/*

 * Copyright 2007-2018 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/x509.h>

#include <openssl/x509v3.h>

#include <openssl/evp.h>

#include <openssl/err.h>

#include "crypto/poly1305.h"

#include "poly1305_local.h"

#include "crypto/evp.h"

/* POLY1305 pkey context structure */

typedef struct {

    ASN1_OCTET_STRING ktmp;     /* Temp storage for key */

    POLY1305 ctx;

} POLY1305_PKEY_CTX;

static int pkey_poly1305_init(EVP_PKEY_CTX *ctx)

{

    POLY1305_PKEY_CTX *pctx;

    if ((pctx = OPENSSL_zalloc(sizeof(*pctx))) == NULL) {

        CRYPTOerr(CRYPTO_F_PKEY_POLY1305_INIT, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    pctx->ktmp.type = V_ASN1_OCTET_STRING;

    EVP_PKEY_CTX_set_data(ctx, pctx);

    EVP_PKEY_CTX_set0_keygen_info(ctx, NULL, 0);

    return 1;

}

static void pkey_poly1305_cleanup(EVP_PKEY_CTX *ctx)

{

    POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    if (pctx != NULL) {

        OPENSSL_clear_free(pctx->ktmp.data, pctx->ktmp.length);

        OPENSSL_clear_free(pctx, sizeof(*pctx));

        EVP_PKEY_CTX_set_data(ctx, NULL);

    }

}

static int pkey_poly1305_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)

{

    POLY1305_PKEY_CTX *sctx, *dctx;

    /* allocate memory for dst->data and a new POLY1305_CTX in dst->data->ctx */

    if (!pkey_poly1305_init(dst))

        return 0;

    sctx = EVP_PKEY_CTX_get_data(src);

    dctx = EVP_PKEY_CTX_get_data(dst);

    if (ASN1_STRING_get0_data(&sctx->ktmp) != NULL &&

        !ASN1_STRING_copy(&dctx->ktmp, &sctx->ktmp)) {

        /* cleanup and free the POLY1305_PKEY_CTX in dst->data */

        pkey_poly1305_cleanup(dst);

        return 0;

    }

    memcpy(&dctx->ctx, &sctx->ctx, sizeof(POLY1305));

    return 1;

}

static int pkey_poly1305_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)

{

    ASN1_OCTET_STRING *key;

    POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    if (ASN1_STRING_get0_data(&pctx->ktmp) == NULL)

        return 0;

    key = ASN1_OCTET_STRING_dup(&pctx->ktmp);

    if (key == NULL)

        return 0;

    return EVP_PKEY_assign_POLY1305(pkey, key);

}

static int int_update(EVP_MD_CTX *ctx, const void *data, size_t count)

{

    POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(EVP_MD_CTX_pkey_ctx(ctx));

    Poly1305_Update(&pctx->ctx, data, count);

    return 1;

}

static int poly1305_signctx_init(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)

{

    POLY1305_PKEY_CTX *pctx = ctx->data;

    ASN1_OCTET_STRING *key = (ASN1_OCTET_STRING *)ctx->pkey->pkey.ptr;

    if (key->length != POLY1305_KEY_SIZE)

        return 0;

    EVP_MD_CTX_set_flags(mctx, EVP_MD_CTX_FLAG_NO_INIT);

    EVP_MD_CTX_set_update_fn(mctx, int_update);

    Poly1305_Init(&pctx->ctx, key->data);

    return 1;

}

static int poly1305_signctx(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,

                            EVP_MD_CTX *mctx)

{

    POLY1305_PKEY_CTX *pctx = ctx->data;

    *siglen = POLY1305_DIGEST_SIZE;

    if (sig != NULL)

        Poly1305_Final(&pctx->ctx, sig);

    return 1;

}

static int pkey_poly1305_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)

{

    POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    const unsigned char *key;

    size_t len;

    switch (type) {

    case EVP_PKEY_CTRL_MD:

        /* ignore */

        break;

    case EVP_PKEY_CTRL_SET_MAC_KEY:

    case EVP_PKEY_CTRL_DIGESTINIT:

        if (type == EVP_PKEY_CTRL_SET_MAC_KEY) {

            /* user explicitly setting the key */

            key = p2;

            len = p1;

        } else {

            /* user indirectly setting the key via EVP_DigestSignInit */

            key = EVP_PKEY_get0_poly1305(EVP_PKEY_CTX_get0_pkey(ctx), &len);

        }

        if (key == NULL || len != POLY1305_KEY_SIZE ||

            !ASN1_OCTET_STRING_set(&pctx->ktmp, key, len))

            return 0;

        Poly1305_Init(&pctx->ctx, ASN1_STRING_get0_data(&pctx->ktmp));

        break;

    default:

        return -2;

    }

    return 1;

}

static int pkey_poly1305_ctrl_str(EVP_PKEY_CTX *ctx,

                                  const char *type, const char *value)

{

    if (value == NULL)

        return 0;

    if (strcmp(type, "key") == 0)

        return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, value);

    if (strcmp(type, "hexkey") == 0)

        return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, value);

    return -2;

}

const EVP_PKEY_METHOD poly1305_pkey_meth = {

    EVP_PKEY_POLY1305,

    EVP_PKEY_FLAG_SIGCTX_CUSTOM, /* we don't deal with a separate MD */

    pkey_poly1305_init,

    pkey_poly1305_copy,

    pkey_poly1305_cleanup,

    0, 0,

    0,

    pkey_poly1305_keygen,

    0, 0,

    0, 0,

    0, 0,

    poly1305_signctx_init,

    poly1305_signctx,

    0, 0,

    0, 0,

    0, 0,

    0, 0,

    pkey_poly1305_ctrl,

    pkey_poly1305_ctrl_str

};