Add sha1.*. Remove UTF-8 encode. Protocol handling.

Add common/sha1.h and common/sha1.c so that we have the SHA routines
even if openssl is not available. From the IETF SHA RFC example code.

Remove the UTF-8 encoding hack. This was really just an experiment.

If the protocol passed in the handshake has "binary" then don't base64
encode for the HyBi protocol. This will allow noVNC to request the
binary data be passed raw and not base64 encoded. Unfortunately, the
client doesn't speak first in VNC protocol (bad original design). If
it did then we could determine whether to base64 encode or not based
on the first HyBi frame from the client and whether the binary bit is
set or not. Oh well.

Misc Cleanup:

- Always free response and buf in handshake routine.

- Remove some unused variables.

common/sha1.c

+/*
+ * Copyright (C) The Internet Society (2001).  All Rights Reserved.
+ *
+ * This document and translations of it may be copied and furnished to
+ * others, and derivative works that comment on or otherwise explain it
+ * or assist in its implementation may be prepared, copied, published
+ * and distributed, in whole or in part, without restriction of any
+ * kind, provided that the above copyright notice and this paragraph are
+ * included on all such copies and derivative works.  However, this
+ * document itself may not be modified in any way, such as by removing
+ * the copyright notice or references to the Internet Society or other
+ * Internet organizations, except as needed for the purpose of
+ * developing Internet standards in which case the procedures for
+ * copyrights defined in the Internet Standards process must be
+ * followed, or as required to translate it into languages other than
+ * English.
+ *
+ * The limited permissions granted above are perpetual and will not be
+ * revoked by the Internet Society or its successors or assigns.
+ *
+ * This document and the information contained herein is provided on an
+ * "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+ * TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+ * HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+ *  sha1.c
+ *
+ *  Description:
+ *      This file implements the Secure Hashing Algorithm 1 as
+ *      defined in FIPS PUB 180-1 published April 17, 1995.
+ *
+ *      The SHA-1, produces a 160-bit message digest for a given
+ *      data stream.  It should take about 2**n steps to find a
+ *      message with the same digest as a given message and
+ *      2**(n/2) to find any two messages with the same digest,
+ *      when n is the digest size in bits.  Therefore, this
+ *      algorithm can serve as a means of providing a
+ *      "fingerprint" for a message.
+ *
+ *  Portability Issues:
+ *      SHA-1 is defined in terms of 32-bit "words".  This code
+ *      uses <stdint.h> (included via "sha1.h" to define 32 and 8
+ *      bit unsigned integer types.  If your C compiler does not
+ *      support 32 bit unsigned integers, this code is not
+ *      appropriate.
+ *
+ *  Caveats:
+ *      SHA-1 is designed to work with messages less than 2^64 bits
+ *      long.  Although SHA-1 allows a message digest to be generated
+ *      for messages of any number of bits less than 2^64, this
+ *      implementation only works with messages with a length that is
+ *      a multiple of the size of an 8-bit character.
+ *
+ */
+
+#include "sha1.h"
+
+/*
+ *  Define the SHA1 circular left shift macro
+ */
+#define SHA1CircularShift(bits,word) \
+                (((word) << (bits)) | ((word) >> (32-(bits))))
+
+/* Local Function Prototyptes */
+void SHA1PadMessage(SHA1Context *);
+void SHA1ProcessMessageBlock(SHA1Context *);
+
+/*
+ *  SHA1Reset
+ *
+ *  Description:
+ *      This function will initialize the SHA1Context in preparation
+ *      for computing a new SHA1 message digest.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to reset.
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Reset(SHA1Context *context)
+{
+    if (!context)
+    {
+        return shaNull;
+    }
+
+    context->Length_Low             = 0;
+    context->Length_High            = 0;
+    context->Message_Block_Index    = 0;
+
+    context->Intermediate_Hash[0]   = 0x67452301;
+    context->Intermediate_Hash[1]   = 0xEFCDAB89;
+    context->Intermediate_Hash[2]   = 0x98BADCFE;
+    context->Intermediate_Hash[3]   = 0x10325476;
+    context->Intermediate_Hash[4]   = 0xC3D2E1F0;
+
+    context->Computed   = 0;
+    context->Corrupted  = 0;
+    return shaSuccess;
+}
+
+/*
+ *  SHA1Result
+ *
+ *  Description:
+ *      This function will return the 160-bit message digest into the
+ *      Message_Digest array  provided by the caller.
+ *      NOTE: The first octet of hash is stored in the 0th element,
+ *            the last octet of hash in the 19th element.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to use to calculate the SHA-1 hash.
+ *      Message_Digest: [out]
+ *          Where the digest is returned.
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Result( SHA1Context *context,
+                uint8_t Message_Digest[SHA1HashSize])
+{
+    int i;
+
+    if (!context || !Message_Digest)
+    {
+        return shaNull;
+    }
+
+    if (context->Corrupted)
+    {
+        return context->Corrupted;
+    }
+
+    if (!context->Computed)
+    {
+        SHA1PadMessage(context);
+        for(i=0; i<64; ++i)
+        {
+            /* message may be sensitive, clear it out */
+            context->Message_Block[i] = 0;
+        }
+        context->Length_Low = 0;    /* and clear length */
+        context->Length_High = 0;
+        context->Computed = 1;
+    }
+
+    for(i = 0; i < SHA1HashSize; ++i)
+    {
+        Message_Digest[i] = context->Intermediate_Hash[i>>2]
+                            >> 8 * ( 3 - ( i & 0x03 ) );
+    }
+
+    return shaSuccess;
+}
+
+/*
+ *  SHA1Input
+ *
+ *  Description:
+ *      This function accepts an array of octets as the next portion
+ *      of the message.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The SHA context to update
+ *      message_array: [in]
+ *          An array of characters representing the next portion of
+ *          the message.
+ *      length: [in]
+ *          The length of the message in message_array
+ *
+ *  Returns:
+ *      sha Error Code.
+ *
+ */
+int SHA1Input(    SHA1Context    *context,
+                  const uint8_t  *message_array,
+                  unsigned       length)
+{
+    if (!length)
+    {
+        return shaSuccess;
+    }
+
+    if (!context || !message_array)
+    {
+        return shaNull;
+    }
+
+    if (context->Computed)
+    {
+        context->Corrupted = shaStateError;
+        return shaStateError;
+    }
+
+    if (context->Corrupted)
+    {
+         return context->Corrupted;
+    }
+    while(length-- && !context->Corrupted)
+    {
+    context->Message_Block[context->Message_Block_Index++] =
+                    (*message_array & 0xFF);
+
+    context->Length_Low += 8;
+    if (context->Length_Low == 0)
+    {
+        context->Length_High++;
+        if (context->Length_High == 0)
+        {
+            /* Message is too long */
+            context->Corrupted = 1;
+        }
+    }
+
+    if (context->Message_Block_Index == 64)
+    {
+        SHA1ProcessMessageBlock(context);
+    }
+
+    message_array++;
+    }
+
+    return shaSuccess;
+}
+
+/*
+ *  SHA1ProcessMessageBlock
+ *
+ *  Description:
+ *      This function will process the next 512 bits of the message
+ *      stored in the Message_Block array.
+ *
+ *  Parameters:
+ *      None.
+ *
+ *  Returns:
+ *      Nothing.
+ *
+ *  Comments:
+ *      Many of the variable names in this code, especially the
+ *      single character names, were used because those were the
+ *      names used in the publication.
+ *
+ *
+ */
+void SHA1ProcessMessageBlock(SHA1Context *context)
+{
+    const uint32_t K[] =    {       /* Constants defined in SHA-1   */
+                            0x5A827999,
+                            0x6ED9EBA1,
+                            0x8F1BBCDC,
+                            0xCA62C1D6
+                            };
+    int           t;                 /* Loop counter                */
+    uint32_t      temp;              /* Temporary word value        */
+    uint32_t      W[80];             /* Word sequence               */
+    uint32_t      A, B, C, D, E;     /* Word buffers                */
+
+    /*
+     *  Initialize the first 16 words in the array W
+     */
+    for(t = 0; t < 16; t++)
+    {
+        W[t] = context->Message_Block[t * 4] << 24;
+        W[t] |= context->Message_Block[t * 4 + 1] << 16;
+        W[t] |= context->Message_Block[t * 4 + 2] << 8;
+        W[t] |= context->Message_Block[t * 4 + 3];
+    }
+
+    for(t = 16; t < 80; t++)
+    {
+       W[t] = SHA1CircularShift(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+    }
+
+    A = context->Intermediate_Hash[0];
+    B = context->Intermediate_Hash[1];
+    C = context->Intermediate_Hash[2];
+    D = context->Intermediate_Hash[3];
+    E = context->Intermediate_Hash[4];
+
+    for(t = 0; t < 20; t++)
+    {
+        temp =  SHA1CircularShift(5,A) +
+                ((B & C) | ((~B) & D)) + E + W[t] + K[0];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 20; t < 40; t++)
+    {
+        temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[1];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 40; t < 60; t++)
+    {
+        temp = SHA1CircularShift(5,A) +
+               ((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    for(t = 60; t < 80; t++)
+    {
+        temp = SHA1CircularShift(5,A) + (B ^ C ^ D) + E + W[t] + K[3];
+        E = D;
+        D = C;
+        C = SHA1CircularShift(30,B);
+        B = A;
+        A = temp;
+    }
+
+    context->Intermediate_Hash[0] += A;
+    context->Intermediate_Hash[1] += B;
+    context->Intermediate_Hash[2] += C;
+    context->Intermediate_Hash[3] += D;
+    context->Intermediate_Hash[4] += E;
+
+    context->Message_Block_Index = 0;
+}
+
+
+/*
+ *  SHA1PadMessage
+ *
+ *  Description:
+ *      According to the standard, the message must be padded to an even
+ *      512 bits.  The first padding bit must be a '1'.  The last 64
+ *      bits represent the length of the original message.  All bits in
+ *      between should be 0.  This function will pad the message
+ *      according to those rules by filling the Message_Block array
+ *      accordingly.  It will also call the ProcessMessageBlock function
+ *      provided appropriately.  When it returns, it can be assumed that
+ *      the message digest has been computed.
+ *
+ *  Parameters:
+ *      context: [in/out]
+ *          The context to pad
+ *      ProcessMessageBlock: [in]
+ *          The appropriate SHA*ProcessMessageBlock function
+ *  Returns:
+ *      Nothing.
+ *
+ */
+
+void SHA1PadMessage(SHA1Context *context)
+{
+    /*
+     *  Check to see if the current message block is too small to hold
+     *  the initial padding bits and length.  If so, we will pad the
+     *  block, process it, and then continue padding into a second
+     *  block.
+     */
+    if (context->Message_Block_Index > 55)
+    {
+        context->Message_Block[context->Message_Block_Index++] = 0x80;
+        while(context->Message_Block_Index < 64)
+        {
+            context->Message_Block[context->Message_Block_Index++] = 0;
+        }
+
+        SHA1ProcessMessageBlock(context);
+
+        while(context->Message_Block_Index < 56)
+        {
+            context->Message_Block[context->Message_Block_Index++] = 0;
+        }
+    }
+    else
+    {
+        context->Message_Block[context->Message_Block_Index++] = 0x80;
+        while(context->Message_Block_Index < 56)
+        {
+            context->Message_Block[context->Message_Block_Index++] = 0;
+        }
+    }
+
+    /*
+     *  Store the message length as the last 8 octets
+     */
+    context->Message_Block[56] = context->Length_High >> 24;
+    context->Message_Block[57] = context->Length_High >> 16;
+    context->Message_Block[58] = context->Length_High >> 8;
+    context->Message_Block[59] = context->Length_High;
+    context->Message_Block[60] = context->Length_Low >> 24;
+    context->Message_Block[61] = context->Length_Low >> 16;
+    context->Message_Block[62] = context->Length_Low >> 8;
+    context->Message_Block[63] = context->Length_Low;
+
+    SHA1ProcessMessageBlock(context);
+}

common/sha1.h

+/*
+ * Copyright (C) The Internet Society (2001).  All Rights Reserved.
+ *
+ * This document and translations of it may be copied and furnished to
+ * others, and derivative works that comment on or otherwise explain it
+ * or assist in its implementation may be prepared, copied, published
+ * and distributed, in whole or in part, without restriction of any
+ * kind, provided that the above copyright notice and this paragraph are
+ * included on all such copies and derivative works.  However, this
+ * document itself may not be modified in any way, such as by removing
+ * the copyright notice or references to the Internet Society or other
+ * Internet organizations, except as needed for the purpose of
+ * developing Internet standards in which case the procedures for
+ * copyrights defined in the Internet Standards process must be
+ * followed, or as required to translate it into languages other than
+ * English.
+ *
+ * The limited permissions granted above are perpetual and will not be
+ * revoked by the Internet Society or its successors or assigns.
+ *
+ * This document and the information contained herein is provided on an
+ * "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+ * TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+ * HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+ *  sha1.h
+ *
+ *  Description:
+ *      This is the header file for code which implements the Secure
+ *      Hashing Algorithm 1 as defined in FIPS PUB 180-1 published
+ *      April 17, 1995.
+ *
+ *      Many of the variable names in this code, especially the
+ *      single character names, were used because those were the names
+ *      used in the publication.
+ *
+ *      Please read the file sha1.c for more information.
+ *
+ */
+
+
+#ifndef _SHA1_H_
+#define _SHA1_H_
+
+#include <stdint.h>
+/*
+ * If you do not have the ISO standard stdint.h header file, then you
+ * must typdef the following:
+ *    name              meaning
+ *  uint32_t         unsigned 32 bit integer
+ *  uint8_t          unsigned 8 bit integer (i.e., unsigned char)
+ *  int_least16_t    integer of >= 16 bits
+ *
+ */
+
+#ifndef _SHA_enum_
+#define _SHA_enum_
+enum
+{
+    shaSuccess = 0,
+    shaNull,            /* Null pointer parameter */
+    shaInputTooLong,    /* input data too long */
+    shaStateError       /* called Input after Result */
+};
+#endif
+#define SHA1HashSize 20
+
+/*
+ *  This structure will hold context information for the SHA-1
+ *  hashing operation
+ */
+typedef struct SHA1Context
+{
+    uint32_t Intermediate_Hash[SHA1HashSize/4]; /* Message Digest  */
+
+    uint32_t Length_Low;            /* Message length in bits      */
+    uint32_t Length_High;           /* Message length in bits      */
+
+                               /* Index into message block array   */
+    int_least16_t Message_Block_Index;
+    uint8_t Message_Block[64];      /* 512-bit message blocks      */
+
+    int Computed;               /* Is the digest computed?         */
+    int Corrupted;             /* Is the message digest corrupted? */
+} SHA1Context;
+
+/*
+ *  Function Prototypes
+ */
+int SHA1Reset(  SHA1Context *);
+int SHA1Input(  SHA1Context *,
+                const uint8_t *,
+                unsigned int);
+int SHA1Result( SHA1Context *,
+                uint8_t Message_Digest[SHA1HashSize]);
+
+#endif

libvncserver/Makefile.am

@@ -24,7 +24,7 @@ WEBSOCKETSSSLSRCS = rfbssl_none.c
 #endif
 endif
 
-WEBSOCKETSSRCS = websockets.c ../common/md5.c $(WEBSOCKETSSSLSRCS)
+WEBSOCKETSSRCS = websockets.c ../common/md5.c ../common/sha1.c $(WEBSOCKETSSSLSRCS)
 endif
 
 includedir=$(prefix)/include/rfb

libvncserver/websockets.c

@@ -31,8 +31,10 @@
 /* errno */
 #include <errno.h>
 
-#include <md5.h>
 #include <byteswap.h>
+#include <string.h>
+#include "md5.h"
+#include "sha1.h"
 #include "rfbconfig.h"
 #include "rfbssl.h"
 
@@ -58,10 +60,12 @@ enum {
   WEBSOCKETS_VERSION_HYBI
 };
 
+#if 0
 #include <sys/syscall.h>
 static int gettid() {
     return (int)syscall(SYS_gettid);
 }
+#endif
 
 typedef int (*wsEncodeFunc)(rfbClientPtr cl, const char *src, int len, char **dst);
 typedef int (*wsDecodeFunc)(rfbClientPtr cl, char *dst, int len);
@@ -162,23 +166,36 @@ min (int a, int b) {
     return a < b ? a : b;
 }
 
-#ifdef LIBVNCSERVER_WITH_CLIENT_GCRYPT
-#else
-#include <openssl/sha.h>
 
-static void webSocketsGenSha1Key(char *target, int size, char *key)
+void
+webSocketsGenSha1Key(char * target, int size, char *key)
 {
-    SHA_CTX c;
-    unsigned char tmp[SHA_DIGEST_LENGTH];
-
-    SHA1_Init(&c);
-    SHA1_Update(&c, key, strlen(key));
-    SHA1_Update(&c, GUID, sizeof(GUID) - 1);
-    SHA1_Final(tmp, &c);
-    if (-1 == __b64_ntop(tmp, SHA_DIGEST_LENGTH, target, size))
-	rfbErr("b64_ntop failed\n");
+    int len;
+    SHA1Context sha;
+    uint8_t digest[SHA1HashSize];
+    
+    if (size < B64LEN(SHA1HashSize) + 1) {
+        rfbErr("webSocketsGenSha1Key: not enough space in target\n");
+        target[0] = '\0';
+        return;
+    }
+
+    SHA1Reset(&sha);
+    SHA1Input(&sha, (unsigned char *)key, strlen(key));
+    SHA1Input(&sha, (unsigned char *)GUID, strlen(GUID));
+    SHA1Result(&sha, digest);
+
+    len = __b64_ntop((unsigned char *)digest, SHA1HashSize, target, size);
+    if (len < size - 1) {
+        rfbErr("webSocketsGenSha1Key: b64_ntop failed\n");
+        target[0] = '\0';
+        return;
+    }
+
+    target[len] = '\0';
+    return;
 }
-#endif
+
 
 /*
  * rfbWebSocketsHandshake is called to handle new WebSockets connections
@@ -237,7 +254,7 @@ static rfbBool
 webSocketsHandshake(rfbClientPtr cl, char *scheme)
 {
     char *buf, *response, *line;
-    int n, linestart = 0, len = 0, llen, base64 = 0;
+    int n, linestart = 0, len = 0, llen, base64 = TRUE;
     char prefix[5], trailer[17];
     char *path = NULL, *host = NULL, *origin = NULL, *protocol = NULL;
     char *key1 = NULL, *key2 = NULL, *key3 = NULL;
@@ -268,6 +285,8 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
                 rfbLog("webSocketsHandshake: client gone\n");
             else
                 rfbLogPerror("webSocketsHandshake: read");
+            free(response);
+            free(buf);
             return FALSE;
         }
 
@@ -285,6 +304,8 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
                             rfbLog("webSocketsHandshake: client gone\n");
                         else
                             rfbLogPerror("webSocketsHandshake: read");
+                        free(response);
+                        free(buf);
                         return FALSE;
                     }
                     rfbLog("Got key3\n");
@@ -298,7 +319,6 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
                 /* 16 = 4 ("GET ") + 1 ("/.*") + 11 (" HTTP/1.1\r\n") */
                 path = line+4;
                 buf[len-11] = '\0'; /* Trim trailing " HTTP/1.1\r\n" */
-                base64 = TRUE;
                 cl->wspath = strdup(path);
                 /* rfbLog("Got path: %s\n", path); */
             } else if ((strncasecmp("host: ", line, min(llen,6))) == 0) {
@@ -345,14 +365,25 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
         return FALSE;
     }
 
-    /*
-    if ((!protocol) || (!strcasestr(protocol, "base64"))) {
-        rfbErr("webSocketsHandshake: base64 subprotocol not supported by client\n");
-        free(response);
-        free(buf);
-        return FALSE;
+    if ((protocol) && (strstr(protocol, "binary"))) {
+        if (! sec_ws_version) {
+            rfbErr("webSocketsHandshake: 'binary' protocol not supported with Hixie\n");
+            free(response);
+            free(buf);
+            return FALSE;
+        }
+        rfbLog("  - webSocketsHandshake: using binary/raw encoding\n");
+        base64 = FALSE;
+        protocol = "binary";
+    } else {
+        rfbLog("  - webSocketsHandshake: using base64 encoding\n");
+        base64 = TRUE;
+        if ((protocol) && (strstr(protocol, "base64"))) {
+            protocol = "base64";
+        } else {
+            protocol = "";
+        }
     }
-    */
 
     /*
      * Generate the WebSockets server response based on the the headers sent
@@ -360,7 +391,7 @@ webSocketsHandshake(rfbClientPtr cl, char *scheme)
      */
 
     if (sec_ws_version) {
-	char accept[SHA_DIGEST_LENGTH * 3];
+	char accept[B64LEN(SHA1HashSize) + 1];
 	rfbLog("  - WebSockets client version hybi-%02d\n", sec_ws_version);
 	webSocketsGenSha1Key(accept, sizeof(accept), sec_ws_key);
 	len = snprintf(response, WEBSOCKETS_MAX_HANDSHAKE_LEN,
@@ -457,38 +488,16 @@ webSocketsGenMd5(char * target, char *key1, char *key2, char *key3)
 static int
 webSocketsEncodeHixie(rfbClientPtr cl, const char *src, int len, char **dst)
 {
-    int i, sz = 0;
-    unsigned char chr;
+    int sz = 0;
     ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
 
     wsctx->encodeBuf[sz++] = '\x00';
-    if (wsctx->base64) {
-        len = __b64_ntop((unsigned char *)src, len, wsctx->encodeBuf+sz, sizeof(wsctx->encodeBuf) - (sz + 1));
-        if (len < 0) {
-            return len;
-        }
-        sz += len;
-    } else {
-        for (i=0; i < len; i++) {
-            chr = src[i];
-            if (chr < 128) {
-                if (chr == 0x00) {
-                    wsctx->encodeBuf[sz++] = '\xc4';
-                    wsctx->encodeBuf[sz++] = '\x80';
-                } else {
-                    wsctx->encodeBuf[sz++] = chr;
-                }
-            } else {
-                if (chr < 192) {
-                    wsctx->encodeBuf[sz++] = '\xc2';
-                    wsctx->encodeBuf[sz++] = chr;
-                } else {
-                    wsctx->encodeBuf[sz++] = '\xc3';
-                    wsctx->encodeBuf[sz++] = chr - 64;
-                }
-            }
-        }
+    len = __b64_ntop((unsigned char *)src, len, wsctx->encodeBuf+sz, sizeof(wsctx->encodeBuf) - (sz + 1));
+    if (len < 0) {
+        return len;
     }
+    sz += len;
+
     wsctx->encodeBuf[sz++] = '\xff';
     *dst = wsctx->encodeBuf;
     return sz;
@@ -524,9 +533,8 @@ ws_peek(rfbClientPtr cl, char *buf, int len)
 static int
 webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len)
 {
-    int retlen = 0, n, i, avail, modlen, needlen, actual;
+    int retlen = 0, n, i, avail, modlen, needlen;
     char *buf, *end = NULL;
-    unsigned char chr, chr2;
     ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
 
     buf = wsctx->decodeBuf;
@@ -539,133 +547,75 @@ webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len)
     }
 
 
-    if (wsctx->base64) {
-        /* Base64 encoded WebSockets stream */
+    /* Base64 encoded WebSockets stream */
 
-        if (buf[0] == '\xff') {
-            i = ws_read(cl, buf, 1); /* Consume marker */
-            buf++;
-            n--;
-        }
-        if (n == 0) {
-            errno = EAGAIN;
-            return -1;
-        }
-        if (buf[0] == '\x00') {
-            i = ws_read(cl, buf, 1); /* Consume marker */
-            buf++;
-            n--;
-        }
-        if (n == 0) {
-            errno = EAGAIN;
-            return -1;
-        }
-
-        /* end = memchr(buf, '\xff', len*2+2); */
-        end = memchr(buf, '\xff', n);
-        if (!end) {
-            end = buf + n;
-        }
-        avail = end - buf;
-
-        len -= wsctx->carrylen;
-
-        /* Determine how much base64 data we need */
-        modlen = len + (len+2)/3;
-        needlen = modlen;
-        if (needlen % 4) {
-            needlen += 4 - (needlen % 4);
-        }
+    if (buf[0] == '\xff') {
+        i = ws_read(cl, buf, 1); /* Consume marker */
+        buf++;
+        n--;
+    }
+    if (n == 0) {
+        errno = EAGAIN;
+        return -1;
+    }
+    if (buf[0] == '\x00') {
+        i = ws_read(cl, buf, 1); /* Consume marker */
+        buf++;
+        n--;
+    }
+    if (n == 0) {
+        errno = EAGAIN;
+        return -1;
+    }
 
-        if (needlen > avail) {
-            /* rfbLog("Waiting for more base64 data\n"); */
-            errno = EAGAIN;
-            return -1;
-        }
+    /* end = memchr(buf, '\xff', len*2+2); */
+    end = memchr(buf, '\xff', n);
+    if (!end) {
+        end = buf + n;
+    }
+    avail = end - buf;
 
-        /* Any carryover from previous decode */
-        for (i=0; i < wsctx->carrylen; i++) {
-	    /* rfbLog("Adding carryover %d\n", wsctx->carryBuf[i]); */
-            dst[i] = wsctx->carryBuf[i];
-            retlen += 1;
-        }
+    len -= wsctx->carrylen;
 
-        /* Decode the rest of what we need */
-        buf[needlen] = '\x00';  /* Replace end marker with end of string */
-        /* rfbLog("buf: %s\n", buf); */
-        n = __b64_pton(buf, (unsigned char *)dst+retlen, 2+len);
-        if (n < len) {
-            rfbErr("Base64 decode error\n");
-            errno = EIO;
-            return -1;
-        }
-        retlen += n;
+    /* Determine how much base64 data we need */
+    modlen = len + (len+2)/3;
+    needlen = modlen;
+    if (needlen % 4) {
+        needlen += 4 - (needlen % 4);
+    }
 
-        /* Consume the data from socket */
-        i = ws_read(cl, buf, needlen);
+    if (needlen > avail) {
+        /* rfbLog("Waiting for more base64 data\n"); */
+        errno = EAGAIN;
+        return -1;
+    }
 
-        wsctx->carrylen = n - len;
-        retlen -= wsctx->carrylen;
-        for (i=0; i < wsctx->carrylen; i++) {
-            /* rfbLog("Saving carryover %d\n", dst[retlen + i]); */
-            wsctx->carryBuf[i] = dst[retlen + i];
-        }
-    } else {
-        /* UTF-8 encoded WebSockets stream */
-
-        actual = 0;
-        for (needlen = 0; needlen < n && actual < len; needlen++) {
-            chr = buf[needlen];
-            if ((chr > 0) && (chr < 128)) {
-                actual++;
-            } else if ((chr > 127) && (chr < 255)) {
-                if (needlen + 1 >= n) {
-                    break;
-                }
-                needlen++;
-                actual++;
-            }
-        }
+    /* Any carryover from previous decode */
+    for (i=0; i < wsctx->carrylen; i++) {
+        /* rfbLog("Adding carryover %d\n", wsctx->carryBuf[i]); */
+        dst[i] = wsctx->carryBuf[i];
+        retlen += 1;
+    }
 
-        if (actual < len) {
-            errno = EAGAIN;
-            return -1;
-        }
+    /* Decode the rest of what we need */
+    buf[needlen] = '\x00';  /* Replace end marker with end of string */
+    /* rfbLog("buf: %s\n", buf); */
+    n = __b64_pton(buf, (unsigned char *)dst+retlen, 2+len);
+    if (n < len) {
+        rfbErr("Base64 decode error\n");
+        errno = EIO;
+        return -1;
+    }
+    retlen += n;
 
-        /* Consume what we need */
-        if ((n = ws_read(cl, buf, needlen)) < needlen) {
-            return n;
-        }
+    /* Consume the data from socket */
+    i = ws_read(cl, buf, needlen);
 
-        while (retlen < len) {
-            chr = buf[0];
-            buf += 1;
-            if (chr == 0) {
-                /* Begin frame marker, just skip it */
-            } else if (chr == 255) {
-                /* Begin frame marker, just skip it */
-	    } else if (chr < 128) {
-                dst[retlen++] = chr;
-            } else {
-                chr2 = buf[0];
-                buf += 1;
-                switch (chr) {
-                case (unsigned char) '\xc2':
-                    dst[retlen++] = chr2;
-                    break;
-                case (unsigned char) '\xc3':
-                    dst[retlen++] = chr2 + 64;
-                    break;
-                case (unsigned char) '\xc4':
-                    dst[retlen++] = 0;
-                    break;
-                default:
-                    rfbErr("Invalid UTF-8 encoding\n");
-                    errno = EIO;
-                    return -1;
-                }
-            }
-        }
+    wsctx->carrylen = n - len;
+    retlen -= wsctx->carrylen;
+    for (i=0; i < wsctx->carrylen; i++) {
+        /* rfbLog("Saving carryover %d\n", dst[retlen + i]); */
+        wsctx->carryBuf[i] = dst[retlen + i];
     }
 
     /* rfbLog("<< webSocketsDecode, retlen: %d\n", retlen); */
@@ -675,7 +625,7 @@ webSocketsDecodeHixie(rfbClientPtr cl, char *dst, int len)
 static int
 webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len)
 {
-    char *buf, *payload, *rbuf;
+    char *buf, *payload;
     int ret = -1, result = -1;
     int total = 0;
     ws_mask_t mask;
@@ -683,7 +633,7 @@ webSocketsDecodeHybi(rfbClientPtr cl, char *dst, int len)
     int i, j;
     unsigned char opcode;
     ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
-    int flength, fin, fhlen, blen;
+    int flength, fin, fhlen;
 
     // rfbLog(" <== %s[%d]: %d cl: %p, wsctx: %p-%p (%d)\n", __func__, gettid(), len, cl, wsctx, (char *)wsctx + sizeof(ws_ctx_t), sizeof(ws_ctx_t));