lib-mail: message_part_*_parse_from_header() - Replace NULs with 0x80

This avoids truncation of Content-*, Subject, Message-ID, In-Reply-To and
Date headers in IMAP ENVELOPE, BODY and BODYSTRUCTURE replies. Of course,
NULs in headers are violating RFCs already, so the previous behavior wasn't
really wrong either.

diff --git a/src/lib-mail/message-part-data.c b/src/lib-mail/message-part-data.c
index 57f2d012021ed6473d8f94842d51f5f0ac8d53ed..ca06462c467378bdb2651603eef6721eb2f7e8c9 100644 (file)
--- a/src/lib-mail/message-part-data.c
+++ b/src/lib-mail/message-part-data.c
@@ -170,6 +170,23 @@ envelope_get_field(const char *name)
        return ENVELOPE_FIELD_UNKNOWN;
 }
 
+static const char *
+hdr_strdup(pool_t pool, const unsigned char *data, size_t size)
+{
+       char *dest = p_malloc(pool, size+1);
+
+       if (memchr(data, '\0', size) == NULL) {
+               /* fast path */
+               memcpy(dest, data, size);
+       } else {
+               /* slow path - this could be made faster, but it should be
+                  rare so keep it simple */
+               for (size_t i = 0; i < size; i++)
+                       dest[i] = data[i] == '\0' ? 0x80 : data[i];
+       }
+       return dest;
+}
+
 void message_part_envelope_parse_from_header(pool_t pool,
        struct message_part_envelope **data,
        struct message_header_line *hdr)
@@ -238,8 +255,7 @@ void message_part_envelope_parse_from_header(pool_t pool,
                                                hdr->full_value_len,
                                                UINT_MAX, TRUE);
        } else if (str_p != NULL) {
-               *str_p = p_strndup(pool,
-                       hdr->full_value, hdr->full_value_len);
+               *str_p = hdr_strdup(pool, hdr->full_value, hdr->full_value_len);
        }
 }
 
@@ -407,26 +423,25 @@ parse_content_header(struct message_part_data *data,
        pool_t pool, struct message_header_line *hdr)
 {
        const char *name = hdr->name + strlen("Content-");
-       const char *value;
 
        if (hdr->continues) {
                hdr->use_full_value = TRUE;
                return;
        }
 
-       value = t_strndup(hdr->full_value, hdr->full_value_len);
-
        switch (*name) {
        case 'i':
        case 'I':
                if (strcasecmp(name, "ID") == 0 && data->content_id == NULL)
-                       data->content_id = p_strdup(pool, value);
+                       data->content_id = hdr_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 = p_strdup(pool, value);
+                       data->content_md5 = hdr_strdup(pool, hdr->full_value,
+                                                      hdr->full_value_len);
                break;
 
        case 't':
@@ -446,7 +461,9 @@ parse_content_header(struct message_part_data *data,
                                hdr->full_value, hdr->full_value_len);
                } else if (strcasecmp(name, "Location") == 0 &&
                           data->content_location == NULL) {
-                       data->content_location = p_strdup(pool, value);
+                       data->content_location =
+                               hdr_strdup(pool, hdr->full_value,
+                                          hdr->full_value_len);
                }
                break;
 
@@ -454,7 +471,9 @@ parse_content_header(struct message_part_data *data,
        case 'D':
                if (strcasecmp(name, "Description") == 0 &&
                    data->content_description == NULL)
-                       data->content_description = p_strdup(pool, value);
+                       data->content_description =
+                               hdr_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);