sm: Create ECC certificates with AKI and SKI by default.

* sm/certreqgen.c (create_request): Create AKI and SKI by default.
--
GnuPG-bug-id: 4098

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 127 insertions, 31 deletions

diff --git a/sm/certreqgen.c b/sm/certreqgen.c
index e54569ac8..1dd456452 100644
--- a/sm/certreqgen.c
+++ b/sm/certreqgen.c
@@ -630,7 +630,7 @@ proc_parameters (ctrl_t ctrl, struct para_data_s *para,
 
   /* Check the optional AuthorityKeyId.  */
   string = get_parameter_value (para, pAUTHKEYID, 0);
-  if (string)
+  if (string && strcmp (string, "none"))
     {
       for (s=string, i=0; hexdigitp (s); s++, i++)
         ;
@@ -645,7 +645,7 @@ proc_parameters (ctrl_t ctrl, struct para_data_s *para,
 
   /* Check the optional SubjectKeyId.  */
   string = get_parameter_value (para, pSUBJKEYID, 0);
-  if (string)
+  if (string && strcmp (string, "none"))
     {
       for (s=string, i=0; hexdigitp (s); s++, i++)
         ;
@@ -838,13 +838,22 @@ create_request (ctrl_t ctrl,
   int mdalgo;
   membuf_t tbsbuffer;
   membuf_t *tbsmb = NULL;
+  size_t publiclen;
+  size_t sigkeylen;
+  int publicpkalgo;  /* The gcrypt public key algo of the public key.  */
+  int sigkeypkalgo;  /* The gcrypt public key algo of the signing key.  */
 
   err = ksba_certreq_new (&cr);
   if (err)
     return err;
 
-  len = gcry_sexp_canon_len (public, 0, NULL, NULL);
-  if (get_pk_algo_from_canon_sexp (public, len) == GCRY_PK_EDDSA)
+  publiclen = gcry_sexp_canon_len (public, 0, NULL, NULL);
+  sigkeylen = sigkey? gcry_sexp_canon_len (sigkey, 0, NULL, NULL) : 0;
+
+  publicpkalgo = get_pk_algo_from_canon_sexp (public, publiclen);
+  sigkeypkalgo = sigkey? get_pk_algo_from_canon_sexp (public, publiclen) : 0;
+
+  if (publicpkalgo == GCRY_PK_EDDSA)
     {
       mdalgo = GCRY_MD_SHA512;
       md = NULL;  /* We sign the data and not a hash.  */
@@ -957,12 +966,10 @@ create_request (ctrl_t ctrl,
         }
     }
 
-
   err = ksba_certreq_set_public_key (cr, public);
   if (err)
     {
-      log_error ("error setting the public key: %s\n",
-                 gpg_strerror (err));
+      log_error ("error setting the public key: %s\n", gpg_strerror (err));
       rc = err;
       goto leave;
     }
@@ -1158,15 +1165,17 @@ create_request (ctrl_t ctrl,
          given we set it to the public key to create a self-signed
          certificate. */
       if (!sigkey)
-        sigkey = public;
+        {
+          sigkey = public;
+          sigkeylen = publiclen;
+          sigkeypkalgo = publicpkalgo;
+        }
 
+      /* Set the the digestinfo aka siginfo.  */
       {
         unsigned char *siginfo;
 
-
-        err = transform_sigval (sigkey,
-                                gcry_sexp_canon_len (sigkey, 0, NULL, NULL),
-                                mdalgo, &siginfo, NULL);
+        err = transform_sigval (sigkey, sigkeylen, mdalgo, &siginfo, NULL);
         if (!err)
           {
             err = ksba_certreq_set_siginfo (cr, siginfo);
@@ -1181,9 +1190,12 @@ create_request (ctrl_t ctrl,
           }
       }
 
+
       /* Insert the AuthorityKeyId.  */
       string = get_parameter_value (para, pAUTHKEYID, 0);
-      if (string)
+      if (string && !strcmp (string, "none"))
+        ; /* Do not issue an AKI.  */
+      else if (string)
         {
           char *hexbuf;
 
@@ -1209,20 +1221,69 @@ create_request (ctrl_t ctrl,
           hexbuf[2] = 0x80;  /* Context tag for an implicit Octet string.  */
           hexbuf[3] = len;
           err = ksba_certreq_add_extension (cr, oidstr_authorityKeyIdentifier,
-                                            0,
-                                            hexbuf, 4+len);
+                                            0, hexbuf, 4+len);
           xfree (hexbuf);
           if (err)
             {
-              log_error ("error setting the authority-key-id: %s\n",
+              log_error ("error setting the AKI: %s\n", gpg_strerror (err));
+              goto leave;
+            }
+        }
+      else if (publicpkalgo == GCRY_PK_EDDSA || publicpkalgo == GCRY_PK_ECC)
+        {
+          /* For EdDSA and ECC we add the public key as default identifier.  */
+          const unsigned char *q;
+          size_t qlen, derlen;
+          unsigned char *der;
+
+          err = get_ecc_q_from_canon_sexp (public, publiclen, &q, &qlen);
+          if (err)
+            {
+              log_error ("error getting Q from public key: %s\n",
                          gpg_strerror (err));
               goto leave;
             }
+          if (publicpkalgo == GCRY_PK_EDDSA && qlen>32 && (qlen&1) && *q==0x40)
+            {
+              /* Skip our optional native encoding octet.  */
+              q++;
+              qlen--;
+            }
+          /* FIXME: For plain ECC we should better use a compressed
+           * point.  That requires an updated Libgcrypt.  Without that
+           * using nistp521 won't work due to the length check below.  */
+          if (qlen > 125)
+            {
+              err = gpg_error (GPG_ERR_TOO_LARGE);
+              goto leave;
+            }
+          derlen = 4 + qlen;
+          der = xtrymalloc (derlen);
+          if (!der)
+            {
+              err = gpg_error_from_syserror ();
+              goto leave;
+            }
+          der[0] = 0x30; /* Sequence */
+          der[1] = qlen + 2;
+          der[2] = 0x80; /* Context tag for an implict Octet String. */
+          der[3] = qlen;
+          memcpy (der+4, q, qlen);
+          err = ksba_certreq_add_extension (cr, oidstr_authorityKeyIdentifier,
+                                            0, der, derlen);
+          xfree (der);
+          if (err)
+            {
+              log_error ("error setting the AKI: %s\n", gpg_strerror (err));
+              goto leave;
+            }
         }
 
       /* Insert the SubjectKeyId.  */
       string = get_parameter_value (para, pSUBJKEYID, 0);
-      if (string)
+      if (string && !strcmp (string, "none"))
+        ; /* Do not issue an SKI.  */
+      else if (string)
         {
           char *hexbuf;
 
@@ -1250,10 +1311,53 @@ create_request (ctrl_t ctrl,
           xfree (hexbuf);
           if (err)
             {
-              log_error ("error setting the subject-key-id: %s\n",
+              log_error ("error setting SKI: %s\n", gpg_strerror (err));
+              goto leave;
+            }
+        }
+      else if (sigkeypkalgo == GCRY_PK_EDDSA || sigkeypkalgo == GCRY_PK_ECC)
+        {
+          /* For EdDSA and ECC we add the public key as default identifier.  */
+          const unsigned char *q;
+          size_t qlen, derlen;
+          unsigned char *der;
+
+          err = get_ecc_q_from_canon_sexp (sigkey, sigkeylen, &q, &qlen);
+          if (err)
+            {
+              log_error ("error getting Q from signature key: %s\n",
                          gpg_strerror (err));
               goto leave;
             }
+          if (sigkeypkalgo == GCRY_PK_EDDSA && qlen>32 && (qlen&1) && *q==0x40)
+            {
+              /* Skip our optional native encoding octet.  */
+              q++;
+              qlen--;
+            }
+          if (qlen > 127)
+            {
+              err = gpg_error (GPG_ERR_TOO_LARGE);
+              goto leave;
+            }
+          derlen = 2 + qlen;
+          der = xtrymalloc (derlen);
+          if (!der)
+            {
+              err = gpg_error_from_syserror ();
+              goto leave;
+            }
+          der[0] = 0x04; /* Octet String */
+          der[1] = qlen;
+          memcpy (der+2, q, qlen);
+          err = ksba_certreq_add_extension (cr, oidstr_subjectKeyIdentifier, 0,
+                                            der, derlen);
+          xfree (der);
+          if (err)
+            {
+              log_error ("error setting the SKI: %s\n", gpg_strerror (err));
+              goto leave;
+            }
         }
 
       /* Insert additional extensions.  */
@@ -1329,7 +1433,6 @@ create_request (ctrl_t ctrl,
       if (stopreason == KSBA_SR_NEED_SIG)
         {
           gcry_sexp_t s_pkey;
-          size_t n;
           unsigned char grip[20];
           char hexgrip[41];
           unsigned char *sigval, *newsigval;
@@ -1337,14 +1440,7 @@ create_request (ctrl_t ctrl,
           void *tbsdata;
           size_t tbsdatalen;
 
-          n = gcry_sexp_canon_len (sigkey, 0, NULL, NULL);
-          if (!n)
-            {
-              log_error ("libksba did not return a proper S-Exp\n");
-              rc = gpg_error (GPG_ERR_BUG);
-              goto leave;
-            }
-          rc = gcry_sexp_sscan (&s_pkey, NULL, (const char*)sigkey, n);
+          rc = gcry_sexp_sscan (&s_pkey, NULL, (const char*)sigkey, sigkeylen);
           if (rc)
             {
               log_error ("gcry_sexp_scan failed: %s\n", gpg_strerror (rc));
@@ -1360,8 +1456,9 @@ create_request (ctrl_t ctrl,
           gcry_sexp_release (s_pkey);
           bin2hex (grip, 20, hexgrip);
 
-          log_info ("about to sign the %s for key: &%s\n",
-                    certmode? "certificate":"CSR", hexgrip);
+          if (!opt.quiet)
+            log_info ("about to sign the %s for key: &%s\n",
+                      certmode? "certificate":"CSR", hexgrip);
 
           if (carddirect && !certmode)
             {
@@ -1422,8 +1519,7 @@ create_request (ctrl_t ctrl,
               goto leave;
             }
 
-          err = transform_sigval (sigval, siglen, mdalgo,
-                                  &newsigval, NULL);
+          err = transform_sigval (sigval, siglen, mdalgo, &newsigval, NULL);
           xfree (sigval);
           if (!err)
             {