C++ OPENSSL_clear_free函数代码示例

void SSL_SESSION_free(SSL_SESSION *ss)
{
    int i;

    if (ss == NULL)
        return;
    CRYPTO_DOWN_REF(&ss->references, &i, ss->lock);
    REF_PRINT_COUNT("SSL_SESSION", ss);
    if (i > 0)
        return;
    REF_ASSERT_ISNT(i < 0);

    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);

    OPENSSL_cleanse(ss->master_key, sizeof(ss->master_key));
    OPENSSL_cleanse(ss->session_id, sizeof(ss->session_id));
    X509_free(ss->peer);
    sk_X509_pop_free(ss->peer_chain, X509_free);
    sk_SSL_CIPHER_free(ss->ciphers);
    OPENSSL_free(ss->ext.hostname);
    OPENSSL_free(ss->ext.tick);
#ifndef OPENSSL_NO_EC
    OPENSSL_free(ss->ext.ecpointformats);
    ss->ext.ecpointformats = NULL;
    ss->ext.ecpointformats_len = 0;
    OPENSSL_free(ss->ext.supportedgroups);
    ss->ext.supportedgroups = NULL;
    ss->ext.supportedgroups_len = 0;
#endif                          /* OPENSSL_NO_EC */
#ifndef OPENSSL_NO_PSK
    OPENSSL_free(ss->psk_identity_hint);
    OPENSSL_free(ss->psk_identity);
#endif
#ifndef OPENSSL_NO_SRP
    OPENSSL_free(ss->srp_username);
#endif
    OPENSSL_free(ss->ext.alpn_selected);
    OPENSSL_free(ss->ticket_appdata);
    CRYPTO_THREAD_lock_free(ss->lock);
    OPENSSL_clear_free(ss, sizeof(*ss));
}

int PKCS12_key_gen_asc(const char *pass, int passlen, unsigned char *salt,
                       int saltlen, int id, int iter, int n,
                       unsigned char *out, const EVP_MD *md_type)
{
    int ret;
    unsigned char *unipass;
    int uniplen;

    if (!pass) {
        unipass = NULL;
        uniplen = 0;
    } else if (!OPENSSL_asc2uni(pass, passlen, &unipass, &uniplen)) {
        PKCS12err(PKCS12_F_PKCS12_KEY_GEN_ASC, ERR_R_MALLOC_FAILURE);
        return 0;
    }
    ret = PKCS12_key_gen_uni(unipass, uniplen, salt, saltlen,
                             id, iter, n, out, md_type);
    if (ret <= 0)
        return 0;
    OPENSSL_clear_free(unipass, uniplen);
    return ret;
}

void EC_KEY_free(EC_KEY *r)
{
    int i;

    if (r == NULL)
        return;

    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);
#ifdef REF_PRINT
    REF_PRINT("EC_KEY", r);
#endif
    if (i > 0)
        return;
#ifdef REF_CHECK
    if (i < 0) {
        fprintf(stderr, "EC_KEY_free, bad reference count\n");
        abort();
    }
#endif

    if (r->meth->finish != NULL)
        r->meth->finish(r);

#ifndef OPENSSL_NO_ENGINE
    if (r->engine != NULL)
        ENGINE_finish(r->engine);
#endif

    EC_GROUP_free(r->group);
    EC_POINT_free(r->pub_key);
    BN_clear_free(r->priv_key);

    EC_EX_DATA_free_all_data(&r->method_data);

    OPENSSL_clear_free((void *)r, sizeof(EC_KEY));
}

/*-
 * returns
 *      1: correct signature
 *      0: incorrect signature
 *     -1: error
 */
int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
               const unsigned char *sigbuf, int siglen, DSA *dsa)
{
    DSA_SIG *s;
    const unsigned char *p = sigbuf;
    unsigned char *der = NULL;
    int derlen = -1;
    int ret = -1;

    s = DSA_SIG_new();
    if (s == NULL)
        return (ret);
    if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
        goto err;
    /* Ensure signature uses DER and doesn't have trailing garbage */
    derlen = i2d_DSA_SIG(s, &der);
    if (derlen != siglen || memcmp(sigbuf, der, derlen))
        goto err;
    ret = DSA_do_verify(dgst, dgst_len, s, dsa);
 err:
    OPENSSL_clear_free(der, derlen);
    DSA_SIG_free(s);
    return (ret);
}

/*-
 * returns
 *      1: correct signature
 *      0: incorrect signature
 *     -1: error
 */
int ossl_ecdsa_verify(int type, const unsigned char *dgst, int dgst_len,
                      const unsigned char *sigbuf, int sig_len, EC_KEY *eckey)
{
    ECDSA_SIG *s;
    const unsigned char *p = sigbuf;
    unsigned char *der = NULL;
    int derlen = -1;
    int ret = -1;

    s = ECDSA_SIG_new();
    if (s == NULL)
        return (ret);
    if (d2i_ECDSA_SIG(&s, &p, sig_len) == NULL)
        goto err;
    /* Ensure signature uses DER and doesn't have trailing garbage */
    derlen = i2d_ECDSA_SIG(s, &der);
    if (derlen != sig_len || memcmp(sigbuf, der, derlen) != 0)
        goto err;
    ret = ECDSA_do_verify(dgst, dgst_len, s, eckey);
 err:
    OPENSSL_clear_free(der, derlen);
    ECDSA_SIG_free(s);
    return (ret);
}

int RSA_sign_ASN1_OCTET_STRING(int type,
                               const unsigned char *m, unsigned int m_len,
                               unsigned char *sigret, unsigned int *siglen,
                               RSA *rsa)
{
    ASN1_OCTET_STRING sig;
    int i, j, ret = 1;
    unsigned char *p, *s;

    sig.type = V_ASN1_OCTET_STRING;
    sig.length = m_len;
    sig.data = (unsigned char *)m;

    i = i2d_ASN1_OCTET_STRING(&sig, NULL);
    j = RSA_size(rsa);
    if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
        RSAerr(RSA_F_RSA_SIGN_ASN1_OCTET_STRING,
               RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
        return (0);
    }
    s = OPENSSL_malloc((unsigned int)j + 1);
    if (s == NULL) {
        RSAerr(RSA_F_RSA_SIGN_ASN1_OCTET_STRING, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    p = s;
    i2d_ASN1_OCTET_STRING(&sig, &p);
    i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);
    if (i <= 0)
        ret = 0;
    else
        *siglen = i;

    OPENSSL_clear_free(s, (unsigned int)j + 1);
    return (ret);
}

int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
             unsigned char *sigret, unsigned int *siglen, RSA *rsa)
{
    X509_SIG sig;
    ASN1_TYPE parameter;
    int i, j, ret = 1;
    unsigned char *p, *tmps = NULL;
    const unsigned char *s = NULL;
    X509_ALGOR algor;
    ASN1_OCTET_STRING digest;
    if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) {
        return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa);
    }
    /* Special case: SSL signature, just check the length */
    if (type == NID_md5_sha1) {
        if (m_len != SSL_SIG_LENGTH) {
            RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH);
            return (0);
        }
        i = SSL_SIG_LENGTH;
        s = m;
    } else {
        sig.algor = &algor;
        sig.algor->algorithm = OBJ_nid2obj(type);
        if (sig.algor->algorithm == NULL) {
            RSAerr(RSA_F_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE);
            return (0);
        }
        if (OBJ_length(sig.algor->algorithm) == 0) {
            RSAerr(RSA_F_RSA_SIGN,
                   RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
            return (0);
        }
        parameter.type = V_ASN1_NULL;
        parameter.value.ptr = NULL;
        sig.algor->parameter = &parameter;

        sig.digest = &digest;
        sig.digest->data = (unsigned char *)m; /* TMP UGLY CAST */
        sig.digest->length = m_len;

        i = i2d_X509_SIG(&sig, NULL);
    }
    j = RSA_size(rsa);
    if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
        RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
        return (0);
    }
    if (type != NID_md5_sha1) {
        tmps = OPENSSL_malloc((unsigned int)j + 1);
        if (tmps == NULL) {
            RSAerr(RSA_F_RSA_SIGN, ERR_R_MALLOC_FAILURE);
            return (0);
        }
        p = tmps;
        i2d_X509_SIG(&sig, &p);
        s = tmps;
    }
    i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);
    if (i <= 0)
        ret = 0;
    else
        *siglen = i;

    if (type != NID_md5_sha1)
        OPENSSL_clear_free(tmps, (unsigned int)j + 1);
    return (ret);
}

//.........这里部分代码省略.........
    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) {
        EVPerr(EVP_F_EVP_PBE_SCRYPT, 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))) {
            EVPerr(EVP_F_EVP_PBE_SCRYPT, 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) {
        EVPerr(EVP_F_EVP_PBE_SCRYPT, 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) {
        EVPerr(EVP_F_EVP_PBE_SCRYPT, 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) {
        EVPerr(EVP_F_EVP_PBE_SCRYPT, EVP_R_MEMORY_LIMIT_EXCEEDED);
        return 0;
    }

    if (maxmem == 0)
        maxmem = SCRYPT_MAX_MEM;

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

    if (Blen + Vlen > maxmem) {
        EVPerr(EVP_F_EVP_PBE_SCRYPT, 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) {
        EVPerr(EVP_F_EVP_PBE_SCRYPT, ERR_R_MALLOC_FAILURE);
        return 0;
    }
    X = (uint32_t *)(B + Blen);
    T = X + 32 * r;
    V = T + 32 * r;
    if (PKCS5_PBKDF2_HMAC(pass, passlen, salt, saltlen, 1, EVP_sha256(),
                          (int)Blen, B) == 0)
        goto err;

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

    if (PKCS5_PBKDF2_HMAC(pass, passlen, B, (int)Blen, 1, EVP_sha256(),
                          keylen, key) == 0)
        goto err;
    rv = 1;
 err:
    if (rv == 0)
        EVPerr(EVP_F_EVP_PBE_SCRYPT, EVP_R_PBKDF2_ERROR);

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

BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)
{
    BIO *b;
    EVP_CIPHER_CTX *ctx;
    const EVP_CIPHER *ciph;
    X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
    unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;
    unsigned char *tkey = NULL;
    size_t tkeylen = 0;

    int ok = 0;

    int enc, keep_key = 0;

    enc = ec->cipher ? 1 : 0;

    b = BIO_new(BIO_f_cipher());
    if (!b) {
        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
        return NULL;
    }

    BIO_get_cipher_ctx(b, &ctx);

    if (enc) {
        ciph = ec->cipher;
        /*
         * If not keeping key set cipher to NULL so subsequent calls decrypt.
         */
        if (ec->key)
            ec->cipher = NULL;
    } else {
        ciph = EVP_get_cipherbyobj(calg->algorithm);

        if (!ciph) {
            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, CMS_R_UNKNOWN_CIPHER);
            goto err;
        }
    }

    if (EVP_CipherInit_ex(ctx, ciph, NULL, NULL, NULL, enc) <= 0) {
        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
               CMS_R_CIPHER_INITIALISATION_ERROR);
        goto err;
    }

    if (enc) {
        int ivlen;
        calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx));
        /* Generate a random IV if we need one */
        ivlen = EVP_CIPHER_CTX_iv_length(ctx);
        if (ivlen > 0) {
            if (RAND_bytes(iv, ivlen) <= 0)
                goto err;
            piv = iv;
        }
    } else if (EVP_CIPHER_asn1_to_param(ctx, calg->parameter) <= 0) {
        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
               CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
        goto err;
    }
    tkeylen = EVP_CIPHER_CTX_key_length(ctx);
    /* Generate random session key */
    if (!enc || !ec->key) {
        tkey = OPENSSL_malloc(tkeylen);
        if (!tkey) {
            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);
            goto err;
        }
        if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)
            goto err;
    }

    if (!ec->key) {
        ec->key = tkey;
        ec->keylen = tkeylen;
        tkey = NULL;
        if (enc)
            keep_key = 1;
        else
            ERR_clear_error();

    }

    if (ec->keylen != tkeylen) {
        /* If necessary set key length */
        if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) {
            /*
             * Only reveal failure if debugging so we don't leak information
             * which may be useful in MMA.
             */
            if (enc || ec->debug) {
                CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,
                       CMS_R_INVALID_KEY_LENGTH);
                goto err;
            } else {
                /* Use random key */
                OPENSSL_clear_free(ec->key, ec->keylen);
                ec->key = tkey;
                ec->keylen = tkeylen;
//.........这里部分代码省略.........

int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
                       void *x, const EVP_CIPHER *enc, unsigned char *kstr,
                       int klen, pem_password_cb *callback, void *u)
{
    EVP_CIPHER_CTX *ctx = NULL;
    int dsize = 0, i = 0, j = 0, ret = 0;
    unsigned char *p, *data = NULL;
    const char *objstr = NULL;
    char buf[PEM_BUFSIZE];
    unsigned char key[EVP_MAX_KEY_LENGTH];
    unsigned char iv[EVP_MAX_IV_LENGTH];

    if (enc != NULL) {
        objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc));
        if (objstr == NULL || EVP_CIPHER_iv_length(enc) == 0
                || EVP_CIPHER_iv_length(enc) > (int)sizeof(iv)
                   /*
                    * Check "Proc-Type: 4,Encrypted\nDEK-Info: objstr,hex-iv\n"
                    * fits into buf
                    */
                || (strlen(objstr) + 23 + 2 * EVP_CIPHER_iv_length(enc) + 13)
                   > sizeof(buf)) {
            PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_UNSUPPORTED_CIPHER);
            goto err;
        }
    }

    if ((dsize = i2d(x, NULL)) < 0) {
        PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_ASN1_LIB);
        dsize = 0;
        goto err;
    }
    /* dsize + 8 bytes are needed */
    /* actually it needs the cipher block size extra... */
    data = OPENSSL_malloc((unsigned int)dsize + 20);
    if (data == NULL) {
        PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    p = data;
    i = i2d(x, &p);

    if (enc != NULL) {
        if (kstr == NULL) {
            if (callback == NULL)
                klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u);
            else
                klen = (*callback) (buf, PEM_BUFSIZE, 1, u);
            if (klen <= 0) {
                PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_READ_KEY);
                goto err;
            }
#ifdef CHARSET_EBCDIC
            /* Convert the pass phrase from EBCDIC */
            ebcdic2ascii(buf, buf, klen);
#endif
            kstr = (unsigned char *)buf;
        }
        if (RAND_bytes(iv, EVP_CIPHER_iv_length(enc)) <= 0) /* Generate a salt */
            goto err;
        /*
         * The 'iv' is used as the iv and as a salt.  It is NOT taken from
         * the BytesToKey function
         */
        if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL))
            goto err;

        if (kstr == (unsigned char *)buf)
            OPENSSL_cleanse(buf, PEM_BUFSIZE);

        buf[0] = '\0';
        PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
        PEM_dek_info(buf, objstr, EVP_CIPHER_iv_length(enc), (char *)iv);
        /* k=strlen(buf); */

        ret = 1;
        if ((ctx = EVP_CIPHER_CTX_new()) == NULL
            || !EVP_EncryptInit_ex(ctx, enc, NULL, key, iv)
            || !EVP_EncryptUpdate(ctx, data, &j, data, i)
            || !EVP_EncryptFinal_ex(ctx, &(data[j]), &i))
            ret = 0;
        if (ret == 0)
            goto err;
        i += j;
    } else {
        ret = 1;
        buf[0] = '\0';
    }
    i = PEM_write_bio(bp, name, buf, data, i);
    if (i <= 0)
        ret = 0;
 err:
    OPENSSL_cleanse(key, sizeof(key));
    OPENSSL_cleanse(iv, sizeof(iv));
    EVP_CIPHER_CTX_free(ctx);
    OPENSSL_cleanse(buf, PEM_BUFSIZE);
    OPENSSL_clear_free(data, (unsigned int)dsize);
    return ret;
}

static void sha256_freectx(void *vctx)
{
    SHA256_CTX *ctx = (SHA256_CTX *)vctx;

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

EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
                                  void *u)
{
    char *nm = NULL;
    const unsigned char *p = NULL;
    unsigned char *data = NULL;
    long len;
    int slen;
    EVP_PKEY *ret = NULL;

    if (!PEM_bytes_read_bio(&data, &len, &nm, PEM_STRING_EVP_PKEY, bp, cb, u))
        return NULL;
    p = data;

    if (strcmp(nm, PEM_STRING_PKCS8INF) == 0) {
        PKCS8_PRIV_KEY_INFO *p8inf;
        p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, len);
        if (!p8inf)
            goto p8err;
        ret = EVP_PKCS82PKEY(p8inf);
        if (x) {
            EVP_PKEY_free((EVP_PKEY *)*x);
            *x = ret;
        }
        PKCS8_PRIV_KEY_INFO_free(p8inf);
    } else if (strcmp(nm, PEM_STRING_PKCS8) == 0) {
        PKCS8_PRIV_KEY_INFO *p8inf;
        X509_SIG *p8;
        int klen;
        char psbuf[PEM_BUFSIZE];
        p8 = d2i_X509_SIG(NULL, &p, len);
        if (!p8)
            goto p8err;
        if (cb)
            klen = cb(psbuf, PEM_BUFSIZE, 0, u);
        else
            klen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);
        if (klen <= 0) {
            PEMerr(PEM_F_PEM_READ_BIO_PRIVATEKEY, PEM_R_BAD_PASSWORD_READ);
            X509_SIG_free(p8);
            goto err;
        }
        p8inf = PKCS8_decrypt(p8, psbuf, klen);
        X509_SIG_free(p8);
        if (!p8inf)
            goto p8err;
        ret = EVP_PKCS82PKEY(p8inf);
        if (x) {
            EVP_PKEY_free((EVP_PKEY *)*x);
            *x = ret;
        }
        PKCS8_PRIV_KEY_INFO_free(p8inf);
    } else if ((slen = pem_check_suffix(nm, "PRIVATE KEY")) > 0) {
        const EVP_PKEY_ASN1_METHOD *ameth;
        ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
        if (!ameth || !ameth->old_priv_decode)
            goto p8err;
        ret = d2i_PrivateKey(ameth->pkey_id, x, &p, len);
    }
 p8err:
    if (ret == NULL)
        PEMerr(PEM_F_PEM_READ_BIO_PRIVATEKEY, ERR_R_ASN1_LIB);
 err:
    OPENSSL_free(nm);
    OPENSSL_clear_free(data, len);
    return (ret);
}

static int bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom)
{
    unsigned char *buf = NULL;
    int ret = 0, bit, bytes, mask;
    time_t tim;

    if (bits == 0) {
        BN_zero(rnd);
        return 1;
    }

    bytes = (bits + 7) / 8;
    bit = (bits - 1) % 8;
    mask = 0xff << (bit + 1);

    buf = OPENSSL_malloc(bytes);
    if (buf == NULL) {
        BNerr(BN_F_BNRAND, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    /* make a random number and set the top and bottom bits */
    time(&tim);
    RAND_add(&tim, sizeof(tim), 0.0);

    if (pseudorand) {
        if (RAND_bytes(buf, bytes) <= 0)
            goto err;
    } else {
        if (RAND_bytes(buf, bytes) <= 0)
            goto err;
    }

    if (pseudorand == 2) {
        /*
         * generate patterns that are more likely to trigger BN library bugs
         */
        int i;
        unsigned char c;

        for (i = 0; i < bytes; i++) {
            if (RAND_bytes(&c, 1) <= 0)
                goto err;
            if (c >= 128 && i > 0)
                buf[i] = buf[i - 1];
            else if (c < 42)
                buf[i] = 0;
            else if (c < 84)
                buf[i] = 255;
        }
    }

    if (top != -1) {
        if (top) {
            if (bit == 0) {
                buf[0] = 1;
                buf[1] |= 0x80;
            } else {
                buf[0] |= (3 << (bit - 1));
            }
        } else {
            buf[0] |= (1 << bit);
        }
    }
    buf[0] &= ~mask;
    if (bottom)                 /* set bottom bit if requested */
        buf[bytes - 1] |= 1;
    if (!BN_bin2bn(buf, bytes, rnd))
        goto err;
    ret = 1;
 err:
    OPENSSL_clear_free(buf, bytes);
    bn_check_top(rnd);
    return (ret);
}

static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
                                  unsigned char *to, RSA *rsa, int padding)
{
    BIGNUM *f, *ret;
    int i, j, k, num = 0, r = -1;
    unsigned char *buf = NULL;
    BN_CTX *ctx = NULL;

    if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
        return -1;
    }

    if (BN_ucmp(rsa->n, rsa->e) <= 0) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
        return -1;
    }

    /* for large moduli, enforce exponent limit */
    if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
        if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
            RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
            return -1;
        }
    }

    if ((ctx = BN_CTX_new()) == NULL)
        goto err;
    BN_CTX_start(ctx);
    f = BN_CTX_get(ctx);
    ret = BN_CTX_get(ctx);
    num = BN_num_bytes(rsa->n);
    buf = OPENSSL_malloc(num);
    if (ret == NULL || buf == NULL) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    switch (padding) {
    case RSA_PKCS1_PADDING:
        i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
        break;
    case RSA_PKCS1_OAEP_PADDING:
        i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
        break;
    case RSA_SSLV23_PADDING:
        i = RSA_padding_add_SSLv23(buf, num, from, flen);
        break;
    case RSA_NO_PADDING:
        i = RSA_padding_add_none(buf, num, from, flen);
        break;
    default:
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
        goto err;
    }
    if (i <= 0)
        goto err;

    if (BN_bin2bn(buf, num, f) == NULL)
        goto err;

    if (BN_ucmp(f, rsa->n) >= 0) {
        /* usually the padding functions would catch this */
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT,
               RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
        goto err;
    }

    if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
        if (!BN_MONT_CTX_set_locked
            (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
            goto err;

    if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
                               rsa->_method_mod_n))
        goto err;

    /*
     * put in leading 0 bytes if the number is less than the length of the
     * modulus
     */
    j = BN_num_bytes(ret);
    i = BN_bn2bin(ret, &(to[num - j]));
    for (k = 0; k < (num - i); k++)
        to[k] = 0;

    r = num;
 err:
    if (ctx != NULL)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    OPENSSL_clear_free(buf, num);
    return r;
}

/* signature verification */
static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
                                  unsigned char *to, RSA *rsa, int padding)
{
    BIGNUM *f, *ret;
    int i, num = 0, r = -1;
    unsigned char *p;
    unsigned char *buf = NULL;
    BN_CTX *ctx = NULL;

    if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
        return -1;
    }

    if (BN_ucmp(rsa->n, rsa->e) <= 0) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
        return -1;
    }

    /* for large moduli, enforce exponent limit */
    if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
        if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
            RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
            return -1;
        }
    }

    if ((ctx = BN_CTX_new()) == NULL)
        goto err;
    BN_CTX_start(ctx);
    f = BN_CTX_get(ctx);
    ret = BN_CTX_get(ctx);
    num = BN_num_bytes(rsa->n);
    buf = OPENSSL_malloc(num);
    if (ret == NULL || buf == NULL) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    /*
     * This check was for equality but PGP does evil things and chops off the
     * top '0' bytes
     */
    if (flen > num) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
        goto err;
    }

    if (BN_bin2bn(from, flen, f) == NULL)
        goto err;

    if (BN_ucmp(f, rsa->n) >= 0) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT,
               RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
        goto err;
    }

    if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
        if (!BN_MONT_CTX_set_locked
            (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
            goto err;

    if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
                               rsa->_method_mod_n))
        goto err;

    if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
        if (!BN_sub(ret, rsa->n, ret))
            goto err;

    p = buf;
    i = BN_bn2bin(ret, p);

    switch (padding) {
    case RSA_PKCS1_PADDING:
        r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
        break;
    case RSA_X931_PADDING:
        r = RSA_padding_check_X931(to, num, buf, i, num);
        break;
    case RSA_NO_PADDING:
        r = RSA_padding_check_none(to, num, buf, i, num);
        break;
    default:
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
        goto err;
    }
    if (r < 0)
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);

 err:
    if (ctx != NULL)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    OPENSSL_clear_free(buf, num);
    return r;
}