std::span<> for Tweakable_Block_Cipher::set_tweak()

randombit · Jan 4, 2024 · 825007d · 825007d
1 parent d7605c2
commit 825007d
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Showing 3 changed files with 10 additions and 7 deletions.
diff --git a/src/lib/block/block_cipher.h b/src/lib/block/block_cipher.h
@@ -219,7 +219,12 @@ class BOTAN_PUBLIC_API(2, 8) Tweakable_Block_Cipher : public BlockCipher {
       * Different algorithms support different tweak length(s). If called with
       * an unsupported length, Invalid_Argument will be thrown.
       */
-      virtual void set_tweak(const uint8_t tweak[], size_t len) = 0;
+      void set_tweak(std::span<const uint8_t> tweak) { set_tweak_value(tweak); }
+
+      void set_tweak(const uint8_t tweak[], size_t len) { set_tweak_value(std::span(tweak, len)); }
+
+   private:
+      virtual void set_tweak_value(std::span<const uint8_t> tweak) = 0;
 };
 
 /**

diff --git a/src/lib/block/threefish_512/threefish_512.cpp b/src/lib/block/threefish_512/threefish_512.cpp
@@ -249,12 +249,11 @@ void Threefish_512::decrypt_blocks(std::span<const uint8_t> in, std::span<uint8_
    }
 }
 
-void Threefish_512::set_tweak(const uint8_t tweak[], size_t len) {
-   BOTAN_ARG_CHECK(len == 16, "Threefish-512 requires 128 bit tweak");
+void Threefish_512::set_tweak_value(std::span<const uint8_t> tweak) {
+   BOTAN_ARG_CHECK(tweak.size() == 16, "Threefish-512 requires 128 bit tweak");
 
    m_T.resize(3);
-   m_T[0] = load_le<uint64_t>(tweak, 0);
-   m_T[1] = load_le<uint64_t>(tweak, 1);
+   load_le(tweak, m_T[0], m_T[1]);
    m_T[2] = m_T[0] ^ m_T[1];
 }
 

diff --git a/src/lib/block/threefish_512/threefish_512.h b/src/lib/block/threefish_512/threefish_512.h
@@ -17,8 +17,6 @@ namespace Botan {
 */
 class Threefish_512 final : public Block_Cipher_Fixed_Params<64, 64, 0, 1, Tweakable_Block_Cipher> {
    public:
-      void set_tweak(const uint8_t tweak[], size_t len) override;
-
       void clear() override;
 
       std::string name() const override { return "Threefish-512"; }
@@ -29,6 +27,7 @@ class Threefish_512 final : public Block_Cipher_Fixed_Params<64, 64, 0, 1, Tweak
 
    private:
       void key_schedule(std::span<const uint8_t> key) override;
+      void set_tweak_value(std::span<const uint8_t> tweak) override;
       void encrypt_blocks(std::span<const uint8_t> in, std::span<uint8_t> out, size_t blocks) const override;
       void decrypt_blocks(std::span<const uint8_t> in, std::span<uint8_t> out, size_t blocks) const override;