[PATCH v2 02/10] crypto: make shared crypto code behave library-like
Jani Nikula
jani at nikula.org
Sat Sep 23 08:36:18 PDT 2017
On Fri, 15 Sep 2017, Daniel Kahn Gillmor <dkg at fifthhorseman.net> wrote:
> If we're going to reuse the crypto code across both the library and
> the client, then it needs to report error states properly and not
> write to stderr.
> ---
> lib/database.cc | 6 ++++
> lib/notmuch.h | 17 +++++++++++
> mime-node.c | 7 ++++-
> util/crypto.c | 89 ++++++++++++++++++++++++++++-----------------------------
> util/crypto.h | 6 ++--
> 5 files changed, 76 insertions(+), 49 deletions(-)
>
> diff --git a/lib/database.cc b/lib/database.cc
> index 79eb3d69..82a3d463 100644
> --- a/lib/database.cc
> +++ b/lib/database.cc
> @@ -413,6 +413,12 @@ notmuch_status_to_string (notmuch_status_t status)
> return "Operation requires a database upgrade";
> case NOTMUCH_STATUS_PATH_ERROR:
> return "Path supplied is illegal for this function";
> + case NOTMUCH_STATUS_MALFORMED_CRYPTO_PROTOCOL:
> + return "Crypto protocol missing, malformed, or unintelligible";
> + case NOTMUCH_STATUS_FAILED_CRYPTO_CONTEXT_CREATION:
> + return "Crypto engine initialization failure";
> + case NOTMUCH_STATUS_UNKNOWN_CRYPTO_PROTOCOL:
> + return "Unknown crypto protocol";
> default:
> case NOTMUCH_STATUS_LAST_STATUS:
> return "Unknown error status value";
> diff --git a/lib/notmuch.h b/lib/notmuch.h
> index f26565f3..6c76fb40 100644
> --- a/lib/notmuch.h
> +++ b/lib/notmuch.h
> @@ -191,6 +191,23 @@ typedef enum _notmuch_status {
> * function, in a way not covered by a more specific argument.
> */
> NOTMUCH_STATUS_ILLEGAL_ARGUMENT,
> + /**
> + * A MIME object claimed to have cryptographic protection which
> + * notmuch tried to handle, but the protocol was not specified in
> + * an intelligible way.
> + */
> + NOTMUCH_STATUS_MALFORMED_CRYPTO_PROTOCOL,
> + /**
> + * Notmuch attempted to do crypto processing, but could not
> + * initialize the engine needed to do so.
> + */
> + NOTMUCH_STATUS_FAILED_CRYPTO_CONTEXT_CREATION,
> + /**
> + * A MIME object claimed to have cryptographic protection, and
> + * notmuch attempted to process it, but the specific protocol was
> + * something that notmuch doesn't know how to handle.
> + */
> + NOTMUCH_STATUS_UNKNOWN_CRYPTO_PROTOCOL,
> /**
> * Not an actual status value. Just a way to find out how many
> * valid status values there are.
> diff --git a/mime-node.c b/mime-node.c
> index d9ff7de1..6cd7d2de 100644
> --- a/mime-node.c
> +++ b/mime-node.c
> @@ -265,7 +265,12 @@ _mime_node_create (mime_node_t *parent, GMimeObject *part)
> || (GMIME_IS_MULTIPART_SIGNED (part) && node->ctx->crypto->verify)) {
> GMimeContentType *content_type = g_mime_object_get_content_type (part);
> const char *protocol = g_mime_content_type_get_parameter (content_type, "protocol");
> - cryptoctx = _notmuch_crypto_get_gmime_context (node->ctx->crypto, protocol);
> + notmuch_status_t status;
> + status = _notmuch_crypto_get_gmime_ctx_for_protocol (node->ctx->crypto,
> + protocol, &cryptoctx);
> + if (status) /* this is a warning, not an error */
> + fprintf (stderr, "Warning: %s (%s).\n", notmuch_status_to_string (status),
> + protocol ? protocol : "(NULL)");
For NULL protocol this will print "((NULL))".
> if (!cryptoctx)
> return NULL;
I guess this will work because we initialize cryptoctx to NULL, but if
we return the status, I think we should trust status == success means
cryptoctx is fine, and otherwise we shouldn't touch or look at
cryptoctx.
Other than that, LGTM.
BR,
Jani.
> }
> diff --git a/util/crypto.c b/util/crypto.c
> index 97e8c8f4..e7908197 100644
> --- a/util/crypto.c
> +++ b/util/crypto.c
> @@ -27,86 +27,86 @@
> #define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
>
> #if (GMIME_MAJOR_VERSION < 3)
> -/* Create a GPG context (GMime 2.6) */
> -static GMimeCryptoContext*
> -create_gpg_context (_notmuch_crypto_t *crypto)
> +/* Create or pass on a GPG context (GMime 2.6) */
> +static notmuch_status_t
> +get_gpg_context (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx)
> {
> - GMimeCryptoContext *gpgctx;
> + if (ctx == NULL || crypto == NULL)
> + return NOTMUCH_STATUS_NULL_POINTER;
>
> if (crypto->gpgctx) {
> - return crypto->gpgctx;
> + *ctx = crypto->gpgctx;
> + return NOTMUCH_STATUS_SUCCESS;
> }
>
> /* TODO: GMimePasswordRequestFunc */
> - gpgctx = g_mime_gpg_context_new (NULL, crypto->gpgpath ? crypto->gpgpath : "gpg");
> - if (! gpgctx) {
> - fprintf (stderr, "Failed to construct gpg context.\n");
> - return NULL;
> + crypto->gpgctx = g_mime_gpg_context_new (NULL, crypto->gpgpath ? crypto->gpgpath : "gpg");
> + if (! crypto->gpgctx) {
> + return NOTMUCH_STATUS_FAILED_CRYPTO_CONTEXT_CREATION;
> }
> - crypto->gpgctx = gpgctx;
>
> - g_mime_gpg_context_set_use_agent ((GMimeGpgContext *) gpgctx, TRUE);
> - g_mime_gpg_context_set_always_trust ((GMimeGpgContext *) gpgctx, FALSE);
> + g_mime_gpg_context_set_use_agent ((GMimeGpgContext *) crypto->gpgctx, TRUE);
> + g_mime_gpg_context_set_always_trust ((GMimeGpgContext *) crypto->gpgctx, FALSE);
>
> - return crypto->gpgctx;
> + *ctx = crypto->gpgctx;
> + return NOTMUCH_STATUS_SUCCESS;
> }
>
> -/* Create a PKCS7 context (GMime 2.6) */
> -static GMimeCryptoContext*
> -create_pkcs7_context (_notmuch_crypto_t *crypto)
> +/* Create or pass on a PKCS7 context (GMime 2.6) */
> +static notmuch_status_t
> +get_pkcs7_context (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx)
> {
> - GMimeCryptoContext *pkcs7ctx;
> + if (ctx == NULL || crypto == NULL)
> + return NOTMUCH_STATUS_NULL_POINTER;
>
> - if (crypto->pkcs7ctx)
> - return crypto->pkcs7ctx;
> + if (crypto->pkcs7ctx) {
> + *ctx = crypto->pkcs7ctx;
> + return NOTMUCH_STATUS_SUCCESS;
> + }
>
> /* TODO: GMimePasswordRequestFunc */
> - pkcs7ctx = g_mime_pkcs7_context_new (NULL);
> - if (! pkcs7ctx) {
> - fprintf (stderr, "Failed to construct pkcs7 context.\n");
> - return NULL;
> + crypto->pkcs7ctx = g_mime_pkcs7_context_new (NULL);
> + if (! crypto->pkcs7ctx) {
> + return NOTMUCH_STATUS_FAILED_CRYPTO_CONTEXT_CREATION;
> }
> - crypto->pkcs7ctx = pkcs7ctx;
>
> - g_mime_pkcs7_context_set_always_trust ((GMimePkcs7Context *) pkcs7ctx,
> + g_mime_pkcs7_context_set_always_trust ((GMimePkcs7Context *) crypto->pkcs7ctx,
> FALSE);
>
> - return crypto->pkcs7ctx;
> + *ctx = crypto->pkcs7ctx;
> + return NOTMUCH_STATUS_SUCCESS;
> }
> static const struct {
> const char *protocol;
> - GMimeCryptoContext *(*get_context) (_notmuch_crypto_t *crypto);
> + notmuch_status_t (*get_context) (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx);
> } protocols[] = {
> {
> .protocol = "application/pgp-signature",
> - .get_context = create_gpg_context,
> + .get_context = get_gpg_context,
> },
> {
> .protocol = "application/pgp-encrypted",
> - .get_context = create_gpg_context,
> + .get_context = get_gpg_context,
> },
> {
> .protocol = "application/pkcs7-signature",
> - .get_context = create_pkcs7_context,
> + .get_context = get_pkcs7_context,
> },
> {
> .protocol = "application/x-pkcs7-signature",
> - .get_context = create_pkcs7_context,
> + .get_context = get_pkcs7_context,
> },
> };
>
> /* for the specified protocol return the context pointer (initializing
> * if needed) */
> -GMimeCryptoContext *
> -_notmuch_crypto_get_gmime_context (_notmuch_crypto_t *crypto, const char *protocol)
> +notmuch_status_t
> +_notmuch_crypto_get_gmime_ctx_for_protocol (_notmuch_crypto_t *crypto,
> + const char *protocol,
> + GMimeCryptoContext **ctx)
> {
> - GMimeCryptoContext *cryptoctx = NULL;
> - size_t i;
> -
> - if (! protocol) {
> - fprintf (stderr, "Cryptographic protocol is empty.\n");
> - return cryptoctx;
> - }
> + if (! protocol)
> + return NOTMUCH_STATUS_MALFORMED_CRYPTO_PROTOCOL;
>
> /* As per RFC 1847 section 2.1: "the [protocol] value token is
> * comprised of the type and sub-type tokens of the Content-Type".
> @@ -114,15 +114,12 @@ _notmuch_crypto_get_gmime_context (_notmuch_crypto_t *crypto, const char *protoc
> * parameter names as defined in this document are
> * case-insensitive." Thus, we use strcasecmp for the protocol.
> */
> - for (i = 0; i < ARRAY_SIZE (protocols); i++) {
> + for (size_t i = 0; i < ARRAY_SIZE (protocols); i++) {
> if (strcasecmp (protocol, protocols[i].protocol) == 0)
> - return protocols[i].get_context (crypto);
> + return protocols[i].get_context (crypto, ctx);
> }
>
> - fprintf (stderr, "Unknown or unsupported cryptographic protocol %s.\n",
> - protocol);
> -
> - return NULL;
> + return NOTMUCH_STATUS_UNKNOWN_CRYPTO_PROTOCOL;
> }
>
> void
> diff --git a/util/crypto.h b/util/crypto.h
> index 6d15a6ae..d653ffb4 100644
> --- a/util/crypto.h
> +++ b/util/crypto.h
> @@ -21,8 +21,10 @@ typedef struct _notmuch_crypto {
>
>
> #if (GMIME_MAJOR_VERSION < 3)
> -GMimeCryptoContext *
> -_notmuch_crypto_get_gmime_context (_notmuch_crypto_t *crypto, const char *protocol);
> +notmuch_status_t
> +_notmuch_crypto_get_gmime_ctx_for_protocol (_notmuch_crypto_t *crypto,
> + const char *protocol,
> + GMimeCryptoContext **ctx);
> #endif
>
> void
> --
> 2.14.1
>
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