aes: remove unused AES-CTR mode implementations

aes.c

@@ -294,39 +294,6 @@ int rijndael256_encrypt_block(const aes_round_keys_t* key, const uint8_t* plaint
   return ret;
 }
 
-void aes128_ctr_encrypt(const aes_round_keys_t* key, const uint8_t* iv, const uint8_t* plaintext,
-                        uint8_t* ciphertext) {
-  aes_block_t state;
-  load_state(state, iv, AES_BLOCK_WORDS);
-  aes_encrypt(key, state, AES_BLOCK_WORDS, ROUNDS_128);
-
-  for (unsigned int i = 0; i < 16; ++i) {
-    ciphertext[i] = plaintext[i] ^ state[i / 4][i % 4];
-  }
-}
-
-void aes192_ctr_encrypt(const aes_round_keys_t* key, const uint8_t* iv, const uint8_t* plaintext,
-                        uint8_t* ciphertext) {
-  aes_block_t state;
-  load_state(state, iv, AES_BLOCK_WORDS);
-  aes_encrypt(key, state, AES_BLOCK_WORDS, ROUNDS_192);
-
-  for (unsigned int i = 0; i < 16; ++i) {
-    ciphertext[i] = plaintext[i] ^ state[i / 4][i % 4];
-  }
-}
-
-void aes256_ctr_encrypt(const aes_round_keys_t* key, const uint8_t* iv, const uint8_t* plaintext,
-                        uint8_t* ciphertext) {
-  aes_block_t state;
-  load_state(state, iv, AES_BLOCK_WORDS);
-  aes_encrypt(key, state, AES_BLOCK_WORDS, ROUNDS_256);
-
-  for (unsigned int i = 0; i < 16; ++i) {
-    ciphertext[i] = plaintext[i] ^ state[i / 4][i % 4];
-  }
-}
-
 void prg(const uint8_t* key, const uint8_t* iv, uint8_t* out, unsigned int seclvl, size_t outlen) {
 #if !defined(HAVE_OPENSSL)
   uint8_t internal_iv[16];

aes.h

@@ -47,13 +47,6 @@ int rijndael192_encrypt_block(const aes_round_keys_t* key, const uint8_t* plaint
 int rijndael256_encrypt_block(const aes_round_keys_t* key, const uint8_t* plaintext,
                               uint8_t* ciphertext);
 
-void aes128_ctr_encrypt(const aes_round_keys_t* key, const uint8_t* iv, const uint8_t* plaintext,
-                        uint8_t* ciphertext);
-void aes192_ctr_encrypt(const aes_round_keys_t* key, const uint8_t* iv, const uint8_t* plaintext,
-                        uint8_t* ciphertext);
-void aes256_ctr_encrypt(const aes_round_keys_t* key, const uint8_t* iv, const uint8_t* plaintext,
-                        uint8_t* ciphertext);
-
 void aes_increment_iv(uint8_t* iv);
 
 uint8_t* aes_extend_witness(const uint8_t* key, const uint8_t* in, const faest_paramset_t* params);

tests/aes.cpp

@@ -263,24 +263,20 @@ BOOST_AUTO_TEST_CASE(test_aes128) {
       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
       0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
   };
-  constexpr uint8_t iv_128[16] = {
+  constexpr uint8_t plaintext_128[16] = {
       0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
       0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff,
   };
   constexpr block_t expected_128 = {
       0x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30,
       0xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a,
   };
-  constexpr uint8_t plaintext_128[16] = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  };
 
   aes_round_keys_t ctx;
   aes128_init_round_keys(&ctx, key_128);
 
   block_t output_128;
-  aes128_ctr_encrypt(&ctx, iv_128, plaintext_128, output_128.data());
+  aes128_encrypt_block(&ctx, plaintext_128, output_128.data());
 
   BOOST_TEST(output_128 == expected_128);
 }
@@ -290,24 +286,20 @@ BOOST_AUTO_TEST_CASE(test_aes192) {
       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
       0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
   };
-  constexpr uint8_t iv_192[16] = {
+  constexpr uint8_t plaintext_192[16] = {
       0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
       0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff,
   };
   constexpr block_t expected_192 = {
       0xdd, 0xa9, 0x7c, 0xa4, 0x86, 0x4c, 0xdf, 0xe0,
       0x6e, 0xaf, 0x70, 0xa0, 0xec, 0x0d, 0x71, 0x91,
   };
-  constexpr uint8_t plaintext_192[16] = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  };
 
   aes_round_keys_t ctx;
   aes192_init_round_keys(&ctx, key_192);
 
   block_t output_192;
-  aes192_ctr_encrypt(&ctx, iv_192, plaintext_192, output_192.data());
+  aes192_encrypt_block(&ctx, plaintext_192, output_192.data());
 
   BOOST_TEST(output_192 == expected_192);
 }
@@ -318,24 +310,20 @@ BOOST_AUTO_TEST_CASE(test_aes256) {
       0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
       0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
   };
-  constexpr uint8_t iv_256[16] = {
+  constexpr uint8_t plaintext_256[16] = {
       0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
       0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff,
   };
   constexpr block_t expected_256 = {
       0x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf,
       0xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89,
   };
-  constexpr uint8_t plaintext_256[16] = {
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-  };
 
   aes_round_keys_t ctx;
   aes256_init_round_keys(&ctx, key_256);
 
   block_t output_256;
-  aes256_ctr_encrypt(&ctx, iv_256, plaintext_256, output_256.data());
+  aes256_encrypt_block(&ctx, plaintext_256, output_256.data());
 
   BOOST_TEST(output_256 == expected_256);
 }