intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 731 insertions, 0 deletions

diff --git a/contrib/libs/openssl/crypto/srp/srp_vfy.c b/contrib/libs/openssl/crypto/srp/srp_vfy.c
new file mode 100644
index 0000000000..394e1180df
--- /dev/null
+++ b/contrib/libs/openssl/crypto/srp/srp_vfy.c
@@ -0,0 +1,731 @@
+/*
+ * Copyright 2004-2021 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright (c) 2004, EdelKey Project. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (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
+ *
+ * Originally written by Christophe Renou and Peter Sylvester,
+ * for the EdelKey project.
+ */
+
+#ifndef OPENSSL_NO_SRP
+# include "internal/cryptlib.h"
+# include "crypto/evp.h"
+# include <openssl/sha.h>
+# include <openssl/srp.h>
+# include <openssl/evp.h>
+# include <openssl/buffer.h>
+# include <openssl/rand.h>
+# include <openssl/txt_db.h>
+# include <openssl/err.h>
+
+# define SRP_RANDOM_SALT_LEN 20
+# define MAX_LEN 2500
+
+/*
+ * Note that SRP uses its own variant of base 64 encoding. A different base64
+ * alphabet is used and no padding '=' characters are added. Instead we pad to
+ * the front with 0 bytes and subsequently strip off leading encoded padding.
+ * This variant is used for compatibility with other SRP implementations -
+ * notably libsrp, but also others. It is also required for backwards
+ * compatibility in order to load verifier files from other OpenSSL versions.
+ */
+
+/*
+ * Convert a base64 string into raw byte array representation.
+ * Returns the length of the decoded data, or -1 on error.
+ */
+static int t_fromb64(unsigned char *a, size_t alen, const char *src)
+{
+    EVP_ENCODE_CTX *ctx;
+    int outl = 0, outl2 = 0;
+    size_t size, padsize;
+    const unsigned char *pad = (const unsigned char *)"00";
+
+    while (*src == ' ' || *src == '\t' || *src == '\n')
+        ++src;
+    size = strlen(src);
+    padsize = 4 - (size & 3);
+    padsize &= 3;
+
+    /* Four bytes in src become three bytes output. */
+    if (size > INT_MAX || ((size + padsize) / 4) * 3 > alen)
+        return -1;
+
+    ctx = EVP_ENCODE_CTX_new();
+    if (ctx == NULL)
+        return -1;
+
+    /*
+     * This should never occur because 1 byte of data always requires 2 bytes of
+     * encoding, i.e.
+     *  0 bytes unencoded = 0 bytes encoded
+     *  1 byte unencoded  = 2 bytes encoded
+     *  2 bytes unencoded = 3 bytes encoded
+     *  3 bytes unencoded = 4 bytes encoded
+     *  4 bytes unencoded = 6 bytes encoded
+     *  etc
+     */
+    if (padsize == 3) {
+        outl = -1;
+        goto err;
+    }
+
+    /* Valid padsize values are now 0, 1 or 2 */
+
+    EVP_DecodeInit(ctx);
+    evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_USE_SRP_ALPHABET);
+
+    /* Add any encoded padding that is required */
+    if (padsize != 0
+            && EVP_DecodeUpdate(ctx, a, &outl, pad, padsize) < 0) {
+        outl = -1;
+        goto err;
+    }
+    if (EVP_DecodeUpdate(ctx, a, &outl2, (const unsigned char *)src, size) < 0) {
+        outl = -1;
+        goto err;
+    }
+    outl += outl2;
+    EVP_DecodeFinal(ctx, a + outl, &outl2);
+    outl += outl2;
+
+    /* Strip off the leading padding */
+    if (padsize != 0) {
+        if ((int)padsize >= outl) {
+            outl = -1;
+            goto err;
+        }
+
+        /*
+         * If we added 1 byte of padding prior to encoding then we have 2 bytes
+         * of "real" data which gets spread across 4 encoded bytes like this:
+         *   (6 bits pad)(2 bits pad | 4 bits data)(6 bits data)(6 bits data)
+         * So 1 byte of pre-encoding padding results in 1 full byte of encoded
+         * padding.
+         * If we added 2 bytes of padding prior to encoding this gets encoded
+         * as:
+         *   (6 bits pad)(6 bits pad)(4 bits pad | 2 bits data)(6 bits data)
+         * So 2 bytes of pre-encoding padding results in 2 full bytes of encoded
+         * padding, i.e. we have to strip the same number of bytes of padding
+         * from the encoded data as we added to the pre-encoded data.
+         */
+        memmove(a, a + padsize, outl - padsize);
+        outl -= padsize;
+    }
+
+ err:
+    EVP_ENCODE_CTX_free(ctx);
+
+    return outl;
+}
+
+/*
+ * Convert a raw byte string into a null-terminated base64 ASCII string.
+ * Returns 1 on success or 0 on error.
+ */
+static int t_tob64(char *dst, const unsigned char *src, int size)
+{
+    EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
+    int outl = 0, outl2 = 0;
+    unsigned char pad[2] = {0, 0};
+    size_t leadz = 0;
+
+    if (ctx == NULL)
+        return 0;
+
+    EVP_EncodeInit(ctx);
+    evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_NO_NEWLINES
+                                  | EVP_ENCODE_CTX_USE_SRP_ALPHABET);
+
+    /*
+     * We pad at the front with zero bytes until the length is a multiple of 3
+     * so that EVP_EncodeUpdate/EVP_EncodeFinal does not add any of its own "="
+     * padding
+     */
+    leadz = 3 - (size % 3);
+    if (leadz != 3
+            && !EVP_EncodeUpdate(ctx, (unsigned char *)dst, &outl, pad,
+                                 leadz)) {
+        EVP_ENCODE_CTX_free(ctx);
+        return 0;
+    }
+
+    if (!EVP_EncodeUpdate(ctx, (unsigned char *)dst + outl, &outl2, src,
+                          size)) {
+        EVP_ENCODE_CTX_free(ctx);
+        return 0;
+    }
+    outl += outl2;
+    EVP_EncodeFinal(ctx, (unsigned char *)dst + outl, &outl2);
+    outl += outl2;
+
+    /* Strip the encoded padding at the front */
+    if (leadz != 3) {
+        memmove(dst, dst + leadz, outl - leadz);
+        dst[outl - leadz] = '\0';
+    }
+
+    EVP_ENCODE_CTX_free(ctx);
+    return 1;
+}
+
+void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
+{
+    if (user_pwd == NULL)
+        return;
+    BN_free(user_pwd->s);
+    BN_clear_free(user_pwd->v);
+    OPENSSL_free(user_pwd->id);
+    OPENSSL_free(user_pwd->info);
+    OPENSSL_free(user_pwd);
+}
+
+static SRP_user_pwd *SRP_user_pwd_new(void)
+{
+    SRP_user_pwd *ret;
+
+    if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) {
+        /* SRPerr(SRP_F_SRP_USER_PWD_NEW, ERR_R_MALLOC_FAILURE); */ /*ckerr_ignore*/
+        return NULL;
+    }
+    ret->N = NULL;
+    ret->g = NULL;
+    ret->s = NULL;
+    ret->v = NULL;
+    ret->id = NULL;
+    ret->info = NULL;
+    return ret;
+}
+
+static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g,
+                                const BIGNUM *N)
+{
+    vinfo->N = N;
+    vinfo->g = g;
+}
+
+static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id,
+                                const char *info)
+{
+    if (id != NULL && NULL == (vinfo->id = OPENSSL_strdup(id)))
+        return 0;
+    return (info == NULL || NULL != (vinfo->info = OPENSSL_strdup(info)));
+}
+
+static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
+                               const char *v)
+{
+    unsigned char tmp[MAX_LEN];
+    int len;
+
+    vinfo->v = NULL;
+    vinfo->s = NULL;
+
+    len = t_fromb64(tmp, sizeof(tmp), v);
+    if (len < 0)
+        return 0;
+    if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)))
+        return 0;
+    len = t_fromb64(tmp, sizeof(tmp), s);
+    if (len < 0)
+        goto err;
+    vinfo->s = BN_bin2bn(tmp, len, NULL);
+    if (vinfo->s == NULL)
+        goto err;
+    return 1;
+ err:
+    BN_free(vinfo->v);
+    vinfo->v = NULL;
+    return 0;
+}
+
+static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v)
+{
+    vinfo->v = v;
+    vinfo->s = s;
+    return (vinfo->s != NULL && vinfo->v != NULL);
+}
+
+static SRP_user_pwd *srp_user_pwd_dup(SRP_user_pwd *src)
+{
+    SRP_user_pwd *ret;
+
+    if (src == NULL)
+        return NULL;
+    if ((ret = SRP_user_pwd_new()) == NULL)
+        return NULL;
+
+    SRP_user_pwd_set_gN(ret, src->g, src->N);
+    if (!SRP_user_pwd_set_ids(ret, src->id, src->info)
+        || !SRP_user_pwd_set_sv_BN(ret, BN_dup(src->s), BN_dup(src->v))) {
+            SRP_user_pwd_free(ret);
+            return NULL;
+    }
+    return ret;
+}
+
+SRP_VBASE *SRP_VBASE_new(char *seed_key)
+{
+    SRP_VBASE *vb = OPENSSL_malloc(sizeof(*vb));
+
+    if (vb == NULL)
+        return NULL;
+    if ((vb->users_pwd = sk_SRP_user_pwd_new_null()) == NULL
+        || (vb->gN_cache = sk_SRP_gN_cache_new_null()) == NULL) {
+        OPENSSL_free(vb);
+        return NULL;
+    }
+    vb->default_g = NULL;
+    vb->default_N = NULL;
+    vb->seed_key = NULL;
+    if ((seed_key != NULL) && (vb->seed_key = OPENSSL_strdup(seed_key)) == NULL) {
+        sk_SRP_user_pwd_free(vb->users_pwd);
+        sk_SRP_gN_cache_free(vb->gN_cache);
+        OPENSSL_free(vb);
+        return NULL;
+    }
+    return vb;
+}
+
+void SRP_VBASE_free(SRP_VBASE *vb)
+{
+    if (!vb)
+        return;
+    sk_SRP_user_pwd_pop_free(vb->users_pwd, SRP_user_pwd_free);
+    sk_SRP_gN_cache_free(vb->gN_cache);
+    OPENSSL_free(vb->seed_key);
+    OPENSSL_free(vb);
+}
+
+static SRP_gN_cache *SRP_gN_new_init(const char *ch)
+{
+    unsigned char tmp[MAX_LEN];
+    int len;
+    SRP_gN_cache *newgN = OPENSSL_malloc(sizeof(*newgN));
+
+    if (newgN == NULL)
+        return NULL;
+
+    len = t_fromb64(tmp, sizeof(tmp), ch);
+    if (len < 0)
+        goto err;
+
+    if ((newgN->b64_bn = OPENSSL_strdup(ch)) == NULL)
+        goto err;
+
+    if ((newgN->bn = BN_bin2bn(tmp, len, NULL)))
+        return newgN;
+
+    OPENSSL_free(newgN->b64_bn);
+ err:
+    OPENSSL_free(newgN);
+    return NULL;
+}
+
+static void SRP_gN_free(SRP_gN_cache *gN_cache)
+{
+    if (gN_cache == NULL)
+        return;
+    OPENSSL_free(gN_cache->b64_bn);
+    BN_free(gN_cache->bn);
+    OPENSSL_free(gN_cache);
+}
+
+static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab)
+{
+    int i;
+
+    SRP_gN *gN;
+    if (gN_tab != NULL)
+        for (i = 0; i < sk_SRP_gN_num(gN_tab); i++) {
+            gN = sk_SRP_gN_value(gN_tab, i);
+            if (gN && (id == NULL || strcmp(gN->id, id) == 0))
+                return gN;
+        }
+
+    return SRP_get_default_gN(id);
+}
+
+static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch)
+{
+    int i;
+    if (gN_cache == NULL)
+        return NULL;
+
+    /* search if we have already one... */
+    for (i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++) {
+        SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i);
+        if (strcmp(cache->b64_bn, ch) == 0)
+            return cache->bn;
+    }
+    {                           /* it is the first time that we find it */
+        SRP_gN_cache *newgN = SRP_gN_new_init(ch);
+        if (newgN) {
+            if (sk_SRP_gN_cache_insert(gN_cache, newgN, 0) > 0)
+                return newgN->bn;
+            SRP_gN_free(newgN);
+        }
+    }
+    return NULL;
+}
+
+/*
+ * this function parses verifier file. Format is:
+ * string(index):base64(N):base64(g):0
+ * string(username):base64(v):base64(salt):int(index)
+ */
+
+int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file)
+{
+    int error_code;
+    STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null();
+    char *last_index = NULL;
+    int i;
+    char **pp;
+
+    SRP_gN *gN = NULL;
+    SRP_user_pwd *user_pwd = NULL;
+
+    TXT_DB *tmpdb = NULL;
+    BIO *in = BIO_new(BIO_s_file());
+
+    error_code = SRP_ERR_OPEN_FILE;
+
+    if (in == NULL || BIO_read_filename(in, verifier_file) <= 0)
+        goto err;
+
+    error_code = SRP_ERR_VBASE_INCOMPLETE_FILE;
+
+    if ((tmpdb = TXT_DB_read(in, DB_NUMBER)) == NULL)
+        goto err;
+
+    error_code = SRP_ERR_MEMORY;
+
+    if (vb->seed_key) {
+        last_index = SRP_get_default_gN(NULL)->id;
+    }
+    for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++) {
+        pp = sk_OPENSSL_PSTRING_value(tmpdb->data, i);
+        if (pp[DB_srptype][0] == DB_SRP_INDEX) {
+            /*
+             * we add this couple in the internal Stack
+             */
+
+            if ((gN = OPENSSL_malloc(sizeof(*gN))) == NULL)
+                goto err;
+
+            if ((gN->id = OPENSSL_strdup(pp[DB_srpid])) == NULL
+                || (gN->N = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpverifier]))
+                        == NULL
+                || (gN->g = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpsalt]))
+                        == NULL
+                || sk_SRP_gN_insert(SRP_gN_tab, gN, 0) == 0)
+                goto err;
+
+            gN = NULL;
+
+            if (vb->seed_key != NULL) {
+                last_index = pp[DB_srpid];
+            }
+        } else if (pp[DB_srptype][0] == DB_SRP_VALID) {
+            /* it is a user .... */
+            const SRP_gN *lgN;
+
+            if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN], SRP_gN_tab)) != NULL) {
+                error_code = SRP_ERR_MEMORY;
+                if ((user_pwd = SRP_user_pwd_new()) == NULL)
+                    goto err;
+
+                SRP_user_pwd_set_gN(user_pwd, lgN->g, lgN->N);
+                if (!SRP_user_pwd_set_ids
+                    (user_pwd, pp[DB_srpid], pp[DB_srpinfo]))
+                    goto err;
+
+                error_code = SRP_ERR_VBASE_BN_LIB;
+                if (!SRP_user_pwd_set_sv
+                    (user_pwd, pp[DB_srpsalt], pp[DB_srpverifier]))
+                    goto err;
+
+                if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0)
+                    goto err;
+                user_pwd = NULL; /* abandon responsibility */
+            }
+        }
+    }
+
+    if (last_index != NULL) {
+        /* this means that we want to simulate a default user */
+
+        if (((gN = SRP_get_gN_by_id(last_index, SRP_gN_tab)) == NULL)) {
+            error_code = SRP_ERR_VBASE_BN_LIB;
+            goto err;
+        }
+        vb->default_g = gN->g;
+        vb->default_N = gN->N;
+        gN = NULL;
+    }
+    error_code = SRP_NO_ERROR;
+
+ err:
+    /*
+     * there may be still some leaks to fix, if this fails, the application
+     * terminates most likely
+     */
+
+    if (gN != NULL) {
+        OPENSSL_free(gN->id);
+        OPENSSL_free(gN);
+    }
+
+    SRP_user_pwd_free(user_pwd);
+
+    TXT_DB_free(tmpdb);
+    BIO_free_all(in);
+
+    sk_SRP_gN_free(SRP_gN_tab);
+
+    return error_code;
+
+}
+
+static SRP_user_pwd *find_user(SRP_VBASE *vb, char *username)
+{
+    int i;
+    SRP_user_pwd *user;
+
+    if (vb == NULL)
+        return NULL;
+
+    for (i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++) {
+        user = sk_SRP_user_pwd_value(vb->users_pwd, i);
+        if (strcmp(user->id, username) == 0)
+            return user;
+    }
+
+    return NULL;
+}
+
+# if OPENSSL_API_COMPAT < 0x10100000L
+/*
+ * DEPRECATED: use SRP_VBASE_get1_by_user instead.
+ * This method ignores the configured seed and fails for an unknown user.
+ * Ownership of the returned pointer is not released to the caller.
+ * In other words, caller must not free the result.
+ */
+SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username)
+{
+    return find_user(vb, username);
+}
+# endif
+
+/*
+ * Ownership of the returned pointer is released to the caller.
+ * In other words, caller must free the result once done.
+ */
+SRP_user_pwd *SRP_VBASE_get1_by_user(SRP_VBASE *vb, char *username)
+{
+    SRP_user_pwd *user;
+    unsigned char digv[SHA_DIGEST_LENGTH];
+    unsigned char digs[SHA_DIGEST_LENGTH];
+    EVP_MD_CTX *ctxt = NULL;
+
+    if (vb == NULL)
+        return NULL;
+
+    if ((user = find_user(vb, username)) != NULL)
+        return srp_user_pwd_dup(user);
+
+    if ((vb->seed_key == NULL) ||
+        (vb->default_g == NULL) || (vb->default_N == NULL))
+        return NULL;
+
+/* if the user is unknown we set parameters as well if we have a seed_key */
+
+    if ((user = SRP_user_pwd_new()) == NULL)
+        return NULL;
+
+    SRP_user_pwd_set_gN(user, vb->default_g, vb->default_N);
+
+    if (!SRP_user_pwd_set_ids(user, username, NULL))
+        goto err;
+
+    if (RAND_priv_bytes(digv, SHA_DIGEST_LENGTH) <= 0)
+        goto err;
+    ctxt = EVP_MD_CTX_new();
+    if (ctxt == NULL
+        || !EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL)
+        || !EVP_DigestUpdate(ctxt, vb->seed_key, strlen(vb->seed_key))
+        || !EVP_DigestUpdate(ctxt, username, strlen(username))
+        || !EVP_DigestFinal_ex(ctxt, digs, NULL))
+        goto err;
+    EVP_MD_CTX_free(ctxt);
+    ctxt = NULL;
+    if (SRP_user_pwd_set_sv_BN(user,
+                               BN_bin2bn(digs, SHA_DIGEST_LENGTH, NULL),
+                               BN_bin2bn(digv, SHA_DIGEST_LENGTH, NULL)))
+        return user;
+
+ err:
+    EVP_MD_CTX_free(ctxt);
+    SRP_user_pwd_free(user);
+    return NULL;
+}
+
+/*
+ * create a verifier (*salt,*verifier,g and N are in base64)
+ */
+char *SRP_create_verifier(const char *user, const char *pass, char **salt,
+                          char **verifier, const char *N, const char *g)
+{
+    int len;
+    char *result = NULL, *vf = NULL;
+    const BIGNUM *N_bn = NULL, *g_bn = NULL;
+    BIGNUM *N_bn_alloc = NULL, *g_bn_alloc = NULL, *s = NULL, *v = NULL;
+    unsigned char tmp[MAX_LEN];
+    unsigned char tmp2[MAX_LEN];
+    char *defgNid = NULL;
+    int vfsize = 0;
+
+    if ((user == NULL) ||
+        (pass == NULL) || (salt == NULL) || (verifier == NULL))
+        goto err;
+
+    if (N) {
+        if ((len = t_fromb64(tmp, sizeof(tmp), N)) <= 0)
+            goto err;
+        N_bn_alloc = BN_bin2bn(tmp, len, NULL);
+        if (N_bn_alloc == NULL)
+            goto err;
+        N_bn = N_bn_alloc;
+        if ((len = t_fromb64(tmp, sizeof(tmp) ,g)) <= 0)
+            goto err;
+        g_bn_alloc = BN_bin2bn(tmp, len, NULL);
+        if (g_bn_alloc == NULL)
+            goto err;
+        g_bn = g_bn_alloc;
+        defgNid = "*";
+    } else {
+        SRP_gN *gN = SRP_get_gN_by_id(g, NULL);
+        if (gN == NULL)
+            goto err;
+        N_bn = gN->N;
+        g_bn = gN->g;
+        defgNid = gN->id;
+    }
+
+    if (*salt == NULL) {
+        if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
+            goto err;
+
+        s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
+    } else {
+        if ((len = t_fromb64(tmp2, sizeof(tmp2), *salt)) <= 0)
+            goto err;
+        s = BN_bin2bn(tmp2, len, NULL);
+    }
+    if (s == NULL)
+        goto err;
+
+    if (!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn))
+        goto err;
+
+    if (BN_bn2bin(v, tmp) < 0)
+        goto err;
+    vfsize = BN_num_bytes(v) * 2;
+    if (((vf = OPENSSL_malloc(vfsize)) == NULL))
+        goto err;
+    if (!t_tob64(vf, tmp, BN_num_bytes(v)))
+        goto err;
+
+    if (*salt == NULL) {
+        char *tmp_salt;
+
+        if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL) {
+            goto err;
+        }
+        if (!t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN)) {
+            OPENSSL_free(tmp_salt);
+            goto err;
+        }
+        *salt = tmp_salt;
+    }
+
+    *verifier = vf;
+    vf = NULL;
+    result = defgNid;
+
+ err:
+    BN_free(N_bn_alloc);
+    BN_free(g_bn_alloc);
+    OPENSSL_clear_free(vf, vfsize);
+    BN_clear_free(s);
+    BN_clear_free(v);
+    return result;
+}
+
+/*
+ * create a verifier (*salt,*verifier,g and N are BIGNUMs). If *salt != NULL
+ * then the provided salt will be used. On successful exit *verifier will point
+ * to a newly allocated BIGNUM containing the verifier and (if a salt was not
+ * provided) *salt will be populated with a newly allocated BIGNUM containing a
+ * random salt.
+ * The caller is responsible for freeing the allocated *salt and *verifier
+ * BIGNUMS.
+ */
+int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt,
+                           BIGNUM **verifier, const BIGNUM *N,
+                           const BIGNUM *g)
+{
+    int result = 0;
+    BIGNUM *x = NULL;
+    BN_CTX *bn_ctx = BN_CTX_new();
+    unsigned char tmp2[MAX_LEN];
+    BIGNUM *salttmp = NULL, *verif;
+
+    if ((user == NULL) ||
+        (pass == NULL) ||
+        (salt == NULL) ||
+        (verifier == NULL) || (N == NULL) || (g == NULL) || (bn_ctx == NULL))
+        goto err;
+
+    if (*salt == NULL) {
+        if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0)
+            goto err;
+
+        salttmp = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
+        if (salttmp == NULL)
+            goto err;
+    } else {
+        salttmp = *salt;
+    }
+
+    x = SRP_Calc_x(salttmp, user, pass);
+    if (x == NULL)
+        goto err;
+
+    verif = BN_new();
+    if (verif == NULL)
+        goto err;
+
+    if (!BN_mod_exp(verif, g, x, N, bn_ctx)) {
+        BN_clear_free(verif);
+        goto err;
+    }
+
+    result = 1;
+    *salt = salttmp;
+    *verifier = verif;
+
+ err:
+    if (salt != NULL && *salt != salttmp)
+        BN_clear_free(salttmp);
+    BN_clear_free(x);
+    BN_CTX_free(bn_ctx);
+    return result;
+}
+
+#endif