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

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/*
 * 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
 */


#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);
}

/* 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)) {
                    /* 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)) {
                        /* 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)) {
                        /* 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)) {
                    /* 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 */

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;
}

/* 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)) {
                /* 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 */

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: 2025-08-25 06:30

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