diff -Naurp snort-2.9.0.5.orig/src/detection-plugins/sp_byte_jump.c snort-2.9.0.5/src/detection-plugins/sp_byte_jump.c
--- snort-2.9.0.5.orig/src/detection-plugins/sp_byte_jump.c	2011-01-10 22:41:43.000000000 +0000
+++ snort-2.9.0.5/src/detection-plugins/sp_byte_jump.c	2011-04-29 03:20:08.000005000 +0000
@@ -33,6 +33,7 @@
  *      <offset>: number of bytes into the payload to grab the bytes
  *      Optional:
  *      ["relative"]: offset relative to last pattern match
+ *      ["mask"]: bitmask to apply to the converted bytes (bitwise AND)
  *      ["big"]: process data as big endian (default)
  *      ["little"]: process data as little endian
  *      ["string"]: converted bytes represented as a string needing conversion
@@ -162,6 +163,10 @@ uint32_t ByteJumpHash(void *d)
     a += (u_int32_t)data->byte_order_func;
 #endif
 
+    mix(a,b,c);
+
+    a += data->mask;
+
     final(a,b,c);
                                                                      
     return c;
@@ -178,6 +183,7 @@ int ByteJumpCompare(void *l, void *r)
     if (( left->bytes_to_grab == right->bytes_to_grab) &&
         ( left->offset == right->offset) &&
         ( left->offset_var == right->offset_var) &&
+        ( left->mask == right->mask) &&
         ( left->relative_flag == right->relative_flag) &&
         ( left->data_string_convert_flag == right->data_string_convert_flag) &&
         ( left->from_beginning_flag == right->from_beginning_flag) &&
@@ -307,11 +313,12 @@ static void ByteJumpInit(char *data, Opt
     if (add_detection_option(RULE_OPTION_TYPE_BYTE_JUMP, (void *)idx, &idx_dup) == DETECTION_OPTION_EQUAL)
     {
 #ifdef DEBUG_RULE_OPTION_TREE
-        LogMessage("Duplicate ByteJump:\n%d %d %c %c %c %c %c %d %d\n"
-            "%d %d %c %c %c %c %c %d %d %d\n\n",
+        LogMessage("Duplicate ByteJump:\n%d %d %c %d %c %c %c %c %d %d\n"
+            "%d %d %c %d %c %c %c %c %d %d %d\n\n",
             idx->bytes_to_grab,
             idx->offset,
             idx->relative_flag,
+            idx->mask,
             idx->data_string_convert_flag,
             idx->from_beginning_flag,
             idx->align_flag,
@@ -320,6 +327,7 @@ static void ByteJumpInit(char *data, Opt
             ((ByteJumpData *)idx_dup)->bytes_to_grab,
             ((ByteJumpData *)idx_dup)->offset,
             ((ByteJumpData *)idx_dup)->relative_flag,
+            ((ByteJumpData *)idx_dup)->mask,
             ((ByteJumpData *)idx_dup)->data_string_convert_flag,
             ((ByteJumpData *)idx_dup)->from_beginning_flag,
             ((ByteJumpData *)idx_dup)->align_flag,
@@ -423,6 +431,25 @@ static ByteJumpOverrideData * ByteJumpPa
                 /* the offset is relative to the last pattern match */
                 idx->relative_flag = 1;
             }
+            else if(!strncasecmp(cptr, "mask ", 5))
+            {
+                /* Format of this option is mask xx.
+                 * xx is a positive base 10 number.
+                 */
+                char *mval = &cptr[5];
+                long factor = 0;
+                int mask_len = strlen(cptr);
+                if (mask_len > 5)
+                {
+                    factor = strtol(mval, &endp, 10);
+                }
+                if ((factor <= 0) || (endp != cptr + mask_len))
+                {
+                    FatalError("%s(%d): invalid length mask \"%s\"\n", 
+                            file_name, file_line, cptr);
+                }
+                idx->mask = factor;
+            }
             else if(!strcasecmp(cptr, "from_beginning"))
             {
                 idx->from_beginning_flag = 1;
@@ -688,6 +715,10 @@ int ByteJump(void *option_data, Packet *
                             "grabbed %d of %d bytes, value = %08X\n", 
                             payload_bytes_grabbed, bjd->bytes_to_grab, value););
 
+    /* Adjust the value with the bitmask. */
+    if (bjd->mask)
+        value &= bjd->mask;
+
     /* Adjust the jump_value (# bytes to jump forward) with the multiplier. */
     if (bjd->multiplier)
         jump_value = value * bjd->multiplier;
diff -Naurp snort-2.9.0.5.orig/src/detection-plugins/sp_byte_jump.h snort-2.9.0.5/src/detection-plugins/sp_byte_jump.h
--- snort-2.9.0.5.orig/src/detection-plugins/sp_byte_jump.h	2011-01-10 22:41:43.000000000 +0000
+++ snort-2.9.0.5/src/detection-plugins/sp_byte_jump.h	2011-04-28 04:09:34.000002000 +0000
@@ -31,6 +31,7 @@ typedef struct _ByteJumpData
     uint32_t bytes_to_grab; /* number of bytes to compare */
     int32_t offset;
     uint8_t relative_flag;
+    uint32_t mask;
     uint8_t data_string_convert_flag;
     uint8_t from_beginning_flag;
     uint8_t align_flag;