/src/openssl36/providers/implementations/kdfs/scrypt.c

Source
/*
 * Copyright 2017-2025 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
 */
/* clang-format off */

/* clang-format on */

#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/kdf.h>
#include <openssl/err.h>
#include <openssl/core_names.h>
#include <openssl/proverr.h>
#include "crypto/evp.h"
#include "internal/common.h"
#include "internal/numbers.h"
#include "prov/implementations.h"
#include "prov/provider_ctx.h"
#include "prov/providercommon.h"
#include "prov/provider_util.h"

#ifndef OPENSSL_NO_SCRYPT

static OSSL_FUNC_kdf_newctx_fn kdf_scrypt_new;
static OSSL_FUNC_kdf_dupctx_fn kdf_scrypt_dup;
static OSSL_FUNC_kdf_freectx_fn kdf_scrypt_free;
static OSSL_FUNC_kdf_reset_fn kdf_scrypt_reset;
static OSSL_FUNC_kdf_derive_fn kdf_scrypt_derive;
static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
static OSSL_FUNC_kdf_set_ctx_params_fn kdf_scrypt_set_ctx_params;
static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_scrypt_gettable_ctx_params;
static OSSL_FUNC_kdf_get_ctx_params_fn kdf_scrypt_get_ctx_params;

static int scrypt_alg(const char *pass, size_t passlen,
    const unsigned char *salt, size_t saltlen,
    uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
    unsigned char *key, size_t keylen, EVP_MD *sha256,
    OSSL_LIB_CTX *libctx, const char *propq);

typedef struct {
    OSSL_LIB_CTX *libctx;
    char *propq;
    unsigned char *pass;
    size_t pass_len;
    unsigned char *salt;
    size_t salt_len;
    uint64_t N;
    uint64_t r, p;
    uint64_t maxmem_bytes;
    EVP_MD *sha256;
} KDF_SCRYPT;

static void kdf_scrypt_init(KDF_SCRYPT *ctx);

static void *kdf_scrypt_new_inner(OSSL_LIB_CTX *libctx)
{
    KDF_SCRYPT *ctx;

    if (!ossl_prov_is_running())
        return NULL;

    ctx = OPENSSL_zalloc(sizeof(*ctx));
    if (ctx == NULL)
        return NULL;
    ctx->libctx = libctx;
    kdf_scrypt_init(ctx);
    return ctx;
}

static void *kdf_scrypt_new(void *provctx)
{
    return kdf_scrypt_new_inner(PROV_LIBCTX_OF(provctx));
}

static void kdf_scrypt_free(void *vctx)
{
    KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;

    if (ctx != NULL) {
        OPENSSL_free(ctx->propq);
        EVP_MD_free(ctx->sha256);
        kdf_scrypt_reset(ctx);
        OPENSSL_free(ctx);
    }
}

static void kdf_scrypt_reset(void *vctx)
{
    KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;

    OPENSSL_free(ctx->salt);
    ctx->salt = NULL;
    OPENSSL_clear_free(ctx->pass, ctx->pass_len);
    ctx->pass = NULL;
    kdf_scrypt_init(ctx);
}

static void *kdf_scrypt_dup(void *vctx)
{
    const KDF_SCRYPT *src = (const KDF_SCRYPT *)vctx;
    KDF_SCRYPT *dest;

    dest = kdf_scrypt_new_inner(src->libctx);
    if (dest != NULL) {
        if (src->sha256 != NULL && !EVP_MD_up_ref(src->sha256))
            goto err;
        if (src->propq != NULL) {
            dest->propq = OPENSSL_strdup(src->propq);
            if (dest->propq == NULL)
                goto err;
        }
        if (!ossl_prov_memdup(src->salt, src->salt_len,
                &dest->salt, &dest->salt_len)
            || !ossl_prov_memdup(src->pass, src->pass_len,
                &dest->pass, &dest->pass_len))
            goto err;
        dest->N = src->N;
        dest->r = src->r;
        dest->p = src->p;
        dest->maxmem_bytes = src->maxmem_bytes;
        dest->sha256 = src->sha256;
    }
    return dest;

err:
    kdf_scrypt_free(dest);
    return NULL;
}

static void kdf_scrypt_init(KDF_SCRYPT *ctx)
{
    /* Default values are the most conservative recommendation given in the
     * original paper of C. Percival. Derivation uses roughly 1 GiB of memory
     * for this parameter choice (approx. 128 * r * N * p bytes).
     */
    ctx->N = 1 << 20;
    ctx->r = 8;
    ctx->p = 1;
    ctx->maxmem_bytes = 1025 * 1024 * 1024;
}

static int scrypt_set_membuf(unsigned char **buffer, size_t *buflen,
    const OSSL_PARAM *p)
{
    OPENSSL_clear_free(*buffer, *buflen);
    *buffer = NULL;
    *buflen = 0;

    if (p->data_size == 0) {
        if ((*buffer = OPENSSL_malloc(1)) == NULL)
            return 0;
    } else if (p->data != NULL) {
        if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
            return 0;
    }
    return 1;
}

static int set_digest(KDF_SCRYPT *ctx)
{
    EVP_MD_free(ctx->sha256);
    ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
    if (ctx->sha256 == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
        return 0;
    }
    return 1;
}

static int set_property_query(KDF_SCRYPT *ctx, const char *propq)
{
    OPENSSL_free(ctx->propq);
    ctx->propq = NULL;
    if (propq != NULL) {
        ctx->propq = OPENSSL_strdup(propq);
        if (ctx->propq == NULL)
            return 0;
    }
    return 1;
}

static int kdf_scrypt_derive(void *vctx, unsigned char *key, size_t keylen,
    const OSSL_PARAM params[])
{
    KDF_SCRYPT *ctx = (KDF_SCRYPT *)vctx;

    if (!ossl_prov_is_running() || !kdf_scrypt_set_ctx_params(ctx, params))
        return 0;

    if (ctx->pass == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
        return 0;
    }

    if (ctx->salt == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
        return 0;
    }

    if (ctx->sha256 == NULL && !set_digest(ctx))
        return 0;

    return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
        ctx->salt_len, ctx->N, ctx->r, ctx->p,
        ctx->maxmem_bytes, key, keylen, ctx->sha256,
        ctx->libctx, ctx->propq);
}

static int is_power_of_two(uint64_t value)
{
    return (value != 0) && ((value & (value - 1)) == 0);
}

/* clang-format off */
/* Machine generated by util/perl/OpenSSL/paramnames.pm */
#ifndef scrypt_set_ctx_params_list
static const OSSL_PARAM scrypt_set_ctx_params_list[] = {
    OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
    OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
    OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
    OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
    OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
    OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
    OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
    OSSL_PARAM_END
};
#endif

#ifndef scrypt_set_ctx_params_st
struct scrypt_set_ctx_params_st {
    OSSL_PARAM *maxmem;
    OSSL_PARAM *n;
    OSSL_PARAM *p;
    OSSL_PARAM *propq;
    OSSL_PARAM *pw;
    OSSL_PARAM *r;
    OSSL_PARAM *salt;
};
#endif

#ifndef scrypt_set_ctx_params_decoder
static int scrypt_set_ctx_params_decoder
    (const OSSL_PARAM *p, struct scrypt_set_ctx_params_st *r)
{
    const char *s;

    memset(r, 0, sizeof(*r));
    if (p != NULL)
        for (; (s = p->key) != NULL; p++)
            switch(s[0]) {
            default:
                break;
            case 'm':
                if (ossl_likely(strcmp("axmem_bytes", s + 1) == 0)) {
                    /* OSSL_KDF_PARAM_SCRYPT_MAXMEM */
                    if (ossl_unlikely(r->maxmem != NULL)) {
                        ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                       "param %s is repeated", s);
                        return 0;
                    }
                    r->maxmem = (OSSL_PARAM *)p;
                }
                break;
            case 'n':
                switch(s[1]) {
                default:
                    break;
                case '\0':
                    if (ossl_unlikely(r->n != NULL)) {
                        ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                       "param %s is repeated", s);
                        return 0;
                    }
                    r->n = (OSSL_PARAM *)p;
                }
                break;
            case 'p':
                switch(s[1]) {
                default:
                    break;
                case 'a':
                    if (ossl_likely(strcmp("ss", s + 2) == 0)) {
                        /* OSSL_KDF_PARAM_PASSWORD */
                        if (ossl_unlikely(r->pw != NULL)) {
                            ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                           "param %s is repeated", s);
                            return 0;
                        }
                        r->pw = (OSSL_PARAM *)p;
                    }
                    break;
                case 'r':
                    if (ossl_likely(strcmp("operties", s + 2) == 0)) {
                        /* OSSL_KDF_PARAM_PROPERTIES */
                        if (ossl_unlikely(r->propq != NULL)) {
                            ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                           "param %s is repeated", s);
                            return 0;
                        }
                        r->propq = (OSSL_PARAM *)p;
                    }
                    break;
                case '\0':
                    if (ossl_unlikely(r->p != NULL)) {
                        ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                       "param %s is repeated", s);
                        return 0;
                    }
                    r->p = (OSSL_PARAM *)p;
                }
                break;
            case 'r':
                switch(s[1]) {
                default:
                    break;
                case '\0':
                    if (ossl_unlikely(r->r != NULL)) {
                        ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                       "param %s is repeated", s);
                        return 0;
                    }
                    r->r = (OSSL_PARAM *)p;
                }
                break;
            case 's':
                if (ossl_likely(strcmp("alt", s + 1) == 0)) {
                    /* OSSL_KDF_PARAM_SALT */
                    if (ossl_unlikely(r->salt != NULL)) {
                        ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                       "param %s is repeated", s);
                        return 0;
                    }
                    r->salt = (OSSL_PARAM *)p;
                }
            }
    return 1;
}
#endif
/* End of machine generated */
/* clang-format on */

static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
{
    struct scrypt_set_ctx_params_st p;
    KDF_SCRYPT *ctx = vctx;
    uint64_t u64_value;

    if (ctx == NULL || !scrypt_set_ctx_params_decoder(params, &p))
        return 0;

    if (p.pw != NULL && !scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p.pw))
        return 0;

    if (p.salt != NULL && !scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p.salt))
        return 0;

    if (p.n != NULL) {
        if (!OSSL_PARAM_get_uint64(p.n, &u64_value)
            || u64_value <= 1
            || !is_power_of_two(u64_value))
            return 0;
        ctx->N = u64_value;
    }

    if (p.r != NULL) {
        if (!OSSL_PARAM_get_uint64(p.r, &u64_value) || u64_value < 1)
            return 0;
        ctx->r = u64_value;
    }

    if (p.p != NULL) {
        if (!OSSL_PARAM_get_uint64(p.p, &u64_value) || u64_value < 1)
            return 0;
        ctx->p = u64_value;
    }

    if (p.maxmem != NULL) {
        if (!OSSL_PARAM_get_uint64(p.maxmem, &u64_value) || u64_value < 1)
            return 0;
        ctx->maxmem_bytes = u64_value;
    }

    if (p.propq != NULL) {
        if (p.propq->data_type != OSSL_PARAM_UTF8_STRING
            || !set_property_query(ctx, p.propq->data)
            || !set_digest(ctx))
            return 0;
    }
    return 1;
}

static const OSSL_PARAM *kdf_scrypt_settable_ctx_params(ossl_unused void *ctx,
    ossl_unused void *p_ctx)
{
    return scrypt_set_ctx_params_list;
}

/* clang-format off */
/* Machine generated by util/perl/OpenSSL/paramnames.pm */
#ifndef scrypt_get_ctx_params_list
static const OSSL_PARAM scrypt_get_ctx_params_list[] = {
    OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
    OSSL_PARAM_END
};
#endif

#ifndef scrypt_get_ctx_params_st
struct scrypt_get_ctx_params_st {
    OSSL_PARAM *size;
};
#endif

#ifndef scrypt_get_ctx_params_decoder
static int scrypt_get_ctx_params_decoder
    (const OSSL_PARAM *p, struct scrypt_get_ctx_params_st *r)
{
    const char *s;

    memset(r, 0, sizeof(*r));
    if (p != NULL)
        for (; (s = p->key) != NULL; p++)
            if (ossl_likely(strcmp("size", s + 0) == 0)) {
                /* OSSL_KDF_PARAM_SIZE */
                if (ossl_unlikely(r->size != NULL)) {
                    ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
                                   "param %s is repeated", s);
                    return 0;
                }
                r->size = (OSSL_PARAM *)p;
            }
    return 1;
}
#endif
/* End of machine generated */
/* clang-format on */

static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
{
    struct scrypt_get_ctx_params_st p;
    KDF_SCRYPT *ctx = vctx;

    if (ctx == NULL || !scrypt_get_ctx_params_decoder(params, &p))
        return 0;

    if (p.size != NULL && !OSSL_PARAM_set_size_t(p.size, SIZE_MAX))
        return 0;
    return 1;
}

static const OSSL_PARAM *kdf_scrypt_gettable_ctx_params(ossl_unused void *ctx,
    ossl_unused void *p_ctx)
{
    return scrypt_get_ctx_params_list;
}

const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
    { OSSL_FUNC_KDF_NEWCTX, (void (*)(void))kdf_scrypt_new },
    { OSSL_FUNC_KDF_DUPCTX, (void (*)(void))kdf_scrypt_dup },
    { OSSL_FUNC_KDF_FREECTX, (void (*)(void))kdf_scrypt_free },
    { OSSL_FUNC_KDF_RESET, (void (*)(void))kdf_scrypt_reset },
    { OSSL_FUNC_KDF_DERIVE, (void (*)(void))kdf_scrypt_derive },
    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
        (void (*)(void))kdf_scrypt_settable_ctx_params },
    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void (*)(void))kdf_scrypt_set_ctx_params },
    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
        (void (*)(void))kdf_scrypt_gettable_ctx_params },
    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void (*)(void))kdf_scrypt_get_ctx_params },
    OSSL_DISPATCH_END
};

#define R(a, b) (((a) << (b)) | ((a) >> (32 - (b))))
static void salsa208_word_specification(uint32_t inout[16])
{
    int i;
    uint32_t x[16];

    memcpy(x, inout, sizeof(x));
    for (i = 8; i > 0; i -= 2) {
        x[4] ^= R(x[0] + x[12], 7);
        x[8] ^= R(x[4] + x[0], 9);
        x[12] ^= R(x[8] + x[4], 13);
        x[0] ^= R(x[12] + x[8], 18);
        x[9] ^= R(x[5] + x[1], 7);
        x[13] ^= R(x[9] + x[5], 9);
        x[1] ^= R(x[13] + x[9], 13);
        x[5] ^= R(x[1] + x[13], 18);
        x[14] ^= R(x[10] + x[6], 7);
        x[2] ^= R(x[14] + x[10], 9);
        x[6] ^= R(x[2] + x[14], 13);
        x[10] ^= R(x[6] + x[2], 18);
        x[3] ^= R(x[15] + x[11], 7);
        x[7] ^= R(x[3] + x[15], 9);
        x[11] ^= R(x[7] + x[3], 13);
        x[15] ^= R(x[11] + x[7], 18);
        x[1] ^= R(x[0] + x[3], 7);
        x[2] ^= R(x[1] + x[0], 9);
        x[3] ^= R(x[2] + x[1], 13);
        x[0] ^= R(x[3] + x[2], 18);
        x[6] ^= R(x[5] + x[4], 7);
        x[7] ^= R(x[6] + x[5], 9);
        x[4] ^= R(x[7] + x[6], 13);
        x[5] ^= R(x[4] + x[7], 18);
        x[11] ^= R(x[10] + x[9], 7);
        x[8] ^= R(x[11] + x[10], 9);
        x[9] ^= R(x[8] + x[11], 13);
        x[10] ^= R(x[9] + x[8], 18);
        x[12] ^= R(x[15] + x[14], 7);
        x[13] ^= R(x[12] + x[15], 9);
        x[14] ^= R(x[13] + x[12], 13);
        x[15] ^= R(x[14] + x[13], 18);
    }
    for (i = 0; i < 16; ++i)
        inout[i] += x[i];
    OPENSSL_cleanse(x, sizeof(x));
}

static void scryptBlockMix(uint32_t *B_, uint32_t *B, uint64_t r)
{
    uint64_t i, j;
    uint32_t X[16], *pB;

    memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
    pB = B;
    for (i = 0; i < r * 2; i++) {
        for (j = 0; j < 16; j++)
            X[j] ^= *pB++;
        salsa208_word_specification(X);
        memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
    }
    OPENSSL_cleanse(X, sizeof(X));
}

static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
    uint32_t *X, uint32_t *T, uint32_t *V)
{
    unsigned char *pB;
    uint32_t *pV;
    uint64_t i, k;

    /* Convert from little endian input */
    for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
        *pV = *pB++;
        *pV |= *pB++ << 8;
        *pV |= *pB++ << 16;
        *pV |= (uint32_t)*pB++ << 24;
    }

    for (i = 1; i < N; i++, pV += 32 * r)
        scryptBlockMix(pV, pV - 32 * r, r);

    scryptBlockMix(X, V + (N - 1) * 32 * r, r);

    for (i = 0; i < N; i++) {
        uint32_t j;
        j = X[16 * (2 * r - 1)] % N;
        pV = V + 32 * r * j;
        for (k = 0; k < 32 * r; k++)
            T[k] = X[k] ^ *pV++;
        scryptBlockMix(X, T, r);
    }
    /* Convert output to little endian */
    for (i = 0, pB = B; i < 32 * r; i++) {
        uint32_t xtmp = X[i];
        *pB++ = xtmp & 0xff;
        *pB++ = (xtmp >> 8) & 0xff;
        *pB++ = (xtmp >> 16) & 0xff;
        *pB++ = (xtmp >> 24) & 0xff;
    }
}

#ifndef SIZE_MAX
#define SIZE_MAX ((size_t)-1)
#endif

/*
 * Maximum power of two that will fit in uint64_t: this should work on
 * most (all?) platforms.
 */

#define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)

/*
 * Maximum value of p * r:
 * p <= ((2^32-1) * hLen) / MFLen =>
 * p <= ((2^32-1) * 32) / (128 * r) =>
 * p * r <= (2^30-1)
 */

#define SCRYPT_PR_MAX ((1 << 30) - 1)

static int scrypt_alg(const char *pass, size_t passlen,
    const unsigned char *salt, size_t saltlen,
    uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
    unsigned char *key, size_t keylen, EVP_MD *sha256,
    OSSL_LIB_CTX *libctx, const char *propq)
{
    int rv = 0;
    unsigned char *B;
    uint32_t *X, *V, *T;
    uint64_t i, Blen, Vlen;

    /* Sanity check parameters */
    /* initial check, r,p must be non zero, N >= 2 and a power of 2 */
    if (r == 0 || p == 0 || N < 2 || (N & (N - 1)))
        return 0;
    /* Check p * r < SCRYPT_PR_MAX avoiding overflow */
    if (p > SCRYPT_PR_MAX / r) {
        ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
        return 0;
    }

    /*
     * Need to check N: if 2^(128 * r / 8) overflows limit this is
     * automatically satisfied since N <= UINT64_MAX.
     */

    if (16 * r <= LOG2_UINT64_MAX) {
        if (N >= (((uint64_t)1) << (16 * r))) {
            ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
            return 0;
        }
    }

    /* Memory checks: check total allocated buffer size fits in uint64_t */

    /*
     * B size in section 5 step 1.S
     * Note: we know p * 128 * r < UINT64_MAX because we already checked
     * p * r < SCRYPT_PR_MAX
     */
    Blen = p * 128 * r;
    /*
     * Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
     * have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
     */
    if (Blen > INT_MAX) {
        ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
        return 0;
    }

    /*
     * Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
     * This is combined size V, X and T (section 4)
     */
    i = UINT64_MAX / (32 * sizeof(uint32_t));
    if (N + 2 > i / r) {
        ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
        return 0;
    }
    Vlen = 32 * r * (N + 2) * sizeof(uint32_t);

    /* check total allocated size fits in uint64_t */
    if (Blen > UINT64_MAX - Vlen) {
        ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
        return 0;
    }

    /* Check that the maximum memory doesn't exceed a size_t limits */
    if (maxmem > SIZE_MAX)
        maxmem = SIZE_MAX;

    if (Blen + Vlen > maxmem) {
        ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
        return 0;
    }

    /* If no key return to indicate parameters are OK */
    if (key == NULL)
        return 1;

    B = OPENSSL_malloc((size_t)(Blen + Vlen));
    if (B == NULL)
        return 0;
    X = (uint32_t *)(B + Blen);
    T = X + 32 * r;
    V = T + 32 * r;
    if (ossl_pkcs5_pbkdf2_hmac_ex(pass, (int)passlen, salt, (int)saltlen, 1,
            sha256, (int)Blen, B, libctx, propq)
        == 0)
        goto err;

    for (i = 0; i < p; i++)
        scryptROMix(B + 128 * r * i, r, N, X, T, V);

    if (ossl_pkcs5_pbkdf2_hmac_ex(pass, (int)passlen, B, (int)Blen, 1, sha256,
            (int)keylen, key, libctx, propq)
        == 0)
        goto err;
    rv = 1;
err:
    if (rv == 0)
        ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);

    OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
    return rv;
}

#endif

Coverage Report

Created: 2025-12-31 06:58

Line	Count	Source
1		/*
2		* Copyright 2017-2025 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9		/* clang-format off */
10
11		/* clang-format on */
12
13		#include <stdlib.h>
14		#include <stdarg.h>
15		#include <string.h>
16		#include <openssl/evp.h>
17		#include <openssl/kdf.h>
18		#include <openssl/err.h>
19		#include <openssl/core_names.h>
20		#include <openssl/proverr.h>
21		#include "crypto/evp.h"
22		#include "internal/common.h"
23		#include "internal/numbers.h"
24		#include "prov/implementations.h"
25		#include "prov/provider_ctx.h"
26		#include "prov/providercommon.h"
27		#include "prov/provider_util.h"
28
29		#ifndef OPENSSL_NO_SCRYPT
30
31		static OSSL_FUNC_kdf_newctx_fn kdf_scrypt_new;
32		static OSSL_FUNC_kdf_dupctx_fn kdf_scrypt_dup;
33		static OSSL_FUNC_kdf_freectx_fn kdf_scrypt_free;
34		static OSSL_FUNC_kdf_reset_fn kdf_scrypt_reset;
35		static OSSL_FUNC_kdf_derive_fn kdf_scrypt_derive;
36		static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_scrypt_settable_ctx_params;
37		static OSSL_FUNC_kdf_set_ctx_params_fn kdf_scrypt_set_ctx_params;
38		static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_scrypt_gettable_ctx_params;
39		static OSSL_FUNC_kdf_get_ctx_params_fn kdf_scrypt_get_ctx_params;
40
41		static int scrypt_alg(const char *pass, size_t passlen,
42		const unsigned char *salt, size_t saltlen,
43		uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
44		unsigned char key, size_t keylen, EVP_MD sha256,
45		OSSL_LIB_CTX libctx, const char propq);
46
47		typedef struct {
48		OSSL_LIB_CTX *libctx;
49		char *propq;
50		unsigned char *pass;
51		size_t pass_len;
52		unsigned char *salt;
53		size_t salt_len;
54		uint64_t N;
55		uint64_t r, p;
56		uint64_t maxmem_bytes;
57		EVP_MD *sha256;
58		} KDF_SCRYPT;
59
60		static void kdf_scrypt_init(KDF_SCRYPT *ctx);
61
62		static void kdf_scrypt_new_inner(OSSL_LIB_CTX libctx)
63	89	{
64	89	KDF_SCRYPT *ctx;
65
66	89	if (!ossl_prov_is_running())
67	0	return NULL;
68
69	89	ctx = OPENSSL_zalloc(sizeof(*ctx));
70	89	if (ctx == NULL)
71	0	return NULL;
72	89	ctx->libctx = libctx;
73	89	kdf_scrypt_init(ctx);
74	89	return ctx;
75	89	}
76
77		static void kdf_scrypt_new(void provctx)
78	89	{
79	89	return kdf_scrypt_new_inner(PROV_LIBCTX_OF(provctx));
80	89	}
81
82		static void kdf_scrypt_free(void *vctx)
83	89	{
84	89	KDF_SCRYPT ctx = (KDF_SCRYPT )vctx;
85
86	89	if (ctx != NULL) {
87	89	OPENSSL_free(ctx->propq);
88	89	EVP_MD_free(ctx->sha256);
89	89	kdf_scrypt_reset(ctx);
90	89	OPENSSL_free(ctx);
91	89	}
92	89	}
93
94		static void kdf_scrypt_reset(void *vctx)
95	89	{
96	89	KDF_SCRYPT ctx = (KDF_SCRYPT )vctx;
97
98	89	OPENSSL_free(ctx->salt);
99	89	ctx->salt = NULL;
100	89	OPENSSL_clear_free(ctx->pass, ctx->pass_len);
101	89	ctx->pass = NULL;
102	89	kdf_scrypt_init(ctx);
103	89	}
104
105		static void kdf_scrypt_dup(void vctx)
106	0	{
107	0	const KDF_SCRYPT src = (const KDF_SCRYPT )vctx;
108	0	KDF_SCRYPT *dest;
109
110	0	dest = kdf_scrypt_new_inner(src->libctx);
111	0	if (dest != NULL) {
112	0	if (src->sha256 != NULL && !EVP_MD_up_ref(src->sha256))
113	0	goto err;
114	0	if (src->propq != NULL) {
115	0	dest->propq = OPENSSL_strdup(src->propq);
116	0	if (dest->propq == NULL)
117	0	goto err;
118	0	}
119	0	if (!ossl_prov_memdup(src->salt, src->salt_len,
120	0	&dest->salt, &dest->salt_len)
121	0	\|\| !ossl_prov_memdup(src->pass, src->pass_len,
122	0	&dest->pass, &dest->pass_len))
123	0	goto err;
124	0	dest->N = src->N;
125	0	dest->r = src->r;
126	0	dest->p = src->p;
127	0	dest->maxmem_bytes = src->maxmem_bytes;
128	0	dest->sha256 = src->sha256;
129	0	}
130	0	return dest;
131
132	0	err:
133	0	kdf_scrypt_free(dest);
134	0	return NULL;
135	0	}
136
137		static void kdf_scrypt_init(KDF_SCRYPT *ctx)
138	178	{
139		/* Default values are the most conservative recommendation given in the
140		* original paper of C. Percival. Derivation uses roughly 1 GiB of memory
141		* for this parameter choice (approx. 128 * r * N * p bytes).
142		*/
143	178	ctx->N = 1 << 20;
144	178	ctx->r = 8;
145	178	ctx->p = 1;
146	178	ctx->maxmem_bytes = 1025 * 1024 * 1024;
147	178	}
148
149		static int scrypt_set_membuf(unsigned char *buffer, size_t buflen,
150		const OSSL_PARAM *p)
151	178	{
152	178	OPENSSL_clear_free(buffer, buflen);
153	178	*buffer = NULL;
154	178	*buflen = 0;
155
156	178	if (p->data_size == 0) {
157	60	if ((*buffer = OPENSSL_malloc(1)) == NULL)
158	0	return 0;
159	118	} else if (p->data != NULL) {
160	118	if (!OSSL_PARAM_get_octet_string(p, (void **)buffer, 0, buflen))
161	0	return 0;
162	118	}
163	178	return 1;
164	178	}
165
166		static int set_digest(KDF_SCRYPT *ctx)
167	0	{
168	0	EVP_MD_free(ctx->sha256);
169	0	ctx->sha256 = EVP_MD_fetch(ctx->libctx, "sha256", ctx->propq);
170	0	if (ctx->sha256 == NULL) {
171	0	ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_LOAD_SHA256);
172	0	return 0;
173	0	}
174	0	return 1;
175	0	}
176
177		static int set_property_query(KDF_SCRYPT ctx, const char propq)
178	0	{
179	0	OPENSSL_free(ctx->propq);
180	0	ctx->propq = NULL;
181	0	if (propq != NULL) {
182	0	ctx->propq = OPENSSL_strdup(propq);
183	0	if (ctx->propq == NULL)
184	0	return 0;
185	0	}
186	0	return 1;
187	0	}
188
189		static int kdf_scrypt_derive(void vctx, unsigned char key, size_t keylen,
190		const OSSL_PARAM params[])
191	0	{
192	0	KDF_SCRYPT ctx = (KDF_SCRYPT )vctx;
193
194	0	if (!ossl_prov_is_running() \|\| !kdf_scrypt_set_ctx_params(ctx, params))
195	0	return 0;
196
197	0	if (ctx->pass == NULL) {
198	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_PASS);
199	0	return 0;
200	0	}
201
202	0	if (ctx->salt == NULL) {
203	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SALT);
204	0	return 0;
205	0	}
206
207	0	if (ctx->sha256 == NULL && !set_digest(ctx))
208	0	return 0;
209
210	0	return scrypt_alg((char *)ctx->pass, ctx->pass_len, ctx->salt,
211	0	ctx->salt_len, ctx->N, ctx->r, ctx->p,
212	0	ctx->maxmem_bytes, key, keylen, ctx->sha256,
213	0	ctx->libctx, ctx->propq);
214	0	}
215
216		static int is_power_of_two(uint64_t value)
217	0	{
218	0	return (value != 0) && ((value & (value - 1)) == 0);
219	0	}
220
221		/* clang-format off */
222		/* Machine generated by util/perl/OpenSSL/paramnames.pm */
223		#ifndef scrypt_set_ctx_params_list
224		static const OSSL_PARAM scrypt_set_ctx_params_list[] = {
225		OSSL_PARAM_octet_string(OSSL_KDF_PARAM_PASSWORD, NULL, 0),
226		OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
227		OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_N, NULL),
228		OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_R, NULL),
229		OSSL_PARAM_uint32(OSSL_KDF_PARAM_SCRYPT_P, NULL),
230		OSSL_PARAM_uint64(OSSL_KDF_PARAM_SCRYPT_MAXMEM, NULL),
231		OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
232		OSSL_PARAM_END
233		};
234		#endif
235
236		#ifndef scrypt_set_ctx_params_st
237		struct scrypt_set_ctx_params_st {
238		OSSL_PARAM *maxmem;
239		OSSL_PARAM *n;
240		OSSL_PARAM *p;
241		OSSL_PARAM *propq;
242		OSSL_PARAM *pw;
243		OSSL_PARAM *r;
244		OSSL_PARAM *salt;
245		};
246		#endif
247
248		#ifndef scrypt_set_ctx_params_decoder
249		static int scrypt_set_ctx_params_decoder
250		(const OSSL_PARAM p, struct scrypt_set_ctx_params_st r)
251	33	{
252	33	const char *s;
253
254	33	memset(r, 0, sizeof(*r));
255	33	if (p != NULL)
256	264	for (; (s = p->key) != NULL; p++)
257	231	switch(s[0]) {
258	0	default:
259	0	break;
260	33	case 'm':
261	33	if (ossl_likely(strcmp("axmem_bytes", s + 1) == 0)) {
262		/* OSSL_KDF_PARAM_SCRYPT_MAXMEM */
263	33	if (ossl_unlikely(r->maxmem != NULL)) {
264	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
265	0	"param %s is repeated", s);
266	0	return 0;
267	0	}
268	33	r->maxmem = (OSSL_PARAM *)p;
269	33	}
270	33	break;
271	33	case 'n':
272	33	switch(s[1]) {
273	0	default:
274	0	break;
275	33	case '\0':
276	33	if (ossl_unlikely(r->n != NULL)) {
277	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
278	0	"param %s is repeated", s);
279	0	return 0;
280	0	}
281	33	r->n = (OSSL_PARAM *)p;
282	33	}
283	33	break;
284	99	case 'p':
285	99	switch(s[1]) {
286	0	default:
287	0	break;
288	33	case 'a':
289	33	if (ossl_likely(strcmp("ss", s + 2) == 0)) {
290		/* OSSL_KDF_PARAM_PASSWORD */
291	33	if (ossl_unlikely(r->pw != NULL)) {
292	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
293	0	"param %s is repeated", s);
294	0	return 0;
295	0	}
296	33	r->pw = (OSSL_PARAM *)p;
297	33	}
298	33	break;
299	33	case 'r':
300	33	if (ossl_likely(strcmp("operties", s + 2) == 0)) {
301		/* OSSL_KDF_PARAM_PROPERTIES */
302	33	if (ossl_unlikely(r->propq != NULL)) {
303	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
304	0	"param %s is repeated", s);
305	0	return 0;
306	0	}
307	33	r->propq = (OSSL_PARAM *)p;
308	33	}
309	33	break;
310	33	case '\0':
311	33	if (ossl_unlikely(r->p != NULL)) {
312	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
313	0	"param %s is repeated", s);
314	0	return 0;
315	0	}
316	33	r->p = (OSSL_PARAM *)p;
317	99	}
318	99	break;
319	99	case 'r':
320	33	switch(s[1]) {
321	0	default:
322	0	break;
323	33	case '\0':
324	33	if (ossl_unlikely(r->r != NULL)) {
325	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
326	0	"param %s is repeated", s);
327	0	return 0;
328	0	}
329	33	r->r = (OSSL_PARAM *)p;
330	33	}
331	33	break;
332	33	case 's':
333	33	if (ossl_likely(strcmp("alt", s + 1) == 0)) {
334		/* OSSL_KDF_PARAM_SALT */
335	33	if (ossl_unlikely(r->salt != NULL)) {
336	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
337	0	"param %s is repeated", s);
338	0	return 0;
339	0	}
340	33	r->salt = (OSSL_PARAM *)p;
341	33	}
342	231	}
343	33	return 1;
344	33	}
345		#endif
346		/* End of machine generated */
347		/* clang-format on */
348
349		static int kdf_scrypt_set_ctx_params(void *vctx, const OSSL_PARAM params[])
350	33	{
351	33	struct scrypt_set_ctx_params_st p;
352	33	KDF_SCRYPT *ctx = vctx;
353	33	uint64_t u64_value;
354
355	33	if (ctx == NULL \|\| !scrypt_set_ctx_params_decoder(params, &p))
356	0	return 0;
357
358	33	if (p.pw != NULL && !scrypt_set_membuf(&ctx->pass, &ctx->pass_len, p.pw))
359	0	return 0;
360
361	33	if (p.salt != NULL && !scrypt_set_membuf(&ctx->salt, &ctx->salt_len, p.salt))
362	0	return 0;
363
364	33	if (p.n != NULL) {
365	33	if (!OSSL_PARAM_get_uint64(p.n, &u64_value)
366	33	\|\| u64_value <= 1
367	0	\|\| !is_power_of_two(u64_value))
368	33	return 0;
369	0	ctx->N = u64_value;
370	0	}
371
372	0	if (p.r != NULL) {
373	0	if (!OSSL_PARAM_get_uint64(p.r, &u64_value) \|\| u64_value < 1)
374	0	return 0;
375	0	ctx->r = u64_value;
376	0	}
377
378	0	if (p.p != NULL) {
379	0	if (!OSSL_PARAM_get_uint64(p.p, &u64_value) \|\| u64_value < 1)
380	0	return 0;
381	0	ctx->p = u64_value;
382	0	}
383
384	0	if (p.maxmem != NULL) {
385	0	if (!OSSL_PARAM_get_uint64(p.maxmem, &u64_value) \|\| u64_value < 1)
386	0	return 0;
387	0	ctx->maxmem_bytes = u64_value;
388	0	}
389
390	0	if (p.propq != NULL) {
391	0	if (p.propq->data_type != OSSL_PARAM_UTF8_STRING
392	0	\|\| !set_property_query(ctx, p.propq->data)
393	0	\|\| !set_digest(ctx))
394	0	return 0;
395	0	}
396	0	return 1;
397	0	}
398
399		static const OSSL_PARAM kdf_scrypt_settable_ctx_params(ossl_unused void ctx,
400		ossl_unused void *p_ctx)
401	102	{
402	102	return scrypt_set_ctx_params_list;
403	102	}
404
405		/* clang-format off */
406		/* Machine generated by util/perl/OpenSSL/paramnames.pm */
407		#ifndef scrypt_get_ctx_params_list
408		static const OSSL_PARAM scrypt_get_ctx_params_list[] = {
409		OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
410		OSSL_PARAM_END
411		};
412		#endif
413
414		#ifndef scrypt_get_ctx_params_st
415		struct scrypt_get_ctx_params_st {
416		OSSL_PARAM *size;
417		};
418		#endif
419
420		#ifndef scrypt_get_ctx_params_decoder
421		static int scrypt_get_ctx_params_decoder
422		(const OSSL_PARAM p, struct scrypt_get_ctx_params_st r)
423	0	{
424	0	const char *s;
425
426	0	memset(r, 0, sizeof(*r));
427	0	if (p != NULL)
428	0	for (; (s = p->key) != NULL; p++)
429	0	if (ossl_likely(strcmp("size", s + 0) == 0)) {
430		/* OSSL_KDF_PARAM_SIZE */
431	0	if (ossl_unlikely(r->size != NULL)) {
432	0	ERR_raise_data(ERR_LIB_PROV, PROV_R_REPEATED_PARAMETER,
433	0	"param %s is repeated", s);
434	0	return 0;
435	0	}
436	0	r->size = (OSSL_PARAM *)p;
437	0	}
438	0	return 1;
439	0	}
440		#endif
441		/* End of machine generated */
442		/* clang-format on */
443
444		static int kdf_scrypt_get_ctx_params(void *vctx, OSSL_PARAM params[])
445	0	{
446	0	struct scrypt_get_ctx_params_st p;
447	0	KDF_SCRYPT *ctx = vctx;
448
449	0	if (ctx == NULL \|\| !scrypt_get_ctx_params_decoder(params, &p))
450	0	return 0;
451
452	0	if (p.size != NULL && !OSSL_PARAM_set_size_t(p.size, SIZE_MAX))
453	0	return 0;
454	0	return 1;
455	0	}
456
457		static const OSSL_PARAM kdf_scrypt_gettable_ctx_params(ossl_unused void ctx,
458		ossl_unused void *p_ctx)
459	0	{
460	0	return scrypt_get_ctx_params_list;
461	0	}
462
463		const OSSL_DISPATCH ossl_kdf_scrypt_functions[] = {
464		{ OSSL_FUNC_KDF_NEWCTX, (void (*)(void))kdf_scrypt_new },
465		{ OSSL_FUNC_KDF_DUPCTX, (void (*)(void))kdf_scrypt_dup },
466		{ OSSL_FUNC_KDF_FREECTX, (void (*)(void))kdf_scrypt_free },
467		{ OSSL_FUNC_KDF_RESET, (void (*)(void))kdf_scrypt_reset },
468		{ OSSL_FUNC_KDF_DERIVE, (void (*)(void))kdf_scrypt_derive },
469		{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
470		(void (*)(void))kdf_scrypt_settable_ctx_params },
471		{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void (*)(void))kdf_scrypt_set_ctx_params },
472		{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
473		(void (*)(void))kdf_scrypt_gettable_ctx_params },
474		{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void (*)(void))kdf_scrypt_get_ctx_params },
475		OSSL_DISPATCH_END
476		};
477
478	0	#define R(a, b) (((a) << (b)) \| ((a) >> (32 - (b))))
479		static void salsa208_word_specification(uint32_t inout[16])
480	0	{
481	0	int i;
482	0	uint32_t x[16];
483
484	0	memcpy(x, inout, sizeof(x));
485	0	for (i = 8; i > 0; i -= 2) {
486	0	x[4] ^= R(x[0] + x[12], 7);
487	0	x[8] ^= R(x[4] + x[0], 9);
488	0	x[12] ^= R(x[8] + x[4], 13);
489	0	x[0] ^= R(x[12] + x[8], 18);
490	0	x[9] ^= R(x[5] + x[1], 7);
491	0	x[13] ^= R(x[9] + x[5], 9);
492	0	x[1] ^= R(x[13] + x[9], 13);
493	0	x[5] ^= R(x[1] + x[13], 18);
494	0	x[14] ^= R(x[10] + x[6], 7);
495	0	x[2] ^= R(x[14] + x[10], 9);
496	0	x[6] ^= R(x[2] + x[14], 13);
497	0	x[10] ^= R(x[6] + x[2], 18);
498	0	x[3] ^= R(x[15] + x[11], 7);
499	0	x[7] ^= R(x[3] + x[15], 9);
500	0	x[11] ^= R(x[7] + x[3], 13);
501	0	x[15] ^= R(x[11] + x[7], 18);
502	0	x[1] ^= R(x[0] + x[3], 7);
503	0	x[2] ^= R(x[1] + x[0], 9);
504	0	x[3] ^= R(x[2] + x[1], 13);
505	0	x[0] ^= R(x[3] + x[2], 18);
506	0	x[6] ^= R(x[5] + x[4], 7);
507	0	x[7] ^= R(x[6] + x[5], 9);
508	0	x[4] ^= R(x[7] + x[6], 13);
509	0	x[5] ^= R(x[4] + x[7], 18);
510	0	x[11] ^= R(x[10] + x[9], 7);
511	0	x[8] ^= R(x[11] + x[10], 9);
512	0	x[9] ^= R(x[8] + x[11], 13);
513	0	x[10] ^= R(x[9] + x[8], 18);
514	0	x[12] ^= R(x[15] + x[14], 7);
515	0	x[13] ^= R(x[12] + x[15], 9);
516	0	x[14] ^= R(x[13] + x[12], 13);
517	0	x[15] ^= R(x[14] + x[13], 18);
518	0	}
519	0	for (i = 0; i < 16; ++i)
520	0	inout[i] += x[i];
521	0	OPENSSL_cleanse(x, sizeof(x));
522	0	}
523
524		static void scryptBlockMix(uint32_t B_, uint32_t B, uint64_t r)
525	0	{
526	0	uint64_t i, j;
527	0	uint32_t X[16], *pB;
528
529	0	memcpy(X, B + (r * 2 - 1) * 16, sizeof(X));
530	0	pB = B;
531	0	for (i = 0; i < r * 2; i++) {
532	0	for (j = 0; j < 16; j++)
533	0	X[j] ^= *pB++;
534	0	salsa208_word_specification(X);
535	0	memcpy(B_ + (i / 2 + (i & 1) * r) * 16, X, sizeof(X));
536	0	}
537	0	OPENSSL_cleanse(X, sizeof(X));
538	0	}
539
540		static void scryptROMix(unsigned char *B, uint64_t r, uint64_t N,
541		uint32_t X, uint32_t T, uint32_t *V)
542	0	{
543	0	unsigned char *pB;
544	0	uint32_t *pV;
545	0	uint64_t i, k;
546
547		/* Convert from little endian input */
548	0	for (pV = V, i = 0, pB = B; i < 32 * r; i++, pV++) {
549	0	pV = pB++;
550	0	pV \|= pB++ << 8;
551	0	pV \|= pB++ << 16;
552	0	pV \|= (uint32_t)pB++ << 24;
553	0	}
554
555	0	for (i = 1; i < N; i++, pV += 32 * r)
556	0	scryptBlockMix(pV, pV - 32 * r, r);
557
558	0	scryptBlockMix(X, V + (N - 1) * 32 * r, r);
559
560	0	for (i = 0; i < N; i++) {
561	0	uint32_t j;
562	0	j = X[16 * (2 * r - 1)] % N;
563	0	pV = V + 32 * r * j;
564	0	for (k = 0; k < 32 * r; k++)
565	0	T[k] = X[k] ^ *pV++;
566	0	scryptBlockMix(X, T, r);
567	0	}
568		/* Convert output to little endian */
569	0	for (i = 0, pB = B; i < 32 * r; i++) {
570	0	uint32_t xtmp = X[i];
571	0	*pB++ = xtmp & 0xff;
572	0	*pB++ = (xtmp >> 8) & 0xff;
573	0	*pB++ = (xtmp >> 16) & 0xff;
574	0	*pB++ = (xtmp >> 24) & 0xff;
575	0	}
576	0	}
577
578		#ifndef SIZE_MAX
579		#define SIZE_MAX ((size_t)-1)
580		#endif
581
582		/*
583		* Maximum power of two that will fit in uint64_t: this should work on
584		* most (all?) platforms.
585		*/
586
587	0	#define LOG2_UINT64_MAX (sizeof(uint64_t) * 8 - 1)
588
589		/*
590		* Maximum value of p * r:
591		* p <= ((2^32-1) * hLen) / MFLen =>
592		* p <= ((2^32-1) * 32) / (128 * r) =>
593		* p * r <= (2^30-1)
594		*/
595
596	0	#define SCRYPT_PR_MAX ((1 << 30) - 1)
597
598		static int scrypt_alg(const char *pass, size_t passlen,
599		const unsigned char *salt, size_t saltlen,
600		uint64_t N, uint64_t r, uint64_t p, uint64_t maxmem,
601		unsigned char key, size_t keylen, EVP_MD sha256,
602		OSSL_LIB_CTX libctx, const char propq)
603	0	{
604	0	int rv = 0;
605	0	unsigned char *B;
606	0	uint32_t X, V, *T;
607	0	uint64_t i, Blen, Vlen;
608
609		/* Sanity check parameters */
610		/* initial check, r,p must be non zero, N >= 2 and a power of 2 */
611	0	if (r == 0 \|\| p == 0 \|\| N < 2 \|\| (N & (N - 1)))
612	0	return 0;
613		/* Check p * r < SCRYPT_PR_MAX avoiding overflow */
614	0	if (p > SCRYPT_PR_MAX / r) {
615	0	ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
616	0	return 0;
617	0	}
618
619		/*
620		* Need to check N: if 2^(128 * r / 8) overflows limit this is
621		* automatically satisfied since N <= UINT64_MAX.
622		*/
623
624	0	if (16 * r <= LOG2_UINT64_MAX) {
625	0	if (N >= (((uint64_t)1) << (16 * r))) {
626	0	ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
627	0	return 0;
628	0	}
629	0	}
630
631		/* Memory checks: check total allocated buffer size fits in uint64_t */
632
633		/*
634		* B size in section 5 step 1.S
635		* Note: we know p * 128 * r < UINT64_MAX because we already checked
636		* p * r < SCRYPT_PR_MAX
637		*/
638	0	Blen = p * 128 * r;
639		/*
640		* Yet we pass it as integer to PKCS5_PBKDF2_HMAC... [This would
641		* have to be revised when/if PKCS5_PBKDF2_HMAC accepts size_t.]
642		*/
643	0	if (Blen > INT_MAX) {
644	0	ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
645	0	return 0;
646	0	}
647
648		/*
649		* Check 32 * r * (N + 2) * sizeof(uint32_t) fits in uint64_t
650		* This is combined size V, X and T (section 4)
651		*/
652	0	i = UINT64_MAX / (32 * sizeof(uint32_t));
653	0	if (N + 2 > i / r) {
654	0	ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
655	0	return 0;
656	0	}
657	0	Vlen = 32 * r * (N + 2) * sizeof(uint32_t);
658
659		/* check total allocated size fits in uint64_t */
660	0	if (Blen > UINT64_MAX - Vlen) {
661	0	ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
662	0	return 0;
663	0	}
664
665		/* Check that the maximum memory doesn't exceed a size_t limits */
666	0	if (maxmem > SIZE_MAX)
667	0	maxmem = SIZE_MAX;
668
669	0	if (Blen + Vlen > maxmem) {
670	0	ERR_raise(ERR_LIB_EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
671	0	return 0;
672	0	}
673
674		/* If no key return to indicate parameters are OK */
675	0	if (key == NULL)
676	0	return 1;
677
678	0	B = OPENSSL_malloc((size_t)(Blen + Vlen));
679	0	if (B == NULL)
680	0	return 0;
681	0	X = (uint32_t *)(B + Blen);
682	0	T = X + 32 * r;
683	0	V = T + 32 * r;
684	0	if (ossl_pkcs5_pbkdf2_hmac_ex(pass, (int)passlen, salt, (int)saltlen, 1,
685	0	sha256, (int)Blen, B, libctx, propq)
686	0	== 0)
687	0	goto err;
688
689	0	for (i = 0; i < p; i++)
690	0	scryptROMix(B + 128 * r * i, r, N, X, T, V);
691
692	0	if (ossl_pkcs5_pbkdf2_hmac_ex(pass, (int)passlen, B, (int)Blen, 1, sha256,
693	0	(int)keylen, key, libctx, propq)
694	0	== 0)
695	0	goto err;
696	0	rv = 1;
697	0	err:
698	0	if (rv == 0)
699	0	ERR_raise(ERR_LIB_EVP, EVP_R_PBKDF2_ERROR);
700
701	0	OPENSSL_clear_free(B, (size_t)(Blen + Vlen));
702	0	return rv;
703	0	}
704
705		#endif