/* bio_asn1.c */

/*

 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL

 * project.

 */

/* ====================================================================

 * Copyright (c) 2006 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

 *    licensing@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).

 *

 */

/*

 * Experimental ASN1 BIO. When written through the data is converted to an

 * ASN1 string type: default is OCTET STRING. Additional functions can be

 * provided to add prefix and suffix data.

 */

#include <string.h>

#include <openssl/bio.h>

#include <openssl/asn1.h>

/* Must be large enough for biggest tag+length */

#define DEFAULT_ASN1_BUF_SIZE 20

typedef enum {

    ASN1_STATE_START,

    ASN1_STATE_PRE_COPY,

    ASN1_STATE_HEADER,

    ASN1_STATE_HEADER_COPY,

    ASN1_STATE_DATA_COPY,

    ASN1_STATE_POST_COPY,

    ASN1_STATE_DONE

} asn1_bio_state_t;

typedef struct BIO_ASN1_EX_FUNCS_st {

    asn1_ps_func *ex_func;

    asn1_ps_func *ex_free_func;

} BIO_ASN1_EX_FUNCS;

typedef struct BIO_ASN1_BUF_CTX_t {

    /* Internal state */

    asn1_bio_state_t state;

    /* Internal buffer */

    unsigned char *buf;

    /* Size of buffer */

    int bufsize;

    /* Current position in buffer */

    int bufpos;

    /* Current buffer length */

    int buflen;

    /* Amount of data to copy */

    int copylen;

    /* Class and tag to use */

    int asn1_class, asn1_tag;

    asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;

    /* Extra buffer for prefix and suffix data */

    unsigned char *ex_buf;

    int ex_len;

    int ex_pos;

    void *ex_arg;

} BIO_ASN1_BUF_CTX;

static int asn1_bio_write(BIO *h, const char *buf, int num);

static int asn1_bio_read(BIO *h, char *buf, int size);

static int asn1_bio_puts(BIO *h, const char *str);

static int asn1_bio_gets(BIO *h, char *str, int size);

static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);

static int asn1_bio_new(BIO *h);

static int asn1_bio_free(BIO *data);

static long asn1_bio_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);

static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);

static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,

                             asn1_ps_func *cleanup, asn1_bio_state_t next);

static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,

                             asn1_ps_func *setup,

                             asn1_bio_state_t ex_state,

                             asn1_bio_state_t other_state);

static BIO_METHOD methods_asn1 = {

    BIO_TYPE_ASN1,

    "asn1",

    asn1_bio_write,

    asn1_bio_read,

    asn1_bio_puts,

    asn1_bio_gets,

    asn1_bio_ctrl,

    asn1_bio_new,

    asn1_bio_free,

    asn1_bio_callback_ctrl,

};

BIO_METHOD *BIO_f_asn1(void)

{

    return (&methods_asn1);

}

static int asn1_bio_new(BIO *b)

{

    BIO_ASN1_BUF_CTX *ctx;

    ctx = OPENSSL_malloc(sizeof(BIO_ASN1_BUF_CTX));

    if (!ctx)

        return 0;

    if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {

        OPENSSL_free(ctx);

        return 0;

    }

    b->init = 1;

    b->ptr = (char *)ctx;

    b->flags = 0;

    return 1;

}

static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)

{

    ctx->buf = OPENSSL_malloc(size);

    if (!ctx->buf)

        return 0;

    ctx->bufsize = size;

    ctx->bufpos = 0;

    ctx->buflen = 0;

    ctx->copylen = 0;

    ctx->asn1_class = V_ASN1_UNIVERSAL;

    ctx->asn1_tag = V_ASN1_OCTET_STRING;

    ctx->ex_buf = NULL;

    ctx->ex_len = 0;

    ctx->ex_pos = 0;

    ctx->state = ASN1_STATE_START;

    ctx->prefix = ctx->prefix_free = ctx->suffix = ctx->suffix_free = NULL;

    ctx->ex_arg = NULL;

    return 1;

}

static int asn1_bio_free(BIO *b)

{

    BIO_ASN1_BUF_CTX *ctx;

    ctx = (BIO_ASN1_BUF_CTX *)b->ptr;

    if (ctx == NULL)

        return 0;

    if (ctx->buf)

        OPENSSL_free(ctx->buf);

    OPENSSL_free(ctx);

    b->init = 0;

    b->ptr = NULL;

    b->flags = 0;

    return 1;

}

static int asn1_bio_write(BIO *b, const char *in, int inl)

{

    BIO_ASN1_BUF_CTX *ctx;

    int wrmax, wrlen, ret;

    unsigned char *p;

    if (!in || (inl < 0) || (b->next_bio == NULL))

        return 0;

    ctx = (BIO_ASN1_BUF_CTX *)b->ptr;

    if (ctx == NULL)

        return 0;

    wrlen = 0;

    ret = -1;

    for (;;) {

        switch (ctx->state) {

            /* Setup prefix data, call it */

        case ASN1_STATE_START:

            if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,

                                   ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))

                return 0;

            break;

            /* Copy any pre data first */

        case ASN1_STATE_PRE_COPY:

            ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,

                                    ASN1_STATE_HEADER);

            if (ret <= 0)

                goto done;

            break;

        case ASN1_STATE_HEADER:

            ctx->buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;

            OPENSSL_assert(ctx->buflen <= ctx->bufsize);

            p = ctx->buf;

            ASN1_put_object(&p, 0, inl, ctx->asn1_tag, ctx->asn1_class);

            ctx->copylen = inl;

            ctx->state = ASN1_STATE_HEADER_COPY;

            break;

        case ASN1_STATE_HEADER_COPY:

            ret = BIO_write(b->next_bio, ctx->buf + ctx->bufpos, ctx->buflen);

            if (ret <= 0)

                goto done;

            ctx->buflen -= ret;

            if (ctx->buflen)

                ctx->bufpos += ret;

            else {

                ctx->bufpos = 0;

                ctx->state = ASN1_STATE_DATA_COPY;

            }

            break;

        case ASN1_STATE_DATA_COPY:

            if (inl > ctx->copylen)

                wrmax = ctx->copylen;

            else

                wrmax = inl;

            ret = BIO_write(b->next_bio, in, wrmax);

            if (ret <= 0)

                break;

            wrlen += ret;

            ctx->copylen -= ret;

            in += ret;

            inl -= ret;

            if (ctx->copylen == 0)

                ctx->state = ASN1_STATE_HEADER;

            if (inl == 0)

                goto done;

            break;

        default:

            BIO_clear_retry_flags(b);

            return 0;

        }

    }

 done:

    BIO_clear_retry_flags(b);

    BIO_copy_next_retry(b);

    return (wrlen > 0) ? wrlen : ret;

}

static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,

                             asn1_ps_func *cleanup, asn1_bio_state_t next)

{

    int ret;

    if (ctx->ex_len <= 0)

        return 1;

    for (;;) {

        ret = BIO_write(b->next_bio, ctx->ex_buf + ctx->ex_pos, ctx->ex_len);

        if (ret <= 0)

            break;

        ctx->ex_len -= ret;

        if (ctx->ex_len > 0)

            ctx->ex_pos += ret;

        else {

            if (cleanup)

                cleanup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);

            ctx->state = next;

            ctx->ex_pos = 0;

            break;

        }

    }

    return ret;

}

static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,

                             asn1_ps_func *setup,

                             asn1_bio_state_t ex_state,

                             asn1_bio_state_t other_state)

{

    if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {

        BIO_clear_retry_flags(b);

        return 0;

    }

    if (ctx->ex_len > 0)

        ctx->state = ex_state;

    else

        ctx->state = other_state;

    return 1;

}

static int asn1_bio_read(BIO *b, char *in, int inl)

{

    if (!b->next_bio)

        return 0;

    return BIO_read(b->next_bio, in, inl);

}

static int asn1_bio_puts(BIO *b, const char *str)

{

    return asn1_bio_write(b, str, strlen(str));

}

static int asn1_bio_gets(BIO *b, char *str, int size)

{

    if (!b->next_bio)

        return 0;

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

}

static long asn1_bio_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)

{

    if (b->next_bio == NULL)

        return (0);

    return BIO_callback_ctrl(b->next_bio, cmd, fp);

}

static long asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)

{

    BIO_ASN1_BUF_CTX *ctx;

    BIO_ASN1_EX_FUNCS *ex_func;

    long ret = 1;

    ctx = (BIO_ASN1_BUF_CTX *)b->ptr;

    if (ctx == NULL)

        return 0;

    switch (cmd) {

    case BIO_C_SET_PREFIX:

        ex_func = arg2;

        ctx->prefix = ex_func->ex_func;

        ctx->prefix_free = ex_func->ex_free_func;

        break;

    case BIO_C_GET_PREFIX:

        ex_func = arg2;

        ex_func->ex_func = ctx->prefix;

        ex_func->ex_free_func = ctx->prefix_free;

        break;

    case BIO_C_SET_SUFFIX:

        ex_func = arg2;

        ctx->suffix = ex_func->ex_func;

        ctx->suffix_free = ex_func->ex_free_func;

        break;

    case BIO_C_GET_SUFFIX:

        ex_func = arg2;

        ex_func->ex_func = ctx->suffix;

        ex_func->ex_free_func = ctx->suffix_free;

        break;

    case BIO_C_SET_EX_ARG:

        ctx->ex_arg = arg2;

        break;

    case BIO_C_GET_EX_ARG:

        *(void **)arg2 = ctx->ex_arg;

        break;

    case BIO_CTRL_FLUSH:

        if (!b->next_bio)

            return 0;

        /* Call post function if possible */

        if (ctx->state == ASN1_STATE_HEADER) {

            if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,

                                   ASN1_STATE_POST_COPY, ASN1_STATE_DONE))

                return 0;

        }

        if (ctx->state == ASN1_STATE_POST_COPY) {

            ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,

                                    ASN1_STATE_DONE);

            if (ret <= 0)

                return ret;

        }

        if (ctx->state == ASN1_STATE_DONE)

            return BIO_ctrl(b->next_bio, cmd, arg1, arg2);

        else {

            BIO_clear_retry_flags(b);

            return 0;

        }

        break;

    default:

        if (!b->next_bio)

            return 0;

        return BIO_ctrl(b->next_bio, cmd, arg1, arg2);

    }

    return ret;

}

static int asn1_bio_set_ex(BIO *b, int cmd,

                           asn1_ps_func *ex_func, asn1_ps_func *ex_free_func)

{

    BIO_ASN1_EX_FUNCS extmp;

    extmp.ex_func = ex_func;

    extmp.ex_free_func = ex_free_func;

    return BIO_ctrl(b, cmd, 0, &extmp);

}

static int asn1_bio_get_ex(BIO *b, int cmd,

                           asn1_ps_func **ex_func,

                           asn1_ps_func **ex_free_func)

{

    BIO_ASN1_EX_FUNCS extmp;

    int ret;

    ret = BIO_ctrl(b, cmd, 0, &extmp);

    if (ret > 0) {

        *ex_func = extmp.ex_func;

        *ex_free_func = extmp.ex_free_func;

    }

    return ret;

}

int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix,

                        asn1_ps_func *prefix_free)

{

    return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);

}

int BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix,

                        asn1_ps_func **pprefix_free)

{

    return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);

}

int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix,

                        asn1_ps_func *suffix_free)

{

    return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);

}

int BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix,

                        asn1_ps_func **psuffix_free)

{

    return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);

}