Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 594 insertions, 0 deletions

diff --git a/src/lib-mail/message-part-data.c b/src/lib-mail/message-part-data.c
new file mode 100644
index 0000000..a5771f8
--- /dev/null
+++ b/src/lib-mail/message-part-data.c
@@ -0,0 +1,594 @@
+/* Copyright (c) 2014-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "str.h"
+#include "wildcard-match.h"
+#include "array.h"
+#include "rfc822-parser.h"
+#include "rfc2231-parser.h"
+#include "message-address.h"
+#include "message-header-parser.h"
+
+#include "message-part-data.h"
+
+const char *message_part_envelope_headers[] = {
+	"Date", "Subject", "From", "Sender", "Reply-To",
+	"To", "Cc", "Bcc", "In-Reply-To", "Message-ID",
+	NULL
+};
+
+/*
+ *
+ */
+
+bool message_part_data_is_plain_7bit(const struct message_part *part)
+{
+	const struct message_part_data *data = part->data;
+
+	i_assert(data != NULL);
+	i_assert(part->parent == NULL);
+
+	/* if content-type is text/xxx we don't have to check any
+	   multipart stuff */
+	if ((part->flags & MESSAGE_PART_FLAG_TEXT) == 0)
+		return FALSE;
+	if (part->next != NULL || part->children != NULL)
+		return FALSE; /* shouldn't happen normally.. */
+
+	/* must be text/plain */
+	if (data->content_subtype != NULL &&
+	    strcasecmp(data->content_subtype, "plain") != 0)
+		return FALSE;
+
+	/* only allowed parameter is charset=us-ascii, which is also default */
+	if (data->content_type_params_count == 0) {
+		/* charset defaults to us-ascii */
+	} else if (data->content_type_params_count != 1 ||
+		   strcasecmp(data->content_type_params[0].name, "charset") != 0 ||
+		   strcasecmp(data->content_type_params[0].value,
+			      MESSAGE_PART_DEFAULT_CHARSET) != 0)
+		return FALSE;
+
+	if (data->content_id != NULL ||
+	    data->content_description != NULL)
+		return FALSE;
+
+	if (data->content_transfer_encoding != NULL &&
+	    strcasecmp(data->content_transfer_encoding, "7bit") != 0)
+		return FALSE;
+
+	/* BODYSTRUCTURE checks: */
+	if (data->content_md5 != NULL ||
+	    data->content_disposition != NULL ||
+	    data->content_language != NULL ||
+	    data->content_location != NULL)
+		return FALSE;
+
+	return TRUE;
+}
+
+bool message_part_data_get_filename(const struct message_part *part,
+	const char **filename_r)
+{
+	const struct message_part_data *data = part->data;
+	const struct message_part_param *params;
+	unsigned int params_count, i;
+
+	i_assert(data != NULL);
+
+	params = data->content_disposition_params;
+	params_count = data->content_disposition_params_count;
+
+	if (data->content_disposition != NULL &&
+		strcasecmp(data->content_disposition, "attachment") != 0) {
+		return FALSE;
+	}
+	for (i = 0; i < params_count; i++) {
+		if (strcasecmp(params[i].name, "filename") == 0 &&
+			params[i].value != NULL) {
+			*filename_r = params[i].value;
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+/*
+ * Header parsing
+ */
+
+/* Message part envelope */
+
+enum envelope_field {
+	ENVELOPE_FIELD_DATE = 0,
+	ENVELOPE_FIELD_SUBJECT,
+	ENVELOPE_FIELD_FROM,
+	ENVELOPE_FIELD_SENDER,
+	ENVELOPE_FIELD_REPLY_TO,
+	ENVELOPE_FIELD_TO,
+	ENVELOPE_FIELD_CC,
+	ENVELOPE_FIELD_BCC,
+	ENVELOPE_FIELD_IN_REPLY_TO,
+	ENVELOPE_FIELD_MESSAGE_ID,
+
+	ENVELOPE_FIELD_UNKNOWN
+};
+
+static enum envelope_field
+envelope_get_field(const char *name)
+{
+	switch (*name) {
+	case 'B':
+	case 'b':
+		if (strcasecmp(name, "Bcc") == 0)
+			return ENVELOPE_FIELD_BCC;
+		break;
+	case 'C':
+	case 'c':
+		if (strcasecmp(name, "Cc") == 0)
+			return ENVELOPE_FIELD_CC;
+		break;
+	case 'D':
+	case 'd':
+		if (strcasecmp(name, "Date") == 0)
+			return ENVELOPE_FIELD_DATE;
+		break;
+	case 'F':
+	case 'f':
+		if (strcasecmp(name, "From") == 0)
+			return ENVELOPE_FIELD_FROM;
+		break;
+	case 'I':
+	case 'i':
+		if (strcasecmp(name, "In-reply-to") == 0)
+			return ENVELOPE_FIELD_IN_REPLY_TO;
+		break;
+	case 'M':
+	case 'm':
+		if (strcasecmp(name, "Message-id") == 0)
+			return ENVELOPE_FIELD_MESSAGE_ID;
+		break;
+	case 'R':
+	case 'r':
+		if (strcasecmp(name, "Reply-to") == 0)
+			return ENVELOPE_FIELD_REPLY_TO;
+		break;
+	case 'S':
+	case 's':
+		if (strcasecmp(name, "Subject") == 0)
+			return ENVELOPE_FIELD_SUBJECT;
+		if (strcasecmp(name, "Sender") == 0)
+			return ENVELOPE_FIELD_SENDER;
+		break;
+	case 'T':
+	case 't':
+		if (strcasecmp(name, "To") == 0)
+			return ENVELOPE_FIELD_TO;
+		break;
+	}
+
+	return ENVELOPE_FIELD_UNKNOWN;
+}
+
+void message_part_envelope_parse_from_header(pool_t pool,
+	struct message_part_envelope **data,
+	struct message_header_line *hdr)
+{
+	struct message_part_envelope *d;
+	enum envelope_field field;
+	struct message_address **addr_p, *addr;
+	const char **str_p;
+
+	if (*data == NULL) {
+		*data = p_new(pool, struct message_part_envelope, 1);
+	}
+
+	if (hdr == NULL)
+		return;
+	field = envelope_get_field(hdr->name);
+	if (field == ENVELOPE_FIELD_UNKNOWN)
+		return;
+
+	if (hdr->continues) {
+		/* wait for full value */
+		hdr->use_full_value = TRUE;
+		return;
+	}
+
+	d = *data;
+	addr_p = NULL; str_p = NULL;
+	switch (field) {
+	case ENVELOPE_FIELD_DATE:
+		str_p = &d->date;
+		break;
+	case ENVELOPE_FIELD_SUBJECT:
+		str_p = &d->subject;
+		break;
+	case ENVELOPE_FIELD_MESSAGE_ID:
+		str_p = &d->message_id;
+		break;
+	case ENVELOPE_FIELD_IN_REPLY_TO:
+		str_p = &d->in_reply_to;
+		break;
+
+	case ENVELOPE_FIELD_CC:
+		addr_p = &d->cc;
+		break;
+	case ENVELOPE_FIELD_BCC:
+		addr_p = &d->bcc;
+		break;
+	case ENVELOPE_FIELD_FROM:
+		addr_p = &d->from;
+		break;
+	case ENVELOPE_FIELD_SENDER:
+		addr_p = &d->sender;
+		break;
+	case ENVELOPE_FIELD_TO:
+		addr_p = &d->to;
+		break;
+	case ENVELOPE_FIELD_REPLY_TO:
+		addr_p = &d->reply_to;
+		break;
+	case ENVELOPE_FIELD_UNKNOWN:
+		i_unreached();
+	}
+
+	if (addr_p != NULL) {
+		addr = message_address_parse(pool, hdr->full_value,
+					     hdr->full_value_len,
+					     UINT_MAX,
+					     MESSAGE_ADDRESS_PARSE_FLAG_FILL_MISSING);
+		/* Merge multiple headers the same as if they were comma
+		   separated in a single line. This is better from security
+		   point of view, because attacker could intentionally write
+		   addresses in a way that e.g. the first From header is
+		   validated while MUA only shows the second From header. */
+		while (*addr_p != NULL)
+			addr_p = &(*addr_p)->next;
+		*addr_p = addr;
+	} else if (str_p != NULL) {
+		*str_p = message_header_strdup(pool, hdr->full_value,
+					       hdr->full_value_len);
+	}
+}
+
+/* Message part data */
+
+static void
+parse_mime_parameters(struct rfc822_parser_context *parser,
+	pool_t pool, const struct message_part_param **params_r,
+	unsigned int *params_count_r)
+{
+	const char *const *results;
+	struct message_part_param *params;
+	unsigned int params_count, i;
+
+	rfc2231_parse(parser, &results);
+
+	params_count = str_array_length(results);
+	i_assert((params_count % 2) == 0);
+	params_count /= 2;
+
+	if (params_count > 0) {
+		params = p_new(pool, struct message_part_param, params_count);
+		for (i = 0; i < params_count; i++) {
+			params[i].name = p_strdup(pool, results[i*2+0]);
+			params[i].value = p_strdup(pool, results[i*2+1]);
+		}
+		*params_r = params;
+	}
+
+	*params_count_r = params_count;
+}
+
+static void
+parse_content_type(struct message_part_data *data,
+	pool_t pool, struct message_header_line *hdr)
+{
+	struct rfc822_parser_context parser;
+	string_t *str;
+	const char *value;
+	unsigned int i;
+	int ret;
+
+	rfc822_parser_init(&parser, hdr->full_value, hdr->full_value_len, NULL);
+	rfc822_skip_lwsp(&parser);
+
+	str = t_str_new(256);
+	ret = rfc822_parse_content_type(&parser, str);
+
+	/* Save content type and subtype */
+	value = str_c(str);
+	for (i = 0; value[i] != '\0'; i++) {
+		if (value[i] == '/') {
+			data->content_subtype = p_strdup(pool, value + i+1);
+			break;
+		}
+	}
+	str_truncate(str, i);
+	data->content_type = p_strdup(pool, str_c(str));
+	if (data->content_subtype == NULL) {
+		/* The Content-Type is invalid. Don't leave it NULL so that
+		   callers can assume that if content_type != NULL,
+		   content_subtype != NULL also. */
+		data->content_subtype = p_strdup(pool, "");
+	}
+
+	if (ret < 0) {
+		/* Content-Type is broken, but we wanted to get it as well as
+		   we could. Don't try to read the parameters anymore though.
+
+		   We don't completely ignore a broken Content-Type, because
+		   then it would be written as text/plain. This would cause a
+		   mismatch with the message_part's MESSAGE_PART_FLAG_TEXT. */
+		return;
+	}
+
+	parse_mime_parameters(&parser, pool,
+		&data->content_type_params,
+		&data->content_type_params_count);
+	rfc822_parser_deinit(&parser);
+}
+
+static void
+parse_content_transfer_encoding(struct message_part_data *data,
+	pool_t pool, struct message_header_line *hdr)
+{
+	struct rfc822_parser_context parser;
+	string_t *str;
+
+	rfc822_parser_init(&parser, hdr->full_value, hdr->full_value_len, NULL);
+	rfc822_skip_lwsp(&parser);
+
+	str = t_str_new(256);
+	if (rfc822_parse_mime_token(&parser, str) >= 0 &&
+	    rfc822_skip_lwsp(&parser) == 0 && str_len(str) > 0) {
+		data->content_transfer_encoding =
+			p_strdup(pool, str_c(str));
+	}
+	rfc822_parser_deinit(&parser);
+}
+
+static void
+parse_content_disposition(struct message_part_data *data,
+	pool_t pool, struct message_header_line *hdr)
+{
+	struct rfc822_parser_context parser;
+	string_t *str;
+
+	rfc822_parser_init(&parser, hdr->full_value, hdr->full_value_len, NULL);
+	rfc822_skip_lwsp(&parser);
+
+	str = t_str_new(256);
+	if (rfc822_parse_mime_token(&parser, str) < 0) {
+		rfc822_parser_deinit(&parser);
+		return;
+	}
+	data->content_disposition = p_strdup(pool, str_c(str));
+
+	parse_mime_parameters(&parser, pool,
+		&data->content_disposition_params,
+		&data->content_disposition_params_count);
+	rfc822_parser_deinit(&parser);
+}
+
+static void
+parse_content_language(struct message_part_data *data,
+	pool_t pool, const unsigned char *value, size_t value_len)
+{
+	struct rfc822_parser_context parser;
+	ARRAY_TYPE(const_string) langs;
+	string_t *str;
+
+	/* Language-Header = "Content-Language" ":" 1#Language-tag
+	   Language-Tag = Primary-tag *( "-" Subtag )
+	   Primary-tag = 1*8ALPHA
+	   Subtag = 1*8ALPHA */
+
+	rfc822_parser_init(&parser, value, value_len, NULL);
+
+	t_array_init(&langs, 16);
+	str = t_str_new(128);
+
+	rfc822_skip_lwsp(&parser);
+	while (rfc822_parse_atom(&parser, str) >= 0) {
+		const char *lang = p_strdup(pool, str_c(str));
+
+		array_push_back(&langs, &lang);
+		str_truncate(str, 0);
+
+		if (parser.data >= parser.end || *parser.data != ',')
+			break;
+		parser.data++;
+		rfc822_skip_lwsp(&parser);
+	}
+	rfc822_parser_deinit(&parser);
+
+	if (array_count(&langs) > 0) {
+		array_append_zero(&langs);
+		data->content_language =
+			p_strarray_dup(pool, array_front(&langs));
+	}
+}
+
+static void
+parse_content_header(struct message_part_data *data,
+	pool_t pool, struct message_header_line *hdr)
+{
+	const char *name = hdr->name + strlen("Content-");
+
+	if (hdr->continues) {
+		hdr->use_full_value = TRUE;
+		return;
+	}
+
+	switch (*name) {
+	case 'i':
+	case 'I':
+		if (strcasecmp(name, "ID") == 0 && data->content_id == NULL)
+			data->content_id =
+				message_header_strdup(pool, hdr->full_value,
+						      hdr->full_value_len);
+		break;
+
+	case 'm':
+	case 'M':
+		if (strcasecmp(name, "MD5") == 0 && data->content_md5 == NULL)
+			data->content_md5 =
+				message_header_strdup(pool, hdr->full_value,
+						      hdr->full_value_len);
+		break;
+
+	case 't':
+	case 'T':
+		if (strcasecmp(name, "Type") == 0 && data->content_type == NULL)
+			parse_content_type(data, pool, hdr);
+		else if (strcasecmp(name, "Transfer-Encoding") == 0 &&
+			 data->content_transfer_encoding == NULL)
+			parse_content_transfer_encoding(data, pool, hdr);
+		break;
+
+	case 'l':
+	case 'L':
+		if (strcasecmp(name, "Language") == 0 &&
+		    data->content_language == NULL) {
+			parse_content_language(data, pool,
+				hdr->full_value, hdr->full_value_len);
+		} else if (strcasecmp(name, "Location") == 0 &&
+			   data->content_location == NULL) {
+			data->content_location =
+				message_header_strdup(pool, hdr->full_value,
+						      hdr->full_value_len);
+		}
+		break;
+
+	case 'd':
+	case 'D':
+		if (strcasecmp(name, "Description") == 0 &&
+		    data->content_description == NULL)
+			data->content_description =
+				message_header_strdup(pool, hdr->full_value,
+						      hdr->full_value_len);
+		else if (strcasecmp(name, "Disposition") == 0 &&
+			 data->content_disposition_params == NULL)
+			parse_content_disposition(data, pool, hdr);
+		break;
+	}
+}
+
+void message_part_data_parse_from_header(pool_t pool,
+	struct message_part *part,
+	struct message_header_line *hdr)
+{
+	struct message_part_data *part_data;
+	struct message_part_envelope *envelope;
+	bool parent_rfc822;
+
+	if (hdr == NULL) {
+		if (part->data == NULL) {
+			/* no Content-* headers. add an empty context
+			   structure anyway. */
+			part->data = p_new(pool, struct message_part_data, 1);
+		} else if ((part->flags & MESSAGE_PART_FLAG_IS_MIME) == 0) {
+			/* If there was no Mime-Version, forget all
+			   the Content-stuff */
+			part_data = part->data;
+			envelope = part_data->envelope;
+
+			i_zero(part_data);
+			part_data->envelope = envelope;
+		}
+		return;
+	}
+
+	if (hdr->eoh)
+		return;
+
+	parent_rfc822 = part->parent != NULL &&
+		(part->parent->flags & MESSAGE_PART_FLAG_MESSAGE_RFC822) != 0;
+	if (!parent_rfc822 && strncasecmp(hdr->name, "Content-", 8) != 0)
+		return;
+
+	if (part->data == NULL) {
+		/* initialize message part data */
+		part->data = p_new(pool, struct message_part_data, 1);
+	}
+	part_data = part->data;
+
+	if (strncasecmp(hdr->name, "Content-", 8) == 0) {
+		T_BEGIN {
+			parse_content_header(part_data, pool, hdr);
+		} T_END;
+	}
+
+	if (parent_rfc822) {
+		/* message/rfc822, we need the envelope */
+		message_part_envelope_parse_from_header(pool, &part_data->envelope, hdr);
+	}
+}
+
+bool message_part_has_content_types(struct message_part *part,
+				    const char *const *types)
+{
+	struct message_part_data *data = part->data;
+	bool ret = TRUE;
+	const char *const *ptr;
+	const char *content_type;
+
+	i_assert(data != NULL);
+
+	if (data->content_type == NULL)
+		return FALSE;
+	else if (data->content_subtype == NULL)
+		content_type = t_strdup_printf("%s/", data->content_type);
+	else
+		content_type = t_strdup_printf("%s/%s", data->content_type,
+							data->content_subtype);
+	for(ptr = types; *ptr != NULL; ptr++) {
+		bool exclude = (**ptr == '!');
+		if (wildcard_match_icase(content_type, (*ptr)+(exclude?1:0)))
+			ret = !exclude;
+	}
+
+	return ret;
+}
+
+bool message_part_has_parameter(struct message_part *part, const char *parameter,
+				bool has_value)
+{
+	struct message_part_data *data = part->data;
+
+	i_assert(data != NULL);
+
+	for (unsigned int i = 0; i < data->content_disposition_params_count; i++) {
+		const struct message_part_param *param =
+			&data->content_disposition_params[i];
+		if (strcasecmp(param->name, parameter) == 0 &&
+		    (!has_value || *param->value != '\0')) {
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+bool message_part_is_attachment(struct message_part *part,
+				const struct message_part_attachment_settings *set)
+{
+	struct message_part_data *data = part->data;
+
+	i_assert(data != NULL);
+
+	/* see if the content-type is excluded */
+	if (set->content_type_filter != NULL &&
+	    !message_part_has_content_types(part, set->content_type_filter))
+		return FALSE;
+
+	/* accept any attachment, or any inlined attachment with filename,
+	   unless inlined ones are excluded */
+	if (null_strcasecmp(data->content_disposition, "attachment") == 0 ||
+	    (!set->exclude_inlined &&
+	     null_strcasecmp(data->content_disposition, "inline") == 0 &&
+	     message_part_has_parameter(part, "filename", FALSE)))
+		return TRUE;
+	return FALSE;
+}