1 files changed, 573 insertions, 0 deletions
diff --git a/dnsdist-crypto.cc b/dnsdist-crypto.cc
new file mode 100644
index 0000000..df4beeb
--- /dev/null
+++ b/dnsdist-crypto.cc
@@ -0,0 +1,573 @@
+/*
+ * This file is part of PowerDNS or dnsdist.
+ * Copyright -- PowerDNS.COM B.V. and its contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * In addition, for the avoidance of any doubt, permission is granted to
+ * link this program with OpenSSL and to (re)distribute the binaries
+ * produced as the result of such linking.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include <iostream>
+#include <arpa/inet.h>
+
+#include "dnsdist-crypto.hh"
+
+#include "namespaces.hh"
+#include "noinitvector.hh"
+#include "misc.hh"
+#include "base64.hh"
+
+namespace dnsdist::crypto::authenticated
+{
+#ifdef HAVE_LIBSODIUM
+string newKey(bool base64Encoded)
+{
+  std::string key;
+  key.resize(crypto_secretbox_KEYBYTES);
+
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  randombytes_buf(reinterpret_cast<unsigned char*>(key.data()), key.size());
+
+  if (!base64Encoded) {
+    return key;
+  }
+  return "\"" + Base64Encode(key) + "\"";
+}
+
+bool isValidKey(const std::string& key)
+{
+  return key.size() == crypto_secretbox_KEYBYTES;
+}
+
+std::string encryptSym(const std::string_view& msg, const std::string& key, Nonce& nonce, bool incrementNonce)
+{
+  if (!isValidKey(key)) {
+    throw std::runtime_error("Invalid encryption key of size " + std::to_string(key.size()) + " (" + std::to_string(crypto_secretbox_KEYBYTES) + " expected), use setKey() to set a valid key");
+  }
+
+  std::string ciphertext;
+  ciphertext.resize(msg.length() + crypto_secretbox_MACBYTES);
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  crypto_secretbox_easy(reinterpret_cast<unsigned char*>(ciphertext.data()),
+                        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+                        reinterpret_cast<const unsigned char*>(msg.data()),
+                        msg.length(),
+                        nonce.value.data(),
+                        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+                        reinterpret_cast<const unsigned char*>(key.data()));
+
+  if (incrementNonce) {
+    nonce.increment();
+  }
+
+  return ciphertext;
+}
+
+std::string decryptSym(const std::string_view& msg, const std::string& key, Nonce& nonce, bool incrementNonce)
+{
+  std::string decrypted;
+
+  if (msg.length() < crypto_secretbox_MACBYTES) {
+    throw std::runtime_error("Could not decrypt message of size " + std::to_string(msg.length()));
+  }
+
+  if (!isValidKey(key)) {
+    throw std::runtime_error("Invalid decryption key of size " + std::to_string(key.size()) + ", use setKey() to set a valid key");
+  }
+
+  decrypted.resize(msg.length() - crypto_secretbox_MACBYTES);
+
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (crypto_secretbox_open_easy(reinterpret_cast<unsigned char*>(decrypted.data()),
+                                 // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+                                 reinterpret_cast<const unsigned char*>(msg.data()),
+                                 msg.length(),
+                                 nonce.value.data(),
+                                 // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+                                 reinterpret_cast<const unsigned char*>(key.data()))
+      != 0) {
+    throw std::runtime_error("Could not decrypt message, please check that the key configured with setKey() is correct");
+  }
+
+  if (incrementNonce) {
+    nonce.increment();
+  }
+
+  return decrypted;
+}
+
+void Nonce::init()
+{
+  randombytes_buf(value.data(), value.size());
+}
+
+#elif defined(HAVE_LIBCRYPTO)
+#include <openssl/evp.h>
+#include <openssl/rand.h>
+
+static constexpr size_t s_CHACHA20_POLY1305_KEY_SIZE = 32U;
+static constexpr size_t s_POLY1305_BLOCK_SIZE = 16U;
+
+string newKey(bool base64Encoded)
+{
+  std::string key;
+  key.resize(s_CHACHA20_POLY1305_KEY_SIZE);
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (RAND_priv_bytes(reinterpret_cast<unsigned char*>(key.data()), key.size()) != 1) {
+    throw std::runtime_error("Could not initialize random number generator for cryptographic functions");
+  }
+  if (!base64Encoded) {
+    return key;
+  }
+  return "\"" + Base64Encode(key) + "\"";
+}
+
+bool isValidKey(const std::string& key)
+{
+  return key.size() == s_CHACHA20_POLY1305_KEY_SIZE;
+}
+
+std::string encryptSym(const std::string_view& msg, const std::string& key, Nonce& nonce, bool incrementNonce)
+{
+  if (!isValidKey(key)) {
+    throw std::runtime_error("Invalid encryption key of size " + std::to_string(key.size()) + " (" + std::to_string(s_CHACHA20_POLY1305_KEY_SIZE) + " expected), use setKey() to set a valid key");
+  }
+
+  // Each thread gets its own cipher context
+  static thread_local auto ctx = std::unique_ptr<EVP_CIPHER_CTX, decltype(&EVP_CIPHER_CTX_free)>(nullptr, EVP_CIPHER_CTX_free);
+
+  if (!ctx) {
+    ctx = std::unique_ptr<EVP_CIPHER_CTX, decltype(&EVP_CIPHER_CTX_free)>(EVP_CIPHER_CTX_new(), EVP_CIPHER_CTX_free);
+    if (!ctx) {
+      throw std::runtime_error("encryptSym: EVP_CIPHER_CTX_new() could not initialize cipher context");
+    }
+
+    if (EVP_EncryptInit_ex(ctx.get(), EVP_chacha20_poly1305(), nullptr, nullptr, nullptr) != 1) {
+      throw std::runtime_error("encryptSym: EVP_EncryptInit_ex() could not initialize encryption operation");
+    }
+  }
+
+  std::string ciphertext;
+  /* plus one so we can access the last byte in EncryptFinal which does nothing for this algo */
+  ciphertext.resize(s_POLY1305_BLOCK_SIZE + msg.length() + 1);
+  int outLength{0};
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (EVP_EncryptInit_ex(ctx.get(), nullptr, nullptr, reinterpret_cast<const unsigned char*>(key.c_str()), nonce.value.data()) != 1) {
+    throw std::runtime_error("encryptSym: EVP_EncryptInit_ex() could not initialize encryption key and IV");
+  }
+
+  if (!msg.empty()) {
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+    if (EVP_EncryptUpdate(ctx.get(),
+                          reinterpret_cast<unsigned char*>(&ciphertext.at(s_POLY1305_BLOCK_SIZE)), &outLength,
+                          reinterpret_cast<const unsigned char*>(msg.data()), msg.length())
+        != 1) {
+      throw std::runtime_error("encryptSym: EVP_EncryptUpdate() could not encrypt message");
+    }
+  }
+
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (EVP_EncryptFinal_ex(ctx.get(), reinterpret_cast<unsigned char*>(&ciphertext.at(s_POLY1305_BLOCK_SIZE + outLength)), &outLength) != 1) {
+    throw std::runtime_error("encryptSym: EVP_EncryptFinal_ex() could finalize message encryption");
+    ;
+  }
+
+  /* Get the tag */
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_AEAD_GET_TAG, s_POLY1305_BLOCK_SIZE, ciphertext.data()) != 1) {
+    throw std::runtime_error("encryptSym: EVP_CIPHER_CTX_ctrl() could not get tag");
+  }
+
+  if (incrementNonce) {
+    nonce.increment();
+  }
+
+  ciphertext.resize(ciphertext.size() - 1);
+  return ciphertext;
+}
+
+std::string decryptSym(const std::string_view& msg, const std::string& key, Nonce& nonce, bool incrementNonce)
+{
+  if (msg.length() < s_POLY1305_BLOCK_SIZE) {
+    throw std::runtime_error("Could not decrypt message of size " + std::to_string(msg.length()));
+  }
+
+  if (!isValidKey(key)) {
+    throw std::runtime_error("Invalid decryption key of size " + std::to_string(key.size()) + ", use setKey() to set a valid key");
+  }
+
+  if (msg.length() == s_POLY1305_BLOCK_SIZE) {
+    if (incrementNonce) {
+      nonce.increment();
+    }
+    return std::string();
+  }
+
+  // Each thread gets its own cipher context
+  static thread_local auto ctx = std::unique_ptr<EVP_CIPHER_CTX, decltype(&EVP_CIPHER_CTX_free)>(nullptr, EVP_CIPHER_CTX_free);
+  if (!ctx) {
+    ctx = std::unique_ptr<EVP_CIPHER_CTX, decltype(&EVP_CIPHER_CTX_free)>(EVP_CIPHER_CTX_new(), EVP_CIPHER_CTX_free);
+    if (!ctx) {
+      throw std::runtime_error("decryptSym: EVP_CIPHER_CTX_new() could not initialize cipher context");
+    }
+
+    if (EVP_DecryptInit_ex(ctx.get(), EVP_chacha20_poly1305(), nullptr, nullptr, nullptr) != 1) {
+      throw std::runtime_error("decryptSym: EVP_DecryptInit_ex() could not initialize decryption operation");
+    }
+  }
+
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (EVP_DecryptInit_ex(ctx.get(), nullptr, nullptr, reinterpret_cast<const unsigned char*>(key.c_str()), nonce.value.data()) != 1) {
+    throw std::runtime_error("decryptSym: EVP_DecryptInit_ex() could not initialize decryption key and IV");
+  }
+
+  const auto tag = msg.substr(0, s_POLY1305_BLOCK_SIZE);
+  std::string decrypted;
+  /* plus one so we can access the last byte in DecryptFinal, which does nothing */
+  decrypted.resize(msg.length() - s_POLY1305_BLOCK_SIZE + 1);
+  int outLength{0};
+  if (msg.size() > s_POLY1305_BLOCK_SIZE) {
+    if (!EVP_DecryptUpdate(ctx.get(),
+                           // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+                           reinterpret_cast<unsigned char*>(decrypted.data()), &outLength,
+                           // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+                           reinterpret_cast<const unsigned char*>(&msg.at(s_POLY1305_BLOCK_SIZE)), msg.size() - s_POLY1305_BLOCK_SIZE)) {
+      throw std::runtime_error("Could not decrypt message (update failed), please check that the key configured with setKey() is correct");
+    }
+  }
+
+  /* Set expected tag value. Works in OpenSSL 1.0.1d and later */
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast): sorry, OpenSSL's API is terrible
+  if (!EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_AEAD_SET_TAG, s_POLY1305_BLOCK_SIZE, const_cast<char*>(tag.data()))) {
+    throw std::runtime_error("Could not decrypt message (invalid tag), please check that the key configured with setKey() is correct");
+  }
+
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  if (!EVP_DecryptFinal_ex(ctx.get(), reinterpret_cast<unsigned char*>(&decrypted.at(outLength)), &outLength)) {
+    throw std::runtime_error("Could not decrypt message (final failed), please check that the key configured with setKey() is correct");
+  }
+
+  if (incrementNonce) {
+    nonce.increment();
+  }
+
+  decrypted.resize(decrypted.size() - 1);
+  return decrypted;
+}
+
+void Nonce::init()
+{
+  if (RAND_priv_bytes(value.data(), value.size()) != 1) {
+    throw std::runtime_error("Could not initialize random number generator for cryptographic functions");
+  }
+}
+#endif
+
+#if defined(HAVE_LIBSODIUM) || defined(HAVE_LIBCRYPTO)
+void Nonce::merge(const Nonce& lower, const Nonce& higher)
+{
+  constexpr size_t halfSize = std::tuple_size<decltype(value)>{} / 2;
+  memcpy(value.data(), lower.value.data(), halfSize);
+  memcpy(value.data() + halfSize, higher.value.data() + halfSize, halfSize);
+}
+
+void Nonce::increment()
+{
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  auto* ptr = reinterpret_cast<uint32_t*>(value.data());
+  uint32_t count = htonl(*ptr);
+  *ptr = ntohl(++count);
+}
+
+#else
+void Nonce::init()
+{
+}
+
+void Nonce::merge(const Nonce& lower, const Nonce& higher)
+{
+}
+
+void Nonce::increment()
+{
+}
+
+std::string encryptSym(const std::string_view& msg, const std::string& key, Nonce& nonce, bool incrementNonce)
+{
+  return std::string(msg);
+}
+std::string decryptSym(const std::string_view& msg, const std::string& key, Nonce& nonce, bool incrementNonce)
+{
+  return std::string(msg);
+}
+
+string newKey(bool base64Encoded)
+{
+  return "\"plaintext\"";
+}
+
+bool isValidKey(const std::string& key)
+{
+  return true;
+}
+
+#endif
+}
+
+#include <cinttypes>
+
+namespace anonpdns
+{
+static char B64Decode1(char cInChar)
+{
+  // The incoming character will be A-Z, a-z, 0-9, +, /, or =.
+  // The idea is to quickly determine which grouping the
+  // letter belongs to and return the associated value
+  // without having to search the global encoding string
+  // (the value we're looking for would be the resulting
+  // index into that string).
+  //
+  // To do that, we'll play some tricks...
+  unsigned char iIndex = '\0';
+  switch (cInChar) {
+  case '+':
+    iIndex = 62;
+    break;
+
+  case '/':
+    iIndex = 63;
+    break;
+
+  case '=':
+    iIndex = 0;
+    break;
+
+  default:
+    // Must be 'A'-'Z', 'a'-'z', '0'-'9', or an error...
+    //
+    // Numerically, small letters are "greater" in value than
+    // capital letters and numerals (ASCII value), and capital
+    // letters are "greater" than numerals (again, ASCII value),
+    // so we check for numerals first, then capital letters,
+    // and finally small letters.
+    iIndex = '9' - cInChar;
+    if (iIndex > 0x3F) {
+      // Not from '0' to '9'...
+      iIndex = 'Z' - cInChar;
+      if (iIndex > 0x3F) {
+        // Not from 'A' to 'Z'...
+        iIndex = 'z' - cInChar;
+        if (iIndex > 0x3F) {
+          // Invalid character...cannot
+          // decode!
+          iIndex = 0x80; // set the high bit
+        } // if
+        else {
+          // From 'a' to 'z'
+          iIndex = (('z' - iIndex) - 'a') + 26;
+        } // else
+      } // if
+      else {
+        // From 'A' to 'Z'
+        iIndex = ('Z' - iIndex) - 'A';
+      } // else
+    } // if
+    else {
+      // Adjust the index...
+      iIndex = (('9' - iIndex) - '0') + 52;
+    } // else
+    break;
+
+  } // switch
+
+  return static_cast<char>(iIndex);
+}
+
+static inline char B64Encode1(unsigned char input)
+{
+  if (input < 26) {
+    return static_cast<char>('A' + input);
+  }
+  if (input < 52) {
+    return static_cast<char>('a' + (input - 26));
+  }
+  if (input < 62) {
+    return static_cast<char>('0' + (input - 52));
+  }
+  if (input == 62) {
+    return '+';
+  }
+  return '/';
+};
+
+}
+using namespace anonpdns;
+
+template <typename Container>
+int B64Decode(const std::string& strInput, Container& strOutput)
+{
+  // Set up a decoding buffer
+  long cBuf = 0;
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
+  char* pBuf = reinterpret_cast<char*>(&cBuf);
+
+  // Decoding management...
+  int iBitGroup = 0;
+  int iInNum = 0;
+
+  // While there are characters to process...
+  //
+  // We'll decode characters in blocks of 4, as
+  // there are 4 groups of 6 bits in 3 bytes. The
+  // incoming Base64 character is first decoded, and
+  // then it is inserted into the decode buffer
+  // (with any relevant shifting, as required).
+  // Later, after all 3 bytes have been reconstituted,
+  // we assign them to the output string, ultimately
+  // to be returned as the original message.
+  int iInSize = static_cast<int>(strInput.size());
+  unsigned char cChar = '\0';
+  uint8_t pad = 0;
+  while (iInNum < iInSize) {
+    // Fill the decode buffer with 4 groups of 6 bits
+    cBuf = 0; // clear
+    pad = 0;
+    for (iBitGroup = 0; iBitGroup < 4; ++iBitGroup) {
+      if (iInNum < iInSize) {
+        // Decode a character
+        if (strInput.at(iInNum) == '=') {
+          pad++;
+        }
+        while (isspace(strInput.at(iInNum))) {
+          iInNum++;
+        }
+        cChar = B64Decode1(strInput.at(iInNum++));
+
+      } // if
+      else {
+        // Decode a padded zero
+        cChar = '\0';
+      } // else
+
+      // Check for valid decode
+      if (cChar > 0x7F) {
+        return -1;
+      }
+
+      // Adjust the bits
+      switch (iBitGroup) {
+      case 0:
+        // The first group is copied into
+        // the least significant 6 bits of
+        // the decode buffer...these 6 bits
+        // will eventually shift over to be
+        // the most significant bits of the
+        // third byte.
+        cBuf = cBuf | cChar;
+        break;
+
+      default:
+        // For groupings 1-3, simply shift
+        // the bits in the decode buffer over
+        // by 6 and insert the 6 from the
+        // current decode character.
+        cBuf = (cBuf << 6) | cChar;
+        break;
+
+      } // switch
+    } // for
+
+    // Interpret the resulting 3 bytes...note there
+    // may have been padding, so those padded bytes
+    // are actually ignored.
+#if BYTE_ORDER == BIG_ENDIAN
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    strOutput.push_back(pBuf[sizeof(long) - 3]);
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    strOutput.push_back(pBuf[sizeof(long) - 2]);
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    strOutput.push_back(pBuf[sizeof(long) - 1]);
+#else
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    strOutput.push_back(pBuf[2]);
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    strOutput.push_back(pBuf[1]);
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
+    strOutput.push_back(pBuf[0]);
+#endif
+  } // while
+  if (pad) {
+    strOutput.resize(strOutput.size() - pad);
+  }
+
+  return 1;
+}
+
+template int B64Decode<std::vector<uint8_t>>(const std::string& strInput, std::vector<uint8_t>& strOutput);
+template int B64Decode<PacketBuffer>(const std::string& strInput, PacketBuffer& strOutput);
+template int B64Decode<std::string>(const std::string& strInput, std::string& strOutput);
+
+/*
+www.kbcafe.com
+Copyright 2001-2002 Randy Charles Morin
+The Encode static method takes an array of 8-bit values and returns a base-64 stream.
+*/
+
+std::string Base64Encode(const std::string& src)
+{
+  std::string retval;
+  if (src.empty()) {
+    return retval;
+  }
+  for (unsigned int i = 0; i < src.size(); i += 3) {
+    unsigned char by1 = 0;
+    unsigned char by2 = 0;
+    unsigned char by3 = 0;
+    by1 = src[i];
+    if (i + 1 < src.size()) {
+      by2 = src[i + 1];
+    };
+    if (i + 2 < src.size()) {
+      by3 = src[i + 2];
+    }
+    unsigned char by4 = 0;
+    unsigned char by5 = 0;
+    unsigned char by6 = 0;
+    unsigned char by7 = 0;
+    by4 = by1 >> 2;
+    by5 = ((by1 & 0x3) << 4) | (by2 >> 4);
+    by6 = ((by2 & 0xf) << 2) | (by3 >> 6);
+    by7 = by3 & 0x3f;
+    retval += B64Encode1(by4);
+    retval += B64Encode1(by5);
+    if (i + 1 < src.size()) {
+      retval += B64Encode1(by6);
+    }
+    else {
+      retval += "=";
+    };
+    if (i + 2 < src.size()) {
+      retval += B64Encode1(by7);
+    }
+    else {
+      retval += "=";
+    };
+    /*      if ((i % (76 / 4 * 3)) == 0)
+      {
+        retval += "\r\n";
+        }*/
+  };
+  return retval;
+};