1 files changed, 279 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/modes/aead/ccm/ccm.cpp b/comm/third_party/botan/src/lib/modes/aead/ccm/ccm.cpp
new file mode 100644
index 0000000000..ab2cfcb950
--- /dev/null
+++ b/comm/third_party/botan/src/lib/modes/aead/ccm/ccm.cpp
@@ -0,0 +1,279 @@
+/*
+* CCM Mode Encryption
+* (C) 2013,2018 Jack Lloyd
+* (C) 2016 Daniel Neus, Rohde & Schwarz Cybersecurity
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/ccm.h>
+#include <botan/loadstor.h>
+
+namespace Botan {
+
+// 128-bit cipher is intrinsic to CCM definition
+static const size_t CCM_BS = 16;
+
+/*
+* CCM_Mode Constructor
+*/
+CCM_Mode::CCM_Mode(BlockCipher* cipher, size_t tag_size, size_t L) :
+   m_tag_size(tag_size),
+   m_L(L),
+   m_cipher(cipher)
+   {
+   if(m_cipher->block_size() != CCM_BS)
+      throw Invalid_Argument(m_cipher->name() + " cannot be used with CCM mode");
+
+   if(L < 2 || L > 8)
+      throw Invalid_Argument("Invalid CCM L value " + std::to_string(L));
+
+   if(tag_size < 4 || tag_size > 16 || tag_size % 2 != 0)
+      throw Invalid_Argument("invalid CCM tag length " + std::to_string(tag_size));
+   }
+
+void CCM_Mode::clear()
+   {
+   m_cipher->clear();
+   reset();
+   }
+
+void CCM_Mode::reset()
+   {
+   m_nonce.clear();
+   m_msg_buf.clear();
+   m_ad_buf.clear();
+   }
+
+std::string CCM_Mode::name() const
+   {
+   return (m_cipher->name() + "/CCM(" + std::to_string(tag_size()) + "," + std::to_string(L())) + ")";
+   }
+
+bool CCM_Mode::valid_nonce_length(size_t n) const
+   {
+   return (n == (15-L()));
+   }
+
+size_t CCM_Mode::default_nonce_length() const
+   {
+   return (15-L());
+   }
+
+size_t CCM_Mode::update_granularity() const
+   {
+   /*
+   This value does not particularly matter as regardless CCM_Mode::update
+   buffers all input, so in theory this could be 1. However as for instance
+   Transform_Filter creates update_granularity() uint8_t buffers, use a
+   somewhat large size to avoid bouncing on a tiny buffer.
+   */
+   return m_cipher->parallel_bytes();
+   }
+
+Key_Length_Specification CCM_Mode::key_spec() const
+   {
+   return m_cipher->key_spec();
+   }
+
+void CCM_Mode::key_schedule(const uint8_t key[], size_t length)
+   {
+   m_cipher->set_key(key, length);
+   }
+
+void CCM_Mode::set_associated_data(const uint8_t ad[], size_t length)
+   {
+   m_ad_buf.clear();
+
+   if(length)
+      {
+      // FIXME: support larger AD using length encoding rules
+      BOTAN_ARG_CHECK(length < (0xFFFF - 0xFF), "Supported CCM AD length");
+
+      m_ad_buf.push_back(get_byte(0, static_cast<uint16_t>(length)));
+      m_ad_buf.push_back(get_byte(1, static_cast<uint16_t>(length)));
+      m_ad_buf += std::make_pair(ad, length);
+      while(m_ad_buf.size() % CCM_BS)
+         m_ad_buf.push_back(0); // pad with zeros to full block size
+      }
+   }
+
+void CCM_Mode::start_msg(const uint8_t nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   m_nonce.assign(nonce, nonce + nonce_len);
+   m_msg_buf.clear();
+   }
+
+size_t CCM_Mode::process(uint8_t buf[], size_t sz)
+   {
+   BOTAN_STATE_CHECK(m_nonce.size() > 0);
+   m_msg_buf.insert(m_msg_buf.end(), buf, buf + sz);
+   return 0; // no output until finished
+   }
+
+void CCM_Mode::encode_length(uint64_t len, uint8_t out[])
+   {
+   const size_t len_bytes = L();
+
+   BOTAN_ASSERT_NOMSG(len_bytes >= 2 && len_bytes <= 8);
+
+   for(size_t i = 0; i != len_bytes; ++i)
+      out[len_bytes-1-i] = get_byte(sizeof(uint64_t)-1-i, len);
+
+   if(len_bytes < 8 && (len >> (len_bytes*8)) > 0)
+      throw Encoding_Error("CCM message length too long to encode in L field");
+   }
+
+void CCM_Mode::inc(secure_vector<uint8_t>& C)
+   {
+   for(size_t i = 0; i != C.size(); ++i)
+      if(++C[C.size()-i-1])
+         break;
+   }
+
+secure_vector<uint8_t> CCM_Mode::format_b0(size_t sz)
+   {
+   if(m_nonce.size() != 15-L())
+      throw Invalid_State("CCM mode must set nonce");
+   secure_vector<uint8_t> B0(CCM_BS);
+
+   const uint8_t b_flags =
+      static_cast<uint8_t>((m_ad_buf.size() ? 64 : 0) + (((tag_size()/2)-1) << 3) + (L()-1));
+
+   B0[0] = b_flags;
+   copy_mem(&B0[1], m_nonce.data(), m_nonce.size());
+   encode_length(sz, &B0[m_nonce.size()+1]);
+
+   return B0;
+   }
+
+secure_vector<uint8_t> CCM_Mode::format_c0()
+   {
+   if(m_nonce.size() != 15-L())
+      throw Invalid_State("CCM mode must set nonce");
+   secure_vector<uint8_t> C(CCM_BS);
+
+   const uint8_t a_flags = static_cast<uint8_t>(L() - 1);
+
+   C[0] = a_flags;
+   copy_mem(&C[1], m_nonce.data(), m_nonce.size());
+
+   return C;
+   }
+
+void CCM_Encryption::finish(secure_vector<uint8_t>& buffer, size_t offset)
+   {
+   BOTAN_ARG_CHECK(buffer.size() >= offset, "Offset is sane");
+
+   buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
+
+   const size_t sz = buffer.size() - offset;
+   uint8_t* buf = buffer.data() + offset;
+
+   const secure_vector<uint8_t>& ad = ad_buf();
+   BOTAN_ARG_CHECK(ad.size() % CCM_BS == 0, "AD is block size multiple");
+
+   const BlockCipher& E = cipher();
+
+   secure_vector<uint8_t> T(CCM_BS);
+   E.encrypt(format_b0(sz), T);
+
+   for(size_t i = 0; i != ad.size(); i += CCM_BS)
+      {
+      xor_buf(T.data(), &ad[i], CCM_BS);
+      E.encrypt(T);
+      }
+
+   secure_vector<uint8_t> C = format_c0();
+   secure_vector<uint8_t> S0(CCM_BS);
+   E.encrypt(C, S0);
+   inc(C);
+
+   secure_vector<uint8_t> X(CCM_BS);
+
+   const uint8_t* buf_end = &buf[sz];
+
+   while(buf != buf_end)
+      {
+      const size_t to_proc = std::min<size_t>(CCM_BS, buf_end - buf);
+
+      xor_buf(T.data(), buf, to_proc);
+      E.encrypt(T);
+
+      E.encrypt(C, X);
+      xor_buf(buf, X.data(), to_proc);
+      inc(C);
+
+      buf += to_proc;
+      }
+
+   T ^= S0;
+
+   buffer += std::make_pair(T.data(), tag_size());
+
+   reset();
+   }
+
+void CCM_Decryption::finish(secure_vector<uint8_t>& buffer, size_t offset)
+   {
+   BOTAN_ARG_CHECK(buffer.size() >= offset, "Offset is sane");
+
+   buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
+
+   const size_t sz = buffer.size() - offset;
+   uint8_t* buf = buffer.data() + offset;
+
+   BOTAN_ASSERT(sz >= tag_size(), "We have the tag");
+
+   const secure_vector<uint8_t>& ad = ad_buf();
+   BOTAN_ARG_CHECK(ad.size() % CCM_BS == 0, "AD is block size multiple");
+
+   const BlockCipher& E = cipher();
+
+   secure_vector<uint8_t> T(CCM_BS);
+   E.encrypt(format_b0(sz - tag_size()), T);
+
+   for(size_t i = 0; i != ad.size(); i += CCM_BS)
+      {
+      xor_buf(T.data(), &ad[i], CCM_BS);
+      E.encrypt(T);
+      }
+
+   secure_vector<uint8_t> C = format_c0();
+
+   secure_vector<uint8_t> S0(CCM_BS);
+   E.encrypt(C, S0);
+   inc(C);
+
+   secure_vector<uint8_t> X(CCM_BS);
+
+   const uint8_t* buf_end = &buf[sz - tag_size()];
+
+   while(buf != buf_end)
+      {
+      const size_t to_proc = std::min<size_t>(CCM_BS, buf_end - buf);
+
+      E.encrypt(C, X);
+      xor_buf(buf, X.data(), to_proc);
+      inc(C);
+
+      xor_buf(T.data(), buf, to_proc);
+      E.encrypt(T);
+
+      buf += to_proc;
+      }
+
+   T ^= S0;
+
+   if(!constant_time_compare(T.data(), buf_end, tag_size()))
+      throw Invalid_Authentication_Tag("CCM tag check failed");
+
+   buffer.resize(buffer.size() - tag_size());
+
+   reset();
+   }
+
+}