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| author | Ivan Nardi <12729895+IvanNardi@users.noreply.github.com> | 2021-11-24 10:46:48 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-11-24 10:46:48 +0100 |
| commit | a8ffcd8bb0273d59600c6310a80b81206096c113 (patch) | |
| tree | 2a62911824363509ea5e7c69afa189e98556e495 /example/reader_util.h | |
| parent | fd02e1b3043eecc5711eb8254aadaa3f43ca7503 (diff) | |
Rework how hostname/SNI info is saved (#1330)
Looking at `struct ndpi_flow_struct` the two bigger fields are
`host_server_name[240]` (mainly for HTTP hostnames and DNS domains) and
`protos.tls_quic.client_requested_server_name[256]`
(for TLS/QUIC SNIs).
This commit aims to reduce `struct ndpi_flow_struct` size, according to
two simple observations:
1) maximum one of these two fields is used for each flow. So it seems safe
to merge them;
2) even if hostnames/SNIs might be very long, in practice they are rarely
longer than a fews tens of bytes. So, using a (single) large buffer is a
waste of memory for all kinds of flows. If we need to truncate the name,
we keep the *last* characters, easing domain matching.
Analyzing some real traffic, it seems safe to assume that the vast
majority of hostnames/SNIs is shorter than 80 bytes.
Hostnames/SNIs are always converted to lowercase.
Attention was given so as to be sure that unit-tests outputs are not
affected by this change.
Because of a bug, TLS/QUIC SNI were always truncated to 64 bytes (the
*first* 64 ones): as a consequence, there were some "Suspicious DGA
domain name" and "TLS Certificate Mismatch" false positives.
Diffstat (limited to 'example/reader_util.h')
| -rw-r--r-- | example/reader_util.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/example/reader_util.h b/example/reader_util.h index bb4747ecc..791829ad1 100644 --- a/example/reader_util.h +++ b/example/reader_util.h @@ -197,7 +197,7 @@ typedef struct ndpi_flow_info { char info[255]; char flow_extra_info[16]; - char host_server_name[240]; + char host_server_name[80]; /* Hostname/SNI */ char *bittorent_hash; char *dhcp_fingerprint; char *dhcp_class_ident; @@ -205,7 +205,7 @@ typedef struct ndpi_flow_info { struct { u_int16_t ssl_version; - char client_requested_server_name[256], server_info[64], + char server_info[64], client_hassh[33], server_hassh[33], *server_names, *tls_alpn, *tls_supported_versions, *tls_issuerDN, *tls_subjectDN, |