[Help-gnutls] Another one: A TLS packet with unexpected length was received.

[Lennart Koopmann]

Hello everyone,

i am currently implementing a handshaking procedure. Everything works
fine when the client chooses not to use TLS. But when TLS is requested,
the gnutls_handshake() fails.

The client reports the following error: GNUTLS ERROR: A TLS packet with
unexpected length was received.

The server reports no error, because gnutls_handshake() seems to wait
for something and just blocks.

Here is some debug data (loglevel 7).

--------------- Server ---------------
REC[93558b8]: Expected Packet[0] Handshake(22) with length: 1
REC[93558b8]: Received Packet[0] Handshake(22) with length: 64
ASSERT: gnutls_cipher.c:204
REC[93558b8]: Decrypted Packet[0] Handshake(22) with length: 64
HSK[93558b8]: CLIENT HELLO was received [64 bytes]
HSK[93558b8]: Client's version: 3.2
ASSERT: gnutls_db.c:238
EXT[93558b8]: Received extension 'CERT_TYPE/9'
EXT[93558b8]: Received extension 'CERT_TYPE/9'
ASSERT: ext_cert_type.c:106
ASSERT: ext_cert_type.c:106
ASSERT: ext_cert_type.c:123
HSK[93558b8]: Keeping ciphersuite: ANON_DH_ARCFOUR_MD5
HSK[93558b8]: Keeping ciphersuite: ANON_DH_3DES_EDE_CBC_SHA1
HSK[93558b8]: Keeping ciphersuite: ANON_DH_AES_128_CBC_SHA1
HSK[93558b8]: Keeping ciphersuite: ANON_DH_AES_256_CBC_SHA1
HSK[93558b8]: Keeping ciphersuite: ANON_DH_CAMELLIA_128_CBC_SHA
HSK[93558b8]: Keeping ciphersuite: ANON_DH_CAMELLIA_256_CBC_SHA1
HSK[93558b8]: Selected cipher suite: ANON_DH_AES_128_CBC_SHA1
HSK[93558b8]: Selected Compression Method: NULL
HSK[93558b8]: SessionID:
259495b9dd31479d1913bed547e77bfedde5f38a4f810a0c79d66b9bd9510f62
HSK[93558b8]: SERVER HELLO was send [74 bytes]
REC[93558b8]: Sending Packet[0] Handshake(22) with length: 74
ASSERT: gnutls_cipher.c:204
REC[93558b8]: Sent Packet[1] Handshake(22) with length: 79
--------------------------------------


--------------- Client ---------------
HSK[9bf1b58]: Keeping ciphersuite: ANON_DH_AES_128_CBC_SHA1
HSK[9bf1b58]: Keeping ciphersuite: ANON_DH_CAMELLIA_128_CBC_SHA1
HSK[9bf1b58]: Keeping ciphersuite: ANON_DH_AES_256_CBC_SHA1
HSK[9bf1b58]: Keeping ciphersuite: ANON_DH_CAMELLIA_256_CBC_SHA1
HSK[9bf1b58]: Keeping ciphersuite: ANON_DH_3DES_EDE_CBC_SHA1
HSK[9bf1b58]: Keeping ciphersuite: ANON_DH_ARCFOUR_MD5
EXT[9bf1b58]: Sending extension CERT_TYPE
HSK[9bf1b58]: CLIENT HELLO was send [64 bytes]
REC[9bf1b58]: Sending Packet[0] Handshake(22) with length: 64
ASSERT: gnutls_cipher.c:204
WRITE: Will write 69 bytes to 4.
WRITE: wrote 69 bytes to 4. Left 0 bytes. Total 69 bytes.
0000 - 16 03 02 00 40 01 00 00 3c 03 02 48 d2 00 41 bb 
0001 - 22 27 d1 ae 80 fd 96 1c e9 81 a2 bc c4 03 95 4b 
0002 - f9 10 2f 9a b7 c3 fe 5a e6 58 4a 00 00 0c 00 34 
0003 - 00 46 00 3a 00 89 00 1b 00 18 01 00 00 07 00 09 
0004 - 00 03 02 00 01 
REC[9bf1b58]: Sent Packet[1] Handshake(22) with length: 69
READ: Got 5 bytes from 4
READ: read 5 bytes from 4
0000 - 16 03 02 00 4a 
RB: Have 0 bytes into buffer. Adding 5 bytes.
RB: Requested 5 bytes
REC[9bf1b58]: Expected Packet[0] Handshake(22) with length: 1
REC[9bf1b58]: Received Packet[0] Handshake(22) with length: 74
READ: Got 74 bytes from 4
READ: read 74 bytes from 4
0000 - 02 00 00 46 03 02 48 d2 00 41 8e 8a 8d 30 de 33 
0001 - 5f 2b f8 3f 93 bf 0e e8 5f 1a 68 ed f0 d6 82 1c 
0002 - cd d7 d9 97 8b 64 20 25 94 95 b9 dd 31 47 9d 19 
0003 - 13 be d5 47 e7 7b fe dd e5 f3 8a 4f 81 0a 0c 79 
0004 - d6 6b 9b d9 51 0f 62 00 34 00 
RB: Have 5 bytes into buffer. Adding 74 bytes.
RB: Requested 79 bytes
ASSERT: gnutls_cipher.c:204
REC[9bf1b58]: Decrypted Packet[0] Handshake(22) with length: 74
HSK[9bf1b58]: SERVER HELLO was received [74 bytes]
HSK[9bf1b58]: Server's version: 3.2
HSK[9bf1b58]: SessionID length: 32
HSK[9bf1b58]: SessionID
259495b9dd31479d1913bed547e77bfedde5f38a4f810a0c79d66b9bd9510f62
HSK[9bf1b58]: Selected cipher suite: ANON_DH_AES_128_CBC_SHA1
ASSERT: gnutls_extensions.c:125
READ: Got 0 bytes from 4
READ: read 0 bytes from 4
0000 - 
ASSERT: gnutls_buffers.c:638
ASSERT: gnutls_record.c:909
ASSERT: gnutls_buffers.c:1150
ASSERT: gnutls_handshake.c:1043
ASSERT: gnutls_kx.c:410
ASSERT: gnutls_handshake.c:2364
--------------------------------------

As there seems to be handshaking conversation and the client starts the
conversation I don't know where to search for the error. Client and
server and both on the same machine, using the same GNUTLS library.

Can anybody help me?

Thank you!

So long
Lennart