sm: Support import and verification of EdDSA certificates.

* sm/certdump.c (gpgsm_get_serial): New.
* sm/certcheck.c (gpgsm_check_cert_sig): Support EdDSA signatures.
--

Note that this does not work with the self-signed RFC-8410 sample
certificate; see the code for comments.

The Ed488 case has not been tested due to a lack of support in
Libgcrypt.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/sm/certdump.c b/sm/certdump.c
index ef60358d7..7d0dfdbf9 100644
--- a/sm/certdump.c
+++ b/sm/certdump.c
@@ -48,6 +48,28 @@ struct dn_array_s {
 };
 
 
+/* Get the first first element from the s-expression SN and return a
+ * pointer to it.  Stores the length at R_LENGTH.  Returns NULL for no
+ * value or an invalid expression.  */
+const void *
+gpgsm_get_serial (ksba_const_sexp_t sn, size_t *r_length)
+{
+  const char *p = (const char *)sn;
+  unsigned long n;
+  char *endp;
+
+  if (!p || *p != '(')
+    return NULL;
+  p++;
+  n = strtoul (p, &endp, 10);
+  p = endp;
+  if (*p++ != ':')
+    return NULL;
+  *r_length = n;
+  return p;
+}
+
+
 /* Print the first element of an S-Expression. */
 void
 gpgsm_print_serial (estream_t fp, ksba_const_sexp_t sn)