Bdtjtk

I'm currently writing a DTLS server. I encountered a problem with DTLSv1_Listen that fails with error code SSL_ERROR_SSL.

The handshake sequence is the following :
Client Hello
Content Type: Handshake (22)
Version: DTLS 1.2 (0xfefd)
Epoch: 0
Sequence Number: 0
Length: 145
Handshake Protocol: Client Hello
Handshake Type: Client Hello (1)
Length: 133
Message Sequence: 0
Fragment Offset: 0
Fragment Length: 133
Version: DTLS 1.2 (0xfefd)
Random: 10a0b17d31c7b374d08d51f3fdd3e6b5ecb13658a9e554a3...
Session ID Length: 0
Cookie Length: 0
Cipher Suites Length: 6
Cipher Suites (3 suites)
Compression Methods Length: 1
Compression Methods (1 method)
Extensions Length: 85
Extension: ec_point_formats (len=4)
Extension: supported_groups (len=28)
Extension: SessionTicket TLS (len=0)
Extension: signature_algorithms (len=32)
Extension: heartbeat (len=1)

Hello Verify Request
Content Type: Handshake (22)
Version: DTLS 1.2 (0xfefd)
Epoch: 0
Sequence Number: 0
Length: 35
Handshake Protocol: Hello Verify Request
Handshake Type: Hello Verify Request (3)
Length: 23
Message Sequence: 0
Fragment Offset: 0
Fragment Length: 23
Version: DTLS 1.0 (0xfeff)
Cookie Length: 20
Cookie: c4994e593cd77b26208a374cde0b48372a1636db

DTLSv1.2 Record Layer: Alert (Level: Fatal, Description: Handshake Failure)
Content Type: Alert (21)
Version: DTLS 1.2 (0xfefd)
Epoch: 0
Sequence Number: 1
Length: 2
Alert Message

My ssl context is initialized that way :

 SSL_library_init ();

 SSL_load_error_strings ();

 ERR_load_BIO_strings();

 OpenSSL_add_all_algorithms();



 pServerContext = SSL_CTX_new(DTLSv1_2_server_method());



    if (SSL_CTX_set_cipher_list(pServerContext, "ALL") != 1)

    {

      getLogger()->error("DTLS : unable to load ciphers, exitingn");

      exit(1);

    }

[... set certificates, key, etc...]

The cookie returned is correct, and i don't see what is wrong. The only strange point is the Version: DTLS 1.0 sent in the verify request (strange because i initialized with DTLSv1_2_server_method).
Is there an explanation of why it fails?

Thanks for any input!