nx-sha256.c

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#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <linux/module.h>
#include <asm/vio.h>

#include "nx_csbcpb.h"
#include "nx.h"


static int nx_sha256_init(struct shash_desc *desc)
{
    struct sha256_state *sctx = shash_desc_ctx(desc);
    struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
    struct nx_sg *out_sg;

    nx_ctx_init(nx_ctx, HCOP_FC_SHA);

    memset(sctx, 0, sizeof *sctx);

    nx_ctx->ap = &nx_ctx->props[NX_PROPS_SHA256];

    NX_CPB_SET_DIGEST_SIZE(nx_ctx->csbcpb, NX_DS_SHA256);
    out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
                  SHA256_DIGEST_SIZE, nx_ctx->ap->sglen);
    nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);

    return 0;
}

static int nx_sha256_update(struct shash_desc *desc, const u8 *data,
                unsigned int len)
{
    struct sha256_state *sctx = shash_desc_ctx(desc);
    struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
    struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
    struct nx_sg *in_sg;
    u64 to_process, leftover;
    int rc = 0;

    if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
        /* we've hit the nx chip previously and we're updating again,
         * so copy over the partial digest */
        memcpy(csbcpb->cpb.sha256.input_partial_digest,
               csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
    }

    /* 2 cases for total data len:
     *  1: <= SHA256_BLOCK_SIZE: copy into state, return 0
     *  2: > SHA256_BLOCK_SIZE: process X blocks, copy in leftover
     */
    if (len + sctx->count <= SHA256_BLOCK_SIZE) {
        memcpy(sctx->buf + sctx->count, data, len);
        sctx->count += len;
        goto out;
    }

    /* to_process: the SHA256_BLOCK_SIZE data chunk to process in this
     * update */
    to_process = (sctx->count + len) & ~(SHA256_BLOCK_SIZE - 1);
    leftover = (sctx->count + len) & (SHA256_BLOCK_SIZE - 1);

    if (sctx->count) {
        in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buf,
                     sctx->count, nx_ctx->ap->sglen);
        in_sg = nx_build_sg_list(in_sg, (u8 *)data,
                     to_process - sctx->count,
                     nx_ctx->ap->sglen);
        nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
                    sizeof(struct nx_sg);
    } else {
        in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)data,
                     to_process, nx_ctx->ap->sglen);
        nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
                    sizeof(struct nx_sg);
    }

    NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;

    if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
        rc = -EINVAL;
        goto out;
    }

    rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
               desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
    if (rc)
        goto out;

    atomic_inc(&(nx_ctx->stats->sha256_ops));

    /* copy the leftover back into the state struct */
    memcpy(sctx->buf, data + len - leftover, leftover);
    sctx->count = leftover;

    csbcpb->cpb.sha256.message_bit_length += (u64)
        (csbcpb->cpb.sha256.spbc * 8);

    /* everything after the first update is continuation */
    NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
out:
    return rc;
}

static int nx_sha256_final(struct shash_desc *desc, u8 *out)
{
    struct sha256_state *sctx = shash_desc_ctx(desc);
    struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
    struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
    struct nx_sg *in_sg, *out_sg;
    int rc;

    if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
        /* we've hit the nx chip previously, now we're finalizing,
         * so copy over the partial digest */
        memcpy(csbcpb->cpb.sha256.input_partial_digest,
               csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
    }

    /* final is represented by continuing the operation and indicating that
     * this is not an intermediate operation */
    NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;

    csbcpb->cpb.sha256.message_bit_length += (u64)(sctx->count * 8);

    in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buf,
                 sctx->count, nx_ctx->ap->sglen);
    out_sg = nx_build_sg_list(nx_ctx->out_sg, out, SHA256_DIGEST_SIZE,
                  nx_ctx->ap->sglen);
    nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
    nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);

    if (!nx_ctx->op.outlen) {
        rc = -EINVAL;
        goto out;
    }

    rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
               desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
    if (rc)
        goto out;

    atomic_inc(&(nx_ctx->stats->sha256_ops));

    atomic64_add(csbcpb->cpb.sha256.message_bit_length,
             &(nx_ctx->stats->sha256_bytes));
    memcpy(out, csbcpb->cpb.sha256.message_digest, SHA256_DIGEST_SIZE);
out:
    return rc;
}

static int nx_sha256_export(struct shash_desc *desc, void *out)
{
    struct sha256_state *sctx = shash_desc_ctx(desc);
    struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
    struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
    struct sha256_state *octx = out;

    octx->count = sctx->count +
              (csbcpb->cpb.sha256.message_bit_length / 8);
    memcpy(octx->buf, sctx->buf, sizeof(octx->buf));

    /* if no data has been processed yet, we need to export SHA256's
     * initial data, in case this context gets imported into a software
     * context */
    if (csbcpb->cpb.sha256.message_bit_length)
        memcpy(octx->state, csbcpb->cpb.sha256.message_digest,
               SHA256_DIGEST_SIZE);
    else {
        octx->state[0] = SHA256_H0;
        octx->state[1] = SHA256_H1;
        octx->state[2] = SHA256_H2;
        octx->state[3] = SHA256_H3;
        octx->state[4] = SHA256_H4;
        octx->state[5] = SHA256_H5;
        octx->state[6] = SHA256_H6;
        octx->state[7] = SHA256_H7;
    }

    return 0;
}

static int nx_sha256_import(struct shash_desc *desc, const void *in)
{
    struct sha256_state *sctx = shash_desc_ctx(desc);
    struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
    struct nx_csbcpb *csbcpb = (struct nx_csbcpb *)nx_ctx->csbcpb;
    const struct sha256_state *ictx = in;

    memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf));

    sctx->count = ictx->count & 0x3f;
    csbcpb->cpb.sha256.message_bit_length = (ictx->count & ~0x3f) * 8;

    if (csbcpb->cpb.sha256.message_bit_length) {
        memcpy(csbcpb->cpb.sha256.message_digest, ictx->state,
               SHA256_DIGEST_SIZE);

        NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
        NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
    }

    return 0;
}

struct shash_alg nx_shash_sha256_alg = {
    .digestsize = SHA256_DIGEST_SIZE,
    .init       = nx_sha256_init,
    .update     = nx_sha256_update,
    .final      = nx_sha256_final,
    .export     = nx_sha256_export,
    .import     = nx_sha256_import,
    .descsize   = sizeof(struct sha256_state),
    .statesize  = sizeof(struct sha256_state),
    .base       = {
        .cra_name        = "sha256",
        .cra_driver_name = "sha256-nx",
        .cra_priority    = 300,
        .cra_flags       = CRYPTO_ALG_TYPE_SHASH,
        .cra_blocksize   = SHA256_BLOCK_SIZE,
        .cra_module      = THIS_MODULE,
        .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
        .cra_init        = nx_crypto_ctx_sha_init,
        .cra_exit        = nx_crypto_ctx_exit,
    }
};