False Start support. (Called "cut through" for historical reasons in this patch.) Enables SSL3+ clients to send application data immediately following the Finished message even when negotiating full-handshakes. With this patch, clients can negotiate SSL connections in 1-RTT even when performing full-handshakes.
diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c index 9698916..ba0410a 100644 --- a/ssl/s3_clnt.c +++ b/ssl/s3_clnt.c
@@ -209,6 +209,12 @@ } #endif + if (SSL_get_mode(s) & SSL_MODE_HANDSHAKE_CUTTHROUGH) + { + /* Send app data along with CCS/Finished */ + s->s3->flags |= SSL3_FLAGS_DELAY_CLIENT_FINISHED; + } + for (;;) { state=s->state; @@ -518,14 +524,32 @@ } else { -#ifndef OPENSSL_NO_TLSEXT - /* Allow NewSessionTicket if ticket expected */ - if (s->tlsext_ticket_expected) - s->s3->tmp.next_state=SSL3_ST_CR_SESSION_TICKET_A; + if ((SSL_get_mode(s) & SSL_MODE_HANDSHAKE_CUTTHROUGH) + && ssl3_can_cutthrough(s) + && s->s3->previous_server_finished_len == 0 /* no cutthrough on renegotiation (would complicate the state machine) */ + ) + { + if (s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED) + { + s->state=SSL3_ST_CUTTHROUGH_COMPLETE; + s->s3->flags|=SSL3_FLAGS_POP_BUFFER; + s->s3->delay_buf_pop_ret=0; + } + else + { + s->s3->tmp.next_state=SSL3_ST_CUTTHROUGH_COMPLETE; + } + } else + { +#ifndef OPENSSL_NO_TLSEXT + /* Allow NewSessionTicket if ticket expected */ + if (s->tlsext_ticket_expected) + s->s3->tmp.next_state=SSL3_ST_CR_SESSION_TICKET_A; + else #endif - - s->s3->tmp.next_state=SSL3_ST_CR_FINISHED_A; + s->s3->tmp.next_state=SSL3_ST_CR_FINISHED_A; + } } s->init_num=0; break; @@ -573,6 +597,24 @@ s->state=s->s3->tmp.next_state; break; + case SSL3_ST_CUTTHROUGH_COMPLETE: +#ifndef OPENSSL_NO_TLSEXT + /* Allow NewSessionTicket if ticket expected */ + if (s->tlsext_ticket_expected) + s->state=SSL3_ST_CR_SESSION_TICKET_A; + else +#endif + s->state=SSL3_ST_CR_FINISHED_A; + + /* SSL_write() will take care of flushing buffered data if + * DELAY_CLIENT_FINISHED is set. + */ + if (!(s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED)) + ssl_free_wbio_buffer(s); + ret = 1; + goto end; + /* break; */ + case SSL_ST_OK: /* clean a few things up */ ssl3_cleanup_key_block(s);
diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c index 3a53c68..edffd21 100644 --- a/ssl/s3_lib.c +++ b/ssl/s3_lib.c
@@ -3963,9 +3963,22 @@ static int ssl3_read_internal(SSL *s, void *buf, int len, int peek) { - int ret; + int n,ret; ERR_clear_system_error(); + if ((s->s3->flags & SSL3_FLAGS_POP_BUFFER) && (s->wbio == s->bbio)) + { + /* Deal with an application that calls SSL_read() when handshake data + * is yet to be written. + */ + if (BIO_wpending(s->wbio) > 0) + { + s->rwstate=SSL_WRITING; + n=BIO_flush(s->wbio); + if (n <= 0) return(n); + s->rwstate=SSL_NOTHING; + } + } if (s->s3->renegotiate) ssl3_renegotiate_check(s); s->s3->in_read_app_data=1; ret=s->method->ssl_read_bytes(s,SSL3_RT_APPLICATION_DATA,buf,len,peek);
diff --git a/ssl/ssl.h b/ssl/ssl.h index 91f52ce..e5aa03a 100644 --- a/ssl/ssl.h +++ b/ssl/ssl.h
@@ -689,6 +689,7 @@ * TLS only.) "Released" buffers are put onto a free-list in the context * or just freed (depending on the context's setting for freelist_max_len). */ #define SSL_MODE_RELEASE_BUFFERS 0x00000010L + /* Send the current time in the Random fields of the ClientHello and * ServerHello records for compatibility with hypothetical implementations * that require it. @@ -752,6 +753,11 @@ #define SSL_CONF_TYPE_FILE 0x2 #define SSL_CONF_TYPE_DIR 0x3 +/* When set, clients may send application data before receipt of CCS + * and Finished. This mode enables full-handshakes to 'complete' in + * one RTT. */ +#define SSL_MODE_HANDSHAKE_CUTTHROUGH 0x00000080L + /* Note: SSL[_CTX]_set_{options,mode} use |= op on the previous value, * they cannot be used to clear bits. */ @@ -1560,10 +1566,12 @@ /* Is the SSL_connection established? */ #define SSL_get_state(a) SSL_state(a) #define SSL_is_init_finished(a) (SSL_state(a) == SSL_ST_OK) -#define SSL_in_init(a) (SSL_state(a)&SSL_ST_INIT) +#define SSL_in_init(a) ((SSL_state(a)&SSL_ST_INIT) && \ + !SSL_cutthrough_complete(a)) #define SSL_in_before(a) (SSL_state(a)&SSL_ST_BEFORE) #define SSL_in_connect_init(a) (SSL_state(a)&SSL_ST_CONNECT) #define SSL_in_accept_init(a) (SSL_state(a)&SSL_ST_ACCEPT) +int SSL_cutthrough_complete(const SSL *s); /* The following 2 states are kept in ssl->rstate when reads fail, * you should not need these */
diff --git a/ssl/ssl3.h b/ssl/ssl3.h index e2bb36f..eb179e2 100644 --- a/ssl/ssl3.h +++ b/ssl/ssl3.h
@@ -597,6 +597,7 @@ /*client */ /* extra state */ #define SSL3_ST_CW_FLUSH (0x100|SSL_ST_CONNECT) +#define SSL3_ST_CUTTHROUGH_COMPLETE (0x101|SSL_ST_CONNECT) /* write to server */ #define SSL3_ST_CW_CLNT_HELLO_A (0x110|SSL_ST_CONNECT) #define SSL3_ST_CW_CLNT_HELLO_B (0x111|SSL_ST_CONNECT)
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index eec32b2..c536600 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c
@@ -3308,6 +3308,48 @@ SSL_callback_ctrl(ssl, SSL_CTRL_SET_MSG_CALLBACK, (void (*)(void))cb); } +int SSL_cutthrough_complete(const SSL *s) + { + return (!s->server && /* cutthrough only applies to clients */ + !s->hit && /* full-handshake */ + s->version >= SSL3_VERSION && + s->s3->in_read_app_data == 0 && /* cutthrough only applies to write() */ + (SSL_get_mode((SSL*)s) & SSL_MODE_HANDSHAKE_CUTTHROUGH) && /* cutthrough enabled */ + ssl3_can_cutthrough(s) && /* cutthrough allowed */ + s->s3->previous_server_finished_len == 0 && /* not a renegotiation handshake */ + (s->state == SSL3_ST_CR_SESSION_TICKET_A || /* ready to write app-data*/ + s->state == SSL3_ST_CR_FINISHED_A)); + } + +int ssl3_can_cutthrough(const SSL *s) + { + const SSL_CIPHER *c; + + /* require a strong enough cipher */ + if (SSL_get_cipher_bits(s, NULL) < 128) + return 0; + + /* require ALPN or NPN extension */ + if (!s->s3->alpn_selected +#ifndef OPENSSL_NO_NEXTPROTONEG + && !s->s3->next_proto_neg_seen +#endif + ) + { + return 0; + } + + /* require a forward-secret cipher */ + c = SSL_get_current_cipher(s); + if (!c || (c->algorithm_mkey != SSL_kEDH && + c->algorithm_mkey != SSL_kEECDH)) + { + return 0; + } + + return 1; + } + /* Allocates new EVP_MD_CTX and sets pointer to it into given pointer * vairable, freeing EVP_MD_CTX previously stored in that variable, if * any. If EVP_MD pointer is passed, initializes ctx with this md
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h index f0b6d42..cbfa172 100644 --- a/ssl/ssl_locl.h +++ b/ssl/ssl_locl.h
@@ -1294,6 +1294,8 @@ void tls1_set_cert_validity(SSL *s); #endif + +int ssl3_can_cutthrough(const SSL *s); EVP_MD_CTX* ssl_replace_hash(EVP_MD_CTX **hash,const EVP_MD *md) ; void ssl_clear_hash_ctx(EVP_MD_CTX **hash); int ssl_add_serverhello_renegotiate_ext(SSL *s, unsigned char *p, int *len,