1 files changed, 88 insertions, 0 deletions
diff --git a/c_src/linux/crypto/poly1305_generic.c b/c_src/linux/crypto/poly1305_generic.c
new file mode 100644
index 00000000..acb554c0
--- /dev/null
+++ b/c_src/linux/crypto/poly1305_generic.c
@@ -0,0 +1,88 @@
+/*
+ * Poly1305 authenticator algorithm, RFC7539
+ *
+ * Copyright (C) 2015 Martin Willi
+ *
+ * Based on public domain code by Andrew Moon and Daniel J. Bernstein.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/byteorder.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <asm/unaligned.h>
+
+#include <linux/crypto.h>
+#include <crypto/algapi.h>
+#include <crypto/hash.h>
+#include <crypto/poly1305.h>
+
+static struct shash_alg poly1305_alg;
+
+struct poly1305_desc_ctx {
+	bool					key_done;
+	crypto_onetimeauth_poly1305_state	s;
+};
+
+static int poly1305_init(struct shash_desc *desc)
+{
+	struct poly1305_desc_ctx *state = (void *) desc->ctx;
+
+	state->key_done = false;
+	return 0;
+}
+
+static int poly1305_update(struct shash_desc *desc,
+			   const u8 *src, unsigned len)
+{
+	struct poly1305_desc_ctx *state = (void *) desc->ctx;
+
+	if (!state->key_done) {
+		BUG_ON(len != crypto_onetimeauth_poly1305_KEYBYTES);
+
+		state->key_done = true;
+		return crypto_onetimeauth_poly1305_init(&state->s, src);
+	}
+
+	return crypto_onetimeauth_poly1305_update(&state->s, src, len);
+}
+
+static int poly1305_final(struct shash_desc *desc, u8 *out)
+{
+	struct poly1305_desc_ctx *state = (void *) desc->ctx;
+
+	return crypto_onetimeauth_poly1305_final(&state->s, out);
+}
+
+static void *poly1305_alloc_tfm(void)
+{
+	struct crypto_shash *tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
+
+	if (!tfm)
+		return NULL;
+
+	tfm->base.alg = &poly1305_alg.base;
+	tfm->descsize = sizeof(struct poly1305_desc_ctx);
+	return tfm;
+}
+
+static struct shash_alg poly1305_alg = {
+	.digestsize	= crypto_onetimeauth_poly1305_BYTES,
+	.init		= poly1305_init,
+	.update		= poly1305_update,
+	.final		= poly1305_final,
+	.descsize	= sizeof(struct poly1305_desc_ctx),
+
+	.base.cra_name	= "poly1305",
+	.base.alloc_tfm	= poly1305_alloc_tfm,
+};
+
+__attribute__((constructor(110)))
+static int poly1305_mod_init(void)
+{
+	return crypto_register_shash(&poly1305_alg);
+}