src/random.h: Add initial implementation of random_{new,free,generate}()

2 files changed, 97 insertions, 1 deletions

diff --git a/src/random.c b/src/random.c
index df2d3ff..b409e6a 100644
--- a/src/random.c
+++ b/src/random.c
@@ -13,6 +13,13 @@
 #include "random.h"
 
 
+
+struct Random {
+	FILE *const file_handle;
+};
+
+
+
 int
 urandom_bytes(const size_t n, uint8_t (*const addr)[]) {
 	int rc = -1;
@@ -32,7 +39,7 @@ urandom_bytes(const size_t n, uint8_t (*const addr)[]) {
 		goto out;
 	}
 
-	const size_t read_count = fread(ret, 1, n, f);
+	const size_t read_count = fread(ret, 1U, n, f);
 	if (ferror(f)) {
 		logerr("fread(): %s", strerror(errno));
 		goto out;
@@ -59,3 +66,76 @@ out:
 	}
 	return rc;
 }
+
+int
+random_generate(
+	const struct Random *const r,
+	const size_t length,
+	uint8_t (*const out)[]
+) {
+	int rc = -1;
+
+	const size_t read_count = fread(out, 1U, length, r->file_handle);
+	if (ferror(r->file_handle)) {
+		logerr("fread(): %s", strerror(errno));
+		goto out;
+	}
+	assert(read_count == length);
+
+	rc = 0;
+out:
+	return rc;
+}
+
+int
+random_new(const struct Random **const out) {
+	int rc = -1;
+
+	const struct Random *ret = NULL;
+	FILE *f = NULL;
+
+	ret = malloc(sizeof(*ret));
+	if (ret == NULL) {
+		logerr("malloc(): %s", strerror(errno));
+		goto out;
+	}
+
+	f = fopen("/dev/urandom", "r");
+	if (f == NULL) {
+		logerr("fopen(): %s", strerror(errno));
+		goto out;
+	}
+
+	memcpy((void *)ret, &(struct Random) {
+		.file_handle = f,
+	}, sizeof(*ret));
+	*out = ret;
+	rc = 0;
+out:
+	if (rc) {
+		random_free(&ret);
+	}
+	return rc;
+}
+
+int
+random_free(const struct Random **const r) {
+	if (r == NULL) {
+		return 0;
+	}
+
+	if (*r == NULL) {
+		return 0;
+	}
+
+	int rc = -1;
+	if (fclose((*r)->file_handle)) {
+		logerr("fclose(): %s", strerror(errno));
+		goto out;
+	}
+
+	rc = 0;
+out:
+	freeit((void *)r);
+	return rc;
+}
diff --git a/src/random.h b/src/random.h
index ffaa69e..4b31abb 100644
--- a/src/random.h
+++ b/src/random.h
@@ -1,2 +1,18 @@
+struct Random;
+
+
 int
 urandom_bytes(const size_t n, uint8_t (*const addr)[]);
+
+int
+random_new(const struct Random **out);
+
+int
+random_free(const struct Random **r);
+
+int
+random_generate(
+	const struct Random *r,
+	const size_t length,
+	uint8_t (*const out)[]
+);