From d4ffd85a71f480ba3ef68b141f6f775ef1c786ae Mon Sep 17 00:00:00 2001
From: Jeff Becker <ampernand@gmail.com>
Date: Thu, 4 Feb 2016 12:04:35 -0500
Subject: [PATCH] add elg tests and fix up dsa tests

---
 src/tests/unit_tests/CMakeLists.txt |  3 +-
 src/tests/unit_tests/crypto/dsa.cpp | 13 ++---
 src/tests/unit_tests/crypto/elg.cpp | 87 +++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+), 9 deletions(-)
 create mode 100644 src/tests/unit_tests/crypto/elg.cpp

diff --git a/src/tests/unit_tests/CMakeLists.txt b/src/tests/unit_tests/CMakeLists.txt
index 9e65c01c..41830e5e 100644
--- a/src/tests/unit_tests/CMakeLists.txt
+++ b/src/tests/unit_tests/CMakeLists.txt
@@ -4,7 +4,8 @@ set(TESTS_SRC
   "Utility.cpp"
   "crypto/aes.cpp"
   "crypto/dsa.cpp"
-  "crypto/ed25519.cpp")
+  "crypto/ed25519.cpp"
+  "crypto/elg.cpp")
 
 include_directories(
   "../../"
diff --git a/src/tests/unit_tests/crypto/dsa.cpp b/src/tests/unit_tests/crypto/dsa.cpp
index a8934cc6..215f1067 100644
--- a/src/tests/unit_tests/crypto/dsa.cpp
+++ b/src/tests/unit_tests/crypto/dsa.cpp
@@ -57,6 +57,7 @@ struct DSAFixture {
   uint8_t publicKey[128];
   DSAVerifier* verifier;
   DSASigner* signer;
+  static constexpr size_t messageLen = 1024;
 };
 
 BOOST_FIXTURE_TEST_CASE(DSASHA1KeyLength, DSAFixture) {
@@ -69,7 +70,6 @@ BOOST_FIXTURE_TEST_CASE(DSASHA1SignatureLength, DSAFixture) {
 }
 
 BOOST_FIXTURE_TEST_CASE(DSASHA1SignVerifyValid, DSAFixture) {
-  constexpr size_t messageLen = 1024;
   uint8_t signature[40];
   uint8_t message[messageLen];
   RandBytes(message, messageLen);
@@ -78,33 +78,30 @@ BOOST_FIXTURE_TEST_CASE(DSASHA1SignVerifyValid, DSAFixture) {
   BOOST_CHECK_EQUAL(verifier->Verify(message, messageLen, signature), true);
 }
 BOOST_FIXTURE_TEST_CASE(DSASHA1SignVerifyBadSignature, DSAFixture) {
-  constexpr size_t messageLen = 1024;
   uint8_t signature[40];
   uint8_t message[messageLen];
   RandBytes(message, messageLen);
   signer->Sign(message, messageLen, signature);
   
   // now we fugg up the signature a bit :-DDDD
-  signature[5] = Rand<uint8_t>();
+  signature[5] ^= RandInRange<uint8_t>(1, 128);
   // it should fail verification
   BOOST_CHECK_EQUAL(verifier->Verify(message, messageLen, signature), false);
 
 }
 
 BOOST_FIXTURE_TEST_CASE(DSASHA1SignVerifyBadMessage, DSAFixture) {
-  constexpr size_t messageLen = 1024;
   uint8_t signature[40];
   uint8_t message[messageLen];
   RandBytes(message, messageLen);
   signer->Sign(message, messageLen, signature);
   // fugg up the message
-  message[5] = Rand<uint8_t>();
+  message[5] ^= RandInRange<uint8_t>(1, 128);
   // this should also fail verification
   BOOST_CHECK_EQUAL(verifier->Verify(message, messageLen, signature), false);
 }
 
 BOOST_FIXTURE_TEST_CASE(DSASHA1SignVerifyBadSignatureAndMessage, DSAFixture) {
-  constexpr size_t messageLen = 1024;
   uint8_t signature[40];
   uint8_t message[messageLen];
   RandBytes(message, messageLen);
@@ -112,8 +109,8 @@ BOOST_FIXTURE_TEST_CASE(DSASHA1SignVerifyBadSignatureAndMessage, DSAFixture) {
   signer->Sign(message, messageLen, signature);
 
   // now we fug up both message and signature
-  message[6] = Rand<uint8_t>();
-  signature[2] = Rand<uint8_t>();
+  message[6] ^= RandInRange<uint8_t>(1, 128);
+  signature[2] ^= RandInRange<uint8_t>(1, 128);
   // this should fail verification as well
   BOOST_CHECK_EQUAL(verifier->Verify(message, messageLen, signature), false);
 }
diff --git a/src/tests/unit_tests/crypto/elg.cpp b/src/tests/unit_tests/crypto/elg.cpp
new file mode 100644
index 00000000..e976bd3a
--- /dev/null
+++ b/src/tests/unit_tests/crypto/elg.cpp
@@ -0,0 +1,87 @@
+
+#define BOOST_TEST_DYN_LINK
+
+#include <boost/test/unit_test.hpp>
+#include "crypto/ElGamal.h"
+#include "crypto/Rand.h"
+
+using namespace i2p::crypto;
+
+BOOST_AUTO_TEST_SUITE(ElgamalTests)
+
+struct ElgamalFixture {
+
+  uint8_t privateKey[256];
+  uint8_t publicKey[256];
+  ElGamalEncryption* enc;
+  static constexpr size_t messageLen = 222;
+
+  ElgamalFixture() {
+    // TODO(psi): use static keys
+    GenerateElGamalKeyPair(privateKey, publicKey);
+    enc = new ElGamalEncryption(publicKey);
+  }
+
+  ~ElgamalFixture() {
+    delete enc;
+  }
+  
+
+};
+
+
+BOOST_FIXTURE_TEST_CASE(ElgamalEncryptDecryptSuccess, ElgamalFixture) {
+  uint8_t plaintext[messageLen];
+  uint8_t ciphertext[512];
+  uint8_t result[messageLen];
+  RandBytes(plaintext, messageLen);
+  enc->Encrypt(plaintext, messageLen, ciphertext, false);
+  BOOST_CHECK(ElGamalDecrypt(privateKey, ciphertext, result, false));
+  
+  BOOST_CHECK_EQUAL_COLLECTIONS(
+    plaintext, plaintext + messageLen,
+    result, result + messageLen);
+}
+
+BOOST_FIXTURE_TEST_CASE(ElgamalEncryptDecryptFail, ElgamalFixture) {
+  uint8_t plaintext[messageLen];
+  uint8_t ciphertext[512];
+  uint8_t result[messageLen];
+  RandBytes(plaintext, messageLen);
+  enc->Encrypt(plaintext, messageLen, ciphertext, false);
+  // fug up the ciphertext
+  ciphertext[4] ^= RandInRange<uint8_t>(1, 128);
+
+  BOOST_CHECK(!ElGamalDecrypt(privateKey, ciphertext, result, false));
+}
+
+BOOST_FIXTURE_TEST_CASE(ElgamalEncryptDecryptZeroPaddBadPad, ElgamalFixture) {
+  uint8_t plaintext[messageLen];
+  uint8_t ciphertext[514];
+  uint8_t result[messageLen];
+  RandBytes(plaintext, messageLen);
+  enc->Encrypt(plaintext, messageLen, ciphertext, true);
+  // fug up the ciphertext zeropadding
+  ciphertext[0] = RandInRange<uint8_t>(1, 128);
+  BOOST_CHECK(!ElGamalDecrypt(privateKey, ciphertext, result, true));
+}
+
+
+BOOST_FIXTURE_TEST_CASE(ElgamalEncryptDecryptZeroPadSuccess, ElgamalFixture) {
+  uint8_t plaintext[messageLen];
+  uint8_t ciphertext[514];
+  uint8_t result[messageLen];
+  RandBytes(plaintext, messageLen);
+  enc->Encrypt(plaintext, messageLen, ciphertext, true);
+  
+  bool res = ElGamalDecrypt(privateKey, ciphertext, result, true);
+
+  BOOST_CHECK(res);
+  if (res) {
+    BOOST_CHECK_EQUAL_COLLECTIONS(
+      plaintext, plaintext + messageLen,
+      result, result + messageLen);
+  }
+}
+
+BOOST_AUTO_TEST_SUITE_END()