inet6: only mark autoconf addresses tentative if detached

[dragonfly.git] / crypto / libressl / ssl / ssl_both.c

/* $OpenBSD: ssl_both.c,v 1.42 2022/02/05 14:54:10 jsing Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECC cipher suite support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

#include <limits.h>
#include <stdio.h>
#include <string.h>

#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/objects.h>
#include <openssl/x509.h>

#include "bytestring.h"
#include "dtls_locl.h"
#include "ssl_locl.h"

/*
 * Send s->internal->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
 * SSL3_RT_CHANGE_CIPHER_SPEC).
 */
int
ssl3_do_write(SSL *s, int type)
{
        int ret;

        ret = ssl3_write_bytes(s, type, &s->internal->init_buf->data[s->internal->init_off],
            s->internal->init_num);
        if (ret < 0)
                return (-1);

        if (type == SSL3_RT_HANDSHAKE)
                /*
                 * Should not be done for 'Hello Request's, but in that case
                 * we'll ignore the result anyway.
                 */
                tls1_transcript_record(s,
                    (unsigned char *)&s->internal->init_buf->data[s->internal->init_off], ret);

        if (ret == s->internal->init_num) {
                ssl_msg_callback(s, 1, type, s->internal->init_buf->data,
                    (size_t)(s->internal->init_off + s->internal->init_num));
                return (1);
        }

        s->internal->init_off += ret;
        s->internal->init_num -= ret;

        return (0);
}

int
ssl3_send_finished(SSL *s, int state_a, int state_b)
{
        CBB cbb, finished;

        memset(&cbb, 0, sizeof(cbb));

        if (s->s3->hs.state == state_a) {
                if (!tls12_derive_finished(s))
                        goto err;

                /* Copy finished so we can use it for renegotiation checks. */
                if (!s->server) {
                        memcpy(s->s3->previous_client_finished,
                            s->s3->hs.finished, s->s3->hs.finished_len);
                        s->s3->previous_client_finished_len =
                            s->s3->hs.finished_len;
                } else {
                        memcpy(s->s3->previous_server_finished,
                            s->s3->hs.finished, s->s3->hs.finished_len);
                        s->s3->previous_server_finished_len =
                            s->s3->hs.finished_len;
                }

                if (!ssl3_handshake_msg_start(s, &cbb, &finished,
                    SSL3_MT_FINISHED))
                        goto err;
                if (!CBB_add_bytes(&finished, s->s3->hs.finished,
                    s->s3->hs.finished_len))
                        goto err;
                if (!ssl3_handshake_msg_finish(s, &cbb))
                        goto err;

                s->s3->hs.state = state_b;
        }

        return (ssl3_handshake_write(s));

 err:
        CBB_cleanup(&cbb);

        return (-1);
}

int
ssl3_get_finished(SSL *s, int a, int b)
{
        int al, md_len, ret;
        CBS cbs;

        /* should actually be 36+4 :-) */
        if ((ret = ssl3_get_message(s, a, b, SSL3_MT_FINISHED, 64)) <= 0)
                return ret;

        /* If this occurs, we have missed a message */
        if (!s->s3->change_cipher_spec) {
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerror(s, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
                goto fatal_err;
        }
        s->s3->change_cipher_spec = 0;

        md_len = TLS1_FINISH_MAC_LENGTH;

        if (s->internal->init_num < 0) {
                al = SSL_AD_DECODE_ERROR;
                SSLerror(s, SSL_R_BAD_DIGEST_LENGTH);
                goto fatal_err;
        }

        CBS_init(&cbs, s->internal->init_msg, s->internal->init_num);

        if (s->s3->hs.peer_finished_len != md_len ||
            CBS_len(&cbs) != md_len) {
                al = SSL_AD_DECODE_ERROR;
                SSLerror(s, SSL_R_BAD_DIGEST_LENGTH);
                goto fatal_err;
        }

        if (!CBS_mem_equal(&cbs, s->s3->hs.peer_finished, CBS_len(&cbs))) {
                al = SSL_AD_DECRYPT_ERROR;
                SSLerror(s, SSL_R_DIGEST_CHECK_FAILED);
                goto fatal_err;
        }

        /* Copy finished so we can use it for renegotiation checks. */
        OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE);
        if (s->server) {
                memcpy(s->s3->previous_client_finished,
                    s->s3->hs.peer_finished, md_len);
                s->s3->previous_client_finished_len = md_len;
        } else {
                memcpy(s->s3->previous_server_finished,
                    s->s3->hs.peer_finished, md_len);
                s->s3->previous_server_finished_len = md_len;
        }

        return (1);
 fatal_err:
        ssl3_send_alert(s, SSL3_AL_FATAL, al);
        return (0);
}

int
ssl3_send_change_cipher_spec(SSL *s, int a, int b)
{
        size_t outlen;
        CBB cbb;

        memset(&cbb, 0, sizeof(cbb));

        if (s->s3->hs.state == a) {
                if (!CBB_init_fixed(&cbb, s->internal->init_buf->data,
                    s->internal->init_buf->length))
                        goto err;
                if (!CBB_add_u8(&cbb, SSL3_MT_CCS))
                        goto err;
                if (!CBB_finish(&cbb, NULL, &outlen))
                        goto err;

                if (outlen > INT_MAX)
                        goto err;

                s->internal->init_num = (int)outlen;
                s->internal->init_off = 0;

                if (SSL_is_dtls(s)) {
                        s->d1->handshake_write_seq =
                            s->d1->next_handshake_write_seq;
                        dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
                            s->d1->handshake_write_seq, 0, 0);
                        dtls1_buffer_message(s, 1);
                }

                s->s3->hs.state = b;
        }

        /* SSL3_ST_CW_CHANGE_B */
        return ssl3_record_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);

 err:
        CBB_cleanup(&cbb);

        return -1;
}

static int
ssl3_add_cert(CBB *cbb, X509 *x)
{
        unsigned char *data;
        int cert_len;
        int ret = 0;
        CBB cert;

        if ((cert_len = i2d_X509(x, NULL)) < 0)
                goto err;

        if (!CBB_add_u24_length_prefixed(cbb, &cert))
                goto err;
        if (!CBB_add_space(&cert, &data, cert_len))
                goto err;
        if (i2d_X509(x, &data) < 0)
                goto err;
        if (!CBB_flush(cbb))
                goto err;

        ret = 1;

 err:
        return (ret);
}

int
ssl3_output_cert_chain(SSL *s, CBB *cbb, SSL_CERT_PKEY *cpk)
{
        X509_STORE_CTX *xs_ctx = NULL;
        STACK_OF(X509) *chain;
        CBB cert_list;
        X509 *x;
        int ret = 0;
        int i;

        if (!CBB_add_u24_length_prefixed(cbb, &cert_list))
                goto err;

        /* Send an empty certificate list when no certificate is available. */
        if (cpk == NULL)
                goto done;

        if ((chain = cpk->chain) == NULL)
                chain = s->ctx->extra_certs;

        if (chain != NULL || (s->internal->mode & SSL_MODE_NO_AUTO_CHAIN)) {
                if (!ssl3_add_cert(&cert_list, cpk->x509))
                        goto err;
        } else {
                if ((xs_ctx = X509_STORE_CTX_new()) == NULL)
                        goto err;
                if (!X509_STORE_CTX_init(xs_ctx, s->ctx->cert_store,
                    cpk->x509, NULL)) {
                        SSLerror(s, ERR_R_X509_LIB);
                        goto err;
                }
                X509_VERIFY_PARAM_set_flags(X509_STORE_CTX_get0_param(xs_ctx),
                    X509_V_FLAG_LEGACY_VERIFY);
                X509_verify_cert(xs_ctx);
                ERR_clear_error();
                chain = X509_STORE_CTX_get0_chain(xs_ctx);
        }

        for (i = 0; i < sk_X509_num(chain); i++) {
                x = sk_X509_value(chain, i);
                if (!ssl3_add_cert(&cert_list, x))
                        goto err;
        }

 done:
        if (!CBB_flush(cbb))
                goto err;

        ret = 1;

 err:
        X509_STORE_CTX_free(xs_ctx);

        return (ret);
}

/*
 * Obtain handshake message of message type 'mt' (any if mt == -1),
 * maximum acceptable body length 'max'.
 * The first four bytes (msg_type and length) are read in state 'st1',
 * the body is read in state 'stn'.
 */
int
ssl3_get_message(SSL *s, int st1, int stn, int mt, long max)
{
        unsigned char *p;
        uint32_t l;
        long n;
        int i, al;
        CBS cbs;
        uint8_t u8;

        if (SSL_is_dtls(s))
                return dtls1_get_message(s, st1, stn, mt, max);

        if (s->s3->hs.tls12.reuse_message) {
                s->s3->hs.tls12.reuse_message = 0;
                if ((mt >= 0) && (s->s3->hs.tls12.message_type != mt)) {
                        al = SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
                        goto fatal_err;
                }
                s->internal->init_msg = s->internal->init_buf->data +
                    SSL3_HM_HEADER_LENGTH;
                s->internal->init_num = (int)s->s3->hs.tls12.message_size;
                return 1;
        }

        p = (unsigned char *)s->internal->init_buf->data;

        if (s->s3->hs.state == st1) {
                int skip_message;

                do {
                        while (s->internal->init_num < SSL3_HM_HEADER_LENGTH) {
                                i = s->method->ssl_read_bytes(s,
                                    SSL3_RT_HANDSHAKE, &p[s->internal->init_num],
                                    SSL3_HM_HEADER_LENGTH - s->internal->init_num, 0);
                                if (i <= 0) {
                                        s->internal->rwstate = SSL_READING;
                                        return i;
                                }
                                s->internal->init_num += i;
                        }

                        skip_message = 0;
                        if (!s->server && p[0] == SSL3_MT_HELLO_REQUEST) {
                                /*
                                 * The server may always send 'Hello Request'
                                 * messages -- we are doing a handshake anyway
                                 * now, so ignore them if their format is
                                 * correct.  Does not count for 'Finished' MAC.
                                 */
                                if (p[1] == 0 && p[2] == 0 &&p[3] == 0) {
                                        s->internal->init_num = 0;
                                        skip_message = 1;

                                        ssl_msg_callback(s, 0,
                                            SSL3_RT_HANDSHAKE, p,
                                            SSL3_HM_HEADER_LENGTH);
                                }
                        }
                } while (skip_message);

                if ((mt >= 0) && (*p != mt)) {
                        al = SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
                        goto fatal_err;
                }

                CBS_init(&cbs, p, SSL3_HM_HEADER_LENGTH);
                if (!CBS_get_u8(&cbs, &u8) ||
                    !CBS_get_u24(&cbs, &l)) {
                        SSLerror(s, ERR_R_BUF_LIB);
                        goto err;
                }
                s->s3->hs.tls12.message_type = u8;

                if (l > (unsigned long)max) {
                        al = SSL_AD_ILLEGAL_PARAMETER;
                        SSLerror(s, SSL_R_EXCESSIVE_MESSAGE_SIZE);
                        goto fatal_err;
                }
                if (l && !BUF_MEM_grow_clean(s->internal->init_buf,
                    l + SSL3_HM_HEADER_LENGTH)) {
                        SSLerror(s, ERR_R_BUF_LIB);
                        goto err;
                }
                s->s3->hs.tls12.message_size = l;
                s->s3->hs.state = stn;

                s->internal->init_msg = s->internal->init_buf->data +
                    SSL3_HM_HEADER_LENGTH;
                s->internal->init_num = 0;
        }

        /* next state (stn) */
        p = s->internal->init_msg;
        n = s->s3->hs.tls12.message_size - s->internal->init_num;
        while (n > 0) {
                i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
                    &p[s->internal->init_num], n, 0);
                if (i <= 0) {
                        s->internal->rwstate = SSL_READING;
                        return i;
                }
                s->internal->init_num += i;
                n -= i;
        }

        /* Feed this message into MAC computation. */
        if (s->internal->mac_packet) {
                tls1_transcript_record(s, (unsigned char *)s->internal->init_buf->data,
                    s->internal->init_num + SSL3_HM_HEADER_LENGTH);

                ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE,
                    s->internal->init_buf->data,
                    (size_t)s->internal->init_num + SSL3_HM_HEADER_LENGTH);
        }

        return 1;

 fatal_err:
        ssl3_send_alert(s, SSL3_AL_FATAL, al);
 err:
        return -1;
}

int
ssl_cert_type(EVP_PKEY *pkey)
{
        if (pkey == NULL)
                return -1;

        switch (EVP_PKEY_id(pkey)) {
        case EVP_PKEY_EC:
                return SSL_PKEY_ECC;
        case NID_id_GostR3410_2001:
        case NID_id_GostR3410_2001_cc:
                return SSL_PKEY_GOST01;
        case EVP_PKEY_RSA:
                return SSL_PKEY_RSA;
        }

        return -1;
}

int
ssl_verify_alarm_type(long type)
{
        int al;

        switch (type) {
        case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
        case X509_V_ERR_UNABLE_TO_GET_CRL:
        case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
                al = SSL_AD_UNKNOWN_CA;
                break;
        case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
        case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
        case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
        case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
        case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
        case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
        case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
        case X509_V_ERR_CERT_NOT_YET_VALID:
        case X509_V_ERR_CRL_NOT_YET_VALID:
        case X509_V_ERR_CERT_UNTRUSTED:
        case X509_V_ERR_CERT_REJECTED:
                al = SSL_AD_BAD_CERTIFICATE;
                break;
        case X509_V_ERR_CERT_SIGNATURE_FAILURE:
        case X509_V_ERR_CRL_SIGNATURE_FAILURE:
                al = SSL_AD_DECRYPT_ERROR;
                break;
        case X509_V_ERR_CERT_HAS_EXPIRED:
        case X509_V_ERR_CRL_HAS_EXPIRED:
                al = SSL_AD_CERTIFICATE_EXPIRED;
                break;
        case X509_V_ERR_CERT_REVOKED:
                al = SSL_AD_CERTIFICATE_REVOKED;
                break;
        case X509_V_ERR_OUT_OF_MEM:
                al = SSL_AD_INTERNAL_ERROR;
                break;
        case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
        case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
        case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
        case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
        case X509_V_ERR_CERT_CHAIN_TOO_LONG:
        case X509_V_ERR_PATH_LENGTH_EXCEEDED:
        case X509_V_ERR_INVALID_CA:
                al = SSL_AD_UNKNOWN_CA;
                break;
        case X509_V_ERR_APPLICATION_VERIFICATION:
                al = SSL_AD_HANDSHAKE_FAILURE;
                break;
        case X509_V_ERR_INVALID_PURPOSE:
                al = SSL_AD_UNSUPPORTED_CERTIFICATE;
                break;
        default:
                al = SSL_AD_CERTIFICATE_UNKNOWN;
                break;
        }
        return (al);
}

int
ssl3_setup_init_buffer(SSL *s)
{
        BUF_MEM *buf = NULL;

        if (s->internal->init_buf != NULL)
                return (1);

        if ((buf = BUF_MEM_new()) == NULL)
                goto err;
        if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH))
                goto err;

        s->internal->init_buf = buf;
        return (1);

 err:
        BUF_MEM_free(buf);
        return (0);
}

void
ssl3_release_init_buffer(SSL *s)
{
        BUF_MEM_free(s->internal->init_buf);
        s->internal->init_buf = NULL;
        s->internal->init_msg = NULL;
        s->internal->init_num = 0;
        s->internal->init_off = 0;
}

int
ssl3_setup_read_buffer(SSL *s)
{
        unsigned char *p;
        size_t len, align, headerlen;

        if (SSL_is_dtls(s))
                headerlen = DTLS1_RT_HEADER_LENGTH;
        else
                headerlen = SSL3_RT_HEADER_LENGTH;

        align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);

        if (s->s3->rbuf.buf == NULL) {
                len = SSL3_RT_MAX_PLAIN_LENGTH +
                    SSL3_RT_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
                if ((p = calloc(1, len)) == NULL)
                        goto err;
                s->s3->rbuf.buf = p;
                s->s3->rbuf.len = len;
        }

        s->internal->packet = s->s3->rbuf.buf;
        return 1;

 err:
        SSLerror(s, ERR_R_MALLOC_FAILURE);
        return 0;
}

int
ssl3_setup_write_buffer(SSL *s)
{
        unsigned char *p;
        size_t len, align, headerlen;

        if (SSL_is_dtls(s))
                headerlen = DTLS1_RT_HEADER_LENGTH + 1;
        else
                headerlen = SSL3_RT_HEADER_LENGTH;

        align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);

        if (s->s3->wbuf.buf == NULL) {
                len = s->max_send_fragment +
                    SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
                if (!(s->internal->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
                        len += headerlen + align +
                            SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;

                if ((p = calloc(1, len)) == NULL)
                        goto err;
                s->s3->wbuf.buf = p;
                s->s3->wbuf.len = len;
        }

        return 1;

 err:
        SSLerror(s, ERR_R_MALLOC_FAILURE);
        return 0;
}

int
ssl3_setup_buffers(SSL *s)
{
        if (!ssl3_setup_read_buffer(s))
                return 0;
        if (!ssl3_setup_write_buffer(s))
                return 0;
        return 1;
}

void
ssl3_release_buffer(SSL3_BUFFER_INTERNAL *b)
{
        freezero(b->buf, b->len);
        b->buf = NULL;
        b->len = 0;
}

void
ssl3_release_read_buffer(SSL *s)
{
        ssl3_release_buffer(&s->s3->rbuf);
}

void
ssl3_release_write_buffer(SSL *s)
{
        ssl3_release_buffer(&s->s3->wbuf);
}