Move all BigInt stuff into bigint/. Currently all asm modules are disabled;

configure.pl doesn't understand how to handle this yet (replace logic only
understands stuff in src, not how one module can replace another modules
src, or anything about prioritizing).

Move some hex and base64 stuff out of charset.cpp and into their
codec directories.

1 files changed, 134 insertions, 0 deletions

diff --git a/src/bigint/dsa_gen.cpp b/src/bigint/dsa_gen.cpp
new file mode 100644
index 000000000..baaba66ee
--- /dev/null
+++ b/src/bigint/dsa_gen.cpp
@@ -0,0 +1,134 @@
+/*************************************************
+* DSA Parameter Generation Source File           *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/dl_group.h>
+#include <botan/numthry.h>
+#include <botan/lookup.h>
+#include <botan/parsing.h>
+#include <algorithm>
+#include <memory>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* Check if this size is allowed by FIPS 186-3    *
+*************************************************/
+bool fips186_3_valid_size(u32bit pbits, u32bit qbits)
+   {
+   if(qbits == 160)
+      return (pbits == 512 || pbits == 768 || pbits == 1024);
+
+   if(qbits == 224)
+      return (pbits == 2048);
+
+   if(qbits == 256)
+      return (pbits == 2048 || pbits == 3072);
+
+   return false;
+   }
+
+}
+
+/*************************************************
+* Attempt DSA prime generation with given seed   *
+*************************************************/
+bool DL_Group::generate_dsa_primes(RandomNumberGenerator& rng,
+                                   BigInt& p, BigInt& q,
+                                   u32bit pbits, u32bit qbits,
+                                   const MemoryRegion<byte>& seed_c)
+   {
+   if(!fips186_3_valid_size(pbits, qbits))
+      throw Invalid_Argument(
+         "FIPS 186-3 does not allow DSA domain parameters of " +
+         to_string(pbits) + "/" + to_string(qbits) + " bits long");
+
+   if(qbits == 224)
+      throw Invalid_Argument(
+         "DSA parameter generation with a q of 224 bits not supported");
+
+   if(seed_c.size() * 8 < qbits)
+      throw Invalid_Argument(
+         "Generating a DSA parameter set with a " + to_string(qbits) +
+         "long q requires a seed at least as many bits long");
+
+   std::auto_ptr<HashFunction> hash(get_hash("SHA-" + to_string(qbits)));
+
+   const u32bit HASH_SIZE = hash->OUTPUT_LENGTH;
+
+   class Seed
+      {
+      public:
+         Seed(const MemoryRegion<byte>& s) : seed(s) {}
+
+         operator MemoryRegion<byte>& () { return seed; }
+
+         Seed& operator++()
+            {
+            for(u32bit j = seed.size(); j > 0; --j)
+               if(++seed[j-1])
+                  break;
+            return (*this);
+            }
+      private:
+         SecureVector<byte> seed;
+      };
+
+   Seed seed(seed_c);
+
+   q.binary_decode(hash->process(seed));
+   q.set_bit(qbits-1);
+   q.set_bit(0);
+
+   if(!is_prime(q, rng))
+      return false;
+
+   const u32bit n = (pbits-1) / (HASH_SIZE * 8),
+                b = (pbits-1) % (HASH_SIZE * 8);
+
+   BigInt X;
+   SecureVector<byte> V(HASH_SIZE * (n+1));
+
+   for(u32bit j = 0; j != 4096; ++j)
+      {
+      for(u32bit k = 0; k <= n; ++k)
+         {
+         ++seed;
+         hash->update(seed);
+         hash->final(V + HASH_SIZE * (n-k));
+         }
+
+      X.binary_decode(V + (HASH_SIZE - 1 - b/8),
+                      V.size() - (HASH_SIZE - 1 - b/8));
+      X.set_bit(pbits-1);
+
+      p = X - (X % (2*q) - 1);
+
+      if(p.bits() == pbits && is_prime(p, rng))
+         return true;
+      }
+   return false;
+   }
+
+/*************************************************
+* Generate DSA Primes                            *
+*************************************************/
+SecureVector<byte> DL_Group::generate_dsa_primes(RandomNumberGenerator& rng,
+                                                 BigInt& p, BigInt& q,
+                                                 u32bit pbits, u32bit qbits)
+   {
+   SecureVector<byte> seed(qbits/8);
+
+   while(true)
+      {
+      rng.randomize(seed, seed.size());
+
+      if(generate_dsa_primes(rng, p, q, pbits, qbits, seed))
+         return seed;
+      }
+   }
+
+}