Hi, This patch looks good to me. There is just one minor note below:
On 21/03/2021 15:25, Arne Schwabe wrote: > This patch introduces support for verify-hash inlining. > When inlined, this options now allows to specify multiple fingerprints, > one per line. > > Since this is a new syntax, there is no backwards compatibility to take > care of, therefore we can drop support for SHA1. Inlined fingerprints > are assumed be to SHA-256 only. > > Also print a warning about SHA1 hash being deprecated to verify > certificates as it is not "industry standard" anymore. > > Patch v2: fix/clarify various comments, fix a few minor problems, allow > the option to be specified multiple times and have that > added to the list. > > Patch v3: Remove leftover variable, always call > parse_hash_fingerprint_multiline, add comments clarifying list > appending > > Signed-off-by: Arne Schwabe <a...@rfc2549.org> > --- > doc/man-sections/inline-files.rst | 4 +- > doc/man-sections/tls-options.rst | 10 +++ > src/openvpn/options.c | 102 ++++++++++++++++++++++++++---- > src/openvpn/options.h | 10 ++- > src/openvpn/ssl_common.h | 2 +- > src/openvpn/ssl_verify.c | 16 ++++- > 6 files changed, 127 insertions(+), 17 deletions(-) > > diff --git a/doc/man-sections/inline-files.rst > b/doc/man-sections/inline-files.rst > index 819bd3c8..303bb3c8 100644 > --- a/doc/man-sections/inline-files.rst > +++ b/doc/man-sections/inline-files.rst > @@ -4,8 +4,8 @@ INLINE FILE SUPPORT > OpenVPN allows including files in the main configuration for the ``--ca``, > ``--cert``, ``--dh``, ``--extra-certs``, ``--key``, ``--pkcs12``, > ``--secret``, ``--crl-verify``, ``--http-proxy-user-pass``, ``--tls-auth``, > -``--auth-gen-token-secret``, ``--tls-crypt`` and ``--tls-crypt-v2`` > -options. > +``--auth-gen-token-secret``, ``--tls-crypt``, ``--tls-crypt-v2`` and > +``--verify-hash`` options. > > Each inline file started by the line ``<option>`` and ended by the line > ``</option>`` > diff --git a/doc/man-sections/tls-options.rst > b/doc/man-sections/tls-options.rst > index e13fb3c8..d8f9800e 100644 > --- a/doc/man-sections/tls-options.rst > +++ b/doc/man-sections/tls-options.rst > @@ -582,6 +582,16 @@ certificates and keys: > https://github.com/OpenVPN/easy-rsa > The ``algo`` flag can be either :code:`SHA1` or :code:`SHA256`. If not > provided, it defaults to :code:`SHA1`. > > + This option can also be inlined > + :: > + > + <verify-hash> > + > 00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff > + > 11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00 > + </verify-hash> > + > +If the option is inlined, ``algo`` is always :code:`SHA256`. > + > --verify-x509-name args > Accept connections only if a host's X.509 name is equal to **name.** The > remote host must also pass all other tests of verification. > diff --git a/src/openvpn/options.c b/src/openvpn/options.c > index 86e78b05..3b1c69ba 100644 > --- a/src/openvpn/options.c > +++ b/src/openvpn/options.c > @@ -1078,12 +1078,24 @@ string_substitute(const char *src, int from, int to, > struct gc_arena *gc) > return ret; > } > > -static uint8_t * > +/** > + * Parses a hexstring and checks if the string has the correct length. Return > + * a verify_hash_list containing the parsed hash string. > + * > + * @param str String to check/parse > + * @param nbytes Number of bytes expected in the hexstr (e.g. 20 for > SHA1) > + * @param msglevel message level to use when printing warnings/errors > + * @param gc The returned object will be allocated in this gc > + */ > +static struct verify_hash_list * > parse_hash_fingerprint(const char *str, int nbytes, int msglevel, struct > gc_arena *gc) > { > int i; > const char *cp = str; > - uint8_t *ret = (uint8_t *) gc_malloc(nbytes, true, gc); > + > + struct verify_hash_list *ret; > + ALLOC_OBJ_CLEAR_GC(ret, struct verify_hash_list, gc); > + > char term = 1; > int byte; > char bs[3]; > @@ -1102,7 +1114,7 @@ parse_hash_fingerprint(const char *str, int nbytes, int > msglevel, struct gc_aren > { > msg(msglevel, "format error in hash fingerprint hex byte: %s", > str); > } > - ret[i] = (uint8_t)byte; > + ret->hash[i] = (uint8_t)byte; > term = *cp++; > if (term != ':' && term != 0) > { > @@ -1116,10 +1128,55 @@ parse_hash_fingerprint(const char *str, int nbytes, > int msglevel, struct gc_aren > if (term != 0 || i != nbytes-1) > { > msg(msglevel, "hash fingerprint is different length than expected > (%d bytes): %s", nbytes, str); > + return NULL; The rest of this function assumes that msglevel is set to a FATAL level. As you can also see in the hunk above, if blocks handling other errors have no return statement, because they assume the program will exit there. Personally I find this style very counter intuitive. Also we should consider that the msglevel is a variable here, so this very function CANNOT assume that the msglevel contains the FATAL bit. Imagine using this function in a another context in the future, while forgetting about this hidden assumption: disaster. Now, this problem is mostly unrelated to this patch. We just have to make a decision here: 1) remove the "return NULL" (it's just above my text), in order to follow the current function's style - because the return will never be hit; or 2) accept the patch as is and move on. In both cases, this patch gets my ACK. Acked-by: Antonio Quartulli <anto...@openvpn.net> The error handling in the option parser is a topic we could discuss in a meeting. Cheers, -- Antonio Quartulli _______________________________________________ Openvpn-devel mailing list Openvpn-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-devel
