1 files changed, 96 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/kdf/prf_tls/prf_tls.cpp b/comm/third_party/botan/src/lib/kdf/prf_tls/prf_tls.cpp
new file mode 100644
index 0000000000..c98c7d3516
--- /dev/null
+++ b/comm/third_party/botan/src/lib/kdf/prf_tls/prf_tls.cpp
@@ -0,0 +1,96 @@
+/*
+* TLS v1.0 and v1.2 PRFs
+* (C) 2004-2010 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/prf_tls.h>
+#include <botan/exceptn.h>
+
+namespace Botan {
+
+TLS_PRF::TLS_PRF() :
+   TLS_PRF(MessageAuthenticationCode::create_or_throw("HMAC(MD5)"),
+           MessageAuthenticationCode::create_or_throw("HMAC(SHA-1)"))
+   {
+   }
+
+namespace {
+
+/*
+* TLS PRF P_hash function
+*/
+void P_hash(uint8_t out[], size_t out_len,
+            MessageAuthenticationCode& mac,
+            const uint8_t secret[], size_t secret_len,
+            const uint8_t salt[], size_t salt_len)
+   {
+   try
+      {
+      mac.set_key(secret, secret_len);
+      }
+   catch(Invalid_Key_Length&)
+      {
+      throw Internal_Error("The premaster secret of " +
+                           std::to_string(secret_len) +
+                           " bytes is too long for the PRF");
+      }
+
+   secure_vector<uint8_t> A(salt, salt + salt_len);
+   secure_vector<uint8_t> h;
+
+   size_t offset = 0;
+
+   while(offset != out_len)
+      {
+      A = mac.process(A);
+
+      mac.update(A);
+      mac.update(salt, salt_len);
+      mac.final(h);
+
+      const size_t writing = std::min(h.size(), out_len - offset);
+      xor_buf(&out[offset], h.data(), writing);
+      offset += writing;
+      }
+   }
+
+}
+
+size_t TLS_PRF::kdf(uint8_t key[], size_t key_len,
+                    const uint8_t secret[], size_t secret_len,
+                    const uint8_t salt[], size_t salt_len,
+                    const uint8_t label[], size_t label_len) const
+   {
+   const size_t S1_len = (secret_len + 1) / 2,
+                S2_len = (secret_len + 1) / 2;
+   const uint8_t* S1 = secret;
+   const uint8_t* S2 = secret + (secret_len - S2_len);
+   secure_vector<uint8_t> msg;
+
+   msg.reserve(label_len + salt_len);
+   msg += std::make_pair(label, label_len);
+   msg += std::make_pair(salt, salt_len);
+
+   P_hash(key, key_len, *m_hmac_md5,  S1, S1_len, msg.data(), msg.size());
+   P_hash(key, key_len, *m_hmac_sha1, S2, S2_len, msg.data(), msg.size());
+   return key_len;
+   }
+
+size_t TLS_12_PRF::kdf(uint8_t key[], size_t key_len,
+                       const uint8_t secret[], size_t secret_len,
+                       const uint8_t salt[], size_t salt_len,
+                       const uint8_t label[], size_t label_len) const
+   {
+   secure_vector<uint8_t> msg;
+
+   msg.reserve(label_len + salt_len);
+   msg += std::make_pair(label, label_len);
+   msg += std::make_pair(salt, salt_len);
+
+   P_hash(key, key_len, *m_mac, secret, secret_len, msg.data(), msg.size());
+   return key_len;
+   }
+
+}