ciphercommon.h

/*
 * Copyright 2019-2025 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (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
 */

#ifndef OSSL_PROV_CIPHERCOMMON_H
#define OSSL_PROV_CIPHERCOMMON_H
#pragma once

#include <openssl/params.h>
#include <openssl/core_dispatch.h>
#include <openssl/core_names.h>
#include <openssl/evp.h>
#include "internal/cryptlib.h"
#include "crypto/modes.h"

#define MAXCHUNK ((size_t)1 << 30)
#define MAXBITCHUNK ((size_t)1 << (sizeof(size_t) * 8 - 4))

#define GENERIC_BLOCK_SIZE 16
#define IV_STATE_UNINITIALISED 0 /* initial state is not initialized */
#define IV_STATE_BUFFERED 1 /* iv has been copied to the iv buffer */
#define IV_STATE_COPIED 2 /* iv has been copied from the iv buffer */
#define IV_STATE_FINISHED 3 /* the iv has been used - so don't reuse it */

#define PROV_CIPHER_FUNC(type, name, args) typedef type(*OSSL_##name##_fn) args

typedef struct prov_cipher_hw_st PROV_CIPHER_HW;
typedef struct prov_cipher_ctx_st PROV_CIPHER_CTX;

typedef int(PROV_CIPHER_HW_FN)(PROV_CIPHER_CTX *dat, unsigned char *out,
    const unsigned char *in, size_t len);

/* Internal flags that can be queried */
#define PROV_CIPHER_FLAG_AEAD 0x0001
#define PROV_CIPHER_FLAG_CUSTOM_IV 0x0002
#define PROV_CIPHER_FLAG_CTS 0x0004
#define PROV_CIPHER_FLAG_TLS1_MULTIBLOCK 0x0008
#define PROV_CIPHER_FLAG_RAND_KEY 0x0010
/* Internal flags that are only used within the provider */
#define PROV_CIPHER_FLAG_VARIABLE_LENGTH 0x0100
#define PROV_CIPHER_FLAG_INVERSE_CIPHER 0x0200

struct prov_cipher_ctx_st {
    /* place buffer at the beginning for memory alignment */
    /* The original value of the iv */
    unsigned char oiv[GENERIC_BLOCK_SIZE];
    /* Buffer of partial blocks processed via update calls */
    unsigned char buf[GENERIC_BLOCK_SIZE];
    unsigned char iv[GENERIC_BLOCK_SIZE];

    block128_f block;
    union {
        cbc128_f cbc;
        ctr128_f ctr;
        ecb128_f ecb;
    } stream;

    unsigned int mode;
    size_t keylen; /* key size (in bytes) */
    size_t ivlen;
    size_t blocksize;
    size_t bufsz; /* Number of bytes in buf */
    unsigned int cts_mode; /* Use to set the type for CTS modes */
    unsigned int pad : 1; /* Whether padding should be used or not */
    unsigned int enc : 1; /* Set to 1 for encrypt, or 0 otherwise */
    unsigned int iv_set : 1; /* Set when the iv is copied to the iv/oiv buffers */
    unsigned int key_set : 1; /* Set when key is set on the context */
    unsigned int updated : 1; /* Set to 1 during update for one shot ciphers */
    unsigned int variable_keylength : 1;
    unsigned int inverse_cipher : 1; /* set to 1 to use inverse cipher */
    unsigned int use_bits : 1; /* Set to 0 for cfb1 to use bits instead of bytes */

    unsigned int tlsversion; /* If TLS padding is in use the TLS version number */
    unsigned char *tlsmac; /* tls MAC extracted from the last record */
    int alloced; /*
                  * Whether the tlsmac data has been allocated or
                  * points into the user buffer.
                  */
    size_t tlsmacsize; /* Size of the TLS MAC */
    int removetlspad; /* Whether TLS padding should be removed or not */
    size_t removetlsfixed; /*
                            * Length of the fixed size data to remove when
                            * processing TLS data (equals mac size plus
                            * IV size if applicable)
                            */

    /*
     * num contains the number of bytes of |iv| which are valid for modes that
     * manage partial blocks themselves.
     */
    unsigned int num;
    const PROV_CIPHER_HW *hw; /* hardware specific functions */
    const void *ks; /* Pointer to algorithm specific key data */
    OSSL_LIB_CTX *libctx;
};

struct prov_cipher_hw_st {
    int (*init)(PROV_CIPHER_CTX *dat, const uint8_t *key, size_t keylen);
    PROV_CIPHER_HW_FN *cipher;
    void (*copyctx)(PROV_CIPHER_CTX *dst, const PROV_CIPHER_CTX *src);
};

void ossl_cipher_generic_reset_ctx(PROV_CIPHER_CTX *ctx);
OSSL_FUNC_cipher_encrypt_init_fn ossl_cipher_generic_einit;
OSSL_FUNC_cipher_decrypt_init_fn ossl_cipher_generic_dinit;
OSSL_FUNC_cipher_update_fn ossl_cipher_generic_block_update;
OSSL_FUNC_cipher_final_fn ossl_cipher_generic_block_final;
OSSL_FUNC_cipher_update_fn ossl_cipher_generic_stream_update;
OSSL_FUNC_cipher_final_fn ossl_cipher_generic_stream_final;
OSSL_FUNC_cipher_cipher_fn ossl_cipher_generic_cipher;
OSSL_FUNC_cipher_get_ctx_params_fn ossl_cipher_generic_get_ctx_params;
OSSL_FUNC_cipher_set_ctx_params_fn ossl_cipher_generic_set_ctx_params;
OSSL_FUNC_cipher_gettable_params_fn ossl_cipher_generic_gettable_params;
OSSL_FUNC_cipher_gettable_ctx_params_fn ossl_cipher_generic_gettable_ctx_params;
OSSL_FUNC_cipher_settable_ctx_params_fn ossl_cipher_generic_settable_ctx_params;
OSSL_FUNC_cipher_set_ctx_params_fn ossl_cipher_var_keylen_set_ctx_params;
OSSL_FUNC_cipher_settable_ctx_params_fn ossl_cipher_var_keylen_settable_ctx_params;
OSSL_FUNC_cipher_gettable_ctx_params_fn ossl_cipher_aead_gettable_ctx_params;
OSSL_FUNC_cipher_settable_ctx_params_fn ossl_cipher_aead_settable_ctx_params;
OSSL_FUNC_cipher_encrypt_skey_init_fn ossl_cipher_generic_skey_einit;
OSSL_FUNC_cipher_decrypt_skey_init_fn ossl_cipher_generic_skey_dinit;

int ossl_cipher_generic_get_params(OSSL_PARAM params[], unsigned int md,
    uint64_t flags,
    size_t kbits, size_t blkbits, size_t ivbits);
void ossl_cipher_generic_initkey(void *vctx, size_t kbits, size_t blkbits,
    size_t ivbits, unsigned int mode,
    uint64_t flags,
    const PROV_CIPHER_HW *hw, void *provctx);

#define IMPLEMENT_generic_cipher_func(alg, UCALG, lcmode, UCMODE, flags, kbits,                 \
    blkbits, ivbits, typ)                                                                       \
    const OSSL_DISPATCH ossl_##alg##kbits##lcmode##_functions[] = {                             \
        { OSSL_FUNC_CIPHER_NEWCTX,                                                              \
            (void (*)(void))alg##_##kbits##_##lcmode##_newctx },                                \
        { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))alg##_freectx },                            \
        { OSSL_FUNC_CIPHER_DUPCTX, (void (*)(void))alg##_dupctx },                              \
        { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))ossl_cipher_generic_einit },           \
        { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))ossl_cipher_generic_dinit },           \
        { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))ossl_cipher_generic_##typ##_update },        \
        { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))ossl_cipher_generic_##typ##_final },          \
        { OSSL_FUNC_CIPHER_CIPHER, (void (*)(void))ossl_cipher_generic_cipher },                \
        { OSSL_FUNC_CIPHER_GET_PARAMS,                                                          \
            (void (*)(void))alg##_##kbits##_##lcmode##_get_params },                            \
        { OSSL_FUNC_CIPHER_GET_CTX_PARAMS,                                                      \
            (void (*)(void))ossl_cipher_generic_get_ctx_params },                               \
        { OSSL_FUNC_CIPHER_SET_CTX_PARAMS,                                                      \
            (void (*)(void))ossl_cipher_generic_set_ctx_params },                               \
        { OSSL_FUNC_CIPHER_GETTABLE_PARAMS,                                                     \
            (void (*)(void))ossl_cipher_generic_gettable_params },                              \
        { OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS,                                                 \
            (void (*)(void))ossl_cipher_generic_gettable_ctx_params },                          \
        { OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS,                                                 \
            (void (*)(void))ossl_cipher_generic_settable_ctx_params },                          \
        { OSSL_FUNC_CIPHER_ENCRYPT_SKEY_INIT, (void (*)(void))ossl_cipher_generic_skey_einit }, \
        { OSSL_FUNC_CIPHER_DECRYPT_SKEY_INIT, (void (*)(void))ossl_cipher_generic_skey_dinit }, \
        OSSL_DISPATCH_END                                                                       \
    };

#define IMPLEMENT_var_keylen_cipher_func(alg, UCALG, lcmode, UCMODE, flags,                     \
    kbits, blkbits, ivbits, typ)                                                                \
    const OSSL_DISPATCH ossl_##alg##kbits##lcmode##_functions[] = {                             \
        { OSSL_FUNC_CIPHER_NEWCTX,                                                              \
            (void (*)(void))alg##_##kbits##_##lcmode##_newctx },                                \
        { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))alg##_freectx },                            \
        { OSSL_FUNC_CIPHER_DUPCTX, (void (*)(void))alg##_dupctx },                              \
        { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))ossl_cipher_generic_einit },           \
        { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))ossl_cipher_generic_dinit },           \
        { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))ossl_cipher_generic_##typ##_update },        \
        { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))ossl_cipher_generic_##typ##_final },          \
        { OSSL_FUNC_CIPHER_CIPHER, (void (*)(void))ossl_cipher_generic_cipher },                \
        { OSSL_FUNC_CIPHER_GET_PARAMS,                                                          \
            (void (*)(void))alg##_##kbits##_##lcmode##_get_params },                            \
        { OSSL_FUNC_CIPHER_GET_CTX_PARAMS,                                                      \
            (void (*)(void))ossl_cipher_generic_get_ctx_params },                               \
        { OSSL_FUNC_CIPHER_SET_CTX_PARAMS,                                                      \
            (void (*)(void))ossl_cipher_var_keylen_set_ctx_params },                            \
        { OSSL_FUNC_CIPHER_GETTABLE_PARAMS,                                                     \
            (void (*)(void))ossl_cipher_generic_gettable_params },                              \
        { OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS,                                                 \
            (void (*)(void))ossl_cipher_generic_gettable_ctx_params },                          \
        { OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS,                                                 \
            (void (*)(void))ossl_cipher_var_keylen_settable_ctx_params },                       \
        { OSSL_FUNC_CIPHER_ENCRYPT_SKEY_INIT, (void (*)(void))ossl_cipher_generic_skey_einit }, \
        { OSSL_FUNC_CIPHER_DECRYPT_SKEY_INIT, (void (*)(void))ossl_cipher_generic_skey_dinit }, \
        OSSL_DISPATCH_END                                                                       \
    };

#define IMPLEMENT_generic_cipher_genfn(alg, UCALG, lcmode, UCMODE, flags,               \
    kbits, blkbits, ivbits, typ)                                                        \
    static OSSL_FUNC_cipher_get_params_fn alg##_##kbits##_##lcmode##_get_params;        \
    static int alg##_##kbits##_##lcmode##_get_params(OSSL_PARAM params[])               \
    {                                                                                   \
        return ossl_cipher_generic_get_params(params, EVP_CIPH_##UCMODE##_MODE,         \
            flags, kbits, blkbits, ivbits);                                             \
    }                                                                                   \
    static OSSL_FUNC_cipher_newctx_fn alg##_##kbits##_##lcmode##_newctx;                \
    static void *alg##_##kbits##_##lcmode##_newctx(void *provctx)                       \
    {                                                                                   \
        PROV_##UCALG##_CTX *ctx = ossl_prov_is_running() ? OPENSSL_zalloc(sizeof(*ctx)) \
                                                         : NULL;                        \
        if (ctx != NULL) {                                                              \
            ossl_cipher_generic_initkey(ctx, kbits, blkbits, ivbits,                    \
                EVP_CIPH_##UCMODE##_MODE, flags,                                        \
                ossl_prov_cipher_hw_##alg##_##lcmode(kbits),                            \
                provctx);                                                               \
        }                                                                               \
        return ctx;                                                                     \
    }

#define IMPLEMENT_generic_cipher(alg, UCALG, lcmode, UCMODE, flags, kbits,   \
    blkbits, ivbits, typ)                                                    \
    IMPLEMENT_generic_cipher_genfn(alg, UCALG, lcmode, UCMODE, flags, kbits, \
        blkbits, ivbits, typ)                                                \
    IMPLEMENT_generic_cipher_func(alg, UCALG, lcmode, UCMODE, flags, kbits,  \
        blkbits, ivbits, typ)

#define IMPLEMENT_var_keylen_cipher(alg, UCALG, lcmode, UCMODE, flags, kbits,  \
    blkbits, ivbits, typ)                                                      \
    IMPLEMENT_generic_cipher_genfn(alg, UCALG, lcmode, UCMODE, flags, kbits,   \
        blkbits, ivbits, typ)                                                  \
    IMPLEMENT_var_keylen_cipher_func(alg, UCALG, lcmode, UCMODE, flags, kbits, \
        blkbits, ivbits, typ)

PROV_CIPHER_HW_FN ossl_cipher_hw_generic_cbc;
PROV_CIPHER_HW_FN ossl_cipher_hw_generic_ecb;
PROV_CIPHER_HW_FN ossl_cipher_hw_generic_ofb128;
PROV_CIPHER_HW_FN ossl_cipher_hw_generic_cfb128;
PROV_CIPHER_HW_FN ossl_cipher_hw_generic_cfb8;
PROV_CIPHER_HW_FN ossl_cipher_hw_generic_cfb1;
PROV_CIPHER_HW_FN ossl_cipher_hw_generic_ctr;
PROV_CIPHER_HW_FN ossl_cipher_hw_chunked_cbc;
PROV_CIPHER_HW_FN ossl_cipher_hw_chunked_cfb8;
PROV_CIPHER_HW_FN ossl_cipher_hw_chunked_cfb128;
PROV_CIPHER_HW_FN ossl_cipher_hw_chunked_ofb128;
#define ossl_cipher_hw_chunked_ecb ossl_cipher_hw_generic_ecb
#define ossl_cipher_hw_chunked_ctr ossl_cipher_hw_generic_ctr
#define ossl_cipher_hw_chunked_cfb1 ossl_cipher_hw_generic_cfb1

#define IMPLEMENT_CIPHER_HW_OFB(MODE, NAME, CTX_NAME, KEY_NAME, FUNC_PREFIX) \
    static int cipher_hw_##NAME##_##MODE##_cipher(PROV_CIPHER_CTX *ctx,      \
        unsigned char *out,                                                  \
        const unsigned char *in, size_t len)                                 \
    {                                                                        \
        int num = ctx->num;                                                  \
        KEY_NAME *key = &(((CTX_NAME *)ctx)->ks.ks);                         \
                                                                             \
        while (len >= MAXCHUNK) {                                            \
            FUNC_PREFIX##_encrypt(in, out, MAXCHUNK, key, ctx->iv, &num);    \
            len -= MAXCHUNK;                                                 \
            in += MAXCHUNK;                                                  \
            out += MAXCHUNK;                                                 \
        }                                                                    \
        if (len > 0) {                                                       \
            FUNC_PREFIX##_encrypt(in, out, (long)len, key, ctx->iv, &num);   \
        }                                                                    \
        ctx->num = num;                                                      \
        return 1;                                                            \
    }

#define IMPLEMENT_CIPHER_HW_ECB(MODE, NAME, CTX_NAME, KEY_NAME, FUNC_PREFIX) \
    static int cipher_hw_##NAME##_##MODE##_cipher(PROV_CIPHER_CTX *ctx,      \
        unsigned char *out,                                                  \
        const unsigned char *in, size_t len)                                 \
    {                                                                        \
        size_t i, bl = ctx->blocksize;                                       \
        KEY_NAME *key = &(((CTX_NAME *)ctx)->ks.ks);                         \
                                                                             \
        if (len < bl)                                                        \
            return 1;                                                        \
        for (i = 0, len -= bl; i <= len; i += bl)                            \
            FUNC_PREFIX##_encrypt(in + i, out + i, key, ctx->enc);           \
        return 1;                                                            \
    }

#define IMPLEMENT_CIPHER_HW_CBC(MODE, NAME, CTX_NAME, KEY_NAME, FUNC_PREFIX)   \
    static int cipher_hw_##NAME##_##MODE##_cipher(PROV_CIPHER_CTX *ctx,        \
        unsigned char *out,                                                    \
        const unsigned char *in, size_t len)                                   \
    {                                                                          \
        KEY_NAME *key = &(((CTX_NAME *)ctx)->ks.ks);                           \
                                                                               \
        while (len >= MAXCHUNK) {                                              \
            FUNC_PREFIX##_encrypt(in, out, MAXCHUNK, key, ctx->iv, ctx->enc);  \
            len -= MAXCHUNK;                                                   \
            in += MAXCHUNK;                                                    \
            out += MAXCHUNK;                                                   \
        }                                                                      \
        if (len > 0)                                                           \
            FUNC_PREFIX##_encrypt(in, out, (long)len, key, ctx->iv, ctx->enc); \
        return 1;                                                              \
    }

#define IMPLEMENT_CIPHER_HW_CFB(MODE, NAME, CTX_NAME, KEY_NAME, FUNC_PREFIX) \
    static int cipher_hw_##NAME##_##MODE##_cipher(PROV_CIPHER_CTX *ctx,      \
        unsigned char *out,                                                  \
        const unsigned char *in, size_t len)                                 \
    {                                                                        \
        size_t chunk = MAXCHUNK;                                             \
        KEY_NAME *key = &(((CTX_NAME *)ctx)->ks.ks);                         \
        int num = ctx->num;                                                  \
                                                                             \
        if (len < chunk)                                                     \
            chunk = len;                                                     \
        while (len > 0 && len >= chunk) {                                    \
            FUNC_PREFIX##_encrypt(in, out, (long)chunk, key, ctx->iv, &num,  \
                ctx->enc);                                                   \
            len -= chunk;                                                    \
            in += chunk;                                                     \
            out += chunk;                                                    \
            if (len < chunk)                                                 \
                chunk = len;                                                 \
        }                                                                    \
        ctx->num = num;                                                      \
        return 1;                                                            \
    }

#define IMPLEMENT_CIPHER_HW_COPYCTX(name, CTX_TYPE)                    \
    static void name(PROV_CIPHER_CTX *dst, const PROV_CIPHER_CTX *src) \
    {                                                                  \
        CTX_TYPE *sctx = (CTX_TYPE *)src;                              \
        CTX_TYPE *dctx = (CTX_TYPE *)dst;                              \
                                                                       \
        *dctx = *sctx;                                                 \
        dst->ks = &dctx->ks.ks;                                        \
    }

#define CIPHER_DEFAULT_GETTABLE_CTX_PARAMS_START(name)             \
    static const OSSL_PARAM name##_known_gettable_ctx_params[] = { \
        OSSL_PARAM_size_t(OSSL_CIPHER_PARAM_KEYLEN, NULL),         \
        OSSL_PARAM_size_t(OSSL_CIPHER_PARAM_IVLEN, NULL),          \
        OSSL_PARAM_uint(OSSL_CIPHER_PARAM_PADDING, NULL),          \
        OSSL_PARAM_uint(OSSL_CIPHER_PARAM_NUM, NULL),              \
        OSSL_PARAM_octet_string(OSSL_CIPHER_PARAM_IV, NULL, 0),    \
        OSSL_PARAM_octet_string(OSSL_CIPHER_PARAM_UPDATED_IV, NULL, 0),

#define CIPHER_DEFAULT_GETTABLE_CTX_PARAMS_END(name)                     \
    OSSL_PARAM_END                                                       \
    }                                                                    \
    ;                                                                    \
    const OSSL_PARAM *name##_gettable_ctx_params(ossl_unused void *cctx, \
        ossl_unused void *provctx)                                       \
    {                                                                    \
        return name##_known_gettable_ctx_params;                         \
    }

#define CIPHER_DEFAULT_SETTABLE_CTX_PARAMS_START(name)             \
    static const OSSL_PARAM name##_known_settable_ctx_params[] = { \
        OSSL_PARAM_uint(OSSL_CIPHER_PARAM_PADDING, NULL),          \
        OSSL_PARAM_uint(OSSL_CIPHER_PARAM_NUM, NULL),
#define CIPHER_DEFAULT_SETTABLE_CTX_PARAMS_END(name)                     \
    OSSL_PARAM_END                                                       \
    }                                                                    \
    ;                                                                    \
    const OSSL_PARAM *name##_settable_ctx_params(ossl_unused void *cctx, \
        ossl_unused void *provctx)                                       \
    {                                                                    \
        return name##_known_settable_ctx_params;                         \
    }

int ossl_cipher_generic_initiv(PROV_CIPHER_CTX *ctx, const unsigned char *iv,
    size_t ivlen);

size_t ossl_cipher_fillblock(unsigned char *buf, size_t *buflen,
    size_t blocksize,
    const unsigned char **in, size_t *inlen);
int ossl_cipher_trailingdata(unsigned char *buf, size_t *buflen,
    size_t blocksize,
    const unsigned char **in, size_t *inlen);

#endif