get rid of the unportable bs bigint.h bs; slowcrypt cli wip

slowcrypt/slowcrypt.c

@@ -0,0 +1,198 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define SLOWCRYPT_CHACHA20_IMPL
+#include "../chacha20.h"
+
+#define SLOWCRYPT_POLY1305_IMPL
+#include "../poly1305.h"
+
+struct algo
+{
+  char const* name;
+  void (*run)(char**);
+};
+
+static FILE* file_open(char const* path)
+{
+  FILE* fp;
+
+  if (!strcmp(path, "-"))
+    return stdin;
+
+  fp = fopen(path, "rb");
+  if (!fp) {
+    fprintf(stderr, "Could not open %s\n", path);
+    exit(1);
+  }
+  return fp;
+}
+
+static void file_close(FILE* p)
+{
+  if (!p)
+    return;
+  if (p == stdout || p == stdin || p == stderr)
+    return;
+  fclose(p);
+}
+
+static int anyeq__impl(char const* str, char const** opts)
+{
+  for (; *opts; opts++)
+    if (!strcmp(str, *opts))
+      return 1;
+  return 0;
+}
+#define anyeq(str, ...) anyeq__impl(str, (char const*[]){__VA_ARGS__, 0})
+
+static char const* parse_hex_prefix(char const* msg)
+{
+  if (*msg == 'h')
+    msg++;
+  else if (msg[0] == '0' && msg[1] == 'x')
+    msg++;
+
+  return msg;
+}
+
+static uint8_t parse_hex_nibble(char c)
+{
+  if (c >= '0' && c <= '9')
+    return c - '0';
+  if (c >= 'a' && c <= 'f')
+    return c - 'a' + 0xA;
+  if (c >= 'A' && c <= 'F')
+    return c - 'A' + 0xA;
+  fprintf(stderr, "Not a hexadecimal number!\n");
+  exit(1);
+}
+
+static uint8_t parse_hex(char const** msg)
+{
+  uint8_t res = parse_hex_nibble(*(*msg)++);
+  if (**msg) {
+    res <<= 4;
+    res |= parse_hex_nibble(*(*msg)++);
+  }
+  return res;
+}
+
+static void parse_hex2buf(uint8_t* buf,
+                          unsigned int buflen,
+                          char const* label,
+                          char const* hex)
+{
+  unsigned int num = 0;
+  hex = parse_hex_prefix(hex);
+  for (; num < buflen && *hex; num++)
+    buf[num] = parse_hex(&hex);
+  if (num != buflen || *hex) {
+    fprintf(stderr, "Expected %s to be %u (hexadecimal) bytes!\n", label,
+            buflen);
+    exit(1);
+  }
+}
+
+static unsigned long file_read_chunk(FILE* file,
+                                     uint8_t* buf,
+                                     unsigned long buflen)
+{
+  unsigned long n;
+  if (feof(file))
+    return 0;
+  n = fread(buf, 1, buflen, file);
+  if (ferror(file)) {
+    fprintf(stderr, "File read error!");
+    exit(1);
+  }
+  return n;
+}
+
+static void run_poly1305(char** args)
+{
+  static char const help[] =
+      "poly1305 [--key] <hex-key> [file]\n"
+      "\n"
+      "Run the Poly1305 one-time authenticator on the data from the given file "
+      "or stdin\n";
+  char const* key = 0;
+  char const* fpath = "-";
+  FILE* fp;
+  unsigned int npos = 0;
+  uint8_t keybuf[32];
+  uint8_t chunk[16];
+  slowcrypt_poly1305 poly1305;
+  unsigned int nb;
+
+  if (!*args) {
+    printf("%s", help);
+    exit(0);
+  }
+
+  for (; *args; args++) {
+    if (!key && anyeq(*args, "-k", "-key", "--key") && args[1]) {
+      args++;
+      key = *args;
+    } else if (anyeq(*args, "-h", "-help", "--help")) {
+      printf("%s", help);
+      exit(0);
+    } else if (npos == 1 && ++npos) {
+      fpath = *args;
+    } else if (npos == 0 && ++npos && !key) {
+      key = *args;
+    } else {
+      fprintf(stderr, "Unexpected argument: %s\n", *args);
+      exit(1);
+    }
+  }
+
+  if (!key) {
+    fprintf(stderr, "Missing argument: [--key] <hex-key>");
+    exit(1);
+  }
+
+  fp = file_open(fpath);
+
+  parse_hex2buf(keybuf, 32, "key", key);
+  slowcrypt_poly1305_init(&poly1305, keybuf);
+
+  while ((nb = file_read_chunk(fp, chunk, 16))) {
+    slowcrypt_poly1305_next_block(&poly1305, chunk, nb);
+  }
+  slowcrypt_poly1305_finish(&poly1305, chunk);
+
+  for (nb = 0; nb < 16; nb++)
+    printf("%02x", chunk[nb]);
+  printf("\n");
+
+  file_close(fp);
+}
+
+static struct algo bytes2sum[] = {{"poly1305", run_poly1305}, {0, 0}};
+
+int main(int argc, char** argv)
+{
+  argv++;
+  struct algo* a;
+
+  if (!*argv || anyeq(*argv, "-h", "-help", "--help")) {
+    printf("bytes -> hash\n");
+    for (a = bytes2sum; a->name; a++) {
+      printf("  %s\n", a->name);
+    }
+    return 0;
+  }
+
+  for (a = bytes2sum; a->name; a++) {
+    if (!strcmp(a->name, *argv)) {
+      a->run(argv + 1);
+      return 0;
+    }
+  }
+
+  fprintf(stderr, "Unknown algorithm %s\n", *argv);
+  return 1;
+}