1 files changed, 92 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/kdf/prf_x942/prf_x942.cpp b/comm/third_party/botan/src/lib/kdf/prf_x942/prf_x942.cpp
new file mode 100644
index 0000000000..4a4a3a7f09
--- /dev/null
+++ b/comm/third_party/botan/src/lib/kdf/prf_x942/prf_x942.cpp
@@ -0,0 +1,92 @@
+/*
+* X9.42 PRF
+* (C) 1999-2007 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/prf_x942.h>
+#include <botan/der_enc.h>
+#include <botan/hash.h>
+#include <botan/loadstor.h>
+#include <algorithm>
+
+namespace Botan {
+
+namespace {
+
+/*
+* Encode an integer as an OCTET STRING
+*/
+std::vector<uint8_t> encode_x942_int(uint32_t n)
+   {
+   uint8_t n_buf[4] = { 0 };
+   store_be(n, n_buf);
+
+   std::vector<uint8_t> output;
+   DER_Encoder(output).encode(n_buf, 4, OCTET_STRING);
+   return output;
+   }
+
+}
+
+size_t X942_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
+   {
+   std::unique_ptr<HashFunction> hash(HashFunction::create("SHA-160"));
+
+   secure_vector<uint8_t> h;
+   secure_vector<uint8_t> in;
+   size_t offset = 0;
+   uint32_t counter = 1;
+
+   in.reserve(salt_len + label_len);
+   in += std::make_pair(label,label_len);
+   in += std::make_pair(salt,salt_len);
+
+   while(offset != key_len && counter)
+      {
+      hash->update(secret, secret_len);
+
+      hash->update(
+         DER_Encoder().start_cons(SEQUENCE)
+
+            .start_cons(SEQUENCE)
+               .encode(m_key_wrap_oid)
+               .raw_bytes(encode_x942_int(counter))
+            .end_cons()
+
+            .encode_if(salt_len != 0,
+               DER_Encoder()
+                  .start_explicit(0)
+                     .encode(in, OCTET_STRING)
+                  .end_explicit()
+               )
+
+            .start_explicit(2)
+               .raw_bytes(encode_x942_int(static_cast<uint32_t>(8 * key_len)))
+            .end_explicit()
+
+         .end_cons().get_contents()
+         );
+
+      hash->final(h);
+      const size_t copied = std::min(h.size(), key_len - offset);
+      copy_mem(&key[offset], h.data(), copied);
+      offset += copied;
+
+      ++counter;
+      }
+
+   // FIXME: returns truncated output
+   return offset;
+   }
+
+std::string X942_PRF::name() const
+   {
+   return "X9.42-PRF(" + m_key_wrap_oid.to_formatted_string() + ")";
+   }
+
+}