bio_asn1.c

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/* bio_asn1.c */
/* Written by Dr Stephen N Henson ([email protected]) 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
 *    [email protected].
 *
 * 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
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */

/* 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))
        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 = 0;
    ctx->ex_pos = 0;
    ctx->ex_len = 0;
    ctx->state = ASN1_STATE_START;
    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);
    }