Adds RemoveNulls trasnformation

src/actions/transformations/remove_nulls.cc

@@ -15,6 +15,8 @@
 
 #include "actions/transformations/remove_nulls.h"
 
+#include <string.h>
+
 #include <iostream>
 #include <string>
 #include <algorithm>
@@ -30,20 +32,31 @@ namespace ModSecurity {
 namespace actions {
 namespace transformations {
 
-RemoveNulls::RemoveNulls(std::string action)
-    : Transformation(action) {
-    this->action_kind = 1;
-}
 
 std::string RemoveNulls::evaluate(std::string value,
     Assay *assay) {
-    /**
-     * @todo Implement the transformation RemoveNulls
-     */
-    assay->debug(4, "Transformation RemoveNulls is not implemented yet.");
-    return value;
+    int64_t i, j;
+
+    char *input = reinterpret_cast<char *>(malloc(value.size()
+        * sizeof(char)));
+    memcpy(input, value.c_str(), value.size());
+
+    i = j = 0;
+    while (i < value.size()) {
+        if (input[i] != '\0') {
+            input[j] = input[i];
+            j++;
+        }
+        i++;
+    }
+
+    std::string ret(input, 0, j);
+    free(input);
+
+    return ret;
 }
 
+
 }  // namespace transformations
 }  // namespace actions
 }  // namespace ModSecurity

src/actions/transformations/remove_nulls.h

@@ -30,7 +30,9 @@ namespace transformations {
 
 class RemoveNulls : public Transformation {
  public:
-    explicit RemoveNulls(std::string action);
+    explicit RemoveNulls(std::string action)
+        : Transformation(action) { }
+
     std::string evaluate(std::string exp,
         Assay *assay) override;
 };

src/actions/transformations/transformation.cc

@@ -94,7 +94,7 @@ Transformation* Transformation::instantiate(std::string a) {
     IF_MATCH(parity_zero_7bit) { return new ParityZero7bit(a); }
     IF_MATCH(remove_comments_char) { return new RemoveCommentsChar(a); }
     IF_MATCH(remove_comments) { return new RemoveComments(a); }
-    IF_MATCH(remove_nulls) { return new RemoveNulls(a); }
+    IF_MATCH(removeNulls) { return new RemoveNulls(a); }
     IF_MATCH(remove_whitespace) { return new RemoveWhitespace(a); }
     IF_MATCH(replace_comments) { return new ReplaceComments(a); }
     IF_MATCH(replace_nulls) { return new ReplaceNulls(a); }

src/utils.cc

@@ -809,5 +809,20 @@ static unsigned char x2c(unsigned char *what) {
 }
 
 
+std::string string_to_hex(const std::string& input) {
+    static const char* const lut = "0123456789ABCDEF";
+    size_t len = input.length();
+
+    std::string output;
+    output.reserve(2 * len);
+    for (size_t i = 0; i < len; ++i) {
+        const unsigned char c = input[i];
+        output.push_back(lut[c >> 4]);
+        output.push_back(lut[c & 15]);
+    }
+    return output;
+}
+
+
 }  // namespace ModSecurity
 

src/utils.h

@@ -40,6 +40,7 @@ namespace ModSecurity {
     int html_entities_decode_inplace(unsigned char *input, int input_len);
     int normalize_path_inplace(unsigned char *input, int input_len,
         int win, int *changed);
+    std::string string_to_hex(const std::string& input);
 }  // namespace ModSecurity
 
 #define SRC_UTILS_H_