks(packet2);
ASSERT_TRUE(acks2);
@@ -179,4 +183,19 @@
EXPECT_THAT(*acks2, ::testing::ElementsAreArray({0, 1, 2, 3, 4}));
}
+TEST(DtlsUtils, GetDtls13HandshakeAcks) {
+ // DTLS 1.3 encrypted data, captured with Wireshark. This is a single
+ // encrypted record which can not be parsed and should be skipped.
+ std::vector<uint8_t> packet = {
+ 0x2f, 0x5b, 0x4c, 0x00, 0x23, 0x47, 0xab, 0xe7, 0x90, 0x96,
+ 0xc0, 0xac, 0x2f, 0x25, 0x40, 0x35, 0x35, 0xa3, 0x81, 0x50,
+ 0x0c, 0x38, 0x0a, 0xf6, 0xd4, 0xd5, 0x7d, 0xbe, 0x9a, 0xa3,
+ 0xcb, 0xcb, 0x67, 0xb0, 0x77, 0x79, 0x8b, 0x48, 0x60, 0xf8,
+ };
+
+ std::optional<std::vector<uint16_t>> acks = GetDtlsHandshakeAcks(packet);
+ ASSERT_TRUE(acks);
+ EXPECT_EQ(acks->size(), 0u);
+}
+
} // namespace cricket
