Adds support to the transformations parity[even|odd|zero]7bit

Issues: #968, #969, #967

src/actions/transformations/parity_even_7bit.cc

@@ -30,25 +30,52 @@ namespace modsecurity {
 namespace actions {
 namespace transformations {
 
-ParityEven7bit::ParityEven7bit(std::string action)
-    : Transformation(action) {
-    this->action_kind = 1;
-}
 
 std::string ParityEven7bit::evaluate(std::string value,
     Transaction *transaction) {
-    /**
-     * @todo Implement the transformation ParityEven7bit
-     */
-    if (transaction) {
-#ifndef NO_LOGS
-        transaction->debug(4, "Transformation ParityEven7bit is not" \
-            " implemented yet.");
-#endif
+    std::string ret;
+    unsigned char *input = NULL;
+
+    input = reinterpret_cast<unsigned char *>
+        (malloc(sizeof(char) * value.length()+1));
+
+    if (input == NULL) {
+        return "";
     }
-    return value;
+
+    memcpy(input, value.c_str(), value.length()+1);
+
+    inplace(input, value.length());
+
+    ret.assign(reinterpret_cast<char *>(input), value.length());
+    free(input);
+
+    return ret;
 }
 
+bool ParityEven7bit::inplace(unsigned char *input, u_int64_t input_len) {
+    u_int64_t i;
+
+    i = 0;
+    while (i < input_len) {
+        unsigned int x = input[i];
+
+        input[i] ^= input[i] >> 4;
+        input[i] &= 0xf;
+
+        if ((0x6996 >> input[i]) & 1) {
+            input[i] = x | 0x80;
+        } else {
+            input[i] = x & 0x7f;
+        }
+        i++;
+    }
+
+    return true;
+}
+
+
+
 }  // namespace transformations
 }  // namespace actions
 }  // namespace modsecurity

src/actions/transformations/parity_even_7bit.h

@@ -30,9 +30,10 @@ namespace transformations {
 
 class ParityEven7bit : public Transformation {
  public:
-    explicit ParityEven7bit(std::string action);
-    std::string evaluate(std::string exp,
-        Transaction *transaction) override;
+    explicit ParityEven7bit(std::string action) : Transformation(action) { }
+
+    std::string evaluate(std::string exp, Transaction *transaction) override;
+    static bool inplace(unsigned char *input, u_int64_t input_len);
 };
 
 }  // namespace transformations

src/actions/transformations/parity_odd_7bit.cc

@@ -30,25 +30,51 @@ namespace modsecurity {
 namespace actions {
 namespace transformations {
 
-ParityOdd7bit::ParityOdd7bit(std::string action)
-    : Transformation(action) {
-    this->action_kind = 1;
-}
 
 std::string ParityOdd7bit::evaluate(std::string value,
     Transaction *transaction) {
-    /**
-     * @todo Implement the transformation ParityOdd7bit
-     */
-    if (transaction) {
-#ifndef NO_LOGS
-        transaction->debug(4, "Transformation ParityOdd7bit is not " \
-            "implemented yet.");
-#endif
+    std::string ret;
+    unsigned char *input = NULL;
+
+    input = reinterpret_cast<unsigned char *>
+        (malloc(sizeof(char) * value.length()+1));
+
+    if (input == NULL) {
+        return "";
     }
-    return value;
+
+    memcpy(input, value.c_str(), value.length()+1);
+
+    inplace(input, value.length());
+
+    ret.assign(reinterpret_cast<char *>(input), value.length());
+    free(input);
+
+    return ret;
 }
 
+bool ParityOdd7bit::inplace(unsigned char *input, u_int64_t input_len) {
+    u_int64_t i;
+
+    i = 0;
+    while (i < input_len) {
+        unsigned int x = input[i];
+
+        input[i] ^= input[i] >> 4;
+        input[i] &= 0xf;
+
+        if ((0x6996 >> input[i]) & 1) {
+            input[i] = x & 0x7f;
+        } else {
+            input[i] = x | 0x80;
+        }
+        i++;
+    }
+
+    return true;
+}
+
+
 }  // namespace transformations
 }  // namespace actions
 }  // namespace modsecurity

src/actions/transformations/parity_odd_7bit.h

@@ -30,9 +30,10 @@ namespace transformations {
 
 class ParityOdd7bit : public Transformation {
  public:
-    explicit ParityOdd7bit(std::string action);
-    std::string evaluate(std::string exp,
-        Transaction *transaction) override;
+    explicit ParityOdd7bit(std::string action) : Transformation(action) { }
+
+    std::string evaluate(std::string exp, Transaction *transaction) override;
+    static bool inplace(unsigned char *input, u_int64_t input_len);
 };
 
 }  // namespace transformations

src/actions/transformations/parity_zero_7bit.cc

@@ -30,25 +30,43 @@ namespace modsecurity {
 namespace actions {
 namespace transformations {
 
-ParityZero7bit::ParityZero7bit(std::string action)
-    : Transformation(action) {
-    this->action_kind = 1;
-}
 
 std::string ParityZero7bit::evaluate(std::string value,
     Transaction *transaction) {
-    /**
-     * @todo Implement the transformation ParityZero7bit
-     */
-    if (transaction) {
-#ifndef NO_LOGS
-        transaction->debug(4, "Transformation ParityZero7bit is not" \
-            "implemented yet.");
-#endif
+    std::string ret;
+    unsigned char *input = NULL;
+
+    input = reinterpret_cast<unsigned char *>
+        (malloc(sizeof(char) * value.length()+1));
+
+    if (input == NULL) {
+        return "";
     }
-    return value;
+
+    memcpy(input, value.c_str(), value.length()+1);
+
+    inplace(input, value.length());
+
+    ret.assign(reinterpret_cast<char *>(input), value.length());
+    free(input);
+
+    return ret;
 }
 
+
+bool ParityZero7bit::inplace(unsigned char *input, u_int64_t input_len) {
+    u_int64_t i;
+
+    i = 0;
+    while (i < input_len) {
+        input[i] &= 0x7f;
+        i++;
+    }
+
+    return true;
+}
+
+
 }  // namespace transformations
 }  // namespace actions
 }  // namespace modsecurity

src/actions/transformations/parity_zero_7bit.h

@@ -30,9 +30,10 @@ namespace transformations {
 
 class ParityZero7bit : public Transformation {
  public:
-    explicit ParityZero7bit(std::string action);
-    std::string evaluate(std::string exp,
-        Transaction *transaction) override;
+    explicit ParityZero7bit(std::string action) : Transformation(action) { }
+
+    std::string evaluate(std::string exp, Transaction *transaction) override;
+    static bool inplace(unsigned char *input, u_int64_t input_len);
 };
 
 }  // namespace transformations

src/actions/transformations/transformation.cc

@@ -94,9 +94,9 @@ Transformation* Transformation::instantiate(std::string a) {
     IF_MATCH(normalizePath) { return new NormalisePath(a); }
     IF_MATCH(normalisePath) { return new NormalisePath(a); }
     IF_MATCH(normalisePath) { return new NormalisePath(a); }
-    IF_MATCH(parity_even_7bit) { return new ParityEven7bit(a); }
-    IF_MATCH(parity_odd_7bit) { return new ParityOdd7bit(a); }
-    IF_MATCH(parity_zero_7bit) { return new ParityZero7bit(a); }
+    IF_MATCH(parityEven7bit) { return new ParityEven7bit(a); }
+    IF_MATCH(parityOdd7bit) { return new ParityOdd7bit(a); }
+    IF_MATCH(parityZero7bit) { return new ParityZero7bit(a); }
     IF_MATCH(removeCommentsChar) { return new RemoveCommentsChar(a); }
     IF_MATCH(removeComments) { return new RemoveComments(a); }
     IF_MATCH(removeNulls) { return new RemoveNulls(a); }