Implement 'create' operation, add seeding

Seeding is currently only done on the key you specify, in the future
the user should request data that it can seed.

1 files changed, 55 insertions, 0 deletions

diff --git a/src/Hash.cpp b/src/Hash.cpp
new file mode 100644
index 0000000..5d2f914
--- /dev/null
+++ b/src/Hash.cpp
@@ -0,0 +1,55 @@
+#include "../include/Hash.hpp"
+#include "../include/bin2hex.hpp"
+#include <sodium/crypto_generichash_blake2b.h>
+#include <sodium/core.h>
+#include <cstring>
+
+namespace odhtdb
+{
+    struct SodiumInitializer
+    {
+        SodiumInitializer()
+        {
+            if(sodium_init() < 0)
+                throw std::runtime_error("Failed to initialize libsodium");
+        }
+    };
+    
+    static SodiumInitializer __sodiumInitializer;
+    
+    // Source: https://stackoverflow.com/a/11414104 (public license)
+    static size_t fnvHash(const unsigned char *key, int len)
+    {
+        size_t h = 2166136261;
+        for (int i = 0; i < len; i++)
+            h = (h * 16777619) ^ key[i];
+        return h;
+    }
+    
+    Hash::Hash()
+    {
+        memset(data, 0, HASH_BYTE_SIZE);
+    }
+    
+    Hash::Hash(const void *input, const size_t inputSize)
+    {
+        int result = crypto_generichash_blake2b((unsigned char*)data, HASH_BYTE_SIZE, (const unsigned char*)input, inputSize, nullptr, 0);
+        if(result < 0)
+            throw HashException("Failed to hash data using blake2b");
+    }
+    
+    size_t Hash::operator()() const
+    {
+        return fnvHash((const unsigned char*)data, HASH_BYTE_SIZE);
+    }
+    
+    bool Hash::operator==(const Hash &other) const
+    {
+        return memcmp(data, other.data, HASH_BYTE_SIZE) == 0;
+    }
+    
+    std::string Hash::toString() const
+    {
+        return bin2hex(data, HASH_BYTE_SIZE);
+    }
+}