linux-imx

/*

 * 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/poly1305.h>

#include <linux/crypto.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <asm/unaligned.h>

​

static inline u64 mlt(u64 a, u64 b)

{

    return a * b;

}

​

static inline u32 sr(u64 v, u_char n)

{

    return v >> n;

}

​

static inline u32 and(u32 v, u32 mask)

{

    return v & mask;

}

​

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 = false;

    dctx->sset = false;

​

    return 0;

}

EXPORT_SYMBOL_GPL(crypto_poly1305_init);

​

void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key)

{

    /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */

    key->r[0] = (get_unaligned_le32(raw_key +  0) >> 0) & 0x3ffffff;

    key->r[1] = (get_unaligned_le32(raw_key +  3) >> 2) & 0x3ffff03;

    key->r[2] = (get_unaligned_le32(raw_key +  6) >> 4) & 0x3ffc0ff;

    key->r[3] = (get_unaligned_le32(raw_key +  9) >> 6) & 0x3f03fff;

    key->r[4] = (get_unaligned_le32(raw_key + 12) >> 8) & 0x00fffff;

}

EXPORT_SYMBOL_GPL(poly1305_core_setkey);

​

/*

 * Poly1305 requires a unique key for each tag, which implies that we can't set

 * it on the tfm that gets accessed by multiple users simultaneously. Instead we