Line data    Source code

       1             : #ifndef HEADER_fd_src_discof_failover_fd_failover_tls_h
       2             : #define HEADER_fd_src_discof_failover_fd_failover_tls_h
       3             : 
       4             : /* TLS 1.3 over TCP for one failover candidate, built on fd_tls,
       5             :    fd_tlsrec and fd_tlsrec_sock.  Both ends present an Ed25519 cert for
       6             :    the identity they hand off.  The channel admits a peer before TLS and
       7             :    checks its TLS key against the admitted HELLO.  The caller owns the
       8             :    socket. */
       9             : 
      10             : #include "../../waltz/tlsrec/fd_tlsrec_sock.h"
      11             : #include "../../ballet/chacha/fd_chacha_rng.h"
      12             : 
      13             : /* Max ciphertext accepted from a candidate before it pairs */
      14          33 : #define FD_FAILOVER_TLS_PREPAIR_MAX (32768UL)
      15             : 
      16             : /* Per-channel TLS config, the fd_tls template and its RNG.  The sign
      17             :    tile signs our CertificateVerify, no private key is kept here. */
      18             : 
      19             : struct fd_failover_tls_ctx {
      20             :   fd_tls_t        tls;
      21             :   fd_chacha_rng_t rng[ 1 ];
      22             :   int             ready; /* set by init and wiped by fini, fd_failover_tls_new fails without it */
      23             : };
      24             : typedef struct fd_failover_tls_ctx fd_failover_tls_ctx_t;
      25             : 
      26             : /* One TLS connection. */
      27             : 
      28             : struct fd_failover_tls {
      29             :   fd_tlsrec_conn_t conn;
      30             :   fd_tlsrec_sock_t sock;
      31             :   int              fd;
      32             :   int              verified;          /* handshake done, peer_pubkey is set */
      33             :   int              paired;            /* set by the channel after HELLO */
      34             :   int              peer_closed;       /* orderly EOF or close_notify */
      35             :   uchar            peer_pubkey[ 32 ]; /* the key the peer signed the handshake with */
      36             :   ulong            received;          /* ciphertext bytes read before pairing */
      37             : };
      38             : typedef struct fd_failover_tls fd_failover_tls_t;
      39             : 
      40             : FD_PROTOTYPES_BEGIN
      41             : 
      42             : /* fd_failover_tls_ctx_init sets the public key of our cert and the
      43             :    signer for CertificateVerify and seeds the RNG.  It and every new
      44             :    connection read entropy from getrandom.  Returns 0 on success, -1 if
      45             :    entropy fails. */
      46             : 
      47             : int
      48             : fd_failover_tls_ctx_init( fd_failover_tls_ctx_t * ctx,
      49             :                           uchar const             public_key[ 32 ],
      50             :                           fd_tls_sign_t           signer );
      51             : 
      52             : /* fd_failover_tls_ctx_fini wipes the context. */
      53             : 
      54             : void
      55             : fd_failover_tls_ctx_fini( fd_failover_tls_ctx_t * ctx );
      56             : 
      57             : /* fd_failover_tls_new binds a fresh connection to fd.  The listener
      58             :    requires a client cert.  Returns 0 on success, -1 if ctx is not
      59             :    initialized or entropy fails. */
      60             : 
      61             : int
      62             : fd_failover_tls_new( fd_failover_tls_t *     tls,
      63             :                      fd_failover_tls_ctx_t * ctx,
      64             :                      int                     fd,
      65             :                      int                     dial_peer );
      66             : 
      67             : /* Prepare the outbound ClientHello without sending it, or feed an
      68             :    admitted peer flight to the connection without socket I/O.  The
      69             :    generated reply is left in sock.tx_buf for the caller to capture or
      70             :    flush with fd_tlsrec_sock_flush.  No earlier output may be pending. */
      71             : int
      72             : fd_failover_tls_client_hello( fd_failover_tls_t * tls, uchar * out, ulong * out_sz );
      73             : 
      74             : int
      75             : fd_failover_tls_accept_flight( fd_failover_tls_t * tls, uchar const * data, ulong sz );
      76             : 
      77             : /* fd_failover_tls_fini sends close_notify if the connection is up and
      78             :    wipes the connection state.  The caller closes fd. */
      79             : 
      80             : void
      81             : fd_failover_tls_fini( fd_failover_tls_t * tls );
      82             : 
      83             : /* fd_failover_tls_handshake returns 1 once the handshake is done and
      84             :    the peer signed it with an Ed25519 key, which is then in peer_pubkey,
      85             :    0 while pending, -1 on failure.  fd_failover_tls_read and
      86             :    fd_failover_tls_write return bytes moved, 0 when pending, -1 on error
      87             :    or peer close.  A write may take fewer bytes than offered (at most one
      88             :    record), callers are responsible for retrying to obtain the rest. */
      89             : 
      90             : int
      91             : fd_failover_tls_handshake( fd_failover_tls_t * tls );
      92             : 
      93             : long
      94             : fd_failover_tls_read( fd_failover_tls_t * tls,
      95             :                       void *              buf,
      96             :                       ulong               sz );
      97             : 
      98             : long
      99             : fd_failover_tls_write( fd_failover_tls_t * tls,
     100             :                        void const *        buf,
     101             :                        ulong               sz );
     102             : 
     103             : FD_PROTOTYPES_END
     104             : 
     105             : #endif /* HEADER_fd_src_discof_failover_fd_failover_tls_h */