Coverage Report

Created: 2024-11-21 07:03

/src/openssl/providers/implementations/ciphers/cipher_chacha20_hw.c
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Source (jump to first uncovered line)
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/*
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 * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
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 *
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 * Licensed under the Apache License 2.0 (the "License").  You may not use
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 * this file except in compliance with the License.  You can obtain a copy
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 * in the file LICENSE in the source distribution or at
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 * https://www.openssl.org/source/license.html
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 */
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/* chacha20 cipher implementation */
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#include "cipher_chacha20.h"
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static int chacha20_initkey(PROV_CIPHER_CTX *bctx, const uint8_t *key,
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                            size_t keylen)
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128
{
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128
    PROV_CHACHA20_CTX *ctx = (PROV_CHACHA20_CTX *)bctx;
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128
    unsigned int i;
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    if (key != NULL) {
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1.15k
        for (i = 0; i < CHACHA_KEY_SIZE; i += 4)
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1.02k
            ctx->key.d[i / 4] = CHACHA_U8TOU32(key + i);
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128
    }
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128
    ctx->partial_len = 0;
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128
    return 1;
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128
}
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static int chacha20_initiv(PROV_CIPHER_CTX *bctx)
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256
{
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    PROV_CHACHA20_CTX *ctx = (PROV_CHACHA20_CTX *)bctx;
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256
    unsigned int i;
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256
    if (bctx->iv_set) {
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1.28k
        for (i = 0; i < CHACHA_CTR_SIZE; i += 4)
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1.02k
            ctx->counter[i / 4] = CHACHA_U8TOU32(bctx->oiv + i);
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256
    }
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256
    ctx->partial_len = 0;
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256
    return 1;
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256
}
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static int chacha20_cipher(PROV_CIPHER_CTX *bctx, unsigned char *out,
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                           const unsigned char *in, size_t inl)
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384
{
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    PROV_CHACHA20_CTX *ctx = (PROV_CHACHA20_CTX *)bctx;
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384
    unsigned int n, rem, ctr32;
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384
    n = ctx->partial_len;
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384
    if (n > 0) {
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256
        while (inl > 0 && n < CHACHA_BLK_SIZE) {
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128
            *out++ = *in++ ^ ctx->buf[n++];
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128
            inl--;
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128
        }
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128
        ctx->partial_len = n;
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128
        if (inl == 0)
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128
            return 1;
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0
        if (n == CHACHA_BLK_SIZE) {
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0
            ctx->partial_len = 0;
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0
            ctx->counter[0]++;
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0
            if (ctx->counter[0] == 0)
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0
                ctx->counter[1]++;
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0
        }
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0
    }
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256
    rem = (unsigned int)(inl % CHACHA_BLK_SIZE);
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256
    inl -= rem;
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256
    ctr32 = ctx->counter[0];
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    while (inl >= CHACHA_BLK_SIZE) {
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0
        size_t blocks = inl / CHACHA_BLK_SIZE;
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        /*
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         * 1<<28 is just a not-so-small yet not-so-large number...
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         * Below condition is practically never met, but it has to
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         * be checked for code correctness.
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         */
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0
        if (sizeof(size_t) > sizeof(unsigned int) && blocks > (1U << 28))
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0
            blocks = (1U << 28);
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        /*
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         * As ChaCha20_ctr32 operates on 32-bit counter, caller
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         * has to handle overflow. 'if' below detects the
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         * overflow, which is then handled by limiting the
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         * amount of blocks to the exact overflow point...
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         */
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0
        ctr32 += (unsigned int)blocks;
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0
        if (ctr32 < blocks) {
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0
            blocks -= ctr32;
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0
            ctr32 = 0;
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0
        }
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0
        blocks *= CHACHA_BLK_SIZE;
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0
        ChaCha20_ctr32(out, in, blocks, ctx->key.d, ctx->counter);
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0
        inl -= blocks;
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0
        in += blocks;
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0
        out += blocks;
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        ctx->counter[0] = ctr32;
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0
        if (ctr32 == 0) ctx->counter[1]++;
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0
    }
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    if (rem > 0) {
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        memset(ctx->buf, 0, sizeof(ctx->buf));
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256
        ChaCha20_ctr32(ctx->buf, ctx->buf, CHACHA_BLK_SIZE,
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                       ctx->key.d, ctx->counter);
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512
        for (n = 0; n < rem; n++)
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256
            out[n] = in[n] ^ ctx->buf[n];
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256
        ctx->partial_len = rem;
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    }
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    return 1;
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384
}
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static const PROV_CIPHER_HW_CHACHA20 chacha20_hw = {
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    { chacha20_initkey, chacha20_cipher },
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    chacha20_initiv
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};
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const PROV_CIPHER_HW *ossl_prov_cipher_hw_chacha20(size_t keybits)
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{
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    return (PROV_CIPHER_HW *)&chacha20_hw;
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}
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