From 4720b5ac21163936fb47f524037a6f12ce6e6ce2 Mon Sep 17 00:00:00 2001
From: Egor Tensin <egor@tensin.name>
Date: Wed, 22 Jul 2026 18:31:50 +0200
Subject: rewrite: the beginning

This a giant fuck-you to myself while I have nothing (actually, tons of
things) to do in a hospital.

* The giant screens of preprocessor code are gone, they always sucked,
  fuck them.
* Switched everything to the "boxes" interface as the only one
  remaining.
* Restuctured things in aes/ so that the files they're in make at least
  a little bit of sense.
* Removed a bunch of cruft and prematurely generic code.
* This is half-baked at best: I just made sure that the tests pass. A
  lot of cleanup awaits.
---
 aesxx/utils/decrypt_block.cpp | 133 +++---------------------------------------
 1 file changed, 7 insertions(+), 126 deletions(-)

(limited to 'aesxx/utils/decrypt_block.cpp')

diff --git a/aesxx/utils/decrypt_block.cpp b/aesxx/utils/decrypt_block.cpp
index c8edb34..7a296ff 100644
--- a/aesxx/utils/decrypt_block.cpp
+++ b/aesxx/utils/decrypt_block.cpp
@@ -3,7 +3,6 @@
 // For details, see https://github.com/egor-tensin/aes-tools.
 // Distributed under the MIT License.
 
-#include "helpers/block_dumper.hpp"
 #include "helpers/cmd_parser_block.hpp"
 
 #include <aesxx/all.hpp>
@@ -18,128 +17,16 @@
 
 namespace {
 
-template <aes::Algorithm algorithm, aes::Mode mode>
-void decrypt_with_mode(const BlockSettings::Input& input, bool verbose = false) {
-    typename aes::Types<algorithm>::Block iv;
-    aes::make_block(iv, 0, 0, 0, 0);
-
-    if (input.has_iv()) {
-        aes::from_string<algorithm>(iv, input.get_iv());
-        if (verbose)
-            dump_iv<algorithm>(iv);
-    }
-
-    typename aes::Types<algorithm>::Key key;
-    aes::from_string<algorithm>(key, input.get_key());
-    if (verbose)
-        dump_key<algorithm>(key);
-
-    aes::DecryptWrapper<algorithm, mode> decrypt{key, iv};
-    if (verbose)
-        dump_wrapper<algorithm, mode>(decrypt);
-
-    for (const auto& block : input.get_blocks()) {
-        typename aes::Types<algorithm>::Block ciphertext, plaintext;
-        aes::from_string<algorithm>(ciphertext, block);
-
-        decrypt.decrypt_block(ciphertext, plaintext);
-
-        if (verbose) {
-            dump_ciphertext<algorithm>(ciphertext);
-            dump_plaintext<algorithm>(plaintext);
-            dump_next_iv<algorithm, mode>(decrypt);
-        } else {
-            std::cout << std::format("{}\n", aes::to_string<algorithm>(plaintext));
-        }
-    }
-}
-
-template <aes::Algorithm algorithm>
-void decrypt_with_algorithm(
-    aes::Mode mode,
-    const BlockSettings::Input& input,
-    bool verbose = false
-) {
-    switch (mode) {
-        case AES_ECB:
-            decrypt_with_mode<algorithm, AES_ECB>(input, verbose);
-            break;
-
-        case AES_CBC:
-            decrypt_with_mode<algorithm, AES_CBC>(input, verbose);
-            break;
-
-        case AES_CFB:
-            decrypt_with_mode<algorithm, AES_CFB>(input, verbose);
-            break;
-
-        case AES_OFB:
-            decrypt_with_mode<algorithm, AES_OFB>(input, verbose);
-            break;
-
-        case AES_CTR:
-            decrypt_with_mode<algorithm, AES_CTR>(input, verbose);
-            break;
-
-        default:
-            throw std::runtime_error("the selected mode of operation is not implemented");
-            break;
-    }
-}
-
-void decrypt_using_cxx_api(
-    aes::Algorithm algorithm,
-    aes::Mode mode,
-    const BlockSettings::Input& input,
-    bool verbose = false
-) {
-    switch (algorithm) {
-        case AES_AES128:
-            decrypt_with_algorithm<AES_AES128>(mode, input, verbose);
-            break;
-
-        case AES_AES192:
-            decrypt_with_algorithm<AES_AES192>(mode, input, verbose);
-            break;
-
-        case AES_AES256:
-            decrypt_with_algorithm<AES_AES256>(mode, input, verbose);
-            break;
-
-        default:
-            throw std::runtime_error("the selected algorithm is not implemented");
-            break;
-    }
-}
-
-void decrypt_using_particular_box(aes::Box& box, const std::vector<std::string>& blocks) {
-    for (const auto& block : blocks) {
-        aes::Box::Block ciphertext;
-        box.parse_block(ciphertext, block);
-
-        aes::Box::Block plaintext;
-        box.decrypt_block(ciphertext, plaintext);
-        std::cout << std::format("{}\n", box.format_block(plaintext));
-    }
-}
-
-void decrypt_using_boxes(
-    aes::Algorithm algorithm,
-    aes::Mode mode,
-    const BlockSettings::Input& input
-) {
+void decrypt_blocks(aes::Algorithm algorithm, aes::Mode mode, const BlockSettings::Input& input) {
     aes::Box::Key key;
     aes::Box::parse_key(key, algorithm, input.get_key());
 
-    if (input.has_iv()) {
-        aes::Box::Block iv;
-        aes::Box::parse_block(iv, input.get_iv());
-        aes::Box box{algorithm, key, mode, iv};
+    aes::Box box{algorithm, key, mode, input.get_iv()};
 
-        decrypt_using_particular_box(box, input.get_blocks());
-    } else {
-        aes::Box box{algorithm, key};
-        decrypt_using_particular_box(box, input.get_blocks());
+    for (const auto& ciphertext : input.get_blocks()) {
+        aes::Block plaintext;
+        box.decrypt_block(ciphertext, plaintext);
+        std::cout << std::format("{}\n", plaintext.to_string());
     }
 }
 
@@ -162,13 +49,7 @@ int main(int argc, char** argv) {
         }
 
         for (const auto& input : settings.get_inputs()) {
-            if (settings.use_boxes()) {
-                decrypt_using_boxes(settings.get_algorithm(), settings.get_mode(), input);
-            } else {
-                decrypt_using_cxx_api(
-                    settings.get_algorithm(), settings.get_mode(), input, settings.verbose()
-                );
-            }
+            decrypt_blocks(settings.get_algorithm(), settings.get_mode(), input);
         }
     } catch (const aes::Error& e) {
         std::cerr << e;
-- 
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