// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * SHA-384, SHA-512, HMAC-SHA384, and HMAC-SHA512 library functions
 *
 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
 * Copyright 2025 Google LLC
 */

#include <crypto/hmac.h>
#include <crypto/sha2.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/string.h>
#include <linux/unaligned.h>
#include <linux/wordpart.h>
#include "fips.h"

static const struct sha512_block_state sha384_iv = {
        .h = {
                SHA384_H0, SHA384_H1, SHA384_H2, SHA384_H3,
                SHA384_H4, SHA384_H5, SHA384_H6, SHA384_H7,
        },
};

static const struct sha512_block_state sha512_iv = {
        .h = {
                SHA512_H0, SHA512_H1, SHA512_H2, SHA512_H3,
                SHA512_H4, SHA512_H5, SHA512_H6, SHA512_H7,
        },
};

static const u64 sha512_K[80] = {
        0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
        0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
        0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
        0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
        0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
        0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
        0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
        0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
        0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
        0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
        0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
        0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
        0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
        0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
        0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
        0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
        0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
        0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
        0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
        0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
        0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
        0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
        0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
        0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
        0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
        0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
        0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL,
};

#define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
#define Maj(x, y, z) (((x) & (y)) | ((z) & ((x) | (y))))
#define e0(x) (ror64((x), 28) ^ ror64((x), 34) ^ ror64((x), 39))
#define e1(x) (ror64((x), 14) ^ ror64((x), 18) ^ ror64((x), 41))
#define s0(x) (ror64((x), 1) ^ ror64((x), 8) ^ ((x) >> 7))
#define s1(x) (ror64((x), 19) ^ ror64((x), 61) ^ ((x) >> 6))

static void sha512_block_generic(struct sha512_block_state *state,
                                 const u8 *data)
{
        u64 a = state->h[0];
        u64 b = state->h[1];
        u64 c = state->h[2];
        u64 d = state->h[3];
        u64 e = state->h[4];
        u64 f = state->h[5];
        u64 g = state->h[6];
        u64 h = state->h[7];
        u64 t1, t2;
        u64 W[16];

        for (int j = 0; j < 16; j++)
                W[j] = get_unaligned_be64(data + j * sizeof(u64));

        for (int i = 0; i < 80; i += 8) {
                if ((i & 15) == 0 && i != 0) {
                        for (int j = 0; j < 16; j++) {
                                W[j & 15] += s1(W[(j - 2) & 15]) +
                                             W[(j - 7) & 15] +
                                             s0(W[(j - 15) & 15]);
                        }
                }
                t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i]   + W[(i & 15)];
                t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
                t1 = g + e1(d) + Ch(d, e, f) + sha512_K[i+1] + W[(i & 15) + 1];
                t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
                t1 = f + e1(c) + Ch(c, d, e) + sha512_K[i+2] + W[(i & 15) + 2];
                t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
                t1 = e + e1(b) + Ch(b, c, d) + sha512_K[i+3] + W[(i & 15) + 3];
                t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
                t1 = d + e1(a) + Ch(a, b, c) + sha512_K[i+4] + W[(i & 15) + 4];
                t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
                t1 = c + e1(h) + Ch(h, a, b) + sha512_K[i+5] + W[(i & 15) + 5];
                t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
                t1 = b + e1(g) + Ch(g, h, a) + sha512_K[i+6] + W[(i & 15) + 6];
                t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
                t1 = a + e1(f) + Ch(f, g, h) + sha512_K[i+7] + W[(i & 15) + 7];
                t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
        }

        state->h[0] += a;
        state->h[1] += b;
        state->h[2] += c;
        state->h[3] += d;
        state->h[4] += e;
        state->h[5] += f;
        state->h[6] += g;
        state->h[7] += h;
}

static void __maybe_unused
sha512_blocks_generic(struct sha512_block_state *state,
                      const u8 *data, size_t nblocks)
{
        do {
                sha512_block_generic(state, data);
                data += SHA512_BLOCK_SIZE;
        } while (--nblocks);
}

#ifdef CONFIG_CRYPTO_LIB_SHA512_ARCH
#include "sha512.h" /* $(SRCARCH)/sha512.h */
#else
#define sha512_blocks sha512_blocks_generic
#endif

static void __sha512_init(struct __sha512_ctx *ctx,
                          const struct sha512_block_state *iv,
                          u64 initial_bytecount)
{
        ctx->state = *iv;
        ctx->bytecount_lo = initial_bytecount;
        ctx->bytecount_hi = 0;
}

void sha384_init(struct sha384_ctx *ctx)
{
        __sha512_init(&ctx->ctx, &sha384_iv, 0);
}
EXPORT_SYMBOL_GPL(sha384_init);

void sha512_init(struct sha512_ctx *ctx)
{
        __sha512_init(&ctx->ctx, &sha512_iv, 0);
}
EXPORT_SYMBOL_GPL(sha512_init);

void __sha512_update(struct __sha512_ctx *ctx, const u8 *data, size_t len)
{
        size_t partial = ctx->bytecount_lo % SHA512_BLOCK_SIZE;

        if (check_add_overflow(ctx->bytecount_lo, len, &ctx->bytecount_lo))
                ctx->bytecount_hi++;

        if (partial + len >= SHA512_BLOCK_SIZE) {
                size_t nblocks;

                if (partial) {
                        size_t l = SHA512_BLOCK_SIZE - partial;

                        memcpy(&ctx->buf[partial], data, l);
                        data += l;
                        len -= l;

                        sha512_blocks(&ctx->state, ctx->buf, 1);
                }

                nblocks = len / SHA512_BLOCK_SIZE;
                len %= SHA512_BLOCK_SIZE;

                if (nblocks) {
                        sha512_blocks(&ctx->state, data, nblocks);
                        data += nblocks * SHA512_BLOCK_SIZE;
                }
                partial = 0;
        }
        if (len)
                memcpy(&ctx->buf[partial], data, len);
}
EXPORT_SYMBOL_GPL(__sha512_update);

static void __sha512_final(struct __sha512_ctx *ctx,
                           u8 *out, size_t digest_size)
{
        u64 bitcount_hi = (ctx->bytecount_hi << 3) | (ctx->bytecount_lo >> 61);
        u64 bitcount_lo = ctx->bytecount_lo << 3;
        size_t partial = ctx->bytecount_lo % SHA512_BLOCK_SIZE;

        ctx->buf[partial++] = 0x80;
        if (partial > SHA512_BLOCK_SIZE - 16) {
                memset(&ctx->buf[partial], 0, SHA512_BLOCK_SIZE - partial);
                sha512_blocks(&ctx->state, ctx->buf, 1);
                partial = 0;
        }
        memset(&ctx->buf[partial], 0, SHA512_BLOCK_SIZE - 16 - partial);
        *(__be64 *)&ctx->buf[SHA512_BLOCK_SIZE - 16] = cpu_to_be64(bitcount_hi);
        *(__be64 *)&ctx->buf[SHA512_BLOCK_SIZE - 8] = cpu_to_be64(bitcount_lo);
        sha512_blocks(&ctx->state, ctx->buf, 1);

        for (size_t i = 0; i < digest_size; i += 8)
                put_unaligned_be64(ctx->state.h[i / 8], out + i);
}

void sha384_final(struct sha384_ctx *ctx, u8 out[SHA384_DIGEST_SIZE])
{
        __sha512_final(&ctx->ctx, out, SHA384_DIGEST_SIZE);
        memzero_explicit(ctx, sizeof(*ctx));
}
EXPORT_SYMBOL_GPL(sha384_final);

void sha512_final(struct sha512_ctx *ctx, u8 out[SHA512_DIGEST_SIZE])
{
        __sha512_final(&ctx->ctx, out, SHA512_DIGEST_SIZE);
        memzero_explicit(ctx, sizeof(*ctx));
}
EXPORT_SYMBOL_GPL(sha512_final);

void sha384(const u8 *data, size_t len, u8 out[SHA384_DIGEST_SIZE])
{
        struct sha384_ctx ctx;

        sha384_init(&ctx);
        sha384_update(&ctx, data, len);
        sha384_final(&ctx, out);
}
EXPORT_SYMBOL_GPL(sha384);

void sha512(const u8 *data, size_t len, u8 out[SHA512_DIGEST_SIZE])
{
        struct sha512_ctx ctx;

        sha512_init(&ctx);
        sha512_update(&ctx, data, len);
        sha512_final(&ctx, out);
}
EXPORT_SYMBOL_GPL(sha512);

static void __hmac_sha512_preparekey(struct sha512_block_state *istate,
                                     struct sha512_block_state *ostate,
                                     const u8 *raw_key, size_t raw_key_len,
                                     const struct sha512_block_state *iv)
{
        union {
                u8 b[SHA512_BLOCK_SIZE];
                unsigned long w[SHA512_BLOCK_SIZE / sizeof(unsigned long)];
        } derived_key = { 0 };

        if (unlikely(raw_key_len > SHA512_BLOCK_SIZE)) {
                if (iv == &sha384_iv)
                        sha384(raw_key, raw_key_len, derived_key.b);
                else
                        sha512(raw_key, raw_key_len, derived_key.b);
        } else {
                memcpy(derived_key.b, raw_key, raw_key_len);
        }

        for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
                derived_key.w[i] ^= REPEAT_BYTE(HMAC_IPAD_VALUE);
        *istate = *iv;
        sha512_blocks(istate, derived_key.b, 1);

        for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
                derived_key.w[i] ^= REPEAT_BYTE(HMAC_OPAD_VALUE ^
                                                HMAC_IPAD_VALUE);
        *ostate = *iv;
        sha512_blocks(ostate, derived_key.b, 1);

        memzero_explicit(&derived_key, sizeof(derived_key));
}

void hmac_sha384_preparekey(struct hmac_sha384_key *key,
                            const u8 *raw_key, size_t raw_key_len)
{
        __hmac_sha512_preparekey(&key->key.istate, &key->key.ostate,
                                 raw_key, raw_key_len, &sha384_iv);
}
EXPORT_SYMBOL_GPL(hmac_sha384_preparekey);

void hmac_sha512_preparekey(struct hmac_sha512_key *key,
                            const u8 *raw_key, size_t raw_key_len)
{
        __hmac_sha512_preparekey(&key->key.istate, &key->key.ostate,
                                 raw_key, raw_key_len, &sha512_iv);
}
EXPORT_SYMBOL_GPL(hmac_sha512_preparekey);

void __hmac_sha512_init(struct __hmac_sha512_ctx *ctx,
                        const struct __hmac_sha512_key *key)
{
        __sha512_init(&ctx->sha_ctx, &key->istate, SHA512_BLOCK_SIZE);
        ctx->ostate = key->ostate;
}
EXPORT_SYMBOL_GPL(__hmac_sha512_init);

void hmac_sha384_init_usingrawkey(struct hmac_sha384_ctx *ctx,
                                  const u8 *raw_key, size_t raw_key_len)
{
        __hmac_sha512_preparekey(&ctx->ctx.sha_ctx.state, &ctx->ctx.ostate,
                                 raw_key, raw_key_len, &sha384_iv);
        ctx->ctx.sha_ctx.bytecount_lo = SHA512_BLOCK_SIZE;
        ctx->ctx.sha_ctx.bytecount_hi = 0;
}
EXPORT_SYMBOL_GPL(hmac_sha384_init_usingrawkey);

void hmac_sha512_init_usingrawkey(struct hmac_sha512_ctx *ctx,
                                  const u8 *raw_key, size_t raw_key_len)
{
        __hmac_sha512_preparekey(&ctx->ctx.sha_ctx.state, &ctx->ctx.ostate,
                                 raw_key, raw_key_len, &sha512_iv);
        ctx->ctx.sha_ctx.bytecount_lo = SHA512_BLOCK_SIZE;
        ctx->ctx.sha_ctx.bytecount_hi = 0;
}
EXPORT_SYMBOL_GPL(hmac_sha512_init_usingrawkey);

static void __hmac_sha512_final(struct __hmac_sha512_ctx *ctx,
                                u8 *out, size_t digest_size)
{
        /* Generate the padded input for the outer hash in ctx->sha_ctx.buf. */
        __sha512_final(&ctx->sha_ctx, ctx->sha_ctx.buf, digest_size);
        memset(&ctx->sha_ctx.buf[digest_size], 0,
               SHA512_BLOCK_SIZE - digest_size);
        ctx->sha_ctx.buf[digest_size] = 0x80;
        *(__be32 *)&ctx->sha_ctx.buf[SHA512_BLOCK_SIZE - 4] =
                cpu_to_be32(8 * (SHA512_BLOCK_SIZE + digest_size));

        /* Compute the outer hash, which gives the HMAC value. */
        sha512_blocks(&ctx->ostate, ctx->sha_ctx.buf, 1);
        for (size_t i = 0; i < digest_size; i += 8)
                put_unaligned_be64(ctx->ostate.h[i / 8], out + i);

        memzero_explicit(ctx, sizeof(*ctx));
}

void hmac_sha384_final(struct hmac_sha384_ctx *ctx,
                       u8 out[SHA384_DIGEST_SIZE])
{
        __hmac_sha512_final(&ctx->ctx, out, SHA384_DIGEST_SIZE);
}
EXPORT_SYMBOL_GPL(hmac_sha384_final);

void hmac_sha512_final(struct hmac_sha512_ctx *ctx,
                       u8 out[SHA512_DIGEST_SIZE])
{
        __hmac_sha512_final(&ctx->ctx, out, SHA512_DIGEST_SIZE);
}
EXPORT_SYMBOL_GPL(hmac_sha512_final);

void hmac_sha384(const struct hmac_sha384_key *key,
                 const u8 *data, size_t data_len, u8 out[SHA384_DIGEST_SIZE])
{
        struct hmac_sha384_ctx ctx;

        hmac_sha384_init(&ctx, key);
        hmac_sha384_update(&ctx, data, data_len);
        hmac_sha384_final(&ctx, out);
}
EXPORT_SYMBOL_GPL(hmac_sha384);

void hmac_sha512(const struct hmac_sha512_key *key,
                 const u8 *data, size_t data_len, u8 out[SHA512_DIGEST_SIZE])
{
        struct hmac_sha512_ctx ctx;

        hmac_sha512_init(&ctx, key);
        hmac_sha512_update(&ctx, data, data_len);
        hmac_sha512_final(&ctx, out);
}
EXPORT_SYMBOL_GPL(hmac_sha512);

void hmac_sha384_usingrawkey(const u8 *raw_key, size_t raw_key_len,
                             const u8 *data, size_t data_len,
                             u8 out[SHA384_DIGEST_SIZE])
{
        struct hmac_sha384_ctx ctx;

        hmac_sha384_init_usingrawkey(&ctx, raw_key, raw_key_len);
        hmac_sha384_update(&ctx, data, data_len);
        hmac_sha384_final(&ctx, out);
}
EXPORT_SYMBOL_GPL(hmac_sha384_usingrawkey);

void hmac_sha512_usingrawkey(const u8 *raw_key, size_t raw_key_len,
                             const u8 *data, size_t data_len,
                             u8 out[SHA512_DIGEST_SIZE])
{
        struct hmac_sha512_ctx ctx;

        hmac_sha512_init_usingrawkey(&ctx, raw_key, raw_key_len);
        hmac_sha512_update(&ctx, data, data_len);
        hmac_sha512_final(&ctx, out);
}
EXPORT_SYMBOL_GPL(hmac_sha512_usingrawkey);

#if defined(sha512_mod_init_arch) || defined(CONFIG_CRYPTO_FIPS)
static int __init sha512_mod_init(void)
{
#ifdef sha512_mod_init_arch
        sha512_mod_init_arch();
#endif
        if (fips_enabled) {
                /*
                 * FIPS cryptographic algorithm self-test.  As per the FIPS
                 * Implementation Guidance, testing HMAC-SHA512 satisfies the
                 * test requirement for SHA-384, SHA-512, and HMAC-SHA384 too.
                 */
                u8 mac[SHA512_DIGEST_SIZE];

                hmac_sha512_usingrawkey(fips_test_key, sizeof(fips_test_key),
                                        fips_test_data, sizeof(fips_test_data),
                                        mac);
                if (memcmp(fips_test_hmac_sha512_value, mac, sizeof(mac)) != 0)
                        panic("sha512: FIPS self-test failed\n");
        }
        return 0;
}
subsys_initcall(sha512_mod_init);

static void __exit sha512_mod_exit(void)
{
}
module_exit(sha512_mod_exit);
#endif

MODULE_DESCRIPTION("SHA-384, SHA-512, HMAC-SHA384, and HMAC-SHA512 library functions");
MODULE_LICENSE("GPL");