pk7_mime.c

开源的ssl算法openssl,版本0.9.8H

						BIO_write(out, linebuf, len);
		return 1;
	}
	if(flags & PKCS7_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);
	}
	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))) {
		PKCS7err(PKCS7_F_SMIME_TEXT,PKCS7_R_MIME_PARSE_ERROR);
		return 0;
	}
	if(!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) {
		PKCS7err(PKCS7_F_SMIME_TEXT,PKCS7_R_MIME_NO_CONTENT_TYPE);
		sk_MIME_HEADER_pop_free(headers, mime_hdr_free);
		return 0;
	}
	if (strcmp (hdr->value, "text/plain")) {
		PKCS7err(PKCS7_F_SMIME_TEXT,PKCS7_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);
	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;
	}