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Annotation of embedaddon/strongswan/src/libstrongswan/plugins/openssl/openssl_xof.c, revision 1.1

1.1     ! misho       1: /*
        !             2:  * Copyright (C) 2020 Tobias Brunner
        !             3:  * HSR Hochschule fuer Technik Rapperswil
        !             4:  *
        !             5:  * This program is free software; you can redistribute it and/or modify it
        !             6:  * under the terms of the GNU General Public License as published by the
        !             7:  * Free Software Foundation; either version 2 of the License, or (at your
        !             8:  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
        !             9:  *
        !            10:  * This program is distributed in the hope that it will be useful, but
        !            11:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            12:  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
        !            13:  * for more details.
        !            14:  */
        !            15: 
        !            16: #include <openssl/evp.h>
        !            17: 
        !            18: /* SHA3 was added with 1.1.1 */
        !            19: #if OPENSSL_VERSION_NUMBER >= 0x1010100fL && !defined(OPENSSL_NO_SHAKE)
        !            20: 
        !            21: #include "openssl_xof.h"
        !            22: 
        !            23: #define KECCAK_STATE_SIZE 200 /* 1600 bits*/
        !            24: 
        !            25: typedef struct private_xof_t private_xof_t;
        !            26: 
        !            27: /**
        !            28:  * Private data
        !            29:  */
        !            30: struct private_xof_t {
        !            31: 
        !            32:        /**
        !            33:         * Public interface.
        !            34:         */
        !            35:        xof_t public;
        !            36: 
        !            37:        /**
        !            38:         * XOF algorithm to be used
        !            39:         */
        !            40:        ext_out_function_t algorithm;
        !            41: 
        !            42:        /**
        !            43:         * Internal type reference
        !            44:         */
        !            45:        const EVP_MD *md;
        !            46: 
        !            47:        /**
        !            48:         * Internal context
        !            49:         */
        !            50:        EVP_MD_CTX *ctx;
        !            51: 
        !            52:        /**
        !            53:         * Current seed
        !            54:         */
        !            55:        chunk_t seed;
        !            56: 
        !            57:        /**
        !            58:         * Offset into generated data
        !            59:         */
        !            60:        size_t offset;
        !            61: };
        !            62: 
        !            63: METHOD(xof_t, get_type, ext_out_function_t,
        !            64:        private_xof_t *this)
        !            65: {
        !            66:        return this->algorithm;
        !            67: }
        !            68: 
        !            69: METHOD(xof_t, get_bytes, bool,
        !            70:        private_xof_t *this, size_t out_len, uint8_t *buffer)
        !            71: {
        !            72:        bool success = FALSE;
        !            73:        chunk_t data;
        !            74: 
        !            75:        /* we can call EVP_DigestFinalXOF() only once, so to support an arbitrary
        !            76:         * number of calls to get_bytes(), we request all the data we already
        !            77:         * requested previously and just ignore what we already handed out */
        !            78:        if (EVP_DigestInit_ex(this->ctx, this->md, NULL) == 1 &&
        !            79:                EVP_DigestUpdate(this->ctx, this->seed.ptr, this->seed.len) == 1)
        !            80:        {
        !            81:                data = chunk_alloc(out_len + this->offset);
        !            82:                if (EVP_DigestFinalXOF(this->ctx, data.ptr, data.len) == 1)
        !            83:                {
        !            84:                        memcpy(buffer, data.ptr + this->offset, out_len);
        !            85:                        this->offset += out_len;
        !            86:                        success = TRUE;
        !            87:                }
        !            88:                chunk_clear(&data);
        !            89:        }
        !            90:        return success;
        !            91: }
        !            92: 
        !            93: METHOD(xof_t, allocate_bytes, bool,
        !            94:        private_xof_t *this, size_t out_len, chunk_t *chunk)
        !            95: {
        !            96:        *chunk = chunk_alloc(out_len);
        !            97:        return get_bytes(this, out_len, chunk->ptr);
        !            98: }
        !            99: 
        !           100: METHOD(xof_t, get_block_size, size_t,
        !           101:        private_xof_t *this)
        !           102: {
        !           103:        return EVP_MD_block_size(this->md);
        !           104: }
        !           105: 
        !           106: METHOD(xof_t, get_seed_size, size_t,
        !           107:        private_xof_t *this)
        !           108: {
        !           109:        return KECCAK_STATE_SIZE - EVP_MD_block_size(this->md);
        !           110: }
        !           111: 
        !           112: METHOD(xof_t, set_seed, bool,
        !           113:        private_xof_t *this, chunk_t seed)
        !           114: {
        !           115:        chunk_clear(&this->seed);
        !           116:        this->seed = chunk_clone(seed);
        !           117:        this->offset = 0;
        !           118:        return TRUE;
        !           119: }
        !           120: 
        !           121: METHOD(xof_t, destroy, void,
        !           122:        private_xof_t *this)
        !           123: {
        !           124:        EVP_MD_CTX_free(this->ctx);
        !           125:        chunk_clear(&this->seed);
        !           126:        free(this);
        !           127: }
        !           128: 
        !           129: /*
        !           130:  * Described in header
        !           131:  */
        !           132: xof_t *openssl_xof_create(ext_out_function_t algorithm)
        !           133: {
        !           134:        private_xof_t *this;
        !           135:        const EVP_MD *md;
        !           136: 
        !           137:        switch (algorithm)
        !           138:        {
        !           139:                case XOF_SHAKE_128:
        !           140:                        md = EVP_shake128();
        !           141:                        break;
        !           142:                case XOF_SHAKE_256:
        !           143:                        md = EVP_shake256();
        !           144:                        break;
        !           145:                default:
        !           146:                        return NULL;
        !           147:        }
        !           148: 
        !           149:        INIT(this,
        !           150:                .public = {
        !           151:                        .get_type = _get_type,
        !           152:                        .get_bytes = _get_bytes,
        !           153:                        .allocate_bytes = _allocate_bytes,
        !           154:                        .get_block_size = _get_block_size,
        !           155:                        .get_seed_size = _get_seed_size,
        !           156:                        .set_seed = _set_seed,
        !           157:                        .destroy = _destroy,
        !           158:                },
        !           159:                .algorithm = algorithm,
        !           160:                .md = md,
        !           161:                .ctx = EVP_MD_CTX_new(),
        !           162:        );
        !           163:        return &this->public;
        !           164: }
        !           165: 
        !           166: #endif /* OPENSSL_NO_ECDH */