X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2FKM_prng.cpp;h=031cb3546eb099a604edc2ad98c3460c354c4964;hb=08da7aadab3eb7fd03eae5a9a8038ecf8d05808a;hp=5e3dd48a2107219dca6fb3d2281c0510874e2880;hpb=bfedf725dac9d13f3a02fe69f45c302ab29d2b1e;p=asdcplib.git

diff --git a/src/KM_prng.cpp b/src/KM_prng.cpp
index 5e3dd48..031cb35 100755
--- a/src/KM_prng.cpp
+++ b/src/KM_prng.cpp
@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2006, John Hurst
+Copyright (c) 2006-2009, John Hurst
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -36,32 +36,16 @@ THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assert.h>
 #include <openssl/aes.h>
 #include <openssl/sha.h>
+#include <openssl/bn.h>
 
 using namespace Kumu;
 
 
 #ifdef KM_WIN32
-
-//  make up a byte by sampling the perf counter LSB
-static byte_t get_perf_byte()
-{
-  LARGE_INTEGER ticks;
-  byte_t retval;
-  
-  for ( int i = 0; i < 8; i++ )
-    {
-      QueryPerformanceCounter(&ticks);
-      retval |= (ticks.LowPart & 0x00000001) << i;
-    }
-  
-  return retval;
-}
-
+# include <wincrypt.h>
 #else // KM_WIN32
-
-#include <KM_fileio.h>
+# include <KM_fileio.h>
 const char* DEV_URANDOM = "/dev/urandom";
-
 #endif // KM_WIN32
 
 
@@ -91,9 +75,9 @@ public:
       AutoMutex Lock(m_Lock);
 
 #ifdef KM_WIN32
-      for ( ui32_t i = 0; i < RNG_KEY_SIZE; i++ )
-	rng_key[i] = get_perf_byte();
-
+      HCRYPTPROV hProvider = 0;
+      CryptAcquireContext(&hProvider, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
+      CryptGenRandom(hProvider, RNG_KEY_SIZE, rng_key);
 #else // KM_WIN32
       // on POSIX systems we simply read some seed from /dev/urandom
       FileReader URandom;
@@ -152,8 +136,7 @@ public:
       {
 	byte_t tmp[RNG_BLOCK_SIZE];
 	AES_encrypt(m_ctr_buf, tmp, &m_Context);
-	*(ui32_t*)(m_ctr_buf + 12) += 1;
-	memcpy(buf, tmp, len - gen_count);
+	memcpy(buf + gen_count, tmp, len - gen_count);
       }
   }
 };
@@ -164,7 +147,7 @@ static h__RNG* s_RNG = 0;
 
 //------------------------------------------------------------------------------------------
 //
-// public interface
+// Fortuna public interface
 
 Kumu::FortunaRNG::FortunaRNG()
 {
@@ -208,6 +191,76 @@ Kumu::FortunaRNG::FillRandom(Kumu::ByteString& Buffer)
   return Buffer.Data();
 }
 
+//------------------------------------------------------------------------------------------
+
+//
+// FIPS 186-2 Sec. 3.1 as modified by Change 1, section entitled "General Purpose Random Number Generation"
+void
+Kumu::Gen_FIPS_186_Value(const byte_t* key, ui32_t key_size, byte_t* out_buf, ui32_t out_buf_len)
+{
+  byte_t sha_buf[SHA_DIGEST_LENGTH];
+  ui32_t const xkey_len = 64; // 512/8
+  byte_t xkey[xkey_len];
+  BN_CTX* ctx1 = BN_CTX_new(); // used by BN_* functions
+  assert(ctx1);
+
+  if ( key_size > xkey_len )
+    DefaultLogSink().Warn("Key too large for FIPS 186 seed, truncating to 64 bytes.\n");
+
+  // init key
+  memset(xkey, 0, xkey_len);
+  memcpy(xkey, key, xmin<ui32_t>(key_size, xkey_len));
+
+  if ( key_size < SHA_DIGEST_LENGTH )
+    key_size = SHA_DIGEST_LENGTH; // pad short key ( b < 160 )
+
+  // create the 2^b constant
+  BIGNUM c_2powb, c_2, c_b;
+  BN_init(&c_2powb);  BN_init(&c_2);  BN_init(&c_b);
+  BN_set_word(&c_2, 2);
+  BN_set_word(&c_b, key_size * 8);
+  BN_exp(&c_2powb, &c_2, &c_b, ctx1);
+
+  for (;;)
+    {
+      SHA_CTX SHA;
+
+      // step c -- x = G(t,xkey)
+      SHA1_Init(&SHA); // set t
+      SHA1_Update(&SHA, xkey, xkey_len);
+
+      ui32_t* buf_p = (ui32_t*)sha_buf;
+      *buf_p++ = KM_i32_BE(SHA.h0);
+      *buf_p++ = KM_i32_BE(SHA.h1);
+      *buf_p++ = KM_i32_BE(SHA.h2);
+      *buf_p++ = KM_i32_BE(SHA.h3);
+      *buf_p++ = KM_i32_BE(SHA.h4);
+      memcpy(out_buf, sha_buf, xmin<ui32_t>(out_buf_len, SHA_DIGEST_LENGTH));
+
+      if ( out_buf_len <= SHA_DIGEST_LENGTH )
+	break;
+
+      out_buf_len -= SHA_DIGEST_LENGTH;
+      out_buf += SHA_DIGEST_LENGTH;
+
+      // step d -- XKEY = (1 + XKEY + x) mod 2^b
+      BIGNUM bn_tmp, bn_xkey, bn_x_n;
+      BN_init(&bn_tmp);  BN_init(&bn_xkey);    BN_init(&bn_x_n);
+
+      BN_bin2bn(xkey, key_size, &bn_xkey);
+      BN_bin2bn(sha_buf, SHA_DIGEST_LENGTH, &bn_x_n);
+      BN_add_word(&bn_xkey, 1);            // xkey += 1
+      BN_add(&bn_tmp, &bn_xkey, &bn_x_n);       // xkey += x
+      BN_mod(&bn_xkey, &bn_tmp, &c_2powb, ctx1);  // xkey = xkey mod (2^b)
+
+      memset(xkey, 0, xkey_len);
+      ui32_t bn_buf_len = BN_num_bytes(&bn_xkey);
+      ui32_t idx = ( bn_buf_len < key_size ) ? key_size - bn_buf_len : 0;
+      BN_bn2bin(&bn_xkey, &xkey[idx]);
+    }
+
+  BN_CTX_free(ctx1);
+}
 
 //
 // end KM_prng.cpp