sha1_glue.c

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/* Glue code for SHA1 hashing optimized for sparc64 crypto opcodes.
 *
 * This is based largely upon arch/x86/crypto/sha1_ssse3_glue.c
 *
 * Copyright (c) Alan Smithee.
 * Copyright (c) Andrew McDonald <[email protected]>
 * Copyright (c) Jean-Francois Dive <[email protected]>
 * Copyright (c) Mathias Krause <[email protected]>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/cryptohash.h>
#include <linux/types.h>
#include <crypto/sha.h>

#include <asm/pstate.h>
#include <asm/elf.h>

#include "opcodes.h"

asmlinkage void sha1_sparc64_transform(u32 *digest, const char *data,
                       unsigned int rounds);

static int sha1_sparc64_init(struct shash_desc *desc)
{
    struct sha1_state *sctx = shash_desc_ctx(desc);

    *sctx = (struct sha1_state){
        .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
    };

    return 0;
}

static void __sha1_sparc64_update(struct sha1_state *sctx, const u8 *data,
                  unsigned int len, unsigned int partial)
{
    unsigned int done = 0;

    sctx->count += len;
    if (partial) {
        done = SHA1_BLOCK_SIZE - partial;
        memcpy(sctx->buffer + partial, data, done);
        sha1_sparc64_transform(sctx->state, sctx->buffer, 1);
    }
    if (len - done >= SHA1_BLOCK_SIZE) {
        const unsigned int rounds = (len - done) / SHA1_BLOCK_SIZE;

        sha1_sparc64_transform(sctx->state, data + done, rounds);
        done += rounds * SHA1_BLOCK_SIZE;
    }

    memcpy(sctx->buffer, data + done, len - done);
}

static int sha1_sparc64_update(struct shash_desc *desc, const u8 *data,
                   unsigned int len)
{
    struct sha1_state *sctx = shash_desc_ctx(desc);
    unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;

    /* Handle the fast case right here */
    if (partial + len < SHA1_BLOCK_SIZE) {
        sctx->count += len;
        memcpy(sctx->buffer + partial, data, len);
    } else
        __sha1_sparc64_update(sctx, data, len, partial);

    return 0;
}

/* Add padding and return the message digest. */
static int sha1_sparc64_final(struct shash_desc *desc, u8 *out)
{
    struct sha1_state *sctx = shash_desc_ctx(desc);
    unsigned int i, index, padlen;
    __be32 *dst = (__be32 *)out;
    __be64 bits;
    static const u8 padding[SHA1_BLOCK_SIZE] = { 0x80, };

    bits = cpu_to_be64(sctx->count << 3);

    /* Pad out to 56 mod 64 and append length */
    index = sctx->count % SHA1_BLOCK_SIZE;
    padlen = (index < 56) ? (56 - index) : ((SHA1_BLOCK_SIZE+56) - index);

    /* We need to fill a whole block for __sha1_sparc64_update() */
    if (padlen <= 56) {
        sctx->count += padlen;
        memcpy(sctx->buffer + index, padding, padlen);
    } else {
        __sha1_sparc64_update(sctx, padding, padlen, index);
    }
    __sha1_sparc64_update(sctx, (const u8 *)&bits, sizeof(bits), 56);

    /* Store state in digest */
    for (i = 0; i < 5; i++)
        dst[i] = cpu_to_be32(sctx->state[i]);

    /* Wipe context */
    memset(sctx, 0, sizeof(*sctx));

    return 0;
}

static int sha1_sparc64_export(struct shash_desc *desc, void *out)
{
    struct sha1_state *sctx = shash_desc_ctx(desc);

    memcpy(out, sctx, sizeof(*sctx));

    return 0;
}

static int sha1_sparc64_import(struct shash_desc *desc, const void *in)
{
    struct sha1_state *sctx = shash_desc_ctx(desc);

    memcpy(sctx, in, sizeof(*sctx));

    return 0;
}

static struct shash_alg alg = {
    .digestsize =   SHA1_DIGEST_SIZE,
    .init       =   sha1_sparc64_init,
    .update     =   sha1_sparc64_update,
    .final      =   sha1_sparc64_final,
    .export     =   sha1_sparc64_export,
    .import     =   sha1_sparc64_import,
    .descsize   =   sizeof(struct sha1_state),
    .statesize  =   sizeof(struct sha1_state),
    .base       =   {
        .cra_name   =   "sha1",
        .cra_driver_name=   "sha1-sparc64",
        .cra_priority   =   SPARC_CR_OPCODE_PRIORITY,
        .cra_flags  =   CRYPTO_ALG_TYPE_SHASH,
        .cra_blocksize  =   SHA1_BLOCK_SIZE,
        .cra_module =   THIS_MODULE,
    }
};

static bool __init sparc64_has_sha1_opcode(void)
{
    unsigned long cfr;

    if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
        return false;

    __asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
    if (!(cfr & CFR_SHA1))
        return false;

    return true;
}

static int __init sha1_sparc64_mod_init(void)
{
    if (sparc64_has_sha1_opcode()) {
        pr_info("Using sparc64 sha1 opcode optimized SHA-1 implementation\n");
        return crypto_register_shash(&alg);
    }
    pr_info("sparc64 sha1 opcode not available.\n");
    return -ENODEV;
}

static void __exit sha1_sparc64_mod_fini(void)
{
    crypto_unregister_shash(&alg);
}

module_init(sha1_sparc64_mod_init);
module_exit(sha1_sparc64_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, sparc64 sha1 opcode accelerated");

MODULE_ALIAS("sha1");

#include "crop_devid.c"