From aaa5ff1a464863da10cdb756c504c65d80c47e00 Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Sun, 18 Oct 2020 01:30:28 -0500
Subject: Add sha3sum.

---
 toys/other/sha3sum.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 toys/other/sha3sum.c

(limited to 'toys/other')

diff --git a/toys/other/sha3sum.c b/toys/other/sha3sum.c
new file mode 100644
index 00000000..10290081
--- /dev/null
+++ b/toys/other/sha3sum.c
@@ -0,0 +1,106 @@
+/* sha3sum.c - Keccak-f[1600] permutation, sponge construction
+ *
+ * Copyright 2014 David Leon Gil <coruus@gmail.com>
+ *
+ * https://keccak.team/files/Keccak-reference-3.0.pdf
+ * https://csrc.nist.gov/publications/detail/fips/202/final
+ * https://nvlpubs.nist.gov/nistpubs/specialpublications/nist.sp.800-185.pdf
+
+// Depends on FLAG(b) being 4
+USE_SHA3SUM(NEWTOY(sha3sum, "bSa#<128>512=224", TOYFLAG_USR|TOYFLAG_BIN))
+
+config SHA3SUM
+  bool "sha3sum"
+  default n
+  help
+    usage: sha3sum [-S] [-a BITS] [FILE...]
+
+    Hash function du jour.
+
+    -a	Produce a hash BITS long (default 224)
+    -S	Use SHAKE termination byte instead of SHA3 (ask FIPS why)
+*/
+
+#define FOR_sha3sum
+#include "toys.h"
+
+GLOBALS(
+  long a;
+  unsigned long long rc[24];
+)
+
+static const char rho[] =
+  {1,3,6,10,15,21,28,36,45,55,2,14,27,41,56,8,25,43,62,18,39,61,20,44};
+static const char pi[] =
+  {10,7,11,17,18,3,5,16,8,21,24,4,15,23,19,13,12,2,20,14,22,9,6,1};
+static const char rcpack[] =
+  {0x33,0x07,0xdd,0x16,0x38,0x1b,0x7b,0x2b,0xad,0x6a,0xce,0x4c,0x29,0xfe,0x31,
+   0x68,0x9d,0xb0,0x8f,0x2f,0x0a};
+
+static void keccak(unsigned long long *a)
+{
+  unsigned long long b[5] = {0}, t;
+  int i, x, y;
+
+  for (i = 0; i < 24; i++) {
+    for (x = 0; x<5; x++) for (b[x] = 0, y = 0; y<25; y += 5) b[x] ^= a[x+y];
+    for (x = 0; x<5; x++) for (y = 0; y<25; y += 5) {
+      t = b[(x+1)%5];
+      a[y+x] ^= b[(x+4)%5]^(t<<1|t>>63);
+    }
+    for (t = a[1], x = 0; x<24; x++) {
+      *b = a[pi[x]];
+      a[pi[x]] = (t<<rho[x])|(t>>(64-rho[x]));
+      t = *b;
+    }
+    for (y = 0; y<25; y += 5) {
+      for (x = 0; x<5; x++) b[x] = a[y + x];
+      for (x = 0; x<5; x++) a[y + x] = b[x]^((~b[(x+1)%5])&b[(x+2)%5]);
+    }
+    *a ^= TT.rc[i];
+  }
+}
+
+static void do_sha3sum(int fd, char *name)
+{
+  int span, ii, len, rate = 200-TT.a/4;
+  char *ss = toybuf, buf[200];
+
+  memset(buf, 0, sizeof(buf));
+  for (len = 0;; ss += rate) {
+    if ((span = len-(ss-toybuf))<rate) {
+      memcpy(toybuf, ss, span);
+      len = span += readall(fd, (ss = toybuf)+span, sizeof(toybuf)-span);
+    }
+    if (span>rate) span = rate;
+    for (ii = 0; ii<span; ii++) buf[ii] ^= ss[ii];
+    if (rate!=span) {
+      buf[span] ^= FLAG(S) ? 0x1f : 0x06;
+      buf[rate-1] ^= 0x80;
+    }
+    keccak((void *)buf);
+    if (span<rate) break;
+  }
+
+  for (ii = 0; ii<TT.a/8; ) {
+    printf("%02x", buf[ii%rate]);
+    if (!(++ii%rate)) keccak((void *)buf);
+  }
+  memset(buf, 0, sizeof(buf));
+
+  // Depends on FLAG(b) being 4
+  xprintf("  %s\n"+FLAG(b), name);
+}
+
+// TODO test 224 256 384 512, and shake 128 256
+void sha3sum_main(void)
+{
+  int i, j, k;
+  char *s;
+
+  // Decompress RC table
+  for (s = (void *)rcpack, i = 127; i; s += 3) for (i>>=1,k = j = 0; k<24; k++)
+    if (1&(s[k>>3]>>(7-(k&7)))) TT.rc[k] |= 1ULL<<i;
+
+  loopfiles(toys.optargs, do_sha3sum);
+}
-- 
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