Rewrite code, but keeping the exact same semantic and behaviourHEADmain

- remove `#ifndef TWEETNACL_H` guard inside `tweetnacl.h`: as headers
  shouldn't include other headers;
- remove `#define sv static void` golfing alias;
- remove `#define FOR(i,n) for (i = 0;i < n;++i)` golfing alias;
- assert that the generated `tweetnacl.o` code is identical to the
  original code, available at `tests/assert-identical.sh`;
- remove all extra definitions from tweetnacl.h;
- rewrite code with the correct indentation, spacing and formatting;
- use C99 constructs over C89 (for loop variable declarations inside
  the parentheses);
- use smaller types on loop variables, mostly `u8` over `int`,
  `i64`, etc.;
- fix the public API;
- add fuzz targets;

1 files changed, 74 insertions, 0 deletions

diff --git a/src/random.c b/src/random.c
new file mode 100644
index 0000000..de94783
--- /dev/null
+++ b/src/random.c
@@ -0,0 +1,74 @@
+#include <s.h>
+
+#include <assert.h>
+#include <stdio.h>
+
+#include "random.h"
+
+
+
+static FILE *
+FH = NULL;
+
+
+
+int
+random_init(void) {
+	int rc = -1;
+
+	FH = fopen("/dev/urandom", "r");
+	if (FH == NULL) {
+		perror("fopen()");
+		goto out;
+	}
+
+	rc = 0;
+out:
+	return rc;
+}
+
+int
+random_destroy(void) {
+	if (FH == NULL) {
+		return 0;
+	}
+
+	int rc = -1;
+
+	if (fclose(FH)) {
+		perror("fclose()");
+		goto out;
+	}
+
+	rc = 0;
+out:
+	FH = NULL;
+	return rc;
+}
+
+static int
+random_generate(const unsigned long long length, unsigned char *const out) {
+	int rc = -1;
+
+	const size_t read_count = fread(out, 1U, length, FH);
+	if (ferror(FH)) {
+		perror("fread()");
+		goto out;
+	}
+	assert(read_count == length);
+
+	rc = 0;
+out:
+	return rc;
+}
+
+void
+random_bytes(unsigned char *const out, const unsigned long long length) {
+	assert(FH != NULL);
+	assert(random_generate(length, out) == 0);
+}
+
+void
+randombytes(unsigned char *const out, const unsigned long long length) {
+	random_bytes(out, length);
+}