Merge #15512: Add ChaCha20 encryption option (XOR)

2dfe27517 Add ChaCha20 bench (Jonas Schnelli)
2bc2b8b49 Add ChaCha20 encryption option (XOR) (Jonas Schnelli)

Pull request description:

  The current ChaCha20 implementation does not support message encryption (it can only output the keystream which is sufficient for the RNG).

  This PR adds the actual XORing of the `plaintext` with the `keystream` in order to return the desired `ciphertext`.

  Required for v2 message transport protocol.

ACKs for commit 2dfe27:
  jnewbery:
    Looks good. utACK 2dfe2751713c814aea53b5a7563eb74ad1baea00.
  jnewbery:
    utACK 2dfe2751713c814aea53b5a7563eb74ad1baea00
  sipa:
    utACK 2dfe2751713c814aea53b5a7563eb74ad1baea00
  ryanofsky:
    utACK 2dfe2751713c814aea53b5a7563eb74ad1baea00. Changes since last review are just renaming the Crypt method, adding comments, and simplifying the benchmark.

Tree-SHA512: 84bb234da2ca9fdc44bc29a786d9dd215520f81245270c1aef801ef66b6091b7793e2eb38ad6dbb084925245065c5dce9e5582f2d0fa220ab3e182d43412d5b5

1 files changed, 39 insertions, 8 deletions

diff --git a/src/test/crypto_tests.cpp b/src/test/crypto_tests.cpp
index 0d05b6514f..64458cd7d4 100644
--- a/src/test/crypto_tests.cpp
+++ b/src/test/crypto_tests.cpp
@@ -125,17 +125,36 @@ static void TestAES256CBC(const std::string &hexkey, const std::string &hexiv, b
     }
 }
 
-static void TestChaCha20(const std::string &hexkey, uint64_t nonce, uint64_t seek, const std::string& hexout)
+static void TestChaCha20(const std::string &hex_message, const std::string &hexkey, uint64_t nonce, uint64_t seek, const std::string& hexout)
 {
     std::vector<unsigned char> key = ParseHex(hexkey);
+    std::vector<unsigned char> m = ParseHex(hex_message);
     ChaCha20 rng(key.data(), key.size());
     rng.SetIV(nonce);
     rng.Seek(seek);
     std::vector<unsigned char> out = ParseHex(hexout);
     std::vector<unsigned char> outres;
     outres.resize(out.size());
-    rng.Output(outres.data(), outres.size());
+    assert(hex_message.empty() || m.size() == out.size());
+
+    // perform the ChaCha20 round(s), if message is provided it will output the encrypted ciphertext otherwise the keystream
+    if (!hex_message.empty()) {
+        rng.Crypt(m.data(), outres.data(), outres.size());
+    } else {
+        rng.Keystream(outres.data(), outres.size());
+    }
     BOOST_CHECK(out == outres);
+    if (!hex_message.empty()) {
+        // Manually XOR with the keystream and compare the output
+        rng.SetIV(nonce);
+        rng.Seek(seek);
+        std::vector<unsigned char> only_keystream(outres.size());
+        rng.Keystream(only_keystream.data(), only_keystream.size());
+        for (size_t i = 0; i != m.size(); i++) {
+            outres[i] = m[i] ^ only_keystream[i];
+        }
+        BOOST_CHECK(out == outres);
+    }
 }
 
 static void TestPoly1305(const std::string &hexmessage, const std::string &hexkey, const std::string& hextag)
@@ -420,25 +439,37 @@ BOOST_AUTO_TEST_CASE(aes_cbc_testvectors) {
 BOOST_AUTO_TEST_CASE(chacha20_testvector)
 {
     // Test vector from RFC 7539
-    TestChaCha20("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", 0x4a000000UL, 1,
+
+    // test encryption
+    TestChaCha20("4c616469657320616e642047656e746c656d656e206f662074686520636c617373206f66202739393a204966204920636f756"
+                 "c64206f6666657220796f75206f6e6c79206f6e652074697020666f7220746865206675747572652c2073756e73637265656e"
+                 "20776f756c642062652069742e",
+                 "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", 0x4a000000UL, 1,
+                 "6e2e359a2568f98041ba0728dd0d6981e97e7aec1d4360c20a27afccfd9fae0bf91b65c5524733ab8f593dabcd62b3571639d"
+                 "624e65152ab8f530c359f0861d807ca0dbf500d6a6156a38e088a22b65e52bc514d16ccf806818ce91ab77937365af90bbf74"
+                 "a35be6b40b8eedf2785e42874d"
+                 );
+
+    // test keystream output
+    TestChaCha20("", "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", 0x4a000000UL, 1,
                  "224f51f3401bd9e12fde276fb8631ded8c131f823d2c06e27e4fcaec9ef3cf788a3b0aa372600a92b57974cded2b9334794cb"
                  "a40c63e34cdea212c4cf07d41b769a6749f3f630f4122cafe28ec4dc47e26d4346d70b98c73f3e9c53ac40c5945398b6eda1a"
                  "832c89c167eacd901d7e2bf363");
 
     // Test vectors from https://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-04#section-7
-    TestChaCha20("0000000000000000000000000000000000000000000000000000000000000000", 0, 0,
+    TestChaCha20("", "0000000000000000000000000000000000000000000000000000000000000000", 0, 0,
                  "76b8e0ada0f13d90405d6ae55386bd28bdd219b8a08ded1aa836efcc8b770dc7da41597c5157488d7724e03fb8d84a376a43b"
                  "8f41518a11cc387b669b2ee6586");
-    TestChaCha20("0000000000000000000000000000000000000000000000000000000000000001", 0, 0,
+    TestChaCha20("", "0000000000000000000000000000000000000000000000000000000000000001", 0, 0,
                  "4540f05a9f1fb296d7736e7b208e3c96eb4fe1834688d2604f450952ed432d41bbe2a0b6ea7566d2a5d1e7e20d42af2c53d79"
                  "2b1c43fea817e9ad275ae546963");
-    TestChaCha20("0000000000000000000000000000000000000000000000000000000000000000", 0x0100000000000000ULL, 0,
+    TestChaCha20("", "0000000000000000000000000000000000000000000000000000000000000000", 0x0100000000000000ULL, 0,
                  "de9cba7bf3d69ef5e786dc63973f653a0b49e015adbff7134fcb7df137821031e85a050278a7084527214f73efc7fa5b52770"
                  "62eb7a0433e445f41e3");
-    TestChaCha20("0000000000000000000000000000000000000000000000000000000000000000", 1, 0,
+    TestChaCha20("", "0000000000000000000000000000000000000000000000000000000000000000", 1, 0,
                  "ef3fdfd6c61578fbf5cf35bd3dd33b8009631634d21e42ac33960bd138e50d32111e4caf237ee53ca8ad6426194a88545ddc4"
                  "97a0b466e7d6bbdb0041b2f586b");
-    TestChaCha20("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", 0x0706050403020100ULL, 0,
+    TestChaCha20("", "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f", 0x0706050403020100ULL, 0,
                  "f798a189f195e66982105ffb640bb7757f579da31602fc93ec01ac56f85ac3c134a4547b733b46413042c9440049176905d3b"
                  "e59ea1c53f15916155c2be8241a38008b9a26bc35941e2444177c8ade6689de95264986d95889fb60e84629c9bd9a5acb1cc1"
                  "18be563eb9b3a4a472f82e09a7e778492b562ef7130e88dfe031c79db9d4f7c7a899151b9a475032b63fc385245fe054e3dd5"