1 files changed, 75 insertions, 0 deletions
diff --git a/src/rnd_well512.c b/src/rnd_well512.c
new file mode 100644
index 0000000..5f7b97e
--- /dev/null
+++ b/src/rnd_well512.c
@@ -0,0 +1,75 @@
+#include "rnd.h"
+#include "util_rt.h"
+
+#include <string.h>
+#include <errno.h>
+
+
+typedef struct {
+	uint32_t state[16];
+	size_t index;
+} rnd_well512_ctx_t;
+
+static uint32_t rnd_well512_pull (rnd_well512_ctx_t *ctx) {
+	uint32_t a, b, c, d;
+
+	a = ctx->state[ctx->index];
+	c = ctx->state[(ctx->index + 13) & 15];
+	b = a ^ c ^ (a << 16) ^ (c << 15);
+	c = ctx->state[(ctx->index + 9) & 15];
+	c ^= (c >> 11);
+	a = ctx->state[ctx->index] = b ^ c;
+	d = a ^ ((a << 5) & 0xDA442D24UL);
+	ctx->index = (ctx->index + 15) & 15;
+	a = ctx->state[ctx->index];
+	ctx->state[ctx->index] = a ^ b ^ d ^ (a << 2) ^ (b << 18) ^ (c << 28);
+
+	return ctx->state[ctx->index];
+}
+
+static bool rnd_well512_f (void *p, uint8_t *buf, size_t len) {
+	rnd_well512_ctx_t *ctx = (rnd_well512_ctx_t*)p;
+	size_t consume;
+	uint32_t n;
+
+
+	while (len > 0) {
+		n = rnd_well512_pull(ctx);
+		consume = prne_op_min(len, sizeof(n));
+		memcpy(buf, &n, consume);
+		buf += consume;
+		len -= consume;
+	}
+
+	return true;
+}
+
+static void rnd_free_well512 (void *p) {
+	prne_free(p);
+}
+
+bool prne_rnd_alloc_well512 (
+	prne_rnd_t *p,
+	const uint8_t *is,
+	const size_t is_len)
+{
+	rnd_well512_ctx_t *ctx;
+
+	if (is_len < sizeof(ctx->state)) {
+		errno = EINVAL;
+		return false;
+	}
+
+	ctx = (rnd_well512_ctx_t*)prne_calloc(sizeof(rnd_well512_ctx_t), 1);
+	if (ctx == NULL) {
+		return false;
+	}
+
+	prne_free_rnd(p);
+	memcpy(ctx->state, is, sizeof(ctx->state));
+	p->ctx = ctx;
+	p->free_ctx_f = rnd_free_well512;
+	p->random = rnd_well512_f;
+
+	return true;
+}