openssl: support handshake cut-through
authorBert Belder <bertbelder@gmail.com>
Tue, 11 Sep 2012 19:33:23 +0000 (21:33 +0200)
committerBert Belder <bertbelder@gmail.com>
Wed, 12 Sep 2012 03:23:49 +0000 (05:23 +0200)
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.

This patch is taken from the Android Open Source Project.

deps/openssl/openssl/apps/s_client.c
deps/openssl/openssl/ssl/s3_clnt.c
deps/openssl/openssl/ssl/s3_lib.c
deps/openssl/openssl/ssl/ssl.h
deps/openssl/openssl/ssl/ssl3.h
deps/openssl/openssl/ssl/ssl_lib.c
deps/openssl/openssl/ssl/ssltest.c
deps/openssl/openssl/test/testssl

index fc806eb..6dffa80 100644 (file)
@@ -360,6 +360,7 @@ static void sc_usage(void)
 # if !defined(OPENSSL_NO_NEXTPROTONEG)
        BIO_printf(bio_err," -nextprotoneg arg - enable NPN extension, considering named protocols supported (comma-separated list)\n");
 # endif
+       BIO_printf(bio_err," -cutthrough       - enable 1-RTT full-handshake for strong ciphers\n");
 #endif
        BIO_printf(bio_err," -legacy_renegotiation - enable use of legacy renegotiation (dangerous)\n");
        BIO_printf(bio_err," -use_srtp profiles - Offer SRTP key management with a colon-separated profile list\n");
@@ -573,6 +574,7 @@ int MAIN(int argc, char **argv)
        EVP_PKEY *key = NULL;
        char *CApath=NULL,*CAfile=NULL,*cipher=NULL;
        int reconnect=0,badop=0,verify=SSL_VERIFY_NONE,bugs=0;
+       int cutthrough=0;
        int crlf=0;
        int write_tty,read_tty,write_ssl,read_ssl,tty_on,ssl_pending;
        SSL_CTX *ctx=NULL;
@@ -879,6 +881,8 @@ int MAIN(int argc, char **argv)
                        }
 # endif
 #endif
+               else if (strcmp(*argv,"-cutthrough") == 0)
+                       cutthrough=1;
                else if (strcmp(*argv,"-serverpref") == 0)
                        off|=SSL_OP_CIPHER_SERVER_PREFERENCE;
                else if (strcmp(*argv,"-legacy_renegotiation") == 0)
@@ -1145,6 +1149,15 @@ bad:
         */
        if (socket_type == SOCK_DGRAM) SSL_CTX_set_read_ahead(ctx, 1);
 
+       /* Enable handshake cutthrough for client connections using
+        * strong ciphers. */
+       if (cutthrough)
+               {
+               int ssl_mode = SSL_CTX_get_mode(ctx);
+               ssl_mode |= SSL_MODE_HANDSHAKE_CUTTHROUGH;
+               SSL_CTX_set_mode(ctx, ssl_mode);
+               }
+
 #if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
        if (next_proto.data)
                SSL_CTX_set_next_proto_select_cb(ctx, next_proto_cb, &next_proto);
index b80d052..a250ee1 100644 (file)
@@ -202,6 +202,18 @@ int ssl3_connect(SSL *s)
        
        s->in_handshake++;
        if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 
+#if 0  /* Send app data in separate packet, otherwise, some particular site
+        * (only one site so far) closes the socket.
+        * Note: there is a very small chance that two TCP packets
+        * could be arriving at server combined into a single TCP packet,
+        * then trigger that site to break. We haven't encounter that though.
+        */
+       if (SSL_get_mode(s) & SSL_MODE_HANDSHAKE_CUTTHROUGH)
+               {
+               /* Send app data along with CCS/Finished */
+               s->s3->flags |= SSL3_FLAGS_DELAY_CLIENT_FINISHED;
+               }
+#endif
 
 #ifndef OPENSSL_NO_HEARTBEATS
        /* If we're awaiting a HeartbeatResponse, pretend we
@@ -527,14 +539,31 @@ int ssl3_connect(SSL *s)
                                }
                        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) && SSL_get_cipher_bits(s, NULL) >= 128
+                                   && 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;
@@ -582,6 +611,24 @@ int ssl3_connect(SSL *s)
                        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);
index fb60cde..8b8350c 100644 (file)
@@ -4199,9 +4199,22 @@ int ssl3_write(SSL *s, const void *buf, int len)
 
 static int ssl3_read_internal(SSL *s, void *buf, int len, int peek)
        {
-       int ret;
+       int n,ret;
        
        clear_sys_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);
index e2ec0eb..a7afef5 100644 (file)
@@ -641,6 +641,10 @@ struct ssl_session_st
 /* Use small read and write buffers: (a) lazy allocate read buffers for
  * large incoming records, and (b) limit the size of outgoing records. */
 #define SSL_MODE_SMALL_BUFFERS 0x00000020L
+/* 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 0x00000040L
 
 /* Note: SSL[_CTX]_set_{options,mode} use |= op on the previous value,
  * they cannot be used to clear bits. */
@@ -1409,10 +1413,12 @@ extern "C" {
 /* 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 */
index d8459fa..fb08e72 100644 (file)
@@ -557,6 +557,7 @@ typedef struct ssl3_state_st
 /*client */
 /* extra state */
 #define SSL3_ST_CW_FLUSH               (0x100|SSL_ST_CONNECT)
+#define SSL3_ST_CUTTHROUGH_COMPLETE    (0x101|SSL_ST_CONNECT)
 #ifndef OPENSSL_NO_SCTP
 #define DTLS1_SCTP_ST_CW_WRITE_SOCK                    (0x310|SSL_ST_CONNECT)
 #define DTLS1_SCTP_ST_CR_READ_SOCK                     (0x320|SSL_ST_CONNECT)
index f82d071..518f152 100644 (file)
@@ -3211,6 +3211,19 @@ void SSL_set_msg_callback(SSL *ssl, void (*cb)(int write_p, int version, int con
        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 */
+               SSL_get_cipher_bits(s, NULL) >= 128 &&                      /* strong cipher choosen */
+               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));
+       }
+
 /* 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
index 5fa4466..a950b6e 100644 (file)
@@ -371,6 +371,7 @@ static void sv_usage(void)
        fprintf(stderr," -test_cipherlist - verifies the order of the ssl cipher lists\n");
        fprintf(stderr," -c_small_records - enable client side use of small SSL record buffers\n");
        fprintf(stderr," -s_small_records - enable server side use of small SSL record buffers\n");
+       fprintf(stderr," -cutthrough      - enable 1-RTT full-handshake for strong ciphers\n");
        }
 
 static void print_details(SSL *c_ssl, const char *prefix)
@@ -502,6 +503,7 @@ int opaque_prf_input_cb(SSL *ssl, void *peerinput, size_t len, void *arg_)
        int ssl_mode = 0;
        int c_small_records=0;
        int s_small_records=0;
+       int cutthrough = 0;
 
 int main(int argc, char *argv[])
        {
@@ -778,6 +780,10 @@ int main(int argc, char *argv[])
                        {
                        s_small_records = 1;
                        }
+               else if (strcmp(*argv, "-cutthrough") == 0)
+                       {
+                       cutthrough = 1;
+                       }
                else
                        {
                        fprintf(stderr,"unknown option %s\n",*argv);
@@ -928,6 +934,13 @@ bad:
                ssl_mode |= SSL_MODE_SMALL_BUFFERS;
                SSL_CTX_set_mode(s_ctx, ssl_mode);
                }
+       ssl_mode = 0;
+       if (cutthrough)
+               {
+               ssl_mode = SSL_CTX_get_mode(c_ctx);
+               ssl_mode = SSL_MODE_HANDSHAKE_CUTTHROUGH;
+               SSL_CTX_set_mode(c_ctx, ssl_mode);
+               }
 
 #ifndef OPENSSL_NO_DH
        if (!no_dhe)
index 0e3d6aa..3382a9b 100644 (file)
@@ -79,6 +79,9 @@ $ssltest -server_auth -client_auth -s_small_records $CA $extra || exit 1
 echo test sslv2/sslv3 with both client and server authentication and small client and server buffers
 $ssltest -server_auth -client_auth -c_small_records -s_small_records $CA $extra || exit 1
 
+echo test sslv2/sslv3 with both client and server authentication and handshake cutthrough
+$ssltest -server_auth -client_auth -cutthrough $CA $extra || exit 1
+
 echo test sslv2 via BIO pair
 $ssltest -bio_pair -ssl2 $extra || exit 1