diff options
author | Hans Jerry Illikainen <hji@dyntopia.com> | 2019-11-22 23:23:12 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2019-11-23 03:18:40 +0300 |
commit | 67a6ea63008bcee32a239934ad29eb5c5a554509 (patch) | |
tree | ced58695d6c423f4ae0db505d095dbd3463fe592 /gpg-interface.c | |
parent | 392b862e9aea69acf43532527e27644c97e3ea56 (diff) |
gpg-interface: limit search for primary key fingerprint
The VALIDSIG status line from GnuPG with --status-fd is documented to
have 9 required and 1 optional fields [1]. The final, and optional,
field is used to specify the fingerprint of the primary key that made
the signature in case it was made by a subkey. However, this field is
only available for OpenPGP signatures; not for CMS/X.509.
If the VALIDSIG status line does not have the optional 10th field, the
current code will continue reading onto the next status line. And this
is the case for non-OpenPGP signatures [1].
The consequence is that a subsequent status line may be considered as
the "primary key" for signatures that does not have an actual primary
key.
Limit the search of these 9 or 10 fields to the single line to avoid
this problem. If the 10th field is missing, report that there is no
primary key fingerprint.
[Reference]
[1] GnuPG Details, General status codes
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=blob;f=doc/DETAILS;h=6ce340e8c04794add995e84308bb3091450bd28f;hb=HEAD#l483
The documentation says:
VALIDSIG <args>
The args are:
- <fingerprint_in_hex>
- <sig_creation_date>
- <sig-timestamp>
- <expire-timestamp>
- <sig-version>
- <reserved>
- <pubkey-algo>
- <hash-algo>
- <sig-class>
- [ <primary-key-fpr> ]
This status indicates that the signature is cryptographically
valid. [...] PRIMARY-KEY-FPR is the fingerprint of the primary key
or identical to the first argument.
The primary-key-fpr parameter is used for OpenPGP and not available
for CMS signatures. [...]
Signed-off-by: Hans Jerry Illikainen <hji@dyntopia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'gpg-interface.c')
-rw-r--r-- | gpg-interface.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/gpg-interface.c b/gpg-interface.c index 37162c9a43..131e7d529e 100644 --- a/gpg-interface.c +++ b/gpg-interface.c @@ -156,21 +156,33 @@ static void parse_gpg_output(struct signature_check *sigc) } /* Do we have fingerprint? */ if (sigcheck_gpg_status[i].flags & GPG_STATUS_FINGERPRINT) { + const char *limit; + char **field; + next = strchrnul(line, ' '); replace_cstring(&sigc->fingerprint, line, next); - /* Skip interim fields */ + /* + * Skip interim fields. The search is + * limited to the same line since only + * OpenPGP signatures has a field with + * the primary fingerprint. + */ + limit = strchrnul(line, '\n'); for (j = 9; j > 0; j--) { - if (!*next) + if (!*next || limit <= next) break; line = next + 1; next = strchrnul(line, ' '); } - next = strchrnul(line, '\n'); - free(sigc->primary_key_fingerprint); - replace_cstring(&sigc->primary_key_fingerprint, - line, next); + field = &sigc->primary_key_fingerprint; + if (!j) { + next = strchrnul(line, '\n'); + replace_cstring(field, line, next); + } else { + replace_cstring(field, NULL, NULL); + } } break; |