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-rw-r--r--crypto/poly1305_generic.c149
1 files changed, 149 insertions, 0 deletions
diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c
new file mode 100644
index 0000000000..94af47eb6f
--- /dev/null
+++ b/crypto/poly1305_generic.c
@@ -0,0 +1,149 @@
+/*
+ * 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 <crypto/algapi.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/poly1305.h>
+#include <linux/crypto.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/unaligned.h>
+
+static int crypto_poly1305_init(struct shash_desc *desc)
+{
+ struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ poly1305_core_init(&dctx->h);
+ dctx->buflen = 0;
+ dctx->rset = 0;
+ dctx->sset = false;
+
+ return 0;
+}
+
+static unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
+ const u8 *src, unsigned int srclen)
+{
+ if (!dctx->sset) {
+ if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) {
+ poly1305_core_setkey(&dctx->core_r, src);
+ src += POLY1305_BLOCK_SIZE;
+ srclen -= POLY1305_BLOCK_SIZE;
+ dctx->rset = 2;
+ }
+ if (srclen >= POLY1305_BLOCK_SIZE) {
+ dctx->s[0] = get_unaligned_le32(src + 0);
+ dctx->s[1] = get_unaligned_le32(src + 4);
+ dctx->s[2] = get_unaligned_le32(src + 8);
+ dctx->s[3] = get_unaligned_le32(src + 12);
+ src += POLY1305_BLOCK_SIZE;
+ srclen -= POLY1305_BLOCK_SIZE;
+ dctx->sset = true;
+ }
+ }
+ return srclen;
+}
+
+static void poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
+ unsigned int srclen)
+{
+ unsigned int datalen;
+
+ if (unlikely(!dctx->sset)) {
+ datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
+ src += srclen - datalen;
+ srclen = datalen;
+ }
+
+ poly1305_core_blocks(&dctx->h, &dctx->core_r, src,
+ srclen / POLY1305_BLOCK_SIZE, 1);
+}
+
+static int crypto_poly1305_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen)
+{
+ struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+ unsigned int bytes;
+
+ if (unlikely(dctx->buflen)) {
+ bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
+ memcpy(dctx->buf + dctx->buflen, src, bytes);
+ src += bytes;
+ srclen -= bytes;
+ dctx->buflen += bytes;
+
+ if (dctx->buflen == POLY1305_BLOCK_SIZE) {
+ poly1305_blocks(dctx, dctx->buf,
+ POLY1305_BLOCK_SIZE);
+ dctx->buflen = 0;
+ }
+ }
+
+ if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
+ poly1305_blocks(dctx, src, srclen);
+ src += srclen - (srclen % POLY1305_BLOCK_SIZE);
+ srclen %= POLY1305_BLOCK_SIZE;
+ }
+
+ if (unlikely(srclen)) {
+ dctx->buflen = srclen;
+ memcpy(dctx->buf, src, srclen);
+ }
+
+ return 0;
+}
+
+static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
+{
+ struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+ if (unlikely(!dctx->sset))
+ return -ENOKEY;
+
+ poly1305_final_generic(dctx, dst);
+ return 0;
+}
+
+static struct shash_alg poly1305_alg = {
+ .digestsize = POLY1305_DIGEST_SIZE,
+ .init = crypto_poly1305_init,
+ .update = crypto_poly1305_update,
+ .final = crypto_poly1305_final,
+ .descsize = sizeof(struct poly1305_desc_ctx),
+ .base = {
+ .cra_name = "poly1305",
+ .cra_driver_name = "poly1305-generic",
+ .cra_priority = 100,
+ .cra_blocksize = POLY1305_BLOCK_SIZE,
+ .cra_module = THIS_MODULE,
+ },
+};
+
+static int __init poly1305_mod_init(void)
+{
+ return crypto_register_shash(&poly1305_alg);
+}
+
+static void __exit poly1305_mod_exit(void)
+{
+ crypto_unregister_shash(&poly1305_alg);
+}
+
+subsys_initcall(poly1305_mod_init);
+module_exit(poly1305_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
+MODULE_DESCRIPTION("Poly1305 authenticator");
+MODULE_ALIAS_CRYPTO("poly1305");
+MODULE_ALIAS_CRYPTO("poly1305-generic");