dirmngr: Allow http URLs with "LOOKUP --url"

* dirmngr/crlfetch.c (read_cert_via_http): New.
(fetch_cert_by_url): Implement http scheme.
--

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2020-04-16 17:53:27 +02:00
parent cec397e002
commit 7f1be1ea52
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
1 changed files with 103 additions and 20 deletions

View File

@ -408,40 +408,124 @@ end_cert_fetch (cert_fetch_context_t context)
}
/* Read a certificate from an HTTP URL and return it as an estream
* memory buffer at R_FP. */
static gpg_error_t
read_cert_via_http (ctrl_t ctrl, const char *url, estream_t *r_fp)
{
gpg_error_t err;
estream_t fp = NULL;
estream_t httpfp = NULL;
size_t nread, nwritten;
char buffer[1024];
if ((err = ks_http_fetch (ctrl, url, KS_HTTP_FETCH_TRUST_CFG, &httpfp)))
goto leave;
/* We now read the data from the web server into a memory buffer.
* To DOS we limit the certificate length to 32k. */
fp = es_fopenmem (32*1024, "rw");
if (!fp)
{
err = gpg_error_from_syserror ();
log_error ("error allocating memory buffer: %s\n", gpg_strerror (err));
goto leave;
}
for (;;)
{
if (es_read (httpfp, buffer, sizeof buffer, &nread))
{
err = gpg_error_from_syserror ();
log_error ("error reading '%s': %s\n",
es_fname_get (httpfp), gpg_strerror (err));
goto leave;
}
if (!nread)
break; /* Ready. */
if (es_write (fp, buffer, nread, &nwritten))
{
err = gpg_error_from_syserror ();
log_error ("error writing '%s': %s\n",
es_fname_get (fp), gpg_strerror (err));
goto leave;
}
else if (nread != nwritten)
{
err = gpg_error (GPG_ERR_EIO);
log_error ("error writing '%s': %s\n",
es_fname_get (fp), "short write");
goto leave;
}
}
es_rewind (fp);
*r_fp = fp;
fp = NULL;
leave:
es_fclose (httpfp);
es_fclose (fp);
return err;
}
/* Lookup a cert by it's URL. */
gpg_error_t
fetch_cert_by_url (ctrl_t ctrl, const char *url,
unsigned char **value, size_t *valuelen)
{
const unsigned char *cert_image;
const unsigned char *cert_image = NULL;
size_t cert_image_n;
ksba_reader_t reader;
ksba_cert_t cert;
ksba_reader_t reader = NULL;
ksba_cert_t cert = NULL;
gpg_error_t err;
*value = NULL;
*valuelen = 0;
cert_image = NULL;
reader = NULL;
cert = NULL;
#if USE_LDAP
err = url_fetch_ldap (ctrl, url, NULL, 0, &reader);
#else
(void)ctrl;
(void)url;
err = gpg_error (GPG_ERR_NOT_IMPLEMENTED);
#endif /*USE_LDAP*/
if (err)
goto leave;
err = ksba_cert_new (&cert);
if (err)
goto leave;
err = ksba_cert_read_der (cert, reader);
if (err)
goto leave;
if (url && (!strncmp (url, "http:", 5) || !strncmp (url, "https:", 6)))
{
estream_t stream;
void *der;
size_t derlen;
err = read_cert_via_http (ctrl, url, &stream);
if (err)
goto leave;
if (es_fclose_snatch (stream, &der, &derlen))
{
err = gpg_error_from_syserror ();
goto leave;
}
err = ksba_cert_init_from_mem (cert, der, derlen);
xfree (der);
if (err)
goto leave;
}
else /* Assume LDAP. */
{
#if USE_LDAP
err = url_fetch_ldap (ctrl, url, NULL, 0, &reader);
#else
(void)ctrl;
(void)url;
err = gpg_error (GPG_ERR_NOT_IMPLEMENTED);
#endif /*USE_LDAP*/
if (err)
goto leave;
err = ksba_cert_read_der (cert, reader);
if (err)
goto leave;
}
cert_image = ksba_cert_get_image (cert, &cert_image_n);
if (!cert_image || !cert_image_n)
@ -461,7 +545,6 @@ fetch_cert_by_url (ctrl_t ctrl, const char *url,
*valuelen = cert_image_n;
leave:
ksba_cert_release (cert);
#if USE_LDAP
ldap_wrapper_release_context (reader);