/*

 * Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/evp.h>

#include <openssl/objects.h>

#include <openssl/x509.h>

#include "crypto/evp.h"

#include "evp_local.h"

static int update(EVP_MD_CTX *ctx, const void *data, size_t datalen)

{

    EVPerr(EVP_F_UPDATE, EVP_R_ONLY_ONESHOT_SUPPORTED);

    return 0;

}

static int do_sigver_init(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

                          const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey,

                          int ver)

{

    if (ctx->pctx == NULL)

        ctx->pctx = EVP_PKEY_CTX_new(pkey, e);

    if (ctx->pctx == NULL)

        return 0;

    if (!(ctx->pctx->pmeth->flags & EVP_PKEY_FLAG_SIGCTX_CUSTOM)) {

        if (type == NULL) {

            int def_nid;

            if (EVP_PKEY_get_default_digest_nid(pkey, &def_nid) > 0)

                type = EVP_get_digestbynid(def_nid);

        }

        if (type == NULL) {

            EVPerr(EVP_F_DO_SIGVER_INIT, EVP_R_NO_DEFAULT_DIGEST);

            return 0;

        }

    }

    if (ver) {

        if (ctx->pctx->pmeth->verifyctx_init) {

            if (ctx->pctx->pmeth->verifyctx_init(ctx->pctx, ctx) <= 0)

                return 0;

            ctx->pctx->operation = EVP_PKEY_OP_VERIFYCTX;

        } else if (ctx->pctx->pmeth->digestverify != 0) {

            ctx->pctx->operation = EVP_PKEY_OP_VERIFY;

            ctx->update = update;

        } else if (EVP_PKEY_verify_init(ctx->pctx) <= 0) {

            return 0;

        }

    } else {

        if (ctx->pctx->pmeth->signctx_init) {

            if (ctx->pctx->pmeth->signctx_init(ctx->pctx, ctx) <= 0)

                return 0;

            ctx->pctx->operation = EVP_PKEY_OP_SIGNCTX;

        } else if (ctx->pctx->pmeth->digestsign != 0) {

            ctx->pctx->operation = EVP_PKEY_OP_SIGN;

            ctx->update = update;

        } else if (EVP_PKEY_sign_init(ctx->pctx) <= 0) {

            return 0;

        }

    }

    if (EVP_PKEY_CTX_set_signature_md(ctx->pctx, type) <= 0)

        return 0;

    if (pctx)

        *pctx = ctx->pctx;

    if (ctx->pctx->pmeth->flags & EVP_PKEY_FLAG_SIGCTX_CUSTOM)

        return 1;

    if (!EVP_DigestInit_ex(ctx, type, e))

        return 0;

    /*

     * This indicates the current algorithm requires

     * special treatment before hashing the tbs-message.

     */

    if (ctx->pctx->pmeth->digest_custom != NULL)

        return ctx->pctx->pmeth->digest_custom(ctx->pctx, ctx);

    return 1;

}

int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

                       const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey)

{

    return do_sigver_init(ctx, pctx, type, e, pkey, 0);

}

int EVP_DigestVerifyInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,

                         const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey)

{

    return do_sigver_init(ctx, pctx, type, e, pkey, 1);

}

int EVP_DigestSignFinal(EVP_MD_CTX *ctx, unsigned char *sigret,

                        size_t *siglen)

{

    int sctx = 0, r = 0;

    EVP_PKEY_CTX *pctx = ctx->pctx;

    if (pctx->pmeth->flags & EVP_PKEY_FLAG_SIGCTX_CUSTOM) {

        if (!sigret)

            return pctx->pmeth->signctx(pctx, sigret, siglen, ctx);

        if (ctx->flags & EVP_MD_CTX_FLAG_FINALISE)

            r = pctx->pmeth->signctx(pctx, sigret, siglen, ctx);

        else {

            EVP_PKEY_CTX *dctx = EVP_PKEY_CTX_dup(ctx->pctx);

            if (!dctx)

                return 0;

            r = dctx->pmeth->signctx(dctx, sigret, siglen, ctx);

            EVP_PKEY_CTX_free(dctx);

        }

        return r;

    }

    if (pctx->pmeth->signctx)

        sctx = 1;

    else

        sctx = 0;

    if (sigret) {

        unsigned char md[EVP_MAX_MD_SIZE];

        unsigned int mdlen = 0;

        if (ctx->flags & EVP_MD_CTX_FLAG_FINALISE) {

            if (sctx)

                r = ctx->pctx->pmeth->signctx(ctx->pctx, sigret, siglen, ctx);

            else

                r = EVP_DigestFinal_ex(ctx, md, &mdlen);

        } else {

            EVP_MD_CTX *tmp_ctx = EVP_MD_CTX_new();

            if (tmp_ctx == NULL)

                return 0;

            if (!EVP_MD_CTX_copy_ex(tmp_ctx, ctx)) {

                EVP_MD_CTX_free(tmp_ctx);

                return 0;

            }

            if (sctx)

                r = tmp_ctx->pctx->pmeth->signctx(tmp_ctx->pctx,

                                                  sigret, siglen, tmp_ctx);

            else

                r = EVP_DigestFinal_ex(tmp_ctx, md, &mdlen);

            EVP_MD_CTX_free(tmp_ctx);

        }

        if (sctx || !r)

            return r;

        if (EVP_PKEY_sign(ctx->pctx, sigret, siglen, md, mdlen) <= 0)

            return 0;

    } else {

        if (sctx) {

            if (pctx->pmeth->signctx(pctx, sigret, siglen, ctx) <= 0)

                return 0;

        } else {

            int s = EVP_MD_size(ctx->digest);

            if (s < 0 || EVP_PKEY_sign(pctx, sigret, siglen, NULL, s) <= 0)

                return 0;

        }

    }

    return 1;

}

int EVP_DigestSign(EVP_MD_CTX *ctx, unsigned char *sigret, size_t *siglen,

                   const unsigned char *tbs, size_t tbslen)

{

    if (ctx->pctx->pmeth->digestsign != NULL)

        return ctx->pctx->pmeth->digestsign(ctx, sigret, siglen, tbs, tbslen);

    if (sigret != NULL && EVP_DigestSignUpdate(ctx, tbs, tbslen) <= 0)

        return 0;

    return EVP_DigestSignFinal(ctx, sigret, siglen);

}

int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sig,

                          size_t siglen)

{

    unsigned char md[EVP_MAX_MD_SIZE];

    int r = 0;

    unsigned int mdlen = 0;

    int vctx = 0;

    if (ctx->pctx->pmeth->verifyctx)

        vctx = 1;

    else

        vctx = 0;

    if (ctx->flags & EVP_MD_CTX_FLAG_FINALISE) {

        if (vctx)

            r = ctx->pctx->pmeth->verifyctx(ctx->pctx, sig, siglen, ctx);

        else

            r = EVP_DigestFinal_ex(ctx, md, &mdlen);

    } else {

        EVP_MD_CTX *tmp_ctx = EVP_MD_CTX_new();

        if (tmp_ctx == NULL)

            return -1;

        if (!EVP_MD_CTX_copy_ex(tmp_ctx, ctx)) {

            EVP_MD_CTX_free(tmp_ctx);

            return -1;

        }

        if (vctx)

            r = tmp_ctx->pctx->pmeth->verifyctx(tmp_ctx->pctx,

                                                sig, siglen, tmp_ctx);

        else

            r = EVP_DigestFinal_ex(tmp_ctx, md, &mdlen);

        EVP_MD_CTX_free(tmp_ctx);

    }

    if (vctx || !r)

        return r;

    return EVP_PKEY_verify(ctx->pctx, sig, siglen, md, mdlen);

}

int EVP_DigestVerify(EVP_MD_CTX *ctx, const unsigned char *sigret,

                     size_t siglen, const unsigned char *tbs, size_t tbslen)

{

    if (ctx->pctx->pmeth->digestverify != NULL)

        return ctx->pctx->pmeth->digestverify(ctx, sigret, siglen, tbs, tbslen);

    if (EVP_DigestVerifyUpdate(ctx, tbs, tbslen) <= 0)

        return -1;

    return EVP_DigestVerifyFinal(ctx, sigret, siglen);

}