+/* lengths of messages */
+# define DTLS1_COOKIE_LENGTH 256
+
+# define DTLS1_RT_HEADER_LENGTH 13
+
+# define DTLS1_HM_HEADER_LENGTH 12
+
+# define DTLS1_HM_BAD_FRAGMENT -2
+# define DTLS1_HM_FRAGMENT_RETRY -3
+
+# define DTLS1_CCS_HEADER_LENGTH 1
+
+# ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+# define DTLS1_AL_HEADER_LENGTH 7
+# else
+# define DTLS1_AL_HEADER_LENGTH 2
+# endif
+
+# ifndef OPENSSL_NO_SSL_INTERN
+
+# ifndef OPENSSL_NO_SCTP
+# define DTLS1_SCTP_AUTH_LABEL "EXPORTER_DTLS_OVER_SCTP"
+# endif
+
+/* Max MTU overhead we know about so far is 40 for IPv6 + 8 for UDP */
+# define DTLS1_MAX_MTU_OVERHEAD 48
+
+typedef struct dtls1_bitmap_st {
+ unsigned long map; /* track 32 packets on 32-bit systems and 64
+ * - on 64-bit systems */
+ unsigned char max_seq_num[8]; /* max record number seen so far, 64-bit
+ * value in big-endian encoding */
+} DTLS1_BITMAP;
+
+struct dtls1_retransmit_state {
+ EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
+ EVP_MD_CTX *write_hash; /* used for mac generation */
+# ifndef OPENSSL_NO_COMP
+ COMP_CTX *compress; /* compression */
+# else
+ char *compress;
+# endif
+ SSL_SESSION *session;
+ unsigned short epoch;
+};
+
+struct hm_header_st {
+ unsigned char type;
+ unsigned long msg_len;
+ unsigned short seq;
+ unsigned long frag_off;
+ unsigned long frag_len;
+ unsigned int is_ccs;
+ struct dtls1_retransmit_state saved_retransmit_state;
+};
+
+struct ccs_header_st {
+ unsigned char type;
+ unsigned short seq;
+};
+
+struct dtls1_timeout_st {
+ /* Number of read timeouts so far */
+ unsigned int read_timeouts;
+ /* Number of write timeouts so far */
+ unsigned int write_timeouts;
+ /* Number of alerts received so far */
+ unsigned int num_alerts;
+};
+
+typedef struct record_pqueue_st {
+ unsigned short epoch;
+ pqueue q;
+} record_pqueue;
+
+typedef struct hm_fragment_st {
+ struct hm_header_st msg_header;
+ unsigned char *fragment;
+ unsigned char *reassembly;
+} hm_fragment;
+
+typedef struct dtls1_state_st {
+ unsigned int send_cookie;
+ unsigned char cookie[DTLS1_COOKIE_LENGTH];
+ unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
+ unsigned int cookie_len;
+ /*
+ * The current data and handshake epoch. This is initially
+ * undefined, and starts at zero once the initial handshake is
+ * completed
+ */
+ unsigned short r_epoch;
+ unsigned short w_epoch;
+ /* records being received in the current epoch */
+ DTLS1_BITMAP bitmap;
+ /* renegotiation starts a new set of sequence numbers */
+ DTLS1_BITMAP next_bitmap;
+ /* handshake message numbers */
+ unsigned short handshake_write_seq;
+ unsigned short next_handshake_write_seq;
+ unsigned short handshake_read_seq;
+ /* save last sequence number for retransmissions */
+ unsigned char last_write_sequence[8];
+ /* Received handshake records (processed and unprocessed) */
+ record_pqueue unprocessed_rcds;
+ record_pqueue processed_rcds;
+ /* Buffered handshake messages */
+ pqueue buffered_messages;
+ /* Buffered (sent) handshake records */
+ pqueue sent_messages;
+ /*
+ * Buffered application records. Only for records between CCS and
+ * Finished to prevent either protocol violation or unnecessary message
+ * loss.
+ */
+ record_pqueue buffered_app_data;
+ /* Is set when listening for new connections with dtls1_listen() */
+ unsigned int listen;
+ unsigned int link_mtu; /* max on-the-wire DTLS packet size */
+ unsigned int mtu; /* max DTLS packet size */
+ struct hm_header_st w_msg_hdr;
+ struct hm_header_st r_msg_hdr;
+ struct dtls1_timeout_st timeout;
+ /*
+ * Indicates when the last handshake msg or heartbeat sent will timeout
+ */
+ struct timeval next_timeout;
+ /* Timeout duration */
+ unsigned short timeout_duration;
+ /*
+ * storage for Alert/Handshake protocol data received but not yet
+ * processed by ssl3_read_bytes:
+ */
+ unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
+ unsigned int alert_fragment_len;
+ unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
+ unsigned int handshake_fragment_len;
+ unsigned int retransmitting;
+ /*
+ * Set when the handshake is ready to process peer's ChangeCipherSpec message.
+ * Cleared after the message has been processed.
+ */
+ unsigned int change_cipher_spec_ok;
+# ifndef OPENSSL_NO_SCTP
+ /* used when SSL_ST_XX_FLUSH is entered */
+ int next_state;
+ int shutdown_received;
+# endif
+} DTLS1_STATE;
+
+typedef struct dtls1_record_data_st {
+ unsigned char *packet;
+ unsigned int packet_length;
+ SSL3_BUFFER rbuf;
+ SSL3_RECORD rrec;
+# ifndef OPENSSL_NO_SCTP
+ struct bio_dgram_sctp_rcvinfo recordinfo;
+# endif
+} DTLS1_RECORD_DATA;
+
+# endif