Implements a generic method to retrieve SHA hashes

cpp/src/gandiva/hash_utils.cc

@@ -5,48 +5,13 @@
 
 namespace gandiva {
   const char * HashUtils::hash_using_SHA256(int64_t context, const void *message, size_t message_length) {
-    if(message == nullptr){
-      HashUtils::error_message(context, "A null value was given to be hashed.");
-      return "";
-    }
-
-    EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
-
-    EVP_DigestInit_ex(md_ctx, EVP_sha256(), nullptr);
-
-    EVP_DigestUpdate(md_ctx, message, message_length);
-
-    int sha256_hash_size = EVP_MD_size(EVP_sha256());
-
-    auto* result = static_cast<unsigned char*>(OPENSSL_malloc(sha256_hash_size));
-
-    unsigned int result_length;
-
-    EVP_DigestFinal_ex(md_ctx, result, &result_length);
-
-    char* hex_buffer = new char[4];
-    char* result_buffer = new char[65];
-
-    clean_char_array(hex_buffer);
-    clean_char_array(result_buffer);
-
-    for (unsigned int j = 0; j < result_length; j++) {
-      unsigned char hex_number = result[j];
-      sprintf(hex_buffer, "%02x", hex_number);
-
-      strcat(result_buffer, hex_buffer);
-    }
-
-    result_buffer[64] = '\0';
-
-    // free the resources to avoid memory leaks
-    EVP_MD_CTX_free(md_ctx);
-    delete[] hex_buffer;
-    free(result);
-
-    return result_buffer;
+    return HashUtils::get_hash(context, message, message_length, EVP_sha256());
   }
   const char * HashUtils::hash_using_SHA128(int64_t context, const void *message, size_t message_length) {
+    return HashUtils::get_hash(context, message, message_length, EVP_sha1());
+  }
+
+  const char* HashUtils::get_hash(int64_t context, const void *message, size_t message_length, const EVP_MD *hash_type){
     if(message == nullptr){
       HashUtils::error_message(context, "A null value was given to be hashed.");
       return "";
@@ -54,13 +19,13 @@ namespace gandiva {
 
     EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
 
-    EVP_DigestInit_ex(md_ctx, EVP_sha1(), nullptr);
+    EVP_DigestInit_ex(md_ctx, hash_type, nullptr);
 
     EVP_DigestUpdate(md_ctx, message, message_length);
 
-    int sha128_hash_size = EVP_MD_size(EVP_sha1());
+    int hash_size = EVP_MD_size(hash_type);
 
-    auto* result = static_cast<unsigned char*>(OPENSSL_malloc(sha128_hash_size));
+    auto* result = static_cast<unsigned char*>(OPENSSL_malloc(hash_size));
 
     unsigned int result_length;
 
@@ -89,7 +54,6 @@ namespace gandiva {
     return result_buffer;
   }
 
-
   uint64_t HashUtils::double_to_long(double value) {
     uint64_t result;
     memcpy(&result, &value, sizeof(result));

cpp/src/gandiva/hash_utils.h

@@ -4,17 +4,21 @@
 #include <cstdlib>
 #include <cstdint>
 #include "gandiva/visibility.h"
+#include "openssl/evp.h"
 
 namespace gandiva {
   class GANDIVA_EXPORT HashUtils {
    public:
     static const char * hash_using_SHA256(int64_t context, const void *message, size_t message_length);
+
     static const char *hash_using_SHA128(int64_t context, const void *message, size_t message_length);
 
     static uint64_t double_to_long(double value);
    private:
     static inline void clean_char_array(char *buffer);
 
+    static const char *get_hash(int64_t context, const void *message, size_t message_length, const EVP_MD *hash_type);
+
     static void error_message(int64_t context_ptr, char const *err_msg);
   };
 }