text: /* asn_mime.c */
  /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   * project.
   */
  /* ====================================================================
   * Copyright (c) 1999-2008 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.
   * ====================================================================
   *
   */
  
  #include <stdio.h>
  #include <ctype.h>
  #include "cryptlib.h"
  #include <openssl/rand.h>
  #include <openssl/x509.h>
  #include <openssl/asn1.h>
  #include <openssl/asn1t.h>
  #include "asn1_locl.h"
  
  /* Generalised MIME like utilities for streaming ASN1. Although many
   * have a PKCS7/CMS like flavour others are more general purpose.
   */
  
  /* MIME format structures
   * Note that all are translated to lower case apart from
   * parameter values. Quotes are stripped off
   */
  
  typedef struct {
  char *param_name;			/* Param name e.g. "micalg" */
  char *param_value;			/* Param value e.g. "sha1" */
  } MIME_PARAM;
  
  DECLARE_STACK_OF(MIME_PARAM)
  IMPLEMENT_STACK_OF(MIME_PARAM)
  
  typedef struct {
  char *name;				/* Name of line e.g. "content-type" */
  char *value;				/* Value of line e.g. "text/plain" */
  STACK_OF(MIME_PARAM) *params;		/* Zero or more parameters */
  } MIME_HEADER;
  
  DECLARE_STACK_OF(MIME_HEADER)
  IMPLEMENT_STACK_OF(MIME_HEADER)
  
  static int asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags,
  					const ASN1_ITEM *it);
  static char * strip_ends(char *name);
  static char * strip_start(char *name);
  static char * strip_end(char *name);
  static MIME_HEADER *mime_hdr_new(char *name, char *value);
  static int mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value);
  static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio);
  static int mime_hdr_cmp(const MIME_HEADER * const *a,
  			const MIME_HEADER * const *b);
  static int mime_param_cmp(const MIME_PARAM * const *a,
  			const MIME_PARAM * const *b);
  static void mime_param_free(MIME_PARAM *param);
  static int mime_bound_check(char *line, int linelen, char *bound, int blen);
  static int multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret);
  static int strip_eol(char *linebuf, int *plen);
  static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name);
  static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, char *name);
  static void mime_hdr_free(MIME_HEADER *hdr);
  
  #define MAX_SMLEN 1024
  #define mime_debug(x) /* x */
  
  /* Output an ASN1 structure in BER format streaming if necessary */
  
  int i2d_ASN1_bio_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags,
  				const ASN1_ITEM *it)
  	{
  	/* If streaming create stream BIO and copy all content through it */
  	if (flags & SMIME_STREAM)
  		{
  		BIO *bio, *tbio;
  		bio = BIO_new_NDEF(out, val, it);
  		if (!bio)
  			{
  			ASN1err(ASN1_F_I2D_ASN1_BIO_STREAM,ERR_R_MALLOC_FAILURE);
  			return 0;
  			}
  		SMIME_crlf_copy(in, bio, flags);
  		(void)BIO_flush(bio);
  		/* Free up successive BIOs until we hit the old output BIO */
  		do
  			{
  			tbio = BIO_pop(bio);
  			BIO_free(bio);
  			bio = tbio;
  			} while (bio != out);
  		}
  	/* else just write out ASN1 structure which will have all content
  	 * stored internally
  	 */
  	else
  		ASN1_item_i2d_bio(it, out, val);
  	return 1;
  	}
  
  /* Base 64 read and write of ASN1 structure */
  
  static int B64_write_ASN1(BIO *out, ASN1_VALUE *val, BIO *in, int flags,
  				const ASN1_ITEM *it)
  	{
  	BIO *b64;
  	int r;
  	b64 = BIO_new(BIO_f_base64());
  	if(!b64)
  		{
  		ASN1err(ASN1_F_B64_WRITE_ASN1,ERR_R_MALLOC_FAILURE);
  		return 0;
  		}
  	/* prepend the b64 BIO so all data is base64 encoded.
  	 */
  	out = BIO_push(b64, out);
  	r = i2d_ASN1_bio_stream(out, val, in, flags, it);
  	(void)BIO_flush(out);
  	BIO_pop(out);
  	BIO_free(b64);
  	return r;
  	}
  
  /* Streaming ASN1 PEM write */
  
  int PEM_write_bio_ASN1_stream(BIO *out, ASN1_VALUE *val, BIO *in, int flags,
  				const char *hdr,
  				const ASN1_ITEM *it)
  	{
  	int r;
  	BIO_printf(out, "-----BEGIN %s-----\n", hdr);
  	r = B64_write_ASN1(out, val, in, flags, it);
  	BIO_printf(out, "-----END %s-----\n", hdr);
  	return r;
  	}
  
  static ASN1_VALUE *b64_read_asn1(BIO *bio, const ASN1_ITEM *it)
  {
  	BIO *b64;
  	ASN1_VALUE *val;
  	if(!(b64 = BIO_new(BIO_f_base64()))) {
  		ASN1err(ASN1_F_B64_READ_ASN1,ERR_R_MALLOC_FAILURE);
  		return 0;
  	}
  	bio = BIO_push(b64, bio);
  	val = ASN1_item_d2i_bio(it, bio, NULL);
  	if(!val)
  		ASN1err(ASN1_F_B64_READ_ASN1,ASN1_R_DECODE_ERROR);
  	(void)BIO_flush(bio);
  	bio = BIO_pop(bio);
  	BIO_free(b64);
  	return val;
  }
  
  /* Generate the MIME "micalg" parameter from RFC3851, RFC4490 */
  
  static int asn1_write_micalg(BIO *out, STACK_OF(X509_ALGOR) *mdalgs)
  	{
  	const EVP_MD *md;
  	int i, have_unknown = 0, write_comma, ret = 0, md_nid;
  	have_unknown = 0;
  	write_comma = 0;
  	for (i = 0; i < sk_X509_ALGOR_num(mdalgs); i++)
  		{
  		if (write_comma)
  			BIO_write(out, ",", 1);
  		write_comma = 1;
  		md_nid = OBJ_obj2nid(sk_X509_ALGOR_value(mdalgs, i)->algorithm);
  		md = EVP_get_digestbynid(md_nid);
  		if (md && md->md_ctrl)
  			{
  			int rv;
  			char *micstr;
  			rv = md->md_ctrl(NULL, EVP_MD_CTRL_MICALG, 0, &micstr);
  			if (rv > 0)
  				{
  				BIO_puts(out, micstr);
  				OPENSSL_free(micstr);
  				continue;
  				}
  			if (rv != -2)
  				goto err;
  			}
  		switch(md_nid)
  			{
  			case NID_sha1:
  			BIO_puts(out, "sha1");
  			break;
  
  			case NID_md5:
  			BIO_puts(out, "md5");
  			break;
  
  			case NID_sha256:
  			BIO_puts(out, "sha-256");
  			break;
  
  			case NID_sha384:
  			BIO_puts(out, "sha-384");
  			break;
  
  			case NID_sha512:
  			BIO_puts(out, "sha-512");
  			break;
  
  			case NID_id_GostR3411_94:
  			BIO_puts(out, "gostr3411-94");
  				goto err;
  			break;
  
  			default:
  			if (have_unknown)
  				write_comma = 0;
  			else
  				{
  				BIO_puts(out, "unknown");
  				have_unknown = 1;
  				}
  			break;
  
  			}
  		}
  
  	ret = 1;
  	err:
  
  	return ret;
  
  	}
  
  /* SMIME sender */
  
  int SMIME_write_ASN1(BIO *bio, ASN1_VALUE *val, BIO *data, int flags,
  				int ctype_nid, int econt_nid,
  				STACK_OF(X509_ALGOR) *mdalgs,
  				const ASN1_ITEM *it)
  {
  	char bound[33], c;
  	int i;
  	const char *mime_prefix, *mime_eol, *cname = "smime.p7m";
  	const char *msg_type=NULL;
  	if (flags & SMIME_OLDMIME)
  		mime_prefix = "application/x-pkcs7-";
  	else
  		mime_prefix = "application/pkcs7-";
  
  	if (flags & SMIME_CRLFEOL)
  		mime_eol = "\r\n";
  	else
  		mime_eol = "\n";
  	if((flags & SMIME_DETACHED) && data) {
  	/* We want multipart/signed */
  		/* Generate a random boundary */
  		RAND_pseudo_bytes((unsigned char *)bound, 32);
  		for(i = 0; i < 32; i++) {
  			c = bound[i] & 0xf;
  			if(c < 10) c += '0';
  			else c += 'A' - 10;
  			bound[i] = c;
  		}
  		bound[32] = 0;
  		BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol);
  		BIO_printf(bio, "Content-Type: multipart/signed;");
  		BIO_printf(bio, " protocol=\"%ssignature\";", mime_prefix);
  		BIO_puts(bio, " micalg=\"");
  		asn1_write_micalg(bio, mdalgs);
  		BIO_printf(bio, "\"; boundary=\"----%s\"%s%s",
  						bound, mime_eol, mime_eol);
  		BIO_printf(bio, "This is an S/MIME signed message%s%s",
  						mime_eol, mime_eol);
  		/* Now write out the first part */
  		BIO_printf(bio, "------%s%s", bound, mime_eol);
  		if (!asn1_output_data(bio, data, val, flags, it))
  			return 0;
  		BIO_printf(bio, "%s------%s%s", mime_eol, bound, mime_eol);
  
  		/* Headers for signature */
  
  		BIO_printf(bio, "Content-Type: %ssignature;", mime_prefix); 
  		BIO_printf(bio, " name=\"smime.p7s\"%s", mime_eol);
  		BIO_printf(bio, "Content-Transfer-Encoding: base64%s",
  								mime_eol);
  		BIO_printf(bio, "Content-Disposition: attachment;");
  		BIO_printf(bio, " filename=\"smime.p7s\"%s%s",
  							mime_eol, mime_eol);
  		B64_write_ASN1(bio, val, NULL, 0, it);
  		BIO_printf(bio,"%s------%s--%s%s", mime_eol, bound,
  							mime_eol, mime_eol);
  		return 1;
  	}
  
  	/* Determine smime-type header */
  
  	if (ctype_nid == NID_pkcs7_enveloped)
  		msg_type = "enveloped-data";
  	else if (ctype_nid == NID_pkcs7_signed)
  		{
  		if (econt_nid == NID_id_smime_ct_receipt)
  			msg_type = "signed-receipt";
  		else if (sk_X509_ALGOR_num(mdalgs) >= 0)
  			msg_type = "signed-data";
  		else
  			msg_type = "certs-only";
  		}
  	else if (ctype_nid == NID_id_smime_ct_compressedData)
  		{
  		msg_type = "compressed-data";
  		cname = "smime.p7z";
  		}
  	/* MIME headers */
  	BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol);
  	BIO_printf(bio, "Content-Disposition: attachment;");
  	BIO_printf(bio, " filename=\"%s\"%s", cname, mime_eol);
  	BIO_printf(bio, "Content-Type: %smime;", mime_prefix);
  	if (msg_type)
  		BIO_printf(bio, " smime-type=%s;", msg_type);
  	BIO_printf(bio, " name=\"%s\"%s", cname, mime_eol);
  	BIO_printf(bio, "Content-Transfer-Encoding: base64%s%s",
  						mime_eol, mime_eol);
  	if (!B64_write_ASN1(bio, val, data, flags, it))
  		return 0;
  	BIO_printf(bio, "%s", mime_eol);
  	return 1;
  }
  
  /* Handle output of ASN1 data */
  
  
  static int asn1_output_data(BIO *out, BIO *data, ASN1_VALUE *val, int flags,
  					const ASN1_ITEM *it)
  	{
  	BIO *tmpbio;
  	const ASN1_AUX *aux = it->funcs;
  	ASN1_STREAM_ARG sarg;
  
  	if (!(flags & SMIME_DETACHED))
  		{
  		SMIME_crlf_copy(data, out, flags);
  		return 1;
  		}
  
  	if (!aux || !aux->asn1_cb)
  		{
  		ASN1err(ASN1_F_ASN1_OUTPUT_DATA,
  					ASN1_R_STREAMING_NOT_SUPPORTED);
  		return 0;
  		}
  
  	sarg.out = out;
  	sarg.ndef_bio = NULL;
  	sarg.boundary = NULL;
  
  	/* Let ASN1 code prepend any needed BIOs */
  
  	if (aux->asn1_cb(ASN1_OP_DETACHED_PRE, &val, it, &sarg) <= 0)
  		return 0;
  
  	/* Copy data across, passing through filter BIOs for processing */
  	SMIME_crlf_copy(data, sarg.ndef_bio, flags);
  
  	/* Finalize structure */
  	if (aux->asn1_cb(ASN1_OP_DETACHED_POST, &val, it, &sarg) <= 0)
  		return 0;
  
  	/* Now remove any digests prepended to the BIO */
  
  	while (sarg.ndef_bio != out)
  		{
  		tmpbio = BIO_pop(sarg.ndef_bio);
  		BIO_free(sarg.ndef_bio);
  		sarg.ndef_bio = tmpbio;
  		}
  
  	return 1;
  
  	}
  
  /* SMIME reader: handle multipart/signed and opaque signing.
   * in multipart case the content is placed in a memory BIO
   * pointed to by "bcont". In opaque this is set to NULL
   */
  
  ASN1_VALUE *SMIME_read_ASN1(BIO *bio, BIO **bcont, const ASN1_ITEM *it)
  {
  	BIO *asnin;
  	STACK_OF(MIME_HEADER) *headers = NULL;
  	STACK_OF(BIO) *parts = NULL;
  	MIME_HEADER *hdr;
  	MIME_PARAM *prm;
  	ASN1_VALUE *val;
  	int ret;
  
  	if(bcont) *bcont = NULL;
  
  	if (!(headers = mime_parse_hdr(bio))) {
  		ASN1err(ASN1_F_SMIME_READ_ASN1,ASN1_R_MIME_PARSE_ERROR);
  		return NULL;
  	}
  
  	if(!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) {
  		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  		ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_CONTENT_TYPE);
  		return NULL;
  	}
  
  	/* Handle multipart/signed */
  
  	if(!strcmp(hdr->value, "multipart/signed")) {
  		/* Split into two parts */
  		prm = mime_param_find(hdr, "boundary");
  		if(!prm || !prm->param_value) {
  			sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  			ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_MULTIPART_BOUNDARY);
  			return NULL;
  		}
  		ret = multi_split(bio, prm->param_value, &parts);
  		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  		if(!ret || (sk_BIO_num(parts) != 2) ) {
  			ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_MULTIPART_BODY_FAILURE);
  			sk_BIO_pop_free(parts, BIO_vfree);
  			return NULL;
  		}
  
  		/* Parse the signature piece */
  		asnin = sk_BIO_value(parts, 1);
  
  		if (!(headers = mime_parse_hdr(asnin))) {
  			ASN1err(ASN1_F_SMIME_READ_ASN1,ASN1_R_MIME_SIG_PARSE_ERROR);
  			sk_BIO_pop_free(parts, BIO_vfree);
  			return NULL;
  		}
  
  		/* Get content type */
  
  		if(!(hdr = mime_hdr_find(headers, "content-type")) ||
  								 !hdr->value) {
  			sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  			ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_NO_SIG_CONTENT_TYPE);
  			return NULL;
  		}
  
  		if(strcmp(hdr->value, "application/x-pkcs7-signature") &&
  			strcmp(hdr->value, "application/pkcs7-signature")) {
  			sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  			ASN1err(ASN1_F_SMIME_READ_ASN1,ASN1_R_SIG_INVALID_MIME_TYPE);
  			ERR_add_error_data(2, "type: ", hdr->value);
  			sk_BIO_pop_free(parts, BIO_vfree);
  			return NULL;
  		}
  		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  		/* Read in ASN1 */
  		if(!(val = b64_read_asn1(asnin, it))) {
  			ASN1err(ASN1_F_SMIME_READ_ASN1,ASN1_R_ASN1_SIG_PARSE_ERROR);
  			sk_BIO_pop_free(parts, BIO_vfree);
  			return NULL;
  		}
  
  		if(bcont) {
  			*bcont = sk_BIO_value(parts, 0);
  			BIO_free(asnin);
  			sk_BIO_free(parts);
  		} else sk_BIO_pop_free(parts, BIO_vfree);
  		return val;
  	}
  		
  	/* OK, if not multipart/signed try opaque signature */
  
  	if (strcmp (hdr->value, "application/x-pkcs7-mime") &&
  	    strcmp (hdr->value, "application/pkcs7-mime")) {
  		ASN1err(ASN1_F_SMIME_READ_ASN1,ASN1_R_INVALID_MIME_TYPE);
  		ERR_add_error_data(2, "type: ", hdr->value);
  		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  		return NULL;
  	}
  
  	sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  	
  	if(!(val = b64_read_asn1(bio, it))) {
  		ASN1err(ASN1_F_SMIME_READ_ASN1, ASN1_R_ASN1_PARSE_ERROR);
  		return NULL;
  	}
  	return val;
  
  }
  
  /* Copy text from one BIO to another making the output CRLF at EOL */
  int SMIME_crlf_copy(BIO *in, BIO *out, int flags)
  {
  	BIO *bf;
  	char eol;
  	int len;
  	char linebuf[MAX_SMLEN];
  	/* Buffer output so we don't write one line at a time. This is
  	 * useful when streaming as we don't end up with one OCTET STRING
  	 * per line.
  	 */
  	bf = BIO_new(BIO_f_buffer());
  	if (!bf)
  		return 0;
  	out = BIO_push(bf, out);
  	if(flags & SMIME_BINARY)
  		{
  		while((len = BIO_read(in, linebuf, MAX_SMLEN)) > 0)
  						BIO_write(out, linebuf, len);
  		}
  	else
  		{
  		if(flags & SMIME_TEXT)
  			BIO_printf(out, "Content-Type: text/plain\r\n\r\n");
  		while ((len = BIO_gets(in, linebuf, MAX_SMLEN)) > 0)
  			{
  			eol = strip_eol(linebuf, &len);
  			if (len)
  				BIO_write(out, linebuf, len);
  			if(eol) BIO_write(out, "\r\n", 2);
  			}
  		}
  	(void)BIO_flush(out);
  	BIO_pop(out);
  	BIO_free(bf);
  	return 1;
  }
  
  /* Strip off headers if they are text/plain */
  int SMIME_text(BIO *in, BIO *out)
  {
  	char iobuf[4096];
  	int len;
  	STACK_OF(MIME_HEADER) *headers;
  	MIME_HEADER *hdr;
  
  	if (!(headers = mime_parse_hdr(in))) {
  		ASN1err(ASN1_F_SMIME_TEXT,ASN1_R_MIME_PARSE_ERROR);
  		return 0;
  	}
  	if(!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) {
  		ASN1err(ASN1_F_SMIME_TEXT,ASN1_R_MIME_NO_CONTENT_TYPE);
  		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  		return 0;
  	}
  	if (strcmp (hdr->value, "text/plain")) {
  		ASN1err(ASN1_F_SMIME_TEXT,ASN1_R_INVALID_MIME_TYPE);
  		ERR_add_error_data(2, "type: ", hdr->value);
  		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  		return 0;
  	}
  	sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
  	while ((len = BIO_read(in, iobuf, sizeof(iobuf))) > 0)
  						BIO_write(out, iobuf, len);
  	if (len < 0)
  		return 0;
  	return 1;
  }
  
  /* Split a multipart/XXX message body into component parts: result is
   * canonical parts in a STACK of bios
   */
  
  static int multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret)
  {
  	char linebuf[MAX_SMLEN];
  	int len, blen;
  	int eol = 0, next_eol = 0;
  	BIO *bpart = NULL;
  	STACK_OF(BIO) *parts;
  	char state, part, first;
  
  	blen = strlen(bound);
  	part = 0;
  	state = 0;
  	first = 1;
  	parts = sk_BIO_new_null();
  	*ret = parts;
  	while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) {
  		state = mime_bound_check(linebuf, len, bound, blen);
  		if(state == 1) {
  			first = 1;
  			part++;
  		} else if(state == 2) {
  			sk_BIO_push(parts, bpart);
  			return 1;
  		} else if(part) {
  			/* Strip CR+LF from linebuf */
  			next_eol = strip_eol(linebuf, &len);
  			if(first) {
  				first = 0;
  				if(bpart) sk_BIO_push(parts, bpart);
  				bpart = BIO_new(BIO_s_mem());
  				BIO_set_mem_eof_return(bpart, 0);
  			} else if (eol)
  				BIO_write(bpart, "\r\n", 2);
  			eol = next_eol;
  			if (len)
  				BIO_write(bpart, linebuf, len);
  		}
  	}
  	return 0;
  }
  
  /* This is the big one: parse MIME header lines up to message body */
  
  #define MIME_INVALID	0
  #define MIME_START	1
  #define MIME_TYPE	2
  #define MIME_NAME	3
  #define MIME_VALUE	4
  #define MIME_QUOTE	5
  #define MIME_COMMENT	6
  
  
  static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio)
  {
  	char *p, *q, c;
  	char *ntmp;
  	char linebuf[MAX_SMLEN];
  	MIME_HEADER *mhdr = NULL;
  	STACK_OF(MIME_HEADER) *headers;
  	int len, state, save_state = 0;
  
  	headers = sk_MIME_HEADER_new(mime_hdr_cmp);
  	while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) {
  	/* If whitespace at line start then continuation line */
  	if(mhdr && isspace((unsigned char)linebuf[0])) state = MIME_NAME;
  	else state = MIME_START;
  	ntmp = NULL;
  	/* Go through all characters */
  	for(p = linebuf, q = linebuf; (c = *p) && (c!='\r') && (c!='\n'); p++) {
  
  	/* State machine to handle MIME headers
  	 * if this looks horrible that's because it *is*
           */
  
  		switch(state) {
  			case MIME_START:
  			if(c == ':') {
  				state = MIME_TYPE;
  				*p = 0;
  				ntmp = strip_ends(q);
  				q = p + 1;
  			}
  			break;
  
  			case MIME_TYPE:
  			if(c == ';') {
  				mime_debug("Found End Value\n");
  				*p = 0;
  				mhdr = mime_hdr_new(ntmp, strip_ends(q));
  				sk_MIME_HEADER_push(headers, mhdr);
  				ntmp = NULL;
  				q = p + 1;
  				state = MIME_NAME;
  			} else if(c == '(') {
  				save_state = state;
  				state = MIME_COMMENT;
  			}
  			break;
  
  			case MIME_COMMENT:
  			if(c == ')') {
  				state = save_state;
  			}
  			break;
  
  			case MIME_NAME:
  			if(c == '=') {
  				state = MIME_VALUE;
  				*p = 0;
  				ntmp = strip_ends(q);
  				q = p + 1;
  			}
  			break ;
  
  			case MIME_VALUE:
  			if(c == ';') {
  				state = MIME_NAME;
  				*p = 0;
  				mime_hdr_addparam(mhdr, ntmp, strip_ends(q));
  				ntmp = NULL;
  				q = p + 1;
  			} else if (c == '"') {
  				mime_debug("Found Quote\n");
  				state = MIME_QUOTE;
  			} else if(c == '(') {
  				save_state = state;
  				state = MIME_COMMENT;
  			}
  			break;
  
  			case MIME_QUOTE:
  			if(c == '"') {
  				mime_debug("Found Match Quote\n");
  				state = MIME_VALUE;
  			}
  			break;
  		}
  	}
  
  	if(state == MIME_TYPE) {
  		mhdr = mime_hdr_new(ntmp, strip_ends(q));
  		sk_MIME_HEADER_push(headers, mhdr);
  	} else if(state == MIME_VALUE)
  			 mime_hdr_addparam(mhdr, ntmp, strip_ends(q));
  	if(p == linebuf) break;	/* Blank line means end of headers */
  }
  
  return headers;
  
  }
  
  static char *strip_ends(char *name)
  {
  	return strip_end(strip_start(name));
  }
  
  /* Strip a parameter of whitespace from start of param */
  static char *strip_start(char *name)
  {
  	char *p, c;
  	/* Look for first non white space or quote */
  	for(p = name; (c = *p) ;p++) {
  		if(c == '"') {
  			/* Next char is start of string if non null */
  			if(p[1]) return p + 1;
  			/* Else null string */
  			return NULL;
  		}
  		if(!isspace((unsigned char)c)) return p;
  	}
  	return NULL;
  }
  
  /* As above but strip from end of string : maybe should handle brackets? */
  static char *strip_end(char *name)
  {
  	char *p, c;
  	if(!name) return NULL;
  	/* Look for first non white space or quote */
  	for(p = name + strlen(name) - 1; p >= name ;p--) {
  		c = *p;
  		if(c == '"') {
  			if(p - 1 == name) return NULL;
  			*p = 0;
  			return name;
  		}
  		if(isspace((unsigned char)c)) *p = 0;	
  		else return name;
  	}
  	return NULL;
  }
  
  static MIME_HEADER *mime_hdr_new(char *name, char *value)
  {
  	MIME_HEADER *mhdr;
  	char *tmpname, *tmpval, *p;
  	int c;
  	if(name) {
  		if(!(tmpname = BUF_strdup(name))) return NULL;
  		for(p = tmpname ; *p; p++) {
  			c = *p;
  			if(isupper(c)) {
  				c = tolower(c);
  				*p = c;
  			}
  		}
  	} else tmpname = NULL;
  	if(value) {
  		if(!(tmpval = BUF_strdup(value))) return NULL;
  		for(p = tmpval ; *p; p++) {
  			c = *p;
  			if(isupper(c)) {
  				c = tolower(c);
  				*p = c;
  			}
  		}
  	} else tmpval = NULL;
  	mhdr = (MIME_HEADER *) OPENSSL_malloc(sizeof(MIME_HEADER));
  	if(!mhdr) return NULL;
  	mhdr->name = tmpname;
  	mhdr->value = tmpval;
  	if(!(mhdr->params = sk_MIME_PARAM_new(mime_param_cmp))) return NULL;
  	return mhdr;
  }
  		
  static int mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value)
  {
  	char *tmpname, *tmpval, *p;
  	int c;
  	MIME_PARAM *mparam;
  	if(name) {
  		tmpname = BUF_strdup(name);
  		if(!tmpname) return 0;
  		for(p = tmpname ; *p; p++) {
  			c = *p;
  			if(isupper(c)) {
  				c = tolower(c);
  				*p = c;
  			}
  		}
  	} else tmpname = NULL;
  	if(value) {
  		tmpval = BUF_strdup(value);
  		if(!tmpval) return 0;
  	} else tmpval = NULL;
  	/* Parameter values are case sensitive so leave as is */
  	mparam = (MIME_PARAM *) OPENSSL_malloc(sizeof(MIME_PARAM));
  	if(!mparam) return 0;
  	mparam->param_name = tmpname;
  	mparam->param_value = tmpval;
  	sk_MIME_PARAM_push(mhdr->params, mparam);
  	return 1;
  }
  
  static int mime_hdr_cmp(const MIME_HEADER * const *a,
  			const MIME_HEADER * const *b)
  {
  	return(strcmp((*a)->name, (*b)->name));
  }
  
  static int mime_param_cmp(const MIME_PARAM * const *a,
  			const MIME_PARAM * const *b)
  {
  	return(strcmp((*a)->param_name, (*b)->param_name));
  }
  
  /* Find a header with a given name (if possible) */
  
  static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name)
  {
  	MIME_HEADER htmp;
  	int idx;
  	htmp.name = name;
  	idx = sk_MIME_HEADER_find(hdrs, &htmp);
  	if(idx < 0) return NULL;
  	return sk_MIME_HEADER_value(hdrs, idx);
  }
  
  static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, char *name)
  {
  	MIME_PARAM param;
  	int idx;
  	param.param_name = name;
  	idx = sk_MIME_PARAM_find(hdr->params, &param);
  	if(idx < 0) return NULL;
  	return sk_MIME_PARAM_value(hdr->params, idx);
  }
  
  static void mime_hdr_free(MIME_HEADER *hdr)
  {
  	if(hdr->name) OPENSSL_free(hdr->name);
  	if(hdr->value) OPENSSL_free(hdr->value);
  	if(hdr->params) sk_MIME_PARAM_pop_free(hdr->params, mime_param_free);
  	OPENSSL_free(hdr);
  }
  
  static void mime_param_free(MIME_PARAM *param)
  {
  	if(param->param_name) OPENSSL_free(param->param_name);
  	if(param->param_value) OPENSSL_free(param->param_value);
  	OPENSSL_free(param);
  }
  
  /* Check for a multipart boundary. Returns:
   * 0 : no boundary
   * 1 : part boundary
   * 2 : final boundary
   */
  static int mime_bound_check(char *line, int linelen, char *bound, int blen)
  {
  	if(linelen == -1) linelen = strlen(line);
  	if(blen == -1) blen = strlen(bound);
  	/* Quickly eliminate if line length too short */
  	if(blen + 2 > linelen) return 0;
  	/* Check for part boundary */
  	if(!strncmp(line, "--", 2) && !strncmp(line + 2, bound, blen)) {
  		if(!strncmp(line + blen + 2, "--", 2)) return 2;
  		else return 1;
  	}
  	return 0;
  }
  
  static int strip_eol(char *linebuf, int *plen)
  	{
  	int len = *plen;
  	char *p, c;
  	int is_eol = 0;
  	p = linebuf + len - 1;
  	for (p = linebuf + len - 1; len > 0; len--, p--)
  		{
  		c = *p;
  		if (c == '\n')
  			is_eol = 1;
  		else if (c != '\r')
  			break;
  		}
  	*plen = len;
  	return is_eol;
  	}
  