/*
 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the OpenSSL licenses, (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * https://www.openssl.org/source/license.html
 * or in the file LICENSE in the source distribution.
 */

#include <string.h>
#include <openssl/ssl.h>
#include <openssl/bio.h>
#include <openssl/err.h>

#include "../ssl/packet_locl.h"

/* Should we fragment records or not? 0 = no, !0 = yes*/
static int fragment = 0;

static int async_new(BIO *bi);
static int async_free(BIO *a);
static int async_read(BIO *b, char *out, int outl);
static int async_write(BIO *b, const char *in, int inl);
static long async_ctrl(BIO *b, int cmd, long num, void *ptr);
static int async_gets(BIO *bp, char *buf, int size);
static int async_puts(BIO *bp, const char *str);

/* Choose a sufficiently large type likely to be unused for this custom BIO */
# define BIO_TYPE_ASYNC_FILTER  (0x80 | BIO_TYPE_FILTER)

static BIO_METHOD *methods_async = NULL;

struct async_ctrs {
    unsigned int rctr;
    unsigned int wctr;
};

static const BIO_METHOD *bio_f_async_filter()
{
    if (methods_async == NULL) {
        methods_async = BIO_meth_new(BIO_TYPE_ASYNC_FILTER, "Async filter");
        if (   methods_async == NULL
            || !BIO_meth_set_write(methods_async, async_write)
            || !BIO_meth_set_read(methods_async, async_read)
            || !BIO_meth_set_puts(methods_async, async_puts)
            || !BIO_meth_set_gets(methods_async, async_gets)
            || !BIO_meth_set_ctrl(methods_async, async_ctrl)
            || !BIO_meth_set_create(methods_async, async_new)
            || !BIO_meth_set_destroy(methods_async, async_free))
            return NULL;
    }
    return methods_async;
}

static int async_new(BIO *bio)
{
    struct async_ctrs *ctrs;

    ctrs = OPENSSL_zalloc(sizeof(struct async_ctrs));
    if (ctrs == NULL)
        return 0;

    BIO_set_data(bio, ctrs);
    BIO_set_init(bio, 1);
    return 1;
}

static int async_free(BIO *bio)
{
    struct async_ctrs *ctrs;

    if (bio == NULL)
        return 0;
    ctrs = BIO_get_data(bio);
    OPENSSL_free(ctrs);
    BIO_set_data(bio, NULL);
    BIO_set_init(bio, 0);

    return 1;
}

static int async_read(BIO *bio, char *out, int outl)
{
    struct async_ctrs *ctrs;
    int ret = 0;
    BIO *next = BIO_next(bio);

    if (outl <= 0)
        return 0;
    if (next == NULL)
        return 0;

    ctrs = BIO_get_data(bio);

    BIO_clear_retry_flags(bio);

    if (ctrs->rctr > 0) {
        ret = BIO_read(next, out, 1);
        if (ret <= 0 && BIO_should_read(next))
            BIO_set_retry_read(bio);
        ctrs->rctr = 0;
    } else {
        ctrs->rctr++;
        BIO_set_retry_read(bio);
    }

    return ret;
}

#define MIN_RECORD_LEN  6

#define CONTENTTYPEPOS  0
#define VERSIONHIPOS    1
#define VERSIONLOPOS    2
#define DATAPOS         5

static int async_write(BIO *bio, const char *in, int inl)
{
    struct async_ctrs *ctrs;
    int ret = 0;
    size_t written = 0;
    BIO *next = BIO_next(bio);

    if (inl <= 0)
        return 0;
    if (next == NULL)
        return 0;

    ctrs = BIO_get_data(bio);

    BIO_clear_retry_flags(bio);

    if (ctrs->wctr > 0) {
        ctrs->wctr = 0;
        if (fragment) {
            PACKET pkt;

            if (!PACKET_buf_init(&pkt, (const unsigned char *)in, inl))
                abort();

            while (PACKET_remaining(&pkt) > 0) {
                PACKET payload;
                unsigned int contenttype, versionhi, versionlo, data;

                if (   !PACKET_get_1(&pkt, &contenttype)
                    || !PACKET_get_1(&pkt, &versionhi)
                    || !PACKET_get_1(&pkt, &versionlo)
                    || !PACKET_get_length_prefixed_2(&pkt, &payload))
                    abort();

                /* Pretend we wrote out the record header */
                written += SSL3_RT_HEADER_LENGTH;

                while (PACKET_get_1(&payload, &data)) {
                    /* Create a new one byte long record for each byte in the
                     * record in the input buffer
                     */
                    char smallrec[MIN_RECORD_LEN] = {
                        0, /* Content type */
                        0, /* Version hi */
                        0, /* Version lo */
                        0, /* Length hi */
                        1, /* Length lo */
                        0  /* Data */
                    };

                    smallrec[CONTENTTYPEPOS] = contenttype;
                    smallrec[VERSIONHIPOS] = versionhi;
                    smallrec[VERSIONLOPOS] = versionlo;
                    smallrec[DATAPOS] = data;
                    ret = BIO_write(next, smallrec, MIN_RECORD_LEN);
                    if (ret <= 0)
                        abort();
                    written++;
                }
                /*
                 * We can't fragment anything after the CCS, otherwise we
                 * get a bad record MAC
                 */
                if (contenttype == SSL3_RT_CHANGE_CIPHER_SPEC) {
                    fragment = 0;
                    break;
                }
            }
        }
        /* Write any data we have left after fragmenting */
        ret = 0;
        if ((int)written < inl) {
            ret = BIO_write(next, in + written , inl - written);
        }

        if (ret <= 0 && BIO_should_write(next))
            BIO_set_retry_write(bio);
        else
            ret += written;
    } else {
        ctrs->wctr++;
        BIO_set_retry_write(bio);
    }

    return ret;
}

static long async_ctrl(BIO *bio, int cmd, long num, void *ptr)
{
    long ret;
    BIO *next = BIO_next(bio);

    if (next == NULL)
        return 0;

    switch (cmd) {
    case BIO_CTRL_DUP:
        ret = 0L;
        break;
    default:
        ret = BIO_ctrl(next, cmd, num, ptr);
        break;
    }
    return ret;
}

static int async_gets(BIO *bio, char *buf, int size)
{
    /* We don't support this - not needed anyway */
    return -1;
}

static int async_puts(BIO *bio, const char *str)
{
    return async_write(bio, str, strlen(str));
}

#define MAXLOOPS    100000

int main(int argc, char *argv[])
{
    SSL_CTX *serverctx = NULL, *clientctx = NULL;
    SSL *serverssl = NULL, *clientssl = NULL;
    BIO *s_to_c_bio = NULL, *c_to_s_bio = NULL;
    BIO *s_to_c_fbio = NULL, *c_to_s_fbio = NULL;
    int retc = -1, rets = -1, err, abortctr;
    int test;

    CRYPTO_set_mem_debug(1);
    CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);

    if (argc != 3) {
        printf("Invalid argument count\n");
        goto end;
    }

    serverctx = SSL_CTX_new(TLS_server_method());
    clientctx = SSL_CTX_new(TLS_client_method());
    if (serverctx == NULL || clientctx == NULL) {
        printf("Failed to create SSL_CTX\n");
        goto end;
    }

    if (SSL_CTX_use_certificate_file(serverctx, argv[1],
                                     SSL_FILETYPE_PEM) <= 0) {
        printf("Failed to load server certificate\n");
        goto end;
    }
    if (SSL_CTX_use_PrivateKey_file(serverctx, argv[2],
                                    SSL_FILETYPE_PEM) <= 0) {
        printf("Failed to load server private key\n");
    }
    if (SSL_CTX_check_private_key(serverctx) <= 0) {
        printf("Failed to check private key\n");
        goto end;
    }

    /*
     * We do 2 test runs. The first time around we just do a normal handshake
     * with lots of async io going on. The second time around we also break up
     * all records so that the content is only one byte length (up until the
     * CCS)
     */
    for (test = 1; test < 3; test++) {
        abortctr = 0;
        retc = rets = -1;
        if (test == 2)
            fragment = 1;

        serverssl = SSL_new(serverctx);
        clientssl = SSL_new(clientctx);
        if (serverssl == NULL || clientssl == NULL) {
            printf("Failed to create SSL object\n");
            goto end;
        }

        s_to_c_bio = BIO_new(BIO_s_mem());
        c_to_s_bio = BIO_new(BIO_s_mem());
        if (s_to_c_bio == NULL || c_to_s_bio == NULL) {
            printf("Failed to create mem BIOs\n");
            goto end;
        }

        s_to_c_fbio = BIO_new(bio_f_async_filter());
        c_to_s_fbio = BIO_new(bio_f_async_filter());
        if (s_to_c_fbio == NULL || c_to_s_fbio == NULL) {
            printf("Failed to create filter BIOs\n");
            goto end;
        }

        s_to_c_bio = BIO_push(s_to_c_fbio, s_to_c_bio);
        c_to_s_bio = BIO_push(c_to_s_fbio, c_to_s_bio);
        if (s_to_c_bio == NULL || c_to_s_bio == NULL) {
            printf("Failed to create chained BIOs\n");
            goto end;
        }

        /* Set Non-blocking IO behaviour */
        BIO_set_mem_eof_return(s_to_c_bio, -1);
        BIO_set_mem_eof_return(c_to_s_bio, -1);

        /* Up ref these as we are passing them to two SSL objects */
        BIO_up_ref(s_to_c_bio);
        BIO_up_ref(c_to_s_bio);

        SSL_set_bio(serverssl, c_to_s_bio, s_to_c_bio);
        SSL_set_bio(clientssl, s_to_c_bio, c_to_s_bio);

        do {
            err = SSL_ERROR_WANT_WRITE;
            while (retc <= 0 && err == SSL_ERROR_WANT_WRITE) {
                retc = SSL_connect(clientssl);
                if (retc <= 0)
                    err = SSL_get_error(clientssl, retc);
            }

            if (retc <= 0 && err != SSL_ERROR_WANT_READ) {
                printf("Test %d failed: SSL_connect() failed %d, %d\n",
                       test, retc, err);
                goto end;
            }

            err = SSL_ERROR_WANT_WRITE;
            while (rets <= 0 && err == SSL_ERROR_WANT_WRITE) {
                rets = SSL_accept(serverssl);
                if (rets <= 0)
                    err = SSL_get_error(serverssl, rets);
            }

            if (rets <= 0 && err != SSL_ERROR_WANT_READ) {
                printf("Test %d failed: SSL_accept() failed %d, %d\n",
                       test, retc, err);
                goto end;
            }
            if (++abortctr == MAXLOOPS) {
                printf("Test %d failed: No progress made\n", test);
                goto end;
            }
        } while (retc <=0 || rets <= 0);

        /* Also frees the BIOs */
        SSL_free(clientssl);
        SSL_free(serverssl);
        clientssl = serverssl = NULL;
    }

    printf("Test success\n");

 end:
    if (retc <= 0 || rets <= 0)
        ERR_print_errors_fp(stderr);

    SSL_free(clientssl);
    SSL_free(serverssl);
    SSL_CTX_free(clientctx);
    SSL_CTX_free(serverctx);

# ifndef OPENSSL_NO_CRYPTO_MDEBUG
    CRYPTO_mem_leaks_fp(stderr);
# endif

    return (retc > 0 && rets > 0) ? 0 : 1;
}