/* crypto/evp/bio_b64.c */

/* 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.]

 */

#include <stdio.h>

#include <errno.h>

#include "cryptlib.h"

#include <openssl/buffer.h>

#include <openssl/evp.h>

static int b64_write(BIO *h, const char *buf, int num);

static int b64_read(BIO *h, char *buf, int size);

static int b64_puts(BIO *h, const char *str);

/*

 * static int b64_gets(BIO *h, char *str, int size);

 */

static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);

static int b64_new(BIO *h);

static int b64_free(BIO *data);

static long b64_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);

#define B64_BLOCK_SIZE  1024

#define B64_BLOCK_SIZE2 768

#define B64_NONE        0

#define B64_ENCODE      1

#define B64_DECODE      2

typedef struct b64_struct {

    /*

     * BIO *bio; moved to the BIO structure

     */

    int buf_len;

    int buf_off;

    int tmp_len;                /* used to find the start when decoding */

    int tmp_nl;                 /* If true, scan until '\n' */

    int encode;

    int start;                  /* have we started decoding yet? */

    int cont;                   /* <= 0 when finished */

    EVP_ENCODE_CTX base64;

    char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];

    char tmp[B64_BLOCK_SIZE];

} BIO_B64_CTX;

static BIO_METHOD methods_b64 = {

    BIO_TYPE_BASE64, "base64 encoding",

    b64_write,

    b64_read,

    b64_puts,

    NULL,                       /* b64_gets, */

    b64_ctrl,

    b64_new,

    b64_free,

    b64_callback_ctrl,

};

BIO_METHOD *BIO_f_base64(void)

{

    return (&methods_b64);

}

static int b64_new(BIO *bi)

{

    BIO_B64_CTX *ctx;

    ctx = (BIO_B64_CTX *)OPENSSL_malloc(sizeof(BIO_B64_CTX));

    if (ctx == NULL)

        return (0);

    ctx->buf_len = 0;

    ctx->tmp_len = 0;

    ctx->tmp_nl = 0;

    ctx->buf_off = 0;

    ctx->cont = 1;

    ctx->start = 1;

    ctx->encode = 0;

    bi->init = 1;

    bi->ptr = (char *)ctx;

    bi->flags = 0;

    bi->num = 0;

    return (1);

}

static int b64_free(BIO *a)

{

    if (a == NULL)

        return (0);

    OPENSSL_free(a->ptr);

    a->ptr = NULL;

    a->init = 0;

    a->flags = 0;

    return (1);

}

static int b64_read(BIO *b, char *out, int outl)

{

    int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;

    BIO_B64_CTX *ctx;

    unsigned char *p, *q;

    if (out == NULL)

        return (0);

    ctx = (BIO_B64_CTX *)b->ptr;

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

        return (0);

    BIO_clear_retry_flags(b);

    if (ctx->encode != B64_DECODE) {

        ctx->encode = B64_DECODE;

        ctx->buf_len = 0;

        ctx->buf_off = 0;

        ctx->tmp_len = 0;

        EVP_DecodeInit(&(ctx->base64));

    }

    /* First check if there are bytes decoded/encoded */

    if (ctx->buf_len > 0) {

        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

        i = ctx->buf_len - ctx->buf_off;

        if (i > outl)

            i = outl;

        OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));

        memcpy(out, &(ctx->buf[ctx->buf_off]), i);

        ret = i;

        out += i;

        outl -= i;

        ctx->buf_off += i;

        if (ctx->buf_len == ctx->buf_off) {

            ctx->buf_len = 0;

            ctx->buf_off = 0;

        }

    }

    /*

     * At this point, we have room of outl bytes and an empty buffer, so we

     * should read in some more.

     */

    ret_code = 0;

    while (outl > 0) {

        if (ctx->cont <= 0)

            break;

        i = BIO_read(b->next_bio, &(ctx->tmp[ctx->tmp_len]),

                     B64_BLOCK_SIZE - ctx->tmp_len);

        if (i <= 0) {

            ret_code = i;

            /* Should we continue next time we are called? */

            if (!BIO_should_retry(b->next_bio)) {

                ctx->cont = i;

                /* If buffer empty break */

                if (ctx->tmp_len == 0)

                    break;

                /* Fall through and process what we have */

                else

                    i = 0;

            }

            /* else we retry and add more data to buffer */

            else

                break;

        }

        i += ctx->tmp_len;

        ctx->tmp_len = i;

        /*

         * We need to scan, a line at a time until we have a valid line if we

         * are starting.

         */

        if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {

            /* ctx->start=1; */

            ctx->tmp_len = 0;

        } else if (ctx->start) {

            q = p = (unsigned char *)ctx->tmp;

            num = 0;

            for (j = 0; j < i; j++) {

                if (*(q++) != '\n')

                    continue;

                /*

                 * due to a previous very long line, we need to keep on

                 * scanning for a '\n' before we even start looking for

                 * base64 encoded stuff.

                 */

                if (ctx->tmp_nl) {

                    p = q;

                    ctx->tmp_nl = 0;

                    continue;

                }

                k = EVP_DecodeUpdate(&(ctx->base64),

                                     (unsigned char *)ctx->buf,

                                     &num, p, q - p);

                if ((k <= 0) && (num == 0) && (ctx->start))

                    EVP_DecodeInit(&ctx->base64);

                else {

                    if (p != (unsigned char *)

                        &(ctx->tmp[0])) {

                        i -= (p - (unsigned char *)

                              &(ctx->tmp[0]));

                        for (x = 0; x < i; x++)

                            ctx->tmp[x] = p[x];

                    }

                    EVP_DecodeInit(&ctx->base64);

                    ctx->start = 0;

                    break;

                }

                p = q;

            }

            /* we fell off the end without starting */

            if ((j == i) && (num == 0)) {

                /*

                 * Is this is one long chunk?, if so, keep on reading until a

                 * new line.

                 */

                if (p == (unsigned char *)&(ctx->tmp[0])) {

                    /* Check buffer full */

                    if (i == B64_BLOCK_SIZE) {

                        ctx->tmp_nl = 1;

                        ctx->tmp_len = 0;

                    }

                } else if (p != q) { /* finished on a '\n' */

                    n = q - p;

                    for (ii = 0; ii < n; ii++)

                        ctx->tmp[ii] = p[ii];

                    ctx->tmp_len = n;

                }

                /* else finished on a '\n' */

                continue;

            } else {

                ctx->tmp_len = 0;

            }

        } else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {

            /*

             * If buffer isn't full and we can retry then restart to read in

             * more data.

             */

            continue;

        }

        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {

            int z, jj;

#if 0

            jj = (i >> 2) << 2;

#else

            jj = i & ~3;        /* process per 4 */

#endif

            z = EVP_DecodeBlock((unsigned char *)ctx->buf,

                                (unsigned char *)ctx->tmp, jj);

            if (jj > 2) {

                if (ctx->tmp[jj - 1] == '=') {

                    z--;

                    if (ctx->tmp[jj - 2] == '=')

                        z--;

                }

            }

            /*

             * z is now number of output bytes and jj is the number consumed

             */

            if (jj != i) {

                memmove(ctx->tmp, &ctx->tmp[jj], i - jj);

                ctx->tmp_len = i - jj;

            }

            ctx->buf_len = 0;

            if (z > 0) {

                ctx->buf_len = z;

            }

            i = z;

        } else {

            i = EVP_DecodeUpdate(&(ctx->base64),

                                 (unsigned char *)ctx->buf, &ctx->buf_len,

                                 (unsigned char *)ctx->tmp, i);

            ctx->tmp_len = 0;

        }

        ctx->buf_off = 0;

        if (i < 0) {

            ret_code = 0;

            ctx->buf_len = 0;

            break;

        }

        if (ctx->buf_len <= outl)

            i = ctx->buf_len;

        else

            i = outl;

        memcpy(out, ctx->buf, i);

        ret += i;

        ctx->buf_off = i;

        if (ctx->buf_off == ctx->buf_len) {

            ctx->buf_len = 0;

            ctx->buf_off = 0;

        }

        outl -= i;

        out += i;

    }

    /* BIO_clear_retry_flags(b); */

    BIO_copy_next_retry(b);

    return ((ret == 0) ? ret_code : ret);

}

static int b64_write(BIO *b, const char *in, int inl)

{

    int ret = 0;

    int n;

    int i;

    BIO_B64_CTX *ctx;

    ctx = (BIO_B64_CTX *)b->ptr;

    BIO_clear_retry_flags(b);

    if (ctx->encode != B64_ENCODE) {

        ctx->encode = B64_ENCODE;

        ctx->buf_len = 0;

        ctx->buf_off = 0;

        ctx->tmp_len = 0;

        EVP_EncodeInit(&(ctx->base64));

    }

    OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));

    OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));

    OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

    n = ctx->buf_len - ctx->buf_off;

    while (n > 0) {

        i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);

        if (i <= 0) {

            BIO_copy_next_retry(b);

            return (i);

        }

        OPENSSL_assert(i <= n);

        ctx->buf_off += i;

        OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));

        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

        n -= i;

    }

    /* at this point all pending data has been written */

    ctx->buf_off = 0;

    ctx->buf_len = 0;

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

        return (0);

    while (inl > 0) {

        n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;

        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {

            if (ctx->tmp_len > 0) {

                OPENSSL_assert(ctx->tmp_len <= 3);

                n = 3 - ctx->tmp_len;

                /*

                 * There's a theoretical possibility for this

                 */

                if (n > inl)

                    n = inl;

                memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);

                ctx->tmp_len += n;

                ret += n;

                if (ctx->tmp_len < 3)

                    break;

                ctx->buf_len =

                    EVP_EncodeBlock((unsigned char *)ctx->buf,

                                    (unsigned char *)ctx->tmp, ctx->tmp_len);

                OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));

                OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

                /*

                 * Since we're now done using the temporary buffer, the

                 * length should be 0'd

                 */

                ctx->tmp_len = 0;

            } else {

                if (n < 3) {

                    memcpy(ctx->tmp, in, n);

                    ctx->tmp_len = n;

                    ret += n;

                    break;

                }

                n -= n % 3;

                ctx->buf_len =

                    EVP_EncodeBlock((unsigned char *)ctx->buf,

                                    (const unsigned char *)in, n);

                OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));

                OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

                ret += n;

            }

        } else {

            EVP_EncodeUpdate(&(ctx->base64),

                             (unsigned char *)ctx->buf, &ctx->buf_len,

                             (unsigned char *)in, n);

            OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));

            OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

            ret += n;

        }

        inl -= n;

        in += n;

        ctx->buf_off = 0;

        n = ctx->buf_len;

        while (n > 0) {

            i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);

            if (i <= 0) {

                BIO_copy_next_retry(b);

                return ((ret == 0) ? i : ret);

            }

            OPENSSL_assert(i <= n);

            n -= i;

            ctx->buf_off += i;

            OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));

            OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

        }

        ctx->buf_len = 0;

        ctx->buf_off = 0;

    }

    return (ret);

}

static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)

{

    BIO_B64_CTX *ctx;

    long ret = 1;

    int i;

    ctx = (BIO_B64_CTX *)b->ptr;

    switch (cmd) {

    case BIO_CTRL_RESET:

        ctx->cont = 1;

        ctx->start = 1;

        ctx->encode = B64_NONE;

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

        break;

    case BIO_CTRL_EOF:         /* More to read */

        if (ctx->cont <= 0)

            ret = 1;

        else

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

        break;

    case BIO_CTRL_WPENDING:    /* More to write in buffer */

        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

        ret = ctx->buf_len - ctx->buf_off;

        if ((ret == 0) && (ctx->encode != B64_NONE)

            && (ctx->base64.num != 0))

            ret = 1;

        else if (ret <= 0)

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

        break;

    case BIO_CTRL_PENDING:     /* More to read in buffer */

        OPENSSL_assert(ctx->buf_len >= ctx->buf_off);

        ret = ctx->buf_len - ctx->buf_off;

        if (ret <= 0)

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

        break;

    case BIO_CTRL_FLUSH:

        /* do a final write */

 again:

        while (ctx->buf_len != ctx->buf_off) {

            i = b64_write(b, NULL, 0);

            if (i < 0)

                return i;

        }

        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {

            if (ctx->tmp_len != 0) {

                ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,

                                               (unsigned char *)ctx->tmp,

                                               ctx->tmp_len);

                ctx->buf_off = 0;

                ctx->tmp_len = 0;

                goto again;

            }

        } else if (ctx->encode != B64_NONE && ctx->base64.num != 0) {

            ctx->buf_off = 0;

            EVP_EncodeFinal(&(ctx->base64),

                            (unsigned char *)ctx->buf, &(ctx->buf_len));

            /* push out the bytes */

            goto again;

        }

        /* Finally flush the underlying BIO */

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

        break;

    case BIO_C_DO_STATE_MACHINE:

        BIO_clear_retry_flags(b);

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

        BIO_copy_next_retry(b);

        break;

    case BIO_CTRL_DUP:

        break;

    case BIO_CTRL_INFO:

    case BIO_CTRL_GET:

    case BIO_CTRL_SET:

    default:

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

        break;

    }

    return (ret);

}

static long b64_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 b64_puts(BIO *b, const char *str)

{

    return b64_write(b, str, strlen(str));

}