/*

 * Copyright 1995-2018 The OpenSSL Project Authors. 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

 */

#include <stdio.h>

#include <errno.h>

#include "bio_local.h"

#include "internal/cryptlib.h"

#include <openssl/evp.h>

static int linebuffer_write(BIO *h, const char *buf, int num);

static int linebuffer_read(BIO *h, char *buf, int size);

static int linebuffer_puts(BIO *h, const char *str);

static int linebuffer_gets(BIO *h, char *str, int size);

static long linebuffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);

static int linebuffer_new(BIO *h);

static int linebuffer_free(BIO *data);

static long linebuffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);

/* A 10k maximum should be enough for most purposes */

#define DEFAULT_LINEBUFFER_SIZE 1024*10

/* #define DEBUG */

static const BIO_METHOD methods_linebuffer = {

    BIO_TYPE_LINEBUFFER,

    "linebuffer",

    /* TODO: Convert to new style write function */

    bwrite_conv,

    linebuffer_write,

    /* TODO: Convert to new style read function */

    bread_conv,

    linebuffer_read,

    linebuffer_puts,

    linebuffer_gets,

    linebuffer_ctrl,

    linebuffer_new,

    linebuffer_free,

    linebuffer_callback_ctrl,

};

const BIO_METHOD *BIO_f_linebuffer(void)

{

    return &methods_linebuffer;

}

typedef struct bio_linebuffer_ctx_struct {

    char *obuf;                 /* the output char array */

    int obuf_size;              /* how big is the output buffer */

    int obuf_len;               /* how many bytes are in it */

} BIO_LINEBUFFER_CTX;

static int linebuffer_new(BIO *bi)

{

    BIO_LINEBUFFER_CTX *ctx;

    if ((ctx = OPENSSL_malloc(sizeof(*ctx))) == NULL) {

        BIOerr(BIO_F_LINEBUFFER_NEW, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    ctx->obuf = OPENSSL_malloc(DEFAULT_LINEBUFFER_SIZE);

    if (ctx->obuf == NULL) {

        BIOerr(BIO_F_LINEBUFFER_NEW, ERR_R_MALLOC_FAILURE);

        OPENSSL_free(ctx);

        return 0;

    }

    ctx->obuf_size = DEFAULT_LINEBUFFER_SIZE;

    ctx->obuf_len = 0;

    bi->init = 1;

    bi->ptr = (char *)ctx;

    bi->flags = 0;

    return 1;

}

static int linebuffer_free(BIO *a)

{

    BIO_LINEBUFFER_CTX *b;

    if (a == NULL)

        return 0;

    b = (BIO_LINEBUFFER_CTX *)a->ptr;

    OPENSSL_free(b->obuf);

    OPENSSL_free(a->ptr);

    a->ptr = NULL;

    a->init = 0;

    a->flags = 0;

    return 1;

}

static int linebuffer_read(BIO *b, char *out, int outl)

{

    int ret = 0;

    if (out == NULL)

        return 0;

    if (b->next_bio == NULL)

        return 0;

    ret = BIO_read(b->next_bio, out, outl);

    BIO_clear_retry_flags(b);

    BIO_copy_next_retry(b);

    return ret;

}

static int linebuffer_write(BIO *b, const char *in, int inl)

{

    int i, num = 0, foundnl;

    BIO_LINEBUFFER_CTX *ctx;

    if ((in == NULL) || (inl <= 0))

        return 0;

    ctx = (BIO_LINEBUFFER_CTX *)b->ptr;

    if ((ctx == NULL) || (b->next_bio == NULL))

        return 0;

    BIO_clear_retry_flags(b);

    do {

        const char *p;

        char c;

        for (p = in, c = '\0'; p < in + inl && (c = *p) != '\n'; p++) ;

        if (c == '\n') {

            p++;

            foundnl = 1;

        } else

            foundnl = 0;

        /*

         * If a NL was found and we already have text in the save buffer,

         * concatenate them and write

         */

        while ((foundnl || p - in > ctx->obuf_size - ctx->obuf_len)

               && ctx->obuf_len > 0) {

            int orig_olen = ctx->obuf_len;

            i = ctx->obuf_size - ctx->obuf_len;

            if (p - in > 0) {

                if (i >= p - in) {

                    memcpy(&(ctx->obuf[ctx->obuf_len]), in, p - in);

                    ctx->obuf_len += p - in;

                    inl -= p - in;

                    num += p - in;

                    in = p;

                } else {

                    memcpy(&(ctx->obuf[ctx->obuf_len]), in, i);

                    ctx->obuf_len += i;

                    inl -= i;

                    in += i;

                    num += i;

                }

            }

            i = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);

            if (i <= 0) {

                ctx->obuf_len = orig_olen;

                BIO_copy_next_retry(b);

                if (i < 0)

                    return ((num > 0) ? num : i);

                if (i == 0)

                    return num;

            }

            if (i < ctx->obuf_len)

                memmove(ctx->obuf, ctx->obuf + i, ctx->obuf_len - i);

            ctx->obuf_len -= i;

        }

        /*

         * Now that the save buffer is emptied, let's write the input buffer

         * if a NL was found and there is anything to write.

         */

        if ((foundnl || p - in > ctx->obuf_size) && p - in > 0) {

            i = BIO_write(b->next_bio, in, p - in);

            if (i <= 0) {

                BIO_copy_next_retry(b);

                if (i < 0)

                    return ((num > 0) ? num : i);

                if (i == 0)

                    return num;

            }

            num += i;

            in += i;

            inl -= i;

        }

    }

    while (foundnl && inl > 0);

    /*

     * We've written as much as we can.  The rest of the input buffer, if

     * any, is text that doesn't and with a NL and therefore needs to be

     * saved for the next trip.

     */

    if (inl > 0) {

        memcpy(&(ctx->obuf[ctx->obuf_len]), in, inl);

        ctx->obuf_len += inl;

        num += inl;

    }

    return num;

}

static long linebuffer_ctrl(BIO *b, int cmd, long num, void *ptr)

{

    BIO *dbio;

    BIO_LINEBUFFER_CTX *ctx;

    long ret = 1;

    char *p;

    int r;

    int obs;

    ctx = (BIO_LINEBUFFER_CTX *)b->ptr;

    switch (cmd) {

    case BIO_CTRL_RESET:

        ctx->obuf_len = 0;

        if (b->next_bio == NULL)

            return 0;

        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

        break;

    case BIO_CTRL_INFO:

        ret = (long)ctx->obuf_len;

        break;

    case BIO_CTRL_WPENDING:

        ret = (long)ctx->obuf_len;

        if (ret == 0) {

            if (b->next_bio == NULL)

                return 0;

            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

        }

        break;

    case BIO_C_SET_BUFF_SIZE:

        obs = (int)num;

        p = ctx->obuf;

        if ((obs > DEFAULT_LINEBUFFER_SIZE) && (obs != ctx->obuf_size)) {

            p = OPENSSL_malloc((int)num);

            if (p == NULL)

                goto malloc_error;

        }

        if (ctx->obuf != p) {

            if (ctx->obuf_len > obs) {

                ctx->obuf_len = obs;

            }

            memcpy(p, ctx->obuf, ctx->obuf_len);

            OPENSSL_free(ctx->obuf);

            ctx->obuf = p;

            ctx->obuf_size = obs;

        }

        break;

    case BIO_C_DO_STATE_MACHINE:

        if (b->next_bio == NULL)

            return 0;

        BIO_clear_retry_flags(b);

        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

        BIO_copy_next_retry(b);

        break;

    case BIO_CTRL_FLUSH:

        if (b->next_bio == NULL)

            return 0;

        if (ctx->obuf_len <= 0) {

            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

            break;

        }

        for (;;) {

            BIO_clear_retry_flags(b);

            if (ctx->obuf_len > 0) {

                r = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);

                BIO_copy_next_retry(b);

                if (r <= 0)

                    return (long)r;

                if (r < ctx->obuf_len)

                    memmove(ctx->obuf, ctx->obuf + r, ctx->obuf_len - r);

                ctx->obuf_len -= r;

            } else {

                ctx->obuf_len = 0;

                break;

            }

        }

        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

        break;

    case BIO_CTRL_DUP:

        dbio = (BIO *)ptr;

        if (!BIO_set_write_buffer_size(dbio, ctx->obuf_size))

            ret = 0;

        break;

    default:

        if (b->next_bio == NULL)

            return 0;

        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

        break;

    }

    return ret;

 malloc_error:

    BIOerr(BIO_F_LINEBUFFER_CTRL, ERR_R_MALLOC_FAILURE);

    return 0;

}

static long linebuffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)

{

    long ret = 1;

    if (b->next_bio == NULL)

        return 0;

    switch (cmd) {

    default:

        ret = BIO_callback_ctrl(b->next_bio, cmd, fp);

        break;

    }

    return ret;

}

static int linebuffer_gets(BIO *b, char *buf, int size)

{

    if (b->next_bio == NULL)

        return 0;

    return BIO_gets(b->next_bio, buf, size);

}

static int linebuffer_puts(BIO *b, const char *str)

{

    return linebuffer_write(b, str, strlen(str));

}