From: Adrian Perez <aperez@igalia.com>
To: notmuch@notmuchmail.org
Subject: Re: [PATCH] Add pseudo-compatibility with gmime 2.6
In-Reply-To: <20120117034714.GG16740@mit.edu>
References: <8762gbtd6p.fsf@schnouki.net>
	<1326758199-18058-1-git-send-email-schnouki@schnouki.net>
	<20120117034714.GG16740@mit.edu>
User-Agent: Notmuch/0.11 (http://notmuchmail.org) Emacs/23.3.1
	(x86_64-unknown-linux-gnu)
Date: Tue, 17 Jan 2012 12:48:14 +0200
Message-ID: <87ty3u38r5.fsf@igalia.com>
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	micalg=pgp-sha1; protocol="application/pgp-signature"
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Hi,=20

Just a couple of comments inline :)

On Mon, 16 Jan 2012 22:47:14 -0500, Austin Clements <amdragon@MIT.EDU> wrot=
e:
> Quoth Thomas Jost on Jan 17 at 12:56 am:
> > There are lots of API changes in gmime 2.6 crypto handling. By adding
> > preprocessor directives, it is however possible to add gmime 2.6 compat=
ibility
> > while preserving compatibility with gmime 2.4 too.
>=20
> Awesome.  Comments inline below.
>=20
> > This is mostly based on id:"8762i8hrb9.fsf@bookbinder.fernseed.info".
> >=20
> > This was tested against both gmime 2.6.4 and 2.4.31. With gmime 2.4.31,=
 the
> > crypto tests all work fine (as expected). With gmime 2.6.4, one crypto =
test
> > fails (signature verification with signer key unavailable) but this wil=
l be hard
> > to fix since the new API does not report the reason why a signature ver=
ification
> > fails (other than the human-readable error message).
>=20
> What is the result of this failing test?
>=20
> > ---
> >  mime-node.c      |   50 ++++++++++++++++++++++++++-
> >  notmuch-client.h |   27 ++++++++++++++-
> >  notmuch-reply.c  |    7 ++++
> >  notmuch-show.c   |   97 ++++++++++++++++++++++++++++++++++++++++++++++=
++++++++
> >  show-message.c   |    4 ++
> >  5 files changed, 181 insertions(+), 4 deletions(-)
> >=20
> > diff --git a/mime-node.c b/mime-node.c
> > index d26bb44..ae2473d 100644
> > --- a/mime-node.c
> > +++ b/mime-node.c
> > @@ -33,7 +33,11 @@ typedef struct mime_node_context {
> >      GMimeMessage *mime_message;
> >=20=20
> >      /* Context provided by the caller. */
> > +#ifdef GMIME_26
> > +    GMimeCryptoContext *cryptoctx;
> > +#else
> >      GMimeCipherContext *cryptoctx;
> > +#endif
> >      notmuch_bool_t decrypt;
> >  } mime_node_context_t;
> >=20=20
> > @@ -57,8 +61,12 @@ _mime_node_context_free (mime_node_context_t *res)
> >=20=20
> >  notmuch_status_t
> >  mime_node_open (const void *ctx, notmuch_message_t *message,
> > -		GMimeCipherContext *cryptoctx, notmuch_bool_t decrypt,
> > -		mime_node_t **root_out)
> > +#ifdef GMIME_26
> > +		GMimeCryptoContext *cryptoctx,
> > +#else
> > +		GMimeCipherContext *cryptoctx,
> > +#endif
> > +		notmuch_bool_t decrypt, mime_node_t **root_out)
> >  {
> >      const char *filename =3D notmuch_message_get_filename (message);
> >      mime_node_context_t *mctx;
> > @@ -112,12 +120,21 @@ DONE:
> >      return status;
> >  }
> >=20=20
> > +#ifdef GMIME_26
> > +static int
> > +_signature_list_free (GMimeSignatureList **proxy)
> > +{
> > +    g_object_unref (*proxy);
> > +    return 0;
> > +}
> > +#else
> >  static int
> >  _signature_validity_free (GMimeSignatureValidity **proxy)
> >  {
> >      g_mime_signature_validity_free (*proxy);
> >      return 0;
> >  }
> > +#endif
> >=20=20
> >  static mime_node_t *
> >  _mime_node_create (const mime_node_t *parent, GMimeObject *part)
> > @@ -165,11 +182,23 @@ _mime_node_create (const mime_node_t *parent, GMi=
meObject *part)
> >  	    GMimeMultipartEncrypted *encrypteddata =3D
> >  		GMIME_MULTIPART_ENCRYPTED (part);
> >  	    node->decrypt_attempted =3D TRUE;
> > +#ifdef GMIME_26
> > +	    GMimeDecryptResult *decrypt_result =3D g_mime_decrypt_result_new =
();
>=20
> I think g_mime_multipart_encrypted_decrypt allocates the
> GMimeDecryptResult for you, so this will just leak memory.

Yes, this is a leak. The documentation says that the function is
responsible of allocating the GMimeDecryptResult. The g_object_unref()
is still needed in notmuch's code to free it, though.

See http://git.gnome.org/browse/gmime/tree/gmime/gmime-multipart-encrypted.=
c#n282

> > +	    node->decrypted_child =3D g_mime_multipart_encrypted_decrypt
> > +		(encrypteddata, node->ctx->cryptoctx, &decrypt_result, &err);
> > +	    if (node->decrypted_child) {
> > +		node->decrypt_success =3D node->verify_attempted =3D TRUE;
> > +		node->sig_list =3D g_mime_decrypt_result_get_signatures (decrypt_res=
ult);
> > +		if (!node->sig_list)
> > +		    fprintf (stderr, "Failed to get signatures: %s\n",
> > +			     (err ? err->message : "no error explanation given"));
>=20
> My understanding is that g_mime_decrypt_result_get_signatures returns
> NULL if there are no signatures and that this isn't an error.  This
> differs from 2.4, which would return an empty but non-NULL list.
>=20
> Also, I believe you have to free the sig_list in both branches now,
> which means the talloc_set_destructor can be moved to common logic
> outside of the if decrypted/signed.
>=20
> > +#else
> >  	    node->decrypted_child =3D g_mime_multipart_encrypted_decrypt
> >  		(encrypteddata, node->ctx->cryptoctx, &err);
> >  	    if (node->decrypted_child) {
> >  		node->decrypt_success =3D node->verify_attempted =3D TRUE;
> >  		node->sig_validity =3D g_mime_multipart_encrypted_get_signature_vali=
dity (encrypteddata);
> > +#endif
>=20
> It's confusing to have the open braces in the #ifdef'd region with a
> matching close brace outside of it (and I imagine this confuses
> editors and uncrustify, too).  You could either copy the else part in
> both branches of the #ifdef or avoid duplicated code with something
> like
>=20
> #ifdef GMIME_26
>   .. node->decrypted_child =3D ..
> #else
>   .. node->decrypted_child =3D ..
> #endif
>   if (node->decrypted_child) {
>     node->decrypt_success =3D node->verify_attempted =3D TRUE;
> #ifdef GMIME_26
>     node->sig_list =3D ..
> #else
>     node->sig_validity =3D ..
> #endif
>   } else {
>     fprintf (stderr, ..);
>   }
>=20
> >  	    } else {
> >  		fprintf (stderr, "Failed to decrypt part: %s\n",
> >  			 (err ? err->message : "no error explanation given"));
> > @@ -182,6 +211,18 @@ _mime_node_create (const mime_node_t *parent, GMim=
eObject *part)
> >  		     "(must be exactly 2)\n",
> >  		     node->nchildren);
> >  	} else {
> > +#ifdef GMIME_26
> > +	    GMimeSignatureList *sig_list =3D g_mime_multipart_signed_verify
> > +		(GMIME_MULTIPART_SIGNED (part), node->ctx->cryptoctx, &err);
> > +	    node->verify_attempted =3D TRUE;
> > +	    node->sig_list =3D sig_list;
> > +	    if (sig_list) {
> > +		GMimeSignatureList **proxy =3D
> > +		    talloc (node, GMimeSignatureList *);
> > +		*proxy =3D sig_list;
> > +		talloc_set_destructor (proxy, _signature_list_free);
> > +	    }
> > +#else
> >  	    /* For some reason the GMimeSignatureValidity returned
> >  	     * here is not a const (inconsistent with that
> >  	     * returned by
> > @@ -200,10 +241,15 @@ _mime_node_create (const mime_node_t *parent, GMi=
meObject *part)
> >  		*proxy =3D sig_validity;
> >  		talloc_set_destructor (proxy, _signature_validity_free);
> >  	    }
> > +#endif
> >  	}
> >      }
> >=20=20
> > +#ifdef GMIME_26
> > +    if (node->verify_attempted && !node->sig_list)
>=20
> Hmm.  This is correct for signed parts, but will incorrectly trigger
> for an encrypted part with no signatures.  For 2.6, I think this error
> checking may have to move into the branches of the if encrypted/signed
> since for encrypted parts you have to check if
> g_mime_multipart_encrypted_decrypt returned NULL.
>=20
> > +#else
> >      if (node->verify_attempted && !node->sig_validity)
> > +#endif
> >  	fprintf (stderr, "Failed to verify signed part: %s\n",
> >  		 (err ? err->message : "no error explanation given"));
> >=20=20
> > diff --git a/notmuch-client.h b/notmuch-client.h
> > index 517c010..e85f882 100644
> > --- a/notmuch-client.h
> > +++ b/notmuch-client.h
> > @@ -30,6 +30,12 @@
> >=20=20
> >  #include <gmime/gmime.h>
> >=20=20
> > +/* GMIME_CHECK_VERSION is only available in gmime >=3D 2.5. But so are
> > + * GMIME_MAJOR_VERSION and friends. */
>=20
> Hah.
>=20
> > +#ifdef GMIME_MAJOR_VERSION
> > +#define GMIME_26
> > +#endif
> > +
> >  #include "notmuch.h"
> >=20=20
> >  /* This is separate from notmuch-private.h because we're trying to
> > @@ -69,7 +75,11 @@ typedef struct notmuch_show_format {
> >      void (*part_start) (GMimeObject *part,
> >  			int *part_count);
> >      void (*part_encstatus) (int status);
> > +#ifdef GMIME_26
> > +    void (*part_sigstatus) (GMimeSignatureList* siglist);
> > +#else
> >      void (*part_sigstatus) (const GMimeSignatureValidity* validity);
> > +#endif
> >      void (*part_content) (GMimeObject *part);
> >      void (*part_end) (GMimeObject *part);
> >      const char *part_sep;
> > @@ -83,7 +93,11 @@ typedef struct notmuch_show_params {
> >      int entire_thread;
> >      int raw;
> >      int part;
> > +#ifdef GMIME_26
> > +    GMimeCryptoContext* cryptoctx;
> > +#else
> >      GMimeCipherContext* cryptoctx;
> > +#endif
> >      int decrypt;
> >  } notmuch_show_params_t;
> >=20=20
> > @@ -286,7 +300,12 @@ typedef struct mime_node {
> >       * signature.  May be NULL if signature verification failed.  If
> >       * there are simply no signatures, this will be non-NULL with an
> >       * empty signers list. */
> > +#ifdef GMIME_26
> > +    /* TODO: update the above comment... */
>=20
> Since this behaves very differently in 2.6, I think documenting it is
> important (and being very careful about the differences).  Maybe
>=20
> /* The list of signatures for signed or encrypted containers.  If
>  * there are no signatures, this will be NULL. */
>=20
> > +    GMimeSignatureList* sig_list;
> > +#else
> >      const GMimeSignatureValidity *sig_validity;
> > +#endif
> >=20=20
> >      /* Internal: Context inherited from the root iterator. */
> >      struct mime_node_context *ctx;
> > @@ -311,8 +330,12 @@ typedef struct mime_node {
> >   */
> >  notmuch_status_t
> >  mime_node_open (const void *ctx, notmuch_message_t *message,
> > -		GMimeCipherContext *cryptoctx, notmuch_bool_t decrypt,
> > -		mime_node_t **node_out);
> > +#ifdef GMIME_26
> > +		GMimeCryptoContext *cryptoctx,
> > +#else
> > +		GMimeCipherContext *cryptoctx,
> > +#endif
> > +		notmuch_bool_t decrypt, mime_node_t **node_out);
> >=20=20
> >  /* Return a new MIME node for the requested child part of parent.
> >   * parent will be used as the talloc context for the returned child
> > diff --git a/notmuch-reply.c b/notmuch-reply.c
> > index da3acce..dc37c51 100644
> > --- a/notmuch-reply.c
> > +++ b/notmuch-reply.c
> > @@ -688,15 +688,22 @@ notmuch_reply_command (void *ctx, int argc, char =
*argv[])
> >  	reply_format_func =3D notmuch_reply_format_default;
> >=20=20
> >      if (decrypt) {
> > +#ifdef GMIME_26
> > +	/* TODO: GMimePasswordRequestFunc */
> > +	params.cryptoctx =3D g_mime_gpg_context_new (NULL, "gpg");
> > +#else
> >  	GMimeSession* session =3D g_object_new (g_mime_session_get_type(), NU=
LL);
> >  	params.cryptoctx =3D g_mime_gpg_context_new (session, "gpg");
> > +#endif
> >  	if (params.cryptoctx) {
> >  	    g_mime_gpg_context_set_always_trust ((GMimeGpgContext*) params.cr=
yptoctx, FALSE);
> >  	    params.decrypt =3D TRUE;
> >  	} else {
> >  	    fprintf (stderr, "Failed to construct gpg context.\n");
> >  	}
> > +#ifndef GMIME_26
> >  	g_object_unref (session);
> > +#endif
> >      }
> >=20=20
> >      config =3D notmuch_config_open (ctx, NULL, NULL);
> > diff --git a/notmuch-show.c b/notmuch-show.c
> > index d14dac9..263ab72 100644
> > --- a/notmuch-show.c
> > +++ b/notmuch-show.c
> > @@ -76,7 +76,11 @@ static void
> >  format_part_encstatus_json (int status);
> >=20=20
> >  static void
> > +#ifdef GMIME_26
> > +format_part_sigstatus_json (GMimeSignatureList* siglist);
> > +#else
> >  format_part_sigstatus_json (const GMimeSignatureValidity* validity);
> > +#endif
> >=20=20
> >  static void
> >  format_part_content_json (GMimeObject *part);
> > @@ -486,6 +490,21 @@ show_text_part_content (GMimeObject *part, GMimeSt=
ream *stream_out)
> >  	g_object_unref(stream_filter);
> >  }
> >=20=20
> > +#ifdef GMIME_26
> > +static const char*
> > +signature_status_to_string (GMimeSignatureStatus x)
> > +{
> > +    switch (x) {
> > +    case GMIME_SIGNATURE_STATUS_GOOD:
> > +	return "good";
> > +    case GMIME_SIGNATURE_STATUS_BAD:
> > +	return "bad";
> > +    case GMIME_SIGNATURE_STATUS_ERROR:
> > +	return "error";
> > +    }
> > +    return "unknown";
> > +}
> > +#else
> >  static const char*
> >  signer_status_to_string (GMimeSignerStatus x)
> >  {
> > @@ -501,6 +520,7 @@ signer_status_to_string (GMimeSignerStatus x)
> >      }
> >      return "unknown";
> >  }
> > +#endif
> >=20=20
> >  static void
> >  format_part_start_text (GMimeObject *part, int *part_count)
> > @@ -592,6 +612,75 @@ format_part_encstatus_json (int status)
> >      printf ("}]");
> >  }
> >=20=20
> > +#ifdef GMIME_26
> > +static void
> > +format_part_sigstatus_json (GMimeSignatureList *siglist)
> > +{
> > +    printf (", \"sigstatus\": [");
> > +
> > +    if (!siglist) {
> > +	printf ("]");
> > +	return;
> > +     }
> > +
> > +    void *ctx_quote =3D talloc_new (NULL);
> > +    int i;
> > +    for (i =3D 0; i < g_mime_signature_list_length (siglist); ++i) {
>=20
> Style nit: notmuch uses i++.
>=20
> > +	GMimeSignature *signature =3D g_mime_signature_list_get_signature (si=
glist, i);
> > +
> > +	if (i > 0)
> > +	    printf (", ");
> > +
> > +	printf ("{");
> > +
> > +	/* status */
> > +	GMimeSignatureStatus status =3D g_mime_signature_get_status (signatur=
e);
> > +	printf ("\"status\": %s",
> > +		json_quote_str (ctx_quote,
> > +				signature_status_to_string (status)));
> > +
> > +	GMimeCertificate *certificate =3D g_mime_signature_get_certificate (s=
ignature);
> > +	if (status =3D=3D GMIME_SIGNATURE_STATUS_GOOD)
> > +	{
>=20
> Style nit: break after brace.
>=20
> (Presumably this is copied from the existing
> format_part_sigstatus_json, but since it's technically new code
> there's no reason not to fix these up.)
>=20
> > +	    if (certificate)
> > +		printf (", \"fingerprint\": %s", json_quote_str (ctx_quote, g_mime_c=
ertificate_get_fingerprint (certificate)));
> > +	    /* these dates are seconds since the epoch; should we
> > +	     * provide a more human-readable format string? */
> > +	    time_t created =3D g_mime_signature_get_created (signature);
> > +	    if (created !=3D -1)
> > +		printf (", \"created\": %d", (int) created);
> > +	    time_t expires =3D g_mime_signature_get_expires (signature);
> > +	    if (expires > 0)
> > +		printf (", \"expires\": %d", (int) expires);
>=20
> Is it intentional that the two above checks are different?  I would
> think the second should be expires !=3D -1.

Yes, it should check for =E2=80=9Cexpires !=3D -1=E2=80=9D. Also, wouldn't =
it be needed to
cast do =E2=80=9Cexpires !=3D (time_t) -1=E2=80=9D to avoid compiler warnin=
gs? (time_t may
be different from int.)
=20
> > +	    /* output user id only if validity is FULL or ULTIMATE. */
> > +	    /* note that gmime is using the term "trust" here, which
> > +	     * is WRONG.  It's actually user id "validity". */
> > +	    if (certificate)
> > +	    {
>=20
> Break after brace.
>=20
> > +		const char *name =3D g_mime_certificate_get_name (certificate);
> > +		GMimeCertificateTrust trust =3D g_mime_certificate_get_trust (certif=
icate);
> > +		if (name && (trust =3D=3D GMIME_CERTIFICATE_TRUST_FULLY || trust =3D=
=3D GMIME_CERTIFICATE_TRUST_ULTIMATE))
> > +		    printf (", \"userid\": %s", json_quote_str (ctx_quote, name));
> > +	    }
> > +	} else if (certificate) {
> > +	    const char *key_id =3D g_mime_certificate_get_key_id (certificate=
);
> > +	    if (key_id)
> > +		printf (", \"keyid\": %s", json_quote_str (ctx_quote, key_id));
> > +	}
> > +
> > +	GMimeSignatureError errors =3D g_mime_signature_get_errors (signature=
);
> > +	if (errors !=3D GMIME_SIGNATURE_ERROR_NONE) {
> > +	    printf (", \"errors\": %x", errors);
>=20
> This should be %d (I would say 0x%x, but JSON doesn't support hex
> literals).  I see this bug came from the original
> format_part_sigstatus_json.  Maybe there should be a quick patch
> before this one that fixes the source of the bug?
>=20
> > +	}
> > +
> > +	printf ("}");
> > +     }
> > +
> > +    printf ("]");
> > +
> > +    talloc_free (ctx_quote);
> > +}
> > +#else
> >  static void
> >  format_part_sigstatus_json (const GMimeSignatureValidity* validity)
> >  {
> > @@ -652,6 +741,7 @@ format_part_sigstatus_json (const GMimeSignatureVal=
idity* validity)
> >=20=20
> >      talloc_free (ctx_quote);
> >  }
> > +#endif
> >=20=20
> >  static void
> >  format_part_content_json (GMimeObject *part)
> > @@ -990,13 +1080,20 @@ notmuch_show_command (void *ctx, unused (int arg=
c), unused (char *argv[]))
> >  	} else if ((STRNCMP_LITERAL (argv[i], "--verify") =3D=3D 0) ||
> >  		   (STRNCMP_LITERAL (argv[i], "--decrypt") =3D=3D 0)) {
> >  	    if (params.cryptoctx =3D=3D NULL) {
> > +#ifdef GMIME_26
> > +		/* TODO: GMimePasswordRequestFunc */
> > +		if (NULL =3D=3D (params.cryptoctx =3D g_mime_gpg_context_new(NULL, "=
gpg")))
> > +#else
> >  		GMimeSession* session =3D g_object_new(g_mime_session_get_type(), NU=
LL);
> >  		if (NULL =3D=3D (params.cryptoctx =3D g_mime_gpg_context_new(session=
, "gpg")))
> > +#endif
> >  		    fprintf (stderr, "Failed to construct gpg context.\n");
> >  		else
> >  		    g_mime_gpg_context_set_always_trust((GMimeGpgContext*)params.cry=
ptoctx, FALSE);
> > +#ifndef GMIME_26
> >  		g_object_unref (session);
> >  		session =3D NULL;
> > +#endif
> >  	    }
> >  	    if (STRNCMP_LITERAL (argv[i], "--decrypt") =3D=3D 0)
> >  		params.decrypt =3D 1;
> > diff --git a/show-message.c b/show-message.c
> > index 8768889..65269fd 100644
> > --- a/show-message.c
> > +++ b/show-message.c
> > @@ -48,7 +48,11 @@ show_message_part (mime_node_t *node,
> >  	format->part_encstatus (node->decrypt_success);
> >=20=20
> >      if (node->verify_attempted && format->part_sigstatus)
> > +#ifdef GMIME_26
> > +	format->part_sigstatus (node->sig_list);
> > +#else
> >  	format->part_sigstatus (node->sig_validity);
> > +#endif
> >=20=20
> >      format->part_content (part);
> >=20=20

=2D-=20
Adrian Perez <aperez@igalia.com> - Sent from my toaster
Igalia - Free Software Engineering

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