1 files changed, 147 insertions, 0 deletions
diff --git a/c/main.c b/c/main.c
new file mode 100644
index 0000000..6abd4f3
--- /dev/null
+++ b/c/main.c
@@ -0,0 +1,147 @@
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "blake3.h"
+#include "blake3_impl.h"
+
+#define HASH_MODE 0
+#define KEYED_HASH_MODE 1
+#define DERIVE_KEY_MODE 2
+
+void hex_char_value(uint8_t c, uint8_t *value, bool *valid) {
+  if ('0' <= c && c <= '9') {
+    *value = c - '0';
+    *valid = true;
+  } else if ('a' <= c && c <= 'f') {
+    *value = 10 + c - 'a';
+    *valid = true;
+  } else {
+    *valid = false;
+  }
+}
+
+int parse_key(char *hex_key, uint8_t out[BLAKE3_KEY_LEN]) {
+  size_t hex_len = strlen(hex_key);
+  if (hex_len != 64) {
+    fprintf(stderr, "Expected a 64-char hexadecimal key, got %zu chars.\n",
+            hex_len);
+    return 1;
+  }
+  for (size_t i = 0; i < 64; i++) {
+    uint8_t value;
+    bool valid;
+    hex_char_value(hex_key[i], &value, &valid);
+    if (!valid) {
+      fprintf(stderr, "Invalid hex char.\n");
+      return 1;
+    }
+    if (i % 2 == 0) {
+      out[i / 2] = 0;
+      value <<= 4;
+    }
+    out[i / 2] += value;
+  }
+  return 0;
+}
+
+/* A little repetition here */
+enum cpu_feature {
+    SSE2     = 1 << 0,
+    SSSE3    = 1 << 1,
+    SSE41    = 1 << 2,
+    AVX      = 1 << 3,
+    AVX2     = 1 << 4,
+    AVX512F  = 1 << 5,
+    AVX512VL = 1 << 6,
+    /* ... */
+    UNDEFINED = 1 << 30
+};
+
+extern enum cpu_feature g_cpu_features;
+enum cpu_feature get_cpu_features();
+
+int main(int argc, char **argv) {
+  size_t out_len = BLAKE3_OUT_LEN;
+  uint8_t key[BLAKE3_KEY_LEN];
+  char *context = "";
+  uint8_t mode = HASH_MODE;
+  while (argc > 1) {
+    if (argc <= 2) {
+      fprintf(stderr, "Odd number of arguments.\n");
+      return 1;
+    }
+    if (strcmp("--length", argv[1]) == 0) {
+      char *endptr = NULL;
+      unsigned long long out_len_ll = strtoull(argv[2], &endptr, 10);
+      // TODO: There are so many possible error conditions for parsing a
+      //       non-negative size_t...I probably missed something.
+      if (errno != 0 || out_len > SIZE_MAX || endptr == argv[2] || *endptr != 0) {
+        fprintf(stderr, "Bad length argument.\n");
+        return 1;
+      }
+      // TODO: A more sanitary cast?
+      out_len = (size_t)out_len_ll;
+    } else if (strcmp("--keyed", argv[1]) == 0) {
+      mode = KEYED_HASH_MODE;
+      int ret = parse_key(argv[2], key);
+      if (ret != 0) {
+        return ret;
+      }
+    } else if (strcmp("--derive-key", argv[1]) == 0) {
+      mode = DERIVE_KEY_MODE;
+      context = argv[2];
+    } else {
+      fprintf(stderr, "Unknown flag.\n");
+      return 1;
+    }
+    argc -= 2;
+    argv += 2;
+  }
+
+  uint8_t buf[65536] = {0};
+  size_t n = fread(buf, 1, sizeof(buf), stdin);
+
+  const int mask = get_cpu_features();
+  int feature = 0;
+  do {
+    fprintf(stderr, "Testing 0x%08X\n", feature);
+    g_cpu_features = feature;
+    blake3_hasher hasher;
+    switch(mode) {
+    case HASH_MODE:
+      blake3_hasher_init(&hasher);
+      break;
+    case KEYED_HASH_MODE:
+      blake3_hasher_init_keyed(&hasher, key);
+      break;
+    case DERIVE_KEY_MODE:
+      blake3_hasher_init_derive_key(&hasher, context);
+      break;
+    default:
+      abort();
+    }
+
+    blake3_hasher_update(&hasher, buf, n);
+
+    // TODO: An incremental output reader API to avoid this allocation.
+    uint8_t *out = malloc(out_len);
+    memset(out, 0, out_len);
+    if (out_len > 0 && out == NULL) {
+      fprintf(stderr, "malloc() failed.\n");
+      return 1;
+    }
+    blake3_hasher_finalize(&hasher, out, out_len);
+    for (size_t i = 0; i < out_len; i++) {
+      printf("%02x", out[i]);
+    }
+    printf("\n");
+    free(out);
+    feature = (feature - mask) & mask;
+  } while(feature != 0);
+  return 0;
+}