crypter: add tests for crypter

Verify that results correct (match known values), consistent (encrypt->decrypt
matches the original), and compatible with the previous openssl implementation.

Also check that failed encrypts/decrypts fail the exact same way as openssl.

src/Makefile.test.include

@@ -94,6 +94,7 @@ BITCOIN_TESTS += \
   wallet/test/wallet_test_fixture.h \
   wallet/test/accounting_tests.cpp \
   wallet/test/wallet_tests.cpp \
+  wallet/test/crypto_tests.cpp \
   wallet/test/rpc_wallet_tests.cpp
 endif
 

src/wallet/crypter.h

@@ -67,9 +67,15 @@ public:
 
 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;
 
+namespace wallet_crypto
+{
+    class TestCrypter;
+}
+
 /** Encryption/decryption context with key information */
 class CCrypter
 {
+friend class wallet_crypto::TestCrypter; // for test access to chKey/chIV
 private:
     unsigned char chKey[WALLET_CRYPTO_KEY_SIZE];
     unsigned char chIV[WALLET_CRYPTO_IV_SIZE];

src/wallet/test/crypto_tests.cpp

@@ -0,0 +1,230 @@
+// Copyright (c) 2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "random.h"
+#include "utilstrencodings.h"
+#include "test/test_bitcoin.h"
+#include "wallet/crypter.h"
+
+#include <vector>
+
+#include <boost/test/unit_test.hpp>
+#include <openssl/aes.h>
+#include <openssl/evp.h>
+
+BOOST_FIXTURE_TEST_SUITE(wallet_crypto, BasicTestingSetup)
+
+bool OldSetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod, unsigned char* chKey, unsigned char* chIV)
+{
+    if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
+        return false;
+
+    int i = 0;
+    if (nDerivationMethod == 0)
+        i = EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha512(), &chSalt[0],
+                          (unsigned char *)&strKeyData[0], strKeyData.size(), nRounds, chKey, chIV);
+
+    if (i != (int)WALLET_CRYPTO_KEY_SIZE)
+    {
+        memory_cleanse(chKey, sizeof(chKey));
+        memory_cleanse(chIV, sizeof(chIV));
+        return false;
+    }
+    return true;
+}
+
+bool OldEncrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext, const unsigned char chKey[32], const unsigned char chIV[16])
+{
+    // max ciphertext len for a n bytes of plaintext is
+    // n + AES_BLOCK_SIZE - 1 bytes
+    int nLen = vchPlaintext.size();
+    int nCLen = nLen + AES_BLOCK_SIZE, nFLen = 0;
+    vchCiphertext = std::vector<unsigned char> (nCLen);
+
+    EVP_CIPHER_CTX ctx;
+
+    bool fOk = true;
+
+    EVP_CIPHER_CTX_init(&ctx);
+    if (fOk) fOk = EVP_EncryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV) != 0;
+    if (fOk) fOk = EVP_EncryptUpdate(&ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen) != 0;
+    if (fOk) fOk = EVP_EncryptFinal_ex(&ctx, (&vchCiphertext[0]) + nCLen, &nFLen) != 0;
+    EVP_CIPHER_CTX_cleanup(&ctx);
+
+    if (!fOk) return false;
+
+    vchCiphertext.resize(nCLen + nFLen);
+    return true;
+}
+
+bool OldDecrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext, const unsigned char chKey[32], const unsigned char chIV[16])
+{
+    // plaintext will always be equal to or lesser than length of ciphertext
+    int nLen = vchCiphertext.size();
+    int nPLen = nLen, nFLen = 0;
+
+    vchPlaintext = CKeyingMaterial(nPLen);
+
+    EVP_CIPHER_CTX ctx;
+
+    bool fOk = true;
+
+    EVP_CIPHER_CTX_init(&ctx);
+    if (fOk) fOk = EVP_DecryptInit_ex(&ctx, EVP_aes_256_cbc(), NULL, chKey, chIV) != 0;
+    if (fOk) fOk = EVP_DecryptUpdate(&ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen) != 0;
+    if (fOk) fOk = EVP_DecryptFinal_ex(&ctx, (&vchPlaintext[0]) + nPLen, &nFLen) != 0;
+    EVP_CIPHER_CTX_cleanup(&ctx);
+
+    if (!fOk) return false;
+
+    vchPlaintext.resize(nPLen + nFLen);
+    return true;
+}
+
+class TestCrypter
+{
+public:
+static void TestPassphraseSingle(const std::vector<unsigned char>& vchSalt, const SecureString& passphrase, uint32_t rounds,
+                 const std::vector<unsigned char>& correctKey = std::vector<unsigned char>(),
+                 const std::vector<unsigned char>& correctIV=std::vector<unsigned char>())
+{
+    unsigned char chKey[WALLET_CRYPTO_KEY_SIZE];
+    unsigned char chIV[WALLET_CRYPTO_IV_SIZE];
+
+    CCrypter crypt;
+    crypt.SetKeyFromPassphrase(passphrase, vchSalt, rounds, 0);
+
+    OldSetKeyFromPassphrase(passphrase, vchSalt, rounds, 0, chKey, chIV);
+
+    BOOST_CHECK_MESSAGE(memcmp(chKey, crypt.chKey, sizeof(chKey)) == 0, \
+        HexStr(chKey, chKey+sizeof(chKey)) + std::string(" != ") + HexStr(crypt.chKey, crypt.chKey + (sizeof crypt.chKey)));
+    BOOST_CHECK_MESSAGE(memcmp(chIV, crypt.chIV, sizeof(chIV)) == 0, \
+        HexStr(chIV, chIV+sizeof(chIV)) + std::string(" != ") + HexStr(crypt.chIV, crypt.chIV + (sizeof crypt.chIV)));
+
+    if(!correctKey.empty())
+        BOOST_CHECK_MESSAGE(memcmp(chKey, &correctKey[0], sizeof(chKey)) == 0, \
+            HexStr(chKey, chKey+sizeof(chKey)) + std::string(" != ") + HexStr(correctKey.begin(), correctKey.end()));
+    if(!correctIV.empty())
+        BOOST_CHECK_MESSAGE(memcmp(chIV, &correctIV[0], sizeof(chIV)) == 0,
+            HexStr(chIV, chIV+sizeof(chIV)) + std::string(" != ") + HexStr(correctIV.begin(), correctIV.end()));
+}
+
+static void TestPassphrase(const std::vector<unsigned char>& vchSalt, const SecureString& passphrase, uint32_t rounds,
+                 const std::vector<unsigned char>& correctKey = std::vector<unsigned char>(),
+                 const std::vector<unsigned char>& correctIV=std::vector<unsigned char>())
+{
+    TestPassphraseSingle(vchSalt, passphrase, rounds, correctKey, correctIV);
+    for(SecureString::const_iterator i(passphrase.begin()); i != passphrase.end(); ++i)
+        TestPassphraseSingle(vchSalt, SecureString(i, passphrase.end()), rounds);
+}
+
+
+static void TestDecrypt(const CCrypter& crypt, const std::vector<unsigned char>& vchCiphertext, \
+                        const std::vector<unsigned char>& vchPlaintext = std::vector<unsigned char>())
+{
+    CKeyingMaterial vchDecrypted1;
+    CKeyingMaterial vchDecrypted2;
+    int result1, result2;
+    result1 = crypt.Decrypt(vchCiphertext, vchDecrypted1);
+    result2 = OldDecrypt(vchCiphertext, vchDecrypted2, crypt.chKey, crypt.chIV);
+    BOOST_CHECK(result1 == result2);
+
+    // These two should be equal. However, OpenSSL 1.0.1j introduced a change
+    // that would zero all padding except for the last byte for failed decrypts.
+    // This behavior was reverted for 1.0.1k.
+    if (vchDecrypted1 != vchDecrypted2 && vchDecrypted1.size() >= AES_BLOCK_SIZE && SSLeay() == 0x100010afL)
+    {
+        for(CKeyingMaterial::iterator it = vchDecrypted1.end() - AES_BLOCK_SIZE; it != vchDecrypted1.end() - 1; it++)
+            *it = 0;
+    }
+
+    BOOST_CHECK_MESSAGE(vchDecrypted1 == vchDecrypted2, HexStr(vchDecrypted1.begin(), vchDecrypted1.end()) + " != " + HexStr(vchDecrypted2.begin(), vchDecrypted2.end()));
+
+    if (vchPlaintext.size())
+        BOOST_CHECK(CKeyingMaterial(vchPlaintext.begin(), vchPlaintext.end()) == vchDecrypted2);
+}
+
+static void TestEncryptSingle(const CCrypter& crypt, const CKeyingMaterial& vchPlaintext,
+                       const std::vector<unsigned char>& vchCiphertextCorrect = std::vector<unsigned char>())
+{
+    std::vector<unsigned char> vchCiphertext1;
+    std::vector<unsigned char> vchCiphertext2;
+    int result1 = crypt.Encrypt(vchPlaintext, vchCiphertext1);
+
+    int result2 = OldEncrypt(vchPlaintext, vchCiphertext2, crypt.chKey, crypt.chIV);
+    BOOST_CHECK(result1 == result2);
+    BOOST_CHECK(vchCiphertext1 == vchCiphertext2);
+
+    if (!vchCiphertextCorrect.empty())
+        BOOST_CHECK(vchCiphertext2 == vchCiphertextCorrect);
+
+    const std::vector<unsigned char> vchPlaintext2(vchPlaintext.begin(), vchPlaintext.end());
+
+    if(vchCiphertext1 == vchCiphertext2)
+        TestDecrypt(crypt, vchCiphertext1, vchPlaintext2);
+}
+
+static void TestEncrypt(const CCrypter& crypt, const std::vector<unsigned char>& vchPlaintextIn, \
+                       const std::vector<unsigned char>& vchCiphertextCorrect = std::vector<unsigned char>())
+{
+    TestEncryptSingle(crypt, CKeyingMaterial(vchPlaintextIn.begin(), vchPlaintextIn.end()), vchCiphertextCorrect);
+    for(std::vector<unsigned char>::const_iterator i(vchPlaintextIn.begin()); i != vchPlaintextIn.end(); ++i)
+        TestEncryptSingle(crypt, CKeyingMaterial(i, vchPlaintextIn.end()));
+}
+
+};
+
+BOOST_AUTO_TEST_CASE(passphrase) {
+    // These are expensive.
+
+    TestCrypter::TestPassphrase(ParseHex("0000deadbeef0000"), "test", 25000, \
+                                ParseHex("fc7aba077ad5f4c3a0988d8daa4810d0d4a0e3bcb53af662998898f33df0556a"), \
+                                ParseHex("cf2f2691526dd1aa220896fb8bf7c369"));
+
+    std::string hash(GetRandHash().ToString());
+    std::vector<unsigned char> vchSalt(8);
+    GetRandBytes(&vchSalt[0], vchSalt.size());
+    uint32_t rounds = insecure_rand();
+    if (rounds > 30000)
+        rounds = 30000;
+    TestCrypter::TestPassphrase(vchSalt, SecureString(hash.begin(), hash.end()), rounds);
+}
+
+BOOST_AUTO_TEST_CASE(encrypt) {
+    std::vector<unsigned char> vchSalt = ParseHex("0000deadbeef0000");
+    BOOST_CHECK(vchSalt.size() == WALLET_CRYPTO_SALT_SIZE);
+    CCrypter crypt;
+    crypt.SetKeyFromPassphrase("passphrase", vchSalt, 25000, 0);
+    TestCrypter::TestEncrypt(crypt, ParseHex("22bcade09ac03ff6386914359cfe885cfeb5f77ff0d670f102f619687453b29d"));
+
+    for (int i = 0; i != 100; i++)
+    {
+        uint256 hash(GetRandHash());
+        TestCrypter::TestEncrypt(crypt, std::vector<unsigned char>(hash.begin(), hash.end()));
+    }
+
+}
+
+BOOST_AUTO_TEST_CASE(decrypt) {
+    std::vector<unsigned char> vchSalt = ParseHex("0000deadbeef0000");
+    BOOST_CHECK(vchSalt.size() == WALLET_CRYPTO_SALT_SIZE);
+    CCrypter crypt;
+    crypt.SetKeyFromPassphrase("passphrase", vchSalt, 25000, 0);
+
+    // Some corner cases the came up while testing
+    TestCrypter::TestDecrypt(crypt,ParseHex("795643ce39d736088367822cdc50535ec6f103715e3e48f4f3b1a60a08ef59ca"));
+    TestCrypter::TestDecrypt(crypt,ParseHex("de096f4a8f9bd97db012aa9d90d74de8cdea779c3ee8bc7633d8b5d6da703486"));
+    TestCrypter::TestDecrypt(crypt,ParseHex("32d0a8974e3afd9c6c3ebf4d66aa4e6419f8c173de25947f98cf8b7ace49449c"));
+    TestCrypter::TestDecrypt(crypt,ParseHex("e7c055cca2faa78cb9ac22c9357a90b4778ded9b2cc220a14cea49f931e596ea"));
+    TestCrypter::TestDecrypt(crypt,ParseHex("b88efddd668a6801d19516d6830da4ae9811988ccbaf40df8fbb72f3f4d335fd"));
+    TestCrypter::TestDecrypt(crypt,ParseHex("8cae76aa6a43694e961ebcb28c8ca8f8540b84153d72865e8561ddd93fa7bfa9"));
+
+    for (int i = 0; i != 100; i++)
+    {
+        uint256 hash(GetRandHash());
+        TestCrypter::TestDecrypt(crypt, std::vector<unsigned char>(hash.begin(), hash.end()));
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()