Make sure a bad parameter to RSA_verify_PKCS1_PSS() doesn't lead to a crash.
[openssl.git] / ssl / s3_pkt.c
index f92ec594473af2410741173a3a8585e0472322a3..330918a78aabfde2e893cf96c30f6a262d2fceae 100644 (file)
@@ -129,14 +129,49 @@ int ssl3_read_n(SSL *s, int n, int max, int extend)
         * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
         * [plus s->packet_length bytes if extend == 1].)
         */
-       int i,off,newb;
+       int i,len,left;
+       long align=0;
+       unsigned char *pkt;
+       SSL3_BUFFER *rb;
+
+       if (n <= 0) return n;
+
+       rb    = &(s->s3->rbuf);
+       if (rb->buf == NULL)
+               if (!ssl3_setup_read_buffer(s))
+                       return -1;
+
+       left  = rb->left;
+#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
+       align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
+       align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
+#endif
 
        if (!extend)
                {
                /* start with empty packet ... */
-               if (s->s3->rbuf.left == 0)
-                       s->s3->rbuf.offset = 0;
-               s->packet = s->s3->rbuf.buf + s->s3->rbuf.offset;
+               if (left == 0)
+                       rb->offset = align;
+               else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
+                       {
+                       /* check if next packet length is large
+                        * enough to justify payload alignment... */
+                       pkt = rb->buf + rb->offset;
+                       if (pkt[0] == SSL3_RT_APPLICATION_DATA
+                           && (pkt[3]<<8|pkt[4]) >= 128)
+                               {
+                               /* Note that even if packet is corrupted
+                                * and its length field is insane, we can
+                                * only be led to wrong decision about
+                                * whether memmove will occur or not.
+                                * Header values has no effect on memmove
+                                * arguments and therefore no buffer
+                                * overrun can be triggered. */
+                               memmove (rb->buf+align,pkt,left);
+                               rb->offset = align;
+                               }
+                       }
+               s->packet = rb->buf + rb->offset;
                s->packet_length = 0;
                /* ... now we can act as if 'extend' was set */
                }
@@ -145,57 +180,54 @@ int ssl3_read_n(SSL *s, int n, int max, int extend)
        if ( SSL_version(s) == DTLS1_VERSION &&
                extend)
                {
-               if ( s->s3->rbuf.left > 0 && n > s->s3->rbuf.left)
-                       n = s->s3->rbuf.left;
+               if ( left > 0 && n > left)
+                       n = left;
                }
 
        /* if there is enough in the buffer from a previous read, take some */
-       if (s->s3->rbuf.left >= (int)n)
+       if (left >= n)
                {
                s->packet_length+=n;
-               s->s3->rbuf.left-=n;
-               s->s3->rbuf.offset+=n;
+               rb->left=left-n;
+               rb->offset+=n;
                return(n);
                }
 
        /* else we need to read more data */
-       if (!s->read_ahead)
-               max=n;
 
-       {
-               /* avoid buffer overflow */
-               int max_max = s->s3->rbuf.len - s->packet_length;
-               if (max > max_max)
-                       max = max_max;
-       }
+       len = s->packet_length;
+       pkt = rb->buf+align;
+       /* Move any available bytes to front of buffer:
+        * 'len' bytes already pointed to by 'packet',
+        * 'left' extra ones at the end */
+       if (s->packet != pkt) /* len > 0 */
+               {
+               memmove(pkt, s->packet, len+left);
+               s->packet = pkt;
+               rb->offset = len + align;
+               }
+
+       max = rb->len - rb->offset;
        if (n > max) /* does not happen */
                {
                SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
                return -1;
                }
 
-       off = s->packet_length;
-       newb = s->s3->rbuf.left;
-       /* Move any available bytes to front of buffer:
-        * 'off' bytes already pointed to by 'packet',
-        * 'newb' extra ones at the end */
-       if (s->packet != s->s3->rbuf.buf)
-               {
-               /*  off > 0 */
-               memmove(s->s3->rbuf.buf, s->packet, off+newb);
-               s->packet = s->s3->rbuf.buf;
-               }
+       if (!s->read_ahead)
+               max=n;
 
-       while (newb < n)
+       while (left < n)
                {
-               /* Now we have off+newb bytes at the front of s->s3->rbuf.buf and need
-                * to read in more until we have off+n (up to off+max if possible) */
+               /* Now we have len+left bytes at the front of s->s3->rbuf.buf
+                * and need to read in more until we have len+n (up to
+                * len+max if possible) */
 
                clear_sys_error();
                if (s->rbio != NULL)
                        {
                        s->rwstate=SSL_READING;
-                       i=BIO_read(s->rbio,     &(s->s3->rbuf.buf[off+newb]), max-newb);
+                       i=BIO_read(s->rbio,pkt+len+left, max-left);
                        }
                else
                        {
@@ -205,15 +237,18 @@ int ssl3_read_n(SSL *s, int n, int max, int extend)
 
                if (i <= 0)
                        {
-                       s->s3->rbuf.left = newb;
+                       rb->left = left;
+                       if (s->mode & SSL_MODE_RELEASE_BUFFERS)
+                               if (len+left == 0)
+                                       ssl3_release_read_buffer(s);
                        return(i);
                        }
-               newb+=i;
+               left+=i;
                }
 
        /* done reading, now the book-keeping */
-       s->s3->rbuf.offset = off + n;
-       s->s3->rbuf.left = newb - n;
+       rb->offset += n;
+       rb->left = left - n;
        s->packet_length += n;
        s->rwstate=SSL_NOTHING;
        return(n);
@@ -250,9 +285,9 @@ static int ssl3_get_record(SSL *s)
                extra=SSL3_RT_MAX_EXTRA;
        else
                extra=0;
-       if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
+       if (extra && !s->s3->init_extra)
                {
-               /* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
+               /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
                 * set after ssl3_setup_buffers() was done */
                SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
                return -1;
@@ -275,13 +310,12 @@ again:
                ssl_minor= *(p++);
                version=(ssl_major<<8)|ssl_minor;
                n2s(p,rr->length);
+#if 0
+fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
+#endif
 
                /* Lets check version */
-               if (s->first_packet)
-                       {
-                       s->first_packet=0;
-                       }
-               else
+               if (!s->first_packet)
                        {
                        if (version != s->version)
                                {
@@ -300,7 +334,7 @@ again:
                        goto err;
                        }
 
-               if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
+               if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
                        {
                        al=SSL_AD_RECORD_OVERFLOW;
                        SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
@@ -373,12 +407,13 @@ printf("\n");
        /* r->length is now the compressed data plus mac */
        if (    (sess == NULL) ||
                (s->enc_read_ctx == NULL) ||
-               (s->read_hash == NULL))
+               (EVP_MD_CTX_md(s->read_hash) == NULL))
                clear=1;
 
        if (!clear)
                {
-               mac_size=EVP_MD_size(s->read_hash);
+               /* !clear => s->read_hash != NULL => mac_size != -1 */
+               mac_size=EVP_MD_CTX_size(s->read_hash);
 
                if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
                        {
@@ -466,6 +501,10 @@ printf("\n");
        /* just read a 0 length packet */
        if (rr->length == 0) goto again;
 
+#if 0
+fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
+#endif
+
        return(1);
 
 f_err:
@@ -476,6 +515,7 @@ err:
 
 int ssl3_do_uncompress(SSL *ssl)
        {
+#ifndef OPENSSL_NO_COMP
        int i;
        SSL3_RECORD *rr;
 
@@ -487,12 +527,13 @@ int ssl3_do_uncompress(SSL *ssl)
        else
                rr->length=i;
        rr->data=rr->comp;
-
+#endif
        return(1);
        }
 
 int ssl3_do_compress(SSL *ssl)
        {
+#ifndef OPENSSL_NO_COMP
        int i;
        SSL3_RECORD *wr;
 
@@ -506,6 +547,7 @@ int ssl3_do_compress(SSL *ssl)
                wr->length=i;
 
        wr->input=wr->data;
+#endif
        return(1);
        }
 
@@ -536,8 +578,8 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
        n=(len-tot);
        for (;;)
                {
-               if (n > SSL3_RT_MAX_PLAIN_LENGTH)
-                       nw=SSL3_RT_MAX_PLAIN_LENGTH;
+               if (n > s->max_send_fragment)
+                       nw=s->max_send_fragment;
                else
                        nw=n;
 
@@ -569,14 +611,19 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
        {
        unsigned char *p,*plen;
        int i,mac_size,clear=0;
-       int prefix_len = 0;
+       int prefix_len=0;
+       long align=0;
        SSL3_RECORD *wr;
-       SSL3_BUFFER *wb;
+       SSL3_BUFFER *wb=&(s->s3->wbuf);
        SSL_SESSION *sess;
 
+       if (wb->buf == NULL)
+               if (!ssl3_setup_write_buffer(s))
+                       return -1;
+
        /* first check if there is a SSL3_BUFFER still being written
         * out.  This will happen with non blocking IO */
-       if (s->s3->wbuf.left != 0)
+       if (wb->left != 0)
                return(ssl3_write_pending(s,type,buf,len));
 
        /* If we have an alert to send, lets send it */
@@ -592,18 +639,17 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
                return 0;
 
        wr= &(s->s3->wrec);
-       wb= &(s->s3->wbuf);
        sess=s->session;
 
        if (    (sess == NULL) ||
                (s->enc_write_ctx == NULL) ||
-               (s->write_hash == NULL))
+               (EVP_MD_CTX_md(s->write_hash) == NULL))
                clear=1;
 
        if (clear)
                mac_size=0;
        else
-               mac_size=EVP_MD_size(s->write_hash);
+               mac_size=EVP_MD_CTX_size(s->write_hash);
 
        /* 'create_empty_fragment' is true only when this function calls itself */
        if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
@@ -621,7 +667,8 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
                        if (prefix_len <= 0)
                                goto err;
 
-                       if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
+                       if (prefix_len >
+               (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
                                {
                                /* insufficient space */
                                SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
@@ -632,7 +679,32 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
                s->s3->empty_fragment_done = 1;
                }
 
-       p = wb->buf + prefix_len;
+       if (create_empty_fragment)
+               {
+#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
+               /* extra fragment would be couple of cipher blocks,
+                * which would be multiple of SSL3_ALIGN_PAYLOAD, so
+                * if we want to align the real payload, then we can
+                * just pretent we simply have two headers. */
+               align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
+               align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
+#endif
+               p = wb->buf + align;
+               wb->offset  = align;
+               }
+       else if (prefix_len)
+               {
+               p = wb->buf + wb->offset + prefix_len;
+               }
+       else
+               {
+#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
+               align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
+               align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
+#endif
+               p = wb->buf + align;
+               wb->offset  = align;
+               }
 
        /* write the header */
 
@@ -703,7 +775,6 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 
        /* now let's set up wb */
        wb->left = prefix_len + wr->length;
-       wb->offset = 0;
 
        /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
        s->s3->wpend_tot=len;
@@ -722,6 +793,7 @@ int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
        unsigned int len)
        {
        int i;
+       SSL3_BUFFER *wb=&(s->s3->wbuf);
 
 /* XXXX */
        if ((s->s3->wpend_tot > (int)len)
@@ -740,24 +812,34 @@ int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
                        {
                        s->rwstate=SSL_WRITING;
                        i=BIO_write(s->wbio,
-                               (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
-                               (unsigned int)s->s3->wbuf.left);
+                               (char *)&(wb->buf[wb->offset]),
+                               (unsigned int)wb->left);
                        }
                else
                        {
                        SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
                        i= -1;
                        }
-               if (i == s->s3->wbuf.left)
+               if (i == wb->left)
                        {
-                       s->s3->wbuf.left=0;
+                       wb->left=0;
+                       wb->offset+=i;
+                       if (s->mode & SSL_MODE_RELEASE_BUFFERS)
+                               ssl3_release_write_buffer(s);
                        s->rwstate=SSL_NOTHING;
                        return(s->s3->wpend_ret);
                        }
-               else if (i <= 0)
+               else if (i <= 0) {
+                       if (s->version == DTLS1_VERSION) {
+                               /* For DTLS, just drop it. That's kind of the wh
+ole
+                                  point in using a datagram service */
+                               wb->left = 0;
+                       }
                        return(i);
-               s->s3->wbuf.offset+=i;
-               s->s3->wbuf.left-=i;
+               }
+               wb->offset+=i;
+               wb->left-=i;
                }
        }
 
@@ -796,7 +878,7 @@ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
        void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 
        if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
-               if (!ssl3_setup_buffers(s))
+               if (!ssl3_setup_read_buffer(s))
                        return(-1);
 
        if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
@@ -905,6 +987,8 @@ start:
                                {
                                s->rstate=SSL_ST_READ_HEADER;
                                rr->off=0;
+                               if (s->mode & SSL_MODE_RELEASE_BUFFERS)
+                                       ssl3_release_read_buffer(s);
                                }
                        }
                return(n);
@@ -1087,6 +1171,14 @@ start:
                        goto f_err;
                        }
 
+               /* Check we have a cipher to change to */
+               if (s->s3->tmp.new_cipher == NULL)
+                       {
+                       al=SSL_AD_UNEXPECTED_MESSAGE;
+                       SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
+                       goto f_err;
+                       }
+
                rr->length=0;
 
                if (s->msg_callback)
@@ -1218,6 +1310,13 @@ int ssl3_do_change_cipher_spec(SSL *s)
 
        if (s->s3->tmp.key_block == NULL)
                {
+               if (s->session == NULL) 
+                       {
+                       /* might happen if dtls1_read_bytes() calls this */
+                       SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
+                       return (0);
+                       }
+
                s->session->cipher=s->s3->tmp.new_cipher;
                if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
                }
@@ -1240,8 +1339,6 @@ int ssl3_do_change_cipher_spec(SSL *s)
                }
 
        s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
-               &(s->s3->finish_dgst1),
-               &(s->s3->finish_dgst2),
                sender,slen,s->s3->tmp.peer_finish_md);
 
        return(1);