Adding upstream version 9.1.upstream/9.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 273 insertions, 0 deletions

diff --git a/lib/rand-isaac.c b/lib/rand-isaac.c
new file mode 100644
index 0000000..e19c47a
--- /dev/null
+++ b/lib/rand-isaac.c
@@ -0,0 +1,273 @@
+/* Bob Jenkins's cryptographic random number generators, ISAAC and ISAAC64.
+
+   Copyright (C) 1999-2022 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 1999 Colin Plumb.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+   Written by Colin Plumb and Paul Eggert.  */
+
+/*
+ * --------------------------------------------------------------------
+ * We need a source of random numbers for some data.
+ * Cryptographically secure is desirable, but it's not life-or-death
+ * so I can be a little bit experimental in the choice of RNGs here.
+ *
+ * This generator is based somewhat on RC4, but has analysis
+ * <http://burtleburtle.net/bob/rand/isaacafa.html>
+ * pointing to it actually being better.  I like it because it's nice
+ * and fast, and because the author did good work analyzing it.
+ * --------------------------------------------------------------------
+ */
+#include <config.h>
+
+#include "rand-isaac.h"
+
+#include <limits.h>
+#include <string.h>
+
+/* If the platform supports unaligned access,
+   then don't have -fsanitize=undefined warn about it.  */
+#undef ATTRIBUTE_NO_WARN_SANITIZE_UNDEFINED
+#if !(_STRING_ARCH_unaligned || _STRING_INLINE_unaligned) \
+    || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 9)
+# define ATTRIBUTE_NO_WARN_SANITIZE_UNDEFINED /* empty */
+#else
+# define ATTRIBUTE_NO_WARN_SANITIZE_UNDEFINED \
+  __attribute__ ((__no_sanitize_undefined__))
+#endif
+
+/* A if 32-bit ISAAC, B if 64-bit.  This is a macro, not an inline
+   function, to prevent undefined behavior if the unused argument
+   shifts by more than a word width.  */
+#define IF32(a, b) (ISAAC_BITS == 32 ? (a) : (b))
+
+/* Discard bits outside the desired range.  On typical machines, any
+   decent compiler should optimize this function call away to nothing.
+   But machines with pad bits in integers may need to do more work.  */
+static inline isaac_word
+just (isaac_word a)
+{
+  isaac_word desired_bits = ((isaac_word) 1 << 1 << (ISAAC_BITS - 1)) - 1;
+  return a & desired_bits;
+}
+
+/* The index operation.  */
+static inline isaac_word
+ind (isaac_word const *m, isaac_word x)
+{
+  if (sizeof *m * CHAR_BIT == ISAAC_BITS)
+    {
+      /* The typical case, where words are exactly the right size.
+         Optimize this to a mask, an addition, and an indirect
+         load.  */
+      void const *void_m = m;
+      char const *base_p = void_m;
+      void const *word_p = base_p + (x & ((ISAAC_WORDS - 1) * sizeof *m));
+      isaac_word const *p = word_p;
+      return *p;
+    }
+  else
+    {
+      /* Atypical machines need more work.  */
+      return m[(x / (ISAAC_BITS / CHAR_BIT)) & (ISAAC_WORDS - 1)];
+    }
+}
+
+/* Use and update *S to generate random data to fill RESULT.  */
+void ATTRIBUTE_NO_WARN_SANITIZE_UNDEFINED
+isaac_refill (struct isaac_state *s, isaac_word result[ISAAC_WORDS])
+{
+  /* Caches of S->a and S->b.  */
+  isaac_word a = s->a;
+  isaac_word b = s->b + (++s->c);
+
+  /* Pointers into state array and into result.  */
+  isaac_word *m = s->m;
+  isaac_word *r = result;
+
+  enum { HALF = ISAAC_WORDS / 2 };
+
+  /* The central step.  S->m is the whole state array, while M is a
+     pointer to the current word.  OFF is the offset from M to the
+     word ISAAC_WORDS/2 words away in the SM array, i.e., +/-
+     ISAAC_WORDS/2.  A and B are state variables, and R the result.
+     This updates A, B, M[I], and R[I].  */
+  #define ISAAC_STEP(i, off, mix)                             \
+    {                                                         \
+      isaac_word x, y;                                        \
+      a = (IF32 (a, 0) ^ (mix)) + m[off + (i)];               \
+      x = m[i];                                               \
+      m[i] = y = ind (s->m, x) + a + b;                       \
+      r[i] = b = just (ind (s->m, y >> ISAAC_WORDS_LOG) + x); \
+    }
+
+  do
+    {
+      ISAAC_STEP (0, HALF, IF32 (      a  << 13, ~ (a ^ (a << 21))));
+      ISAAC_STEP (1, HALF, IF32 (just (a) >>  6, a ^ (just (a) >>  5)));
+      ISAAC_STEP (2, HALF, IF32 (      a  <<  2, a ^ (      a  << 12)));
+      ISAAC_STEP (3, HALF, IF32 (just (a) >> 16, a ^ (just (a) >> 33)));
+      r += 4;
+    }
+  while ((m += 4) < s->m + HALF);
+
+  do
+    {
+      ISAAC_STEP (0, -HALF, IF32 (      a  << 13, ~ (a ^ (a << 21))));
+      ISAAC_STEP (1, -HALF, IF32 (just (a) >>  6, a ^ (just (a) >>  5)));
+      ISAAC_STEP (2, -HALF, IF32 (      a  <<  2, a ^ (      a  << 12)));
+      ISAAC_STEP (3, -HALF, IF32 (just (a) >> 16, a ^ (just (a) >> 33)));
+      r += 4;
+    }
+  while ((m += 4) < s->m + ISAAC_WORDS);
+
+  s->a = a;
+  s->b = b;
+}
+
+/*
+ * The basic seed-scrambling step for initialization, based on Bob
+ * Jenkins' 256-bit hash.
+ */
+#if ISAAC_BITS == 32
+ #define mix(a, b, c, d, e, f, g, h)       \
+    {                                      \
+              a ^=       b  << 11; d += a; \
+      b += c; b ^= just (c) >>  2; e += b; \
+      c += d; c ^=       d  <<  8; f += c; \
+      d += e; d ^= just (e) >> 16; g += d; \
+      e += f; e ^=       f  << 10; h += e; \
+      f += g; f ^= just (g) >>  4; a += f; \
+      g += h; g ^=       h  <<  8; b += g; \
+      h += a; h ^= just (a) >>  9; c += h; \
+      a += b;                              \
+    }
+#else
+ #define mix(a, b, c, d, e, f, g, h)       \
+    {                                      \
+      a -= e; f ^= just (h) >>  9; h += a; \
+      b -= f; g ^=       a  <<  9; a += b; \
+      c -= g; h ^= just (b) >> 23; b += c; \
+      d -= h; a ^=       c  << 15; c += d; \
+      e -= a; b ^= just (d) >> 14; d += e; \
+      f -= b; c ^=       e  << 20; e += f; \
+      g -= c; d ^= just (f) >> 17; f += g; \
+      h -= d; e ^=       g  << 14; g += h; \
+    }
+#endif
+
+
+/* The basic ISAAC initialization pass.  */
+#define ISAAC_MIX(s, a, b, c, d, e, f, g, h, seed) \
+  {                                                \
+    int i;                                         \
+                                                   \
+    for (i = 0; i < ISAAC_WORDS; i += 8)           \
+      {                                            \
+        a += seed[i];                              \
+        b += seed[i + 1];                          \
+        c += seed[i + 2];                          \
+        d += seed[i + 3];                          \
+        e += seed[i + 4];                          \
+        f += seed[i + 5];                          \
+        g += seed[i + 6];                          \
+        h += seed[i + 7];                          \
+        mix (a, b, c, d, e, f, g, h);              \
+        s->m[i] = a;                               \
+        s->m[i + 1] = b;                           \
+        s->m[i + 2] = c;                           \
+        s->m[i + 3] = d;                           \
+        s->m[i + 4] = e;                           \
+        s->m[i + 5] = f;                           \
+        s->m[i + 6] = g;                           \
+        s->m[i + 7] = h;                           \
+      }                                            \
+  }
+
+#if 0 /* Provided for reference only; not used in this code */
+/*
+ * Initialize the ISAAC RNG with the given seed material.
+ * Its size MUST be a multiple of ISAAC_BYTES, and may be
+ * stored in the s->m array.
+ *
+ * This is a generalization of the original ISAAC initialization code
+ * to support larger seed sizes.  For seed sizes of 0 and ISAAC_BYTES,
+ * it is identical.
+ */
+static void
+isaac_init (struct isaac_state *s, isaac_word const *seed, size_t seedsize)
+{
+  isaac_word a, b, c, d, e, f, g, h;
+
+  a = b = c = d = e = f = g = h =          /* the golden ratio */
+    IF32 (UINT32_C (0x9e3779b9), UINT64_C (0x9e3779b97f4a7c13));
+  for (int i = 0; i < 4; i++)              /* scramble it */
+    mix (a, b, c, d, e, f, g, h);
+  s->a = s->b = s->c = 0;
+
+  if (seedsize)
+    {
+      /* First pass (as in reference ISAAC code) */
+      ISAAC_MIX (s, a, b, c, d, e, f, g, h, seed);
+      /* Second and subsequent passes (extension to ISAAC) */
+      while (seedsize -= ISAAC_BYTES)
+        {
+          seed += ISAAC_WORDS;
+          for (i = 0; i < ISAAC_WORDS; i++)
+            s->m[i] += seed[i];
+          ISAAC_MIX (s, a, b, c, d, e, f, g, h, s->m);
+        }
+    }
+  else
+    {
+      /* The no seed case (as in reference ISAAC code) */
+      for (i = 0; i < ISAAC_WORDS; i++)
+        s->m[i] = 0;
+    }
+
+  /* Final pass */
+  ISAAC_MIX (s, a, b, c, d, e, f, g, h, s->m);
+}
+#endif
+
+/* Initialize *S to a somewhat-random value, derived from a seed
+   stored in S->m.  */
+void
+isaac_seed (struct isaac_state *s)
+{
+  isaac_word a = IF32 (UINT32_C (0x1367df5a), UINT64_C (0x647c4677a2884b7c));
+  isaac_word b = IF32 (UINT32_C (0x95d90059), UINT64_C (0xb9f8b322c73ac862));
+  isaac_word c = IF32 (UINT32_C (0xc3163e4b), UINT64_C (0x8c0ea5053d4712a0));
+  isaac_word d = IF32 (UINT32_C (0x0f421ad8), UINT64_C (0xb29b2e824a595524));
+  isaac_word e = IF32 (UINT32_C (0xd92a4a78), UINT64_C (0x82f053db8355e0ce));
+  isaac_word f = IF32 (UINT32_C (0xa51a3c49), UINT64_C (0x48fe4a0fa5a09315));
+  isaac_word g = IF32 (UINT32_C (0xc4efea1b), UINT64_C (0xae985bf2cbfc89ed));
+  isaac_word h = IF32 (UINT32_C (0x30609119), UINT64_C (0x98f5704f6c44c0ab));
+
+#if 0
+  /* The initialization of a through h is a precomputed form of: */
+  a = b = c = d = e = f = g = h =          /* the golden ratio */
+    IF32 (UINT32_C (0x9e3779b9), UINT64_C (0x9e3779b97f4a7c13));
+  for (int i = 0; i < 4; i++)              /* scramble it */
+    mix (a, b, c, d, e, f, g, h);
+#endif
+
+  /* Mix S->m so that every part of the seed affects every part of the
+     state.  */
+  ISAAC_MIX (s, a, b, c, d, e, f, g, h, s->m);
+  ISAAC_MIX (s, a, b, c, d, e, f, g, h, s->m);
+
+  s->a = s->b = s->c = 0;
+}