From 51528ecf3d90d09351322e172d91eed0cb45b2e7 Mon Sep 17 00:00:00 2001
From: Aqua-sama <aqua@iserlohn-fortress.net>
Date: Sun, 8 Nov 2020 20:34:13 +0200
Subject: Add more test vectors

---
 blowfish.hpp | 50 +++++++++++++++++++++++++++-----------------------
 1 file changed, 27 insertions(+), 23 deletions(-)

(limited to 'blowfish.hpp')

diff --git a/blowfish.hpp b/blowfish.hpp
index 3637335..88d865a 100644
--- a/blowfish.hpp
+++ b/blowfish.hpp
@@ -4,9 +4,12 @@
 
 #include "blowfish_init.hpp"
 #include <algorithm>
+#include <span>
 
 namespace Blowfish {
-template <std::size_t sz> concept is_valid_key_length = (sz < KEYLEN);
+
+template <std::size_t sz>
+concept is_valid_key_length = (KEYLEN_MIN <= sz && sz <= KEYLEN_MAX);
 
 struct Block {
   constexpr Block(uint64_t x) {
@@ -28,23 +31,21 @@ struct Block {
 template <std::size_t keylen>
 requires is_valid_key_length<keylen> class Context {
 public:
-  constexpr Context(const std::array<uint8_t, keylen> &key) {
+  constexpr Context(const std::span<const uint8_t> &key) {
     for (std::size_t i = 0; i < BOXES; ++i) {
       std::copy(S_INIT[i].begin(), S_INIT[i].end(), S[i].begin());
     }
 
-    //
-    std::size_t k = 0;
     for (std::size_t i = 0; i < SUBKEYS; ++i) {
-      uint32_t qk = 0;
-      for (std::size_t j = 0; j < 4; ++j) {
-        qk = (qk << 8) | key[k];
-        ++k;
-        if (k >= keylen) {
-          k = 0;
-        }
-      }
-      P[i] = P_INIT[i] ^ qk;
+        const auto idx0 = (i * 4 + 0) % keylen;
+        const auto idx1 = (i * 4 + 1) % keylen;
+        const auto idx2 = (i * 4 + 2) % keylen;
+        const auto idx3 = (i * 4 + 3) % keylen;
+        const uint32_t qk = (static_cast<uint32_t>(key[idx0]) << 24) +
+                            (static_cast<uint32_t>(key[idx1]) << 16) +
+                            (static_cast<uint32_t>(key[idx2]) << 8) +
+                            static_cast<uint32_t>(key[idx3]);
+        P[i] = P_INIT[i] ^ qk;
     }
 
     Block x(0, 0);
@@ -54,6 +55,7 @@ public:
       P[i] = x.L;
       P[i + 1] = x.R;
     }
+
     for (std::size_t i = 0; i < BOXES; ++i) {
       for (std::size_t j = 0; j < ENTRIES; j += 2) {
         x = encrypt(x);
@@ -65,11 +67,12 @@ public:
 
   constexpr Block encrypt(const Block &x) const {
     Block y(x);
-    for (std::size_t i = 0; i < ROUNDS; ++i) {
-      y.L = y.L ^ P[i];
-      y.R = F(y.L) ^ y.R;
-      std::swap(y.L, y.R);
-    }
+    for (std::size_t i = 0; i < ROUNDS; ++i)
+      [[likely]] {
+        y.L = y.L ^ P[i];
+        y.R = F(y.L) ^ y.R;
+        std::swap(y.L, y.R);
+      }
     std::swap(y.L, y.R);
     y.R = y.R ^ P[16];
     y.L = y.L ^ P[17];
@@ -79,11 +82,12 @@ public:
 
   constexpr Block decrypt(const Block &x) const {
     Block y(x);
-    for (std::size_t i = ROUNDS + 1; i > 1; --i) {
-      y.L = y.L ^ P[i];
-      y.R = F(y.L) ^ y.R;
-      std::swap(y.L, y.R);
-    }
+    for (std::size_t i = ROUNDS + 1; i > 1; --i)
+      [[likely]] {
+        y.L = y.L ^ P[i];
+        y.R = F(y.L) ^ y.R;
+        std::swap(y.L, y.R);
+      }
     std::swap(y.L, y.R);
     y.R = y.R ^ P[1];
     y.L = y.L ^ P[0];
-- 
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