Core/Authserver: Authserver cleanup (PR#25093)

- Fix a handful of 1/256 bugs with most significant byte zero in BigNumber
- Get rid of (most of) the C-style arrays in authserver
- CryptoRandom as a unified source for cryptographic randomness
- Bring our other crypto APIs into 2020
- BigNumber usability improvements
- Authserver is now actually readable as a result of all of the above

2 files changed, 22 insertions, 42 deletions

diff --git a/src/common/Cryptography/Authentication/AuthCrypt.cpp b/src/common/Cryptography/Authentication/AuthCrypt.cpp
index c4ff701f5d1..9d50fb026c3 100644
--- a/src/common/Cryptography/Authentication/AuthCrypt.cpp
+++ b/src/common/Cryptography/Authentication/AuthCrypt.cpp
@@ -16,58 +16,39 @@
  */
 
 #include "AuthCrypt.h"
-#include "Cryptography/HMACSHA1.h"
-#include "Cryptography/BigNumber.h"
+#include "BigNumber.h"
+#include "Errors.h"
+#include "HMAC.h"
 
 #include <cstring>
 
 AuthCrypt::AuthCrypt() :
-    _clientDecrypt(SHA_DIGEST_LENGTH), _serverEncrypt(SHA_DIGEST_LENGTH),
     _initialized(false)
 { }
 
-void AuthCrypt::Init(BigNumber* K)
+void AuthCrypt::Init(std::array<uint8, 40> const& K)
 {
-    uint8 ServerEncryptionKey[SEED_KEY_SIZE] = { 0xCC, 0x98, 0xAE, 0x04, 0xE8, 0x97, 0xEA, 0xCA, 0x12, 0xDD, 0xC0, 0x93, 0x42, 0x91, 0x53, 0x57 };
-    HmacHash serverEncryptHmac(SEED_KEY_SIZE, (uint8*)ServerEncryptionKey);
-    uint8 *encryptHash = serverEncryptHmac.ComputeHash(K);
-
-    uint8 ServerDecryptionKey[SEED_KEY_SIZE] = { 0xC2, 0xB3, 0x72, 0x3C, 0xC6, 0xAE, 0xD9, 0xB5, 0x34, 0x3C, 0x53, 0xEE, 0x2F, 0x43, 0x67, 0xCE };
-    HmacHash clientDecryptHmac(SEED_KEY_SIZE, (uint8*)ServerDecryptionKey);
-    uint8 *decryptHash = clientDecryptHmac.ComputeHash(K);
-
-    //ARC4 _serverDecrypt(encryptHash);
-    _clientDecrypt.Init(decryptHash);
-    _serverEncrypt.Init(encryptHash);
-    //ARC4 _clientEncrypt(decryptHash);
+    uint8 ServerEncryptionKey[] = { 0xCC, 0x98, 0xAE, 0x04, 0xE8, 0x97, 0xEA, 0xCA, 0x12, 0xDD, 0xC0, 0x93, 0x42, 0x91, 0x53, 0x57 };
+    _serverEncrypt.Init(Trinity::Crypto::HMAC_SHA1::GetDigestOf(ServerEncryptionKey, K));
+    uint8 ServerDecryptionKey[] = { 0xC2, 0xB3, 0x72, 0x3C, 0xC6, 0xAE, 0xD9, 0xB5, 0x34, 0x3C, 0x53, 0xEE, 0x2F, 0x43, 0x67, 0xCE };
+    _clientDecrypt.Init(Trinity::Crypto::HMAC_SHA1::GetDigestOf(ServerDecryptionKey, K));
 
     // Drop first 1024 bytes, as WoW uses ARC4-drop1024.
-    uint8 syncBuf[1024];
-    memset(syncBuf, 0, 1024);
-
-    _serverEncrypt.UpdateData(1024, syncBuf);
-    //_clientEncrypt.UpdateData(1024, syncBuf);
-
-    memset(syncBuf, 0, 1024);
-
-    //_serverDecrypt.UpdateData(1024, syncBuf);
-    _clientDecrypt.UpdateData(1024, syncBuf);
+    std::array<uint8, 1024> syncBuf;
+    _serverEncrypt.UpdateData(syncBuf);
+    _clientDecrypt.UpdateData(syncBuf);
 
     _initialized = true;
 }
 
 void AuthCrypt::DecryptRecv(uint8 *data, size_t len)
 {
-    if (!_initialized)
-        return;
-
-    _clientDecrypt.UpdateData(len, data);
+    ASSERT(_initialized);
+    _clientDecrypt.UpdateData(data, len);
 }
 
 void AuthCrypt::EncryptSend(uint8 *data, size_t len)
 {
-    if (!_initialized)
-        return;
-
-    _serverEncrypt.UpdateData(len, data);
+    ASSERT(_initialized);
+    _serverEncrypt.UpdateData(data, len);
 }
diff --git a/src/common/Cryptography/Authentication/AuthCrypt.h b/src/common/Cryptography/Authentication/AuthCrypt.h
index c6d4066350c..cb1a217297a 100644
--- a/src/common/Cryptography/Authentication/AuthCrypt.h
+++ b/src/common/Cryptography/Authentication/AuthCrypt.h
@@ -18,24 +18,23 @@
 #ifndef _AUTHCRYPT_H
 #define _AUTHCRYPT_H
 
-#include "Cryptography/ARC4.h"
-
-class BigNumber;
+#include "ARC4.h"
+#include <array>
 
 class TC_COMMON_API AuthCrypt
 {
     public:
         AuthCrypt();
 
-        void Init(BigNumber* K);
-        void DecryptRecv(uint8 *, size_t);
-        void EncryptSend(uint8 *, size_t);
+        void Init(std::array<uint8, 40> const& K);
+        void DecryptRecv(uint8* data, size_t len);
+        void EncryptSend(uint8* data, size_t len);
 
         bool IsInitialized() const { return _initialized; }
 
     private:
-        ARC4 _clientDecrypt;
-        ARC4 _serverEncrypt;
+        Trinity::Crypto::ARC4 _clientDecrypt;
+        Trinity::Crypto::ARC4 _serverEncrypt;
         bool _initialized;
 };
 #endif