1 files changed, 64 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/math/bigint/big_rand.cpp b/comm/third_party/botan/src/lib/math/bigint/big_rand.cpp
new file mode 100644
index 0000000000..dd4cb5eaba
--- /dev/null
+++ b/comm/third_party/botan/src/lib/math/bigint/big_rand.cpp
@@ -0,0 +1,64 @@
+/*
+* BigInt Random Generation
+* (C) 1999-2007 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/bigint.h>
+#include <botan/rng.h>
+#include <botan/internal/rounding.h>
+
+namespace Botan {
+
+/*
+* Randomize this number
+*/
+void BigInt::randomize(RandomNumberGenerator& rng,
+                       size_t bitsize, bool set_high_bit)
+   {
+   set_sign(Positive);
+
+   if(bitsize == 0)
+      {
+      clear();
+      }
+   else
+      {
+      secure_vector<uint8_t> array = rng.random_vec(round_up(bitsize, 8) / 8);
+
+      // Always cut unwanted bits
+      if(bitsize % 8)
+         array[0] &= 0xFF >> (8 - (bitsize % 8));
+
+      // Set the highest bit if wanted
+      if (set_high_bit)
+         array[0] |= 0x80 >> ((bitsize % 8) ? (8 - bitsize % 8) : 0);
+
+      binary_decode(array);
+      }
+   }
+
+/*
+* Generate a random integer within given range
+*/
+BigInt BigInt::random_integer(RandomNumberGenerator& rng,
+                              const BigInt& min, const BigInt& max)
+   {
+   if(min.is_negative() || max.is_negative() || max <= min)
+      throw Invalid_Argument("BigInt::random_integer invalid range");
+
+   BigInt r;
+
+   const size_t bits = max.bits();
+
+   do
+      {
+      r.randomize(rng, bits, false);
+      }
+   while(r < min || r >= max);
+
+   return r;
+   }
+
+}