Protocol version selection and negotiation rewrite
[openssl.git] / ssl / d1_lib.c
index 8a8ced8abb9ff0fdbc735fff4a4b44d1ddcda128..3cd4b786e45e1951c475bf324abf4613bd343a0d 100644 (file)
@@ -60,6 +60,7 @@
 #include <stdio.h>
 #define USE_SOCKETS
 #include <openssl/objects.h>
+#include <openssl/rand.h>
 #include "ssl_locl.h"
 
 #if defined(OPENSSL_SYS_VMS)
@@ -76,6 +77,10 @@ static void get_current_time(struct timeval *t);
 static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
 static int dtls1_handshake_write(SSL *s);
 int dtls1_listen(SSL *s, struct sockaddr *client);
+static unsigned int dtls1_link_min_mtu(void);
+
+/* XDTLS:  figure out the right values */
+static const unsigned int g_probable_mtu[] = { 1500, 512, 256 };
 
 const SSL3_ENC_METHOD DTLSv1_enc_data = {
     tls1_enc,
@@ -85,7 +90,6 @@ const SSL3_ENC_METHOD DTLSv1_enc_data = {
     tls1_change_cipher_state,
     tls1_final_finish_mac,
     TLS1_FINISH_MAC_LENGTH,
-    tls1_cert_verify_mac,
     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
     tls1_alert_code,
@@ -104,7 +108,6 @@ const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
     tls1_change_cipher_state,
     tls1_final_finish_mac,
     TLS1_FINISH_MAC_LENGTH,
-    tls1_cert_verify_mac,
     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
     tls1_alert_code,
@@ -150,7 +153,7 @@ int dtls1_new(SSL *s)
     d1->link_mtu = 0;
     d1->mtu = 0;
 
-    if (!d1->buffered_messages || !d1->sent_messages) {
+    if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
         pqueue_free(d1->buffered_messages);
         pqueue_free(d1->sent_messages);
         OPENSSL_free(d1);
@@ -232,7 +235,7 @@ void dtls1_clear(SSL *s)
     if (s->options & SSL_OP_CISCO_ANYCONNECT)
         s->client_version = s->version = DTLS1_BAD_VER;
     else if (s->method->version == DTLS_ANY_VERSION)
-        s->version = DTLS1_2_VERSION;
+        s->version = DTLS_MAX_VERSION;
     else
         s->version = s->method->version;
 }
@@ -253,28 +256,6 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
     case DTLS_CTRL_LISTEN:
         ret = dtls1_listen(s, parg);
         break;
-    case SSL_CTRL_CHECK_PROTO_VERSION:
-        /*
-         * For library-internal use; checks that the current protocol is the
-         * highest enabled version (according to s->ctx->method, as version
-         * negotiation may have changed s->method).
-         */
-        if (s->version == s->ctx->method->version)
-            return 1;
-        /*
-         * Apparently we're using a version-flexible SSL_METHOD (not at its
-         * highest protocol version).
-         */
-        if (s->ctx->method->version == DTLS_method()->version) {
-#if DTLS_MAX_VERSION != DTLS1_2_VERSION
-# error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
-#endif
-            if (!(s->options & SSL_OP_NO_DTLSv1_2))
-                return s->version == DTLS1_2_VERSION;
-            if (!(s->options & SSL_OP_NO_DTLSv1))
-                return s->version == DTLS1_VERSION;
-        }
-        return 0;               /* Unexpected state; fail closed. */
     case DTLS_CTRL_SET_LINK_MTU:
         if (larg < (long)dtls1_link_min_mtu())
             return 0;
@@ -695,8 +676,8 @@ int dtls1_listen(SSL *s, struct sockaddr *client)
         /*
          * Verify client version is supported
          */
-        if ((clientvers > (unsigned int)s->method->version &&
-                              s->method->version != DTLS_ANY_VERSION)) {
+        if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&
+            s->method->version != DTLS_ANY_VERSION) {
             SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
             goto end;
         }
@@ -723,9 +704,9 @@ int dtls1_listen(SSL *s, struct sockaddr *client)
                 /* This is fatal */
                 return -1;
             }
-            if (PACKET_remaining(&cookiepkt) > sizeof(s->d1->rcvd_cookie)
-                || s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
-                    PACKET_remaining(&cookiepkt)) == 0) {
+            if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
+                                             PACKET_remaining(&cookiepkt)) ==
+                0) {
                 /*
                  * We treat invalid cookies in the same was as no cookie as
                  * per RFC6347
@@ -754,15 +735,16 @@ int dtls1_listen(SSL *s, struct sockaddr *client)
 
             /* Generate the cookie */
             if (s->ctx->app_gen_cookie_cb == NULL ||
-                s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0) {
+                s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||
+                cookielen > 255) {
                 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
                 /* This is fatal */
                 return -1;
             }
 
             p = &buf[DTLS1_RT_HEADER_LENGTH];
-            msglen = dtls1_raw_hello_verify_request(p + DTLS1_HM_HEADER_LENGTH,
-                                                    cookie, cookielen);
+            msglen = dtls_raw_hello_verify_request(p + DTLS1_HM_HEADER_LENGTH,
+                                                   cookie, cookielen);
 
             *p++ = DTLS1_MT_HELLO_VERIFY_REQUEST;
 
@@ -868,10 +850,10 @@ int dtls1_listen(SSL *s, struct sockaddr *client)
     SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 
     /*
-     * Put us into the "init" state so that dtls1_accept doesn't clear our
-     * state
+     * Tell the state machine that we've done the initial hello verify
+     * exchange
      */
-    s->state = SSL_ST_ACCEPT;
+    ossl_statem_set_hello_verify_done(s);
 
     if(BIO_dgram_get_peer(rbio, client) <= 0) {
         SSLerr(SSL_F_DTLS1_LISTEN, ERR_R_INTERNAL_ERROR);
@@ -907,3 +889,230 @@ static int dtls1_handshake_write(SSL *s)
 {
     return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 }
+
+#ifndef OPENSSL_NO_HEARTBEATS
+int dtls1_process_heartbeat(SSL *s, unsigned char *p, unsigned int length)
+{
+    unsigned char *pl;
+    unsigned short hbtype;
+    unsigned int payload;
+    unsigned int padding = 16;  /* Use minimum padding */
+
+    if (s->msg_callback)
+        s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
+                        p, length, s, s->msg_callback_arg);
+
+    /* Read type and payload length first */
+    if (1 + 2 + 16 > length)
+        return 0;               /* silently discard */
+    if (length > SSL3_RT_MAX_PLAIN_LENGTH)
+        return 0;               /* silently discard per RFC 6520 sec. 4 */
+
+    hbtype = *p++;
+    n2s(p, payload);
+    if (1 + 2 + payload + 16 > length)
+        return 0;               /* silently discard per RFC 6520 sec. 4 */
+    pl = p;
+
+    if (hbtype == TLS1_HB_REQUEST) {
+        unsigned char *buffer, *bp;
+        unsigned int write_length = 1 /* heartbeat type */  +
+            2 /* heartbeat length */  +
+            payload + padding;
+        int r;
+
+        if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
+            return 0;
+
+        /*
+         * Allocate memory for the response, size is 1 byte message type,
+         * plus 2 bytes payload length, plus payload, plus padding
+         */
+        buffer = OPENSSL_malloc(write_length);
+        if (buffer == NULL)
+            return -1;
+        bp = buffer;
+
+        /* Enter response type, length and copy payload */
+        *bp++ = TLS1_HB_RESPONSE;
+        s2n(payload, bp);
+        memcpy(bp, pl, payload);
+        bp += payload;
+        /* Random padding */
+        if (RAND_bytes(bp, padding) <= 0) {
+            OPENSSL_free(buffer);
+            return -1;
+        }
+
+        r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
+
+        if (r >= 0 && s->msg_callback)
+            s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+                            buffer, write_length, s, s->msg_callback_arg);
+
+        OPENSSL_free(buffer);
+
+        if (r < 0)
+            return r;
+    } else if (hbtype == TLS1_HB_RESPONSE) {
+        unsigned int seq;
+
+        /*
+         * We only send sequence numbers (2 bytes unsigned int), and 16
+         * random bytes, so we just try to read the sequence number
+         */
+        n2s(pl, seq);
+
+        if (payload == 18 && seq == s->tlsext_hb_seq) {
+            dtls1_stop_timer(s);
+            s->tlsext_hb_seq++;
+            s->tlsext_hb_pending = 0;
+        }
+    }
+
+    return 0;
+}
+
+int dtls1_heartbeat(SSL *s)
+{
+    unsigned char *buf, *p;
+    int ret = -1;
+    unsigned int payload = 18;  /* Sequence number + random bytes */
+    unsigned int padding = 16;  /* Use minimum padding */
+
+    /* Only send if peer supports and accepts HB requests... */
+    if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
+        s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
+        return -1;
+    }
+
+    /* ...and there is none in flight yet... */
+    if (s->tlsext_hb_pending) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
+        return -1;
+    }
+
+    /* ...and no handshake in progress. */
+    if (SSL_in_init(s) || ossl_statem_get_in_handshake(s)) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
+        return -1;
+    }
+
+    /*-
+     * Create HeartBeat message, we just use a sequence number
+     * as payload to distuingish different messages and add
+     * some random stuff.
+     *  - Message Type, 1 byte
+     *  - Payload Length, 2 bytes (unsigned int)
+     *  - Payload, the sequence number (2 bytes uint)
+     *  - Payload, random bytes (16 bytes uint)
+     *  - Padding
+     */
+    buf = OPENSSL_malloc(1 + 2 + payload + padding);
+    if (buf == NULL) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_MALLOC_FAILURE);
+        return -1;
+    }
+    p = buf;
+    /* Message Type */
+    *p++ = TLS1_HB_REQUEST;
+    /* Payload length (18 bytes here) */
+    s2n(payload, p);
+    /* Sequence number */
+    s2n(s->tlsext_hb_seq, p);
+    /* 16 random bytes */
+    if (RAND_bytes(p, 16) <= 0) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+    p += 16;
+    /* Random padding */
+    if (RAND_bytes(p, padding) <= 0) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
+    if (ret >= 0) {
+        if (s->msg_callback)
+            s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+                            buf, 3 + payload + padding,
+                            s, s->msg_callback_arg);
+
+        dtls1_start_timer(s);
+        s->tlsext_hb_pending = 1;
+    }
+
+ err:
+    OPENSSL_free(buf);
+
+    return ret;
+}
+#endif
+
+int dtls1_shutdown(SSL *s)
+{
+    int ret;
+#ifndef OPENSSL_NO_SCTP
+    BIO *wbio;
+
+    wbio = SSL_get_wbio(s);
+    if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
+        !(s->shutdown & SSL_SENT_SHUTDOWN)) {
+        ret = BIO_dgram_sctp_wait_for_dry(wbio);
+        if (ret < 0)
+            return -1;
+
+        if (ret == 0)
+            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
+                     NULL);
+    }
+#endif
+    ret = ssl3_shutdown(s);
+#ifndef OPENSSL_NO_SCTP
+    BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
+#endif
+    return ret;
+}
+
+int dtls1_query_mtu(SSL *s)
+{
+    if (s->d1->link_mtu) {
+        s->d1->mtu =
+            s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
+        s->d1->link_mtu = 0;
+    }
+
+    /* AHA!  Figure out the MTU, and stick to the right size */
+    if (s->d1->mtu < dtls1_min_mtu(s)) {
+        if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
+            s->d1->mtu =
+                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
+
+            /*
+             * I've seen the kernel return bogus numbers when it doesn't know
+             * (initial write), so just make sure we have a reasonable number
+             */
+            if (s->d1->mtu < dtls1_min_mtu(s)) {
+                /* Set to min mtu */
+                s->d1->mtu = dtls1_min_mtu(s);
+                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
+                         s->d1->mtu, NULL);
+            }
+        } else
+            return 0;
+    }
+    return 1;
+}
+
+static unsigned int dtls1_link_min_mtu(void)
+{
+    return (g_probable_mtu[(sizeof(g_probable_mtu) /
+                            sizeof(g_probable_mtu[0])) - 1]);
+}
+
+unsigned int dtls1_min_mtu(SSL *s)
+{
+    return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
+}