Fix inconsistent check of UNSAFE_LEGACY_RENEGOTIATION
[openssl.git] / ssl / record / rec_layer_s3.c
index 5aea4b31bdd6262327432c361a8ade2faef3110f..01caf4c3726520640590030e907bf37fe7101022 100644 (file)
@@ -8,7 +8,6 @@
  */
 
 #include <stdio.h>
-#include <assert.h>
 #include <limits.h>
 #include <errno.h>
 #define USE_SOCKETS
@@ -17,6 +16,7 @@
 #include <openssl/buffer.h>
 #include <openssl/rand.h>
 #include "record_locl.h"
+#include "../packet_locl.h"
 
 #if     defined(OPENSSL_SMALL_FOOTPRINT) || \
         !(      defined(AES_ASM) &&     ( \
@@ -47,8 +47,6 @@ void RECORD_LAYER_clear(RECORD_LAYER *rl)
     rl->packet = NULL;
     rl->packet_length = 0;
     rl->wnum = 0;
-    memset(rl->alert_fragment, 0, sizeof(rl->alert_fragment));
-    rl->alert_fragment_len = 0;
     memset(rl->handshake_fragment, 0, sizeof(rl->handshake_fragment));
     rl->handshake_fragment_len = 0;
     rl->wpend_tot = 0;
@@ -77,11 +75,24 @@ void RECORD_LAYER_release(RECORD_LAYER *rl)
     SSL3_RECORD_release(rl->rrec, SSL_MAX_PIPELINES);
 }
 
+/* Checks if we have unprocessed read ahead data pending */
 int RECORD_LAYER_read_pending(const RECORD_LAYER *rl)
 {
     return SSL3_BUFFER_get_left(&rl->rbuf) != 0;
 }
 
+/* Checks if we have decrypted unread record data pending */
+int RECORD_LAYER_processed_read_pending(const RECORD_LAYER *rl)
+{
+    size_t curr_rec = 0, num_recs = RECORD_LAYER_get_numrpipes(rl);
+    const SSL3_RECORD *rr = rl->rrec;
+
+    while (curr_rec < num_recs && SSL3_RECORD_is_read(&rr[curr_rec]))
+        curr_rec++;
+
+    return curr_rec < num_recs;
+}
+
 int RECORD_LAYER_write_pending(const RECORD_LAYER *rl)
 {
     return (rl->numwpipes > 0)
@@ -343,14 +354,25 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, size_t len,
      * promptly send beyond the end of the users buffer ... so we trap and
      * report the error in a way the user will notice
      */
-    if (len < s->rlayer.wnum) {
+    if ((len < s->rlayer.wnum) 
+        || ((wb->left != 0) && (len < (s->rlayer.wnum + s->rlayer.wpend_tot)))) {
         SSLerr(SSL_F_SSL3_WRITE_BYTES, SSL_R_BAD_LENGTH);
         return -1;
     }
 
+    if (s->early_data_state == SSL_EARLY_DATA_WRITING
+            && !early_data_count_ok(s, len, 0, NULL))
+        return -1;
+
     s->rlayer.wnum = 0;
 
-    if (SSL_in_init(s) && !ossl_statem_get_in_handshake(s)) {
+    /*
+     * When writing early data on the server side we could be "in_init" in
+     * between receiving the EoED and the CF - but we don't want to handle those
+     * messages yet.
+     */
+    if (SSL_in_init(s) && !ossl_statem_get_in_handshake(s)
+            && s->early_data_state != SSL_EARLY_DATA_UNAUTH_WRITING) {
         i = s->handshake_func(s);
         if (i < 0)
             return i;
@@ -745,7 +767,7 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
     }
 
     /* Explicit IV length, block ciphers appropriate version flag */
-    if (s->enc_write_ctx && SSL_USE_EXPLICIT_IV(s)) {
+    if (s->enc_write_ctx && SSL_USE_EXPLICIT_IV(s) && !SSL_TREAT_AS_TLS13(s)) {
         int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
         if (mode == EVP_CIPH_CBC_MODE) {
             /* TODO(size_t): Convert me */
@@ -764,7 +786,7 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
     /* Clear our SSL3_RECORD structures */
     memset(wr, 0, sizeof wr);
     for (j = 0; j < numpipes; j++) {
-        unsigned int version = SSL_IS_TLS13(s) ? TLS1_VERSION : s->version;
+        unsigned int version = SSL_TREAT_AS_TLS13(s) ? TLS1_VERSION : s->version;
         unsigned char *compressdata = NULL;
         size_t maxcomplen;
         unsigned int rectype;
@@ -777,7 +799,7 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
          * In TLSv1.3, once encrypting, we always use application data for the
          * record type
          */
-        if (SSL_IS_TLS13(s) && s->enc_write_ctx != NULL)
+        if (SSL_TREAT_AS_TLS13(s) && s->enc_write_ctx != NULL)
             rectype = SSL3_RT_APPLICATION_DATA;
         else
             rectype = type;
@@ -835,16 +857,48 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
             SSL3_RECORD_reset_input(&wr[j]);
         }
 
-        if (SSL_IS_TLS13(s) && s->enc_write_ctx != NULL) {
+        if (SSL_TREAT_AS_TLS13(s) && s->enc_write_ctx != NULL) {
+            size_t rlen;
+
             if (!WPACKET_put_bytes_u8(thispkt, type)) {
                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
                 goto err;
             }
             SSL3_RECORD_add_length(thiswr, 1);
-            /*
-             * TODO(TLS1.3): Padding goes here. Do we need an API to add this?
-             * For now, use no padding
-             */
+
+            /* Add TLS1.3 padding */
+            rlen = SSL3_RECORD_get_length(thiswr);
+            if (rlen < SSL3_RT_MAX_PLAIN_LENGTH) {
+                size_t padding = 0;
+                size_t max_padding = SSL3_RT_MAX_PLAIN_LENGTH - rlen;
+                if (s->record_padding_cb != NULL) {
+                    padding = s->record_padding_cb(s, type, rlen, s->record_padding_arg);
+                } else if (s->block_padding > 0) {
+                    size_t mask = s->block_padding - 1;
+                    size_t remainder;
+
+                    /* optimize for power of 2 */
+                    if ((s->block_padding & mask) == 0)
+                        remainder = rlen & mask;
+                    else
+                        remainder = rlen % s->block_padding;
+                    /* don't want to add a block of padding if we don't have to */
+                    if (remainder == 0)
+                        padding = 0;
+                    else
+                        padding = s->block_padding - remainder;
+                }
+                if (padding > 0) {
+                    /* do not allow the record to exceed max plaintext length */
+                    if (padding > max_padding)
+                        padding = max_padding;
+                    if (!WPACKET_memset(thispkt, 0, padding)) {
+                        SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
+                        goto err;
+                    }
+                    SSL3_RECORD_add_length(thiswr, padding);
+                }
+            }
         }
 
         /*
@@ -887,8 +941,18 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
         SSL3_RECORD_set_length(thiswr, len);
     }
 
-    if (s->method->ssl3_enc->enc(s, wr, numpipes, 1) < 1)
-        goto err;
+    if (s->early_data_state == SSL_EARLY_DATA_WRITING
+            || s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
+        /*
+         * We haven't actually negotiated the version yet, but we're trying to
+         * send early data - so we need to use the the tls13enc function.
+         */
+        if (tls13_enc(s, wr, numpipes, 1) < 1)
+            goto err;
+    } else {
+        if (s->method->ssl3_enc->enc(s, wr, numpipes, 1) < 1)
+            goto err;
+    }
 
     for (j = 0; j < numpipes; j++) {
         size_t origlen;
@@ -929,6 +993,13 @@ int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
             s->msg_callback(1, 0, SSL3_RT_HEADER, recordstart,
                             SSL3_RT_HEADER_LENGTH, s,
                             s->msg_callback_arg);
+
+            if (SSL_TREAT_AS_TLS13(s) && s->enc_write_ctx != NULL) {
+                unsigned char ctype = type;
+
+                s->msg_callback(1, s->version, SSL3_RT_INNER_CONTENT_TYPE,
+                                &ctype, 1, s, s->msg_callback_arg);
+            }
         }
 
         if (!WPACKET_finish(thispkt)) {
@@ -1329,10 +1400,6 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
             dest_maxlen = sizeof s->rlayer.handshake_fragment;
             dest = s->rlayer.handshake_fragment;
             dest_len = &s->rlayer.handshake_fragment_len;
-        } else if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
-            dest_maxlen = sizeof s->rlayer.alert_fragment;
-            dest = s->rlayer.alert_fragment;
-            dest_len = &s->rlayer.alert_fragment_len;
         }
 
         if (dest_maxlen > 0) {
@@ -1341,23 +1408,21 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
                 n = SSL3_RECORD_get_length(rr); /* available bytes */
 
             /* now move 'n' bytes: */
-            while (n-- > 0) {
-                dest[(*dest_len)++] =
-                    SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)];
-                SSL3_RECORD_add_off(rr, 1);
-                SSL3_RECORD_add_length(rr, -1);
-            }
-
-            if (*dest_len < dest_maxlen) {
+            memcpy(dest + *dest_len,
+                   SSL3_RECORD_get_data(rr) + SSL3_RECORD_get_off(rr), n);
+            SSL3_RECORD_add_off(rr, n);
+            SSL3_RECORD_add_length(rr, -n);
+            *dest_len += n;
+            if (SSL3_RECORD_get_length(rr) == 0)
                 SSL3_RECORD_set_read(rr);
+
+            if (*dest_len < dest_maxlen)
                 goto start;     /* fragment was too small */
-            }
         }
     }
 
     /*-
      * s->rlayer.handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
-     * s->rlayer.alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
      * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
      */
 
@@ -1374,21 +1439,29 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
         (s->rlayer.handshake_fragment_len >= 4) &&
         (s->rlayer.handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
         (s->session != NULL) && (s->session->cipher != NULL) &&
-        !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
+        !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
         SSL3_RECORD_set_length(rr, 0);
         SSL3_RECORD_set_read(rr);
         ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
         goto start;
     }
-    if (s->rlayer.alert_fragment_len >= 2) {
-        int alert_level = s->rlayer.alert_fragment[0];
-        int alert_descr = s->rlayer.alert_fragment[1];
-
-        s->rlayer.alert_fragment_len = 0;
+    if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
+        unsigned int alert_level, alert_descr;
+        unsigned char *alert_bytes = SSL3_RECORD_get_data(rr)
+                                     + SSL3_RECORD_get_off(rr);
+        PACKET alert;
+
+        if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr))
+                || !PACKET_get_1(&alert, &alert_level)
+                || !PACKET_get_1(&alert, &alert_descr)
+                || PACKET_remaining(&alert) != 0) {
+            al = SSL_AD_UNEXPECTED_MESSAGE;
+            SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_INVALID_ALERT);
+            goto f_err;
+        }
 
         if (s->msg_callback)
-            s->msg_callback(0, s->version, SSL3_RT_ALERT,
-                            s->rlayer.alert_fragment, 2, s,
+            s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 2, s,
                             s->msg_callback_arg);
 
         if (s->info_callback != NULL)
@@ -1416,6 +1489,15 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
                 return 0;
             }
+            /*
+             * Apart from close_notify the only other warning alert in TLSv1.3
+             * is user_cancelled - which we just ignore.
+             */
+            if (SSL_IS_TLS13(s) && alert_descr != SSL_AD_USER_CANCELLED) {
+                al = SSL_AD_ILLEGAL_PARAMETER;
+                SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
+                goto f_err;
+            }
             /*
              * This is a warning but we receive it if we requested
              * renegotiation and the peer denied it. Terminate with a fatal
@@ -1424,7 +1506,7 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
              * future we might have a renegotiation where we don't care if
              * the peer refused it where we carry on.
              */
-            else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
+            if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
                 al = SSL_AD_HANDSHAKE_FAILURE;
                 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_NO_RENEGOTIATION);
                 goto f_err;
@@ -1470,18 +1552,7 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
      */
     if ((s->rlayer.handshake_fragment_len >= 4)
             && !ossl_statem_get_in_handshake(s)) {
-        /*
-         * To get here we must be trying to read app data but found handshake
-         * data. But if we're trying to read app data, and we're not in init
-         * (which is tested for at the top of this function) then init must be
-         * finished
-         */
-        assert(SSL_is_init_finished(s));
-        if (!SSL_is_init_finished(s)) {
-            al = SSL_AD_INTERNAL_ERROR;
-            SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
-            goto f_err;
-        }
+        int ined = (s->early_data_state == SSL_EARLY_DATA_READING);
 
         /* We found handshake data, so we're going back into init */
         ossl_statem_set_in_init(s, 1);
@@ -1494,6 +1565,14 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
             return -1;
         }
 
+        /*
+         * If we were actually trying to read early data and we found a
+         * handshake message, then we don't want to continue to try and read
+         * the application data any more. It won't be "early" now.
+         */
+        if (ined)
+            return -1;
+
         if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
             if (SSL3_BUFFER_get_left(rbuf) == 0) {
                 /* no read-ahead left? */
@@ -1548,6 +1627,21 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
         if (ossl_statem_app_data_allowed(s)) {
             s->s3->in_read_app_data = 2;
             return -1;
+        } else if (ossl_statem_skip_early_data(s)) {
+            /*
+             * This can happen after a client sends a CH followed by early_data,
+             * but the server responds with a HelloRetryRequest. The server
+             * reads the next record from the client expecting to find a
+             * plaintext ClientHello but gets a record which appears to be
+             * application data. The trial decrypt "works" because null
+             * decryption was applied. We just skip it and move on to the next
+             * record.
+             */
+            if (!early_data_count_ok(s, rr->length,
+                                     EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
+                goto f_err;
+            SSL3_RECORD_set_read(rr);
+            goto start;
         } else {
             al = SSL_AD_UNEXPECTED_MESSAGE;
             SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNEXPECTED_RECORD);