From 0c51995b2bc65536f9d22bb2ba55b6d70b9ac6d5 Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Sat, 6 Jan 2024 14:47:14 -0800
Subject: [PATCH] Add missing sha256sum.c file

---
 build/sha256sum.c | 443 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 443 insertions(+)
 create mode 100644 build/sha256sum.c

diff --git a/build/sha256sum.c b/build/sha256sum.c
new file mode 100644
index 000000000..15aa45cf0
--- /dev/null
+++ b/build/sha256sum.c
@@ -0,0 +1,443 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include <errno.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+// this file should not have dependencies, because everything will be
+// re-downloaded if the o/tool/sha256sum artifact becomes invalidated
+
+#define PROG "sha256sum"
+#define USAGE \
+  "\
+Usage: " PROG " [-?hbctw] [PATH...]\n\
+  -h          help\n\
+  -c          check mode\n\
+  -b          binary mode\n\
+  -t          textual mode\n\
+  -w          warning mode\n"
+
+#define ROTR(a, b)   (((a) >> (b)) | ((a) << (32 - (b))))
+#define CH(x, y, z)  (((x) & (y)) ^ (~(x) & (z)))
+#define MAJ(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+#define EP0(x)       (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define EP1(x)       (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define SIG0(x)      (ROTR(x, 7) ^ ROTR(x, 18) ^ ((x) >> 3))
+#define SIG1(x)      (ROTR(x, 17) ^ ROTR(x, 19) ^ ((x) >> 10))
+
+struct Sha256Ctx {
+  uint8_t data[64];
+  uint32_t datalen;
+  uint64_t bitlen;
+  uint32_t state[8];
+};
+
+static const uint32_t kSha256Tab[64] = {
+    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,  //
+    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,  //
+    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,  //
+    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,  //
+    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,  //
+    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,  //
+    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,  //
+    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,  //
+    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,  //
+    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,  //
+    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,  //
+    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,  //
+    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,  //
+    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,  //
+    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,  //
+    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,  //
+};
+
+static bool g_warn;
+static char g_mode;
+static bool g_check;
+static int g_mismatches;
+
+static void Sha256Transform(uint32_t state[8], const uint8_t data[64]) {
+  unsigned i;
+  uint32_t a, b, c, d, e, f, g, h, t1, t2, m[64];
+  for (i = 0; i < 16; ++i, data += 4) {
+    m[i] = (uint32_t)data[0] << 24 | data[1] << 16 | data[2] << 8 | data[3];
+  }
+  for (; i < 64; ++i) {
+    m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
+  }
+  a = state[0];
+  b = state[1];
+  c = state[2];
+  d = state[3];
+  e = state[4];
+  f = state[5];
+  g = state[6];
+  h = state[7];
+  for (i = 0; i < 64; ++i) {
+    t1 = h + EP1(e) + CH(e, f, g) + kSha256Tab[i] + m[i];
+    t2 = EP0(a) + MAJ(a, b, c);
+    h = g;
+    g = f;
+    f = e;
+    e = d + t1;
+    d = c;
+    c = b;
+    b = a;
+    a = t1 + t2;
+  }
+  state[0] += a;
+  state[1] += b;
+  state[2] += c;
+  state[3] += d;
+  state[4] += e;
+  state[5] += f;
+  state[6] += g;
+  state[7] += h;
+}
+
+static void Sha256Init(struct Sha256Ctx *ctx) {
+  ctx->datalen = 0;
+  ctx->bitlen = 0;
+  ctx->state[0] = 0x6a09e667;
+  ctx->state[1] = 0xbb67ae85;
+  ctx->state[2] = 0x3c6ef372;
+  ctx->state[3] = 0xa54ff53a;
+  ctx->state[4] = 0x510e527f;
+  ctx->state[5] = 0x9b05688c;
+  ctx->state[6] = 0x1f83d9ab;
+  ctx->state[7] = 0x5be0cd19;
+}
+
+static void Sha256Update(struct Sha256Ctx *ctx, const uint8_t *data,
+                         long size) {
+  long i;
+  for (i = 0; i < size; ++i) {
+    ctx->data[ctx->datalen] = data[i];
+    ctx->datalen++;
+    if (ctx->datalen == 64) {
+      Sha256Transform(ctx->state, ctx->data);
+      ctx->bitlen += 512;
+      ctx->datalen = 0;
+    }
+  }
+}
+
+static void Sha256Final(struct Sha256Ctx *ctx, uint8_t *hash) {
+  long i;
+  i = ctx->datalen;
+  ctx->data[i++] = 0x80;
+  if (ctx->datalen < 56) {
+    memset(ctx->data + i, 0, 56 - i);
+  } else {
+    memset(ctx->data + i, 0, 64 - i);
+    Sha256Transform(ctx->state, ctx->data);
+    memset(ctx->data, 0, 56);
+  }
+  ctx->bitlen += ctx->datalen * 8;
+  ctx->data[63] = ctx->bitlen;
+  ctx->data[62] = ctx->bitlen >> 8;
+  ctx->data[61] = ctx->bitlen >> 16;
+  ctx->data[60] = ctx->bitlen >> 24;
+  ctx->data[59] = ctx->bitlen >> 32;
+  ctx->data[58] = ctx->bitlen >> 40;
+  ctx->data[57] = ctx->bitlen >> 48;
+  ctx->data[56] = ctx->bitlen >> 56;
+  Sha256Transform(ctx->state, ctx->data);
+  for (i = 0; i < 4; ++i) {
+    hash[i] = (ctx->state[0] >> (24 - i * 8)) & 0xff;
+    hash[i + 4] = (ctx->state[1] >> (24 - i * 8)) & 0xff;
+    hash[i + 8] = (ctx->state[2] >> (24 - i * 8)) & 0xff;
+    hash[i + 12] = (ctx->state[3] >> (24 - i * 8)) & 0xff;
+    hash[i + 16] = (ctx->state[4] >> (24 - i * 8)) & 0xff;
+    hash[i + 20] = (ctx->state[5] >> (24 - i * 8)) & 0xff;
+    hash[i + 24] = (ctx->state[6] >> (24 - i * 8)) & 0xff;
+    hash[i + 28] = (ctx->state[7] >> (24 - i * 8)) & 0xff;
+  }
+}
+
+static char *FormatUint32(char *p, uint32_t x) {
+  char t;
+  size_t i, a, b;
+  i = 0;
+  do {
+    p[i++] = x % 10 + '0';
+    x = x / 10;
+  } while (x > 0);
+  p[i] = '\0';
+  if (i) {
+    for (a = 0, b = i - 1; a < b; ++a, --b) {
+      t = p[a];
+      p[a] = p[b];
+      p[b] = t;
+    }
+  }
+  return p + i;
+}
+
+static char *FormatInt32(char *p, int32_t x) {
+  if (x < 0) *p++ = '-', x = -(uint32_t)x;
+  return FormatUint32(p, x);
+}
+
+static size_t StrCat(char *dst, const char *src, size_t dsize) {
+  size_t m, n = dsize;
+  const char *p = dst;
+  const char *q = src;
+  while (n-- != 0 && *dst != '\0') dst++;
+  m = dst - p;
+  n = dsize - m;
+  if (n-- == 0) {
+    return m + strlen(src);
+  }
+  while (*src != '\0') {
+    if (n != 0) {
+      *dst++ = *src;
+      n--;
+    }
+    src++;
+  }
+  *dst = '\0';
+  return m + (src - q);
+}
+
+static void GetOpts(int argc, char *argv[]) {
+  int opt;
+  g_mode = ' ';
+  while ((opt = getopt(argc, argv, "?hbctw")) != -1) {
+    switch (opt) {
+      case 'w':
+        g_warn = true;
+        break;
+      case 'c':
+        g_check = true;
+        break;
+      case 't':
+        g_mode = ' ';
+        break;
+      case 'b':
+        g_mode = '*';
+        break;
+      case 'h':
+      case '?':
+        (void)write(1, USAGE, sizeof(USAGE) - 1);
+        exit(0);
+      default:
+        (void)write(2, USAGE, sizeof(USAGE) - 1);
+        exit(64);
+    }
+  }
+}
+
+static void Write(int fd, const char *s, ...) {
+  va_list va;
+  char buf[512];
+  buf[0] = 0;
+  va_start(va, s);
+  do {
+    StrCat(buf, s, sizeof(buf));
+  } while ((s = va_arg(va, const char *)));
+  va_end(va);
+  (void)write(fd, buf, strlen(buf));
+}
+
+static bool IsModeCharacter(char c) {
+  switch (c) {
+    case ' ':
+    case '*':
+      return true;
+    default:
+      return false;
+  }
+}
+
+static bool IsSupportedPath(const char *path) {
+  size_t i;
+  for (i = 0;; ++i) {
+    switch (path[i]) {
+      case 0:
+        if (i) return true;
+        // fallthrough
+      case '\r':
+      case '\n':
+      case '\\':
+        Write(2, PROG, ": ", path, ": unsupported path\n", NULL);
+        return false;
+      default:
+        break;
+    }
+  }
+}
+
+static bool GetDigest(const char *path, FILE *f, uint8_t digest[32]) {
+  size_t got;
+  uint8_t buf[512];
+  struct Sha256Ctx ctx;
+  Sha256Init(&ctx);
+  while ((got = fread(buf, 1, sizeof(buf), f))) {
+    Sha256Update(&ctx, buf, got);
+  }
+  if (ferror(f)) {
+    Write(2, PROG, ": ", path, ": ", strerror(errno), "\n", NULL);
+    return false;
+  }
+  Sha256Final(&ctx, digest);
+  return true;
+}
+
+static char *CopyHex(char *s, const void *p, size_t n) {
+  const char *d, *e;
+  for (d = (const char *)p, e = d + n; d < e; ++d) {
+    *s++ = "0123456789abcdef"[(*d >> 4) & 15];
+    *s++ = "0123456789abcdef"[(*d >> 0) & 15];
+  }
+  *s = 0;
+  return s;
+}
+
+static bool ProduceDigest(const char *path, FILE *f) {
+  char hexdigest[65];
+  char mode[2] = {g_mode};
+  unsigned char digest[32];
+  if (!IsSupportedPath(path)) return false;
+  if (!GetDigest(path, f, digest)) return false;
+  CopyHex(hexdigest, digest, 32);
+  Write(1, hexdigest, " ", mode, path, "\n", NULL);
+  return true;
+}
+
+static char *Chomp(char *line) {
+  size_t i;
+  if (line) {
+    for (i = strlen(line); i--;) {
+      if (line[i] == '\r' || line[i] == '\n') {
+        line[i] = '\0';
+      } else {
+        break;
+      }
+    }
+  }
+  return line;
+}
+
+static int HexToInt(int c) {
+  if ('0' <= c && c <= '9') {
+    return c - '0';
+  } else if ('a' <= c && c <= 'f') {
+    return c - 'a' + 10;
+  } else if ('A' <= c && c <= 'F') {
+    return c - 'A' + 10;
+  } else {
+    return -1;
+  }
+}
+
+static bool CheckDigests(const char *path, FILE *f) {
+  FILE *f2;
+  bool k = true;
+  int a, b, i, line;
+  const char *path2, *status;
+  uint8_t wantdigest[32], gotdigest[32];
+  char buf[64 + 2 + PATH_MAX + 1 + 1], *p;
+  for (line = 0; fgets(buf, sizeof(buf), f); ++line) {
+    if (!*Chomp(buf)) continue;
+    for (p = buf, i = 0; i < 32; ++i) {
+      if ((a = HexToInt(*p++ & 255)) == -1) goto InvalidLine;
+      if ((b = HexToInt(*p++ & 255)) == -1) goto InvalidLine;
+      wantdigest[i] = a << 4 | b;
+    }
+    if (*p++ != ' ') goto InvalidLine;
+    if (!IsModeCharacter(*p++)) goto InvalidLine;
+    path2 = p;
+    if (!*path2) goto InvalidLine;
+    if (!IsSupportedPath(path2)) continue;
+    if ((f2 = fopen(path2, "rb"))) {
+      if (GetDigest(path2, f2, gotdigest)) {
+        if (!memcmp(wantdigest, gotdigest, 32)) {
+          status = "OK";
+        } else {
+          status = "FAILED";
+          ++g_mismatches;
+          k = false;
+        }
+        Write(1, path2, ": ", status, "\n", NULL);
+      } else {
+        k = false;
+      }
+      fclose(f2);
+    } else {
+      Write(2, PROG, ": ", path2, ": ", strerror(errno), "\n", NULL);
+      k = false;
+    }
+    continue;
+  InvalidLine:
+    if (g_warn) {
+      char linestr[12];
+      FormatInt32(linestr, line + 1);
+      Write(2, PROG, ": ", path, ":", linestr, ": ",
+            "improperly formatted checksum line", "\n", NULL);
+    }
+  }
+  if (ferror(f)) {
+    Write(2, PROG, ": ", path, ": ", strerror(errno), "\n", NULL);
+    k = false;
+  }
+  return k;
+}
+
+static bool Process(const char *path, FILE *f) {
+  if (g_check) {
+    return CheckDigests(path, f);
+  } else {
+    return ProduceDigest(path, f);
+  }
+}
+
+int main(int argc, char *argv[]) {
+  int i;
+  FILE *f;
+  bool k = true;
+  GetOpts(argc, argv);
+  if (optind == argc) {
+    f = stdin;
+    k &= Process("-", f);
+  } else {
+    for (i = optind; i < argc; ++i) {
+      if ((f = fopen(argv[i], "rb"))) {
+        k &= Process(argv[i], f);
+        fclose(f);
+      } else {
+        Write(2, PROG, ": ", argv[i], ": ", strerror(errno), "\n", NULL);
+        k = false;
+      }
+    }
+  }
+  if (g_mismatches) {
+    char ibuf[12];
+    FormatInt32(ibuf, g_mismatches);
+    Write(2, PROG, ": WARNING: ", ibuf, " computed checksum did NOT match\n",
+          NULL);
+  }
+  return !k;
+}