sm: Support creation of EdDSA certificates.

* sm/misc.c (transform_sigval): Support EdDSA.
* sm/certreqgen.c (create_request): Support EdDSA cert creation.
* sm/certcheck.c (gpgsm_check_cert_sig): Map some ECC algo OIDs to
hash algos.
* sm/call-agent.c (struct sethash_inq_parm_s): New.
(sethash_inq_cb): New.
(gpgsm_agent_pksign): Add mode to pass plain data for EdDSA.
--

Tested using a parameter file

    Key-Type: EdDSA
    Key-Length: 1024
    Key-Grip: 09D9AE3D494F7888C93BE5106AD8A734A87617F0
    Key-Usage: sign
    Serial: random
    Name-DN: CN=dummy test ed25519

where the keygrip is from a gpg generated Ed25519 key.  ECDSA was
tested using

    Key-Type: ECDSA
    Key-Length: 1024
    Key-Grip: 8E06A180EFFE4C65B812150CAF19BF30C0689A4C
    Key-Usage: sign
    Serial: random
    Name-DN: CN=dummy test nistp256

and RSA using

    Key-Type: RSA
    Key-Length: 2048
    Key-Grip: C6A6390E9388CDBAD71EAEA698233FE5E04F001E
    Key-Usage: sign
    Serial: random
    Name-DN: CN=dummy test rsa

The command used in all cases is

  gpgsm -v --gen-key --batch  a.parm >a.crt
  gpgsm -v --import <a.crt

More support, in particular in the user interface, is required and
will follow soon.

GnuPG-bug-id: 4888
Signed-off-by: Werner Koch <wk@gnupg.org>

4 files changed, 183 insertions, 63 deletions

diff --git a/sm/call-agent.c b/sm/call-agent.c
index 5f4236b69..ec8020517 100644
--- a/sm/call-agent.c
+++ b/sm/call-agent.c
@@ -76,6 +76,13 @@ struct import_key_parm_s
   size_t keylen;
 };
 
+struct sethash_inq_parm_s
+{
+  assuan_context_t ctx;
+  const void *data;
+  size_t datalen;
+};
+
 struct default_inq_parm_s
 {
   ctrl_t ctrl;
@@ -257,8 +264,29 @@ default_inq_cb (void *opaque, const char *line)
 
 
 
+/* This is the inquiry callback required by the SETHASH command.  */
+static gpg_error_t
+sethash_inq_cb (void *opaque, const char *line)
+{
+  gpg_error_t err = 0;
+  struct sethash_inq_parm_s *parm = opaque;
+
+  if (has_leading_keyword (line, "TBSDATA"))
+    {
+      err = assuan_send_data (parm->ctx, parm->data, parm->datalen);
+    }
+  else
+    log_error ("ignoring gpg-agent inquiry '%s'\n", line);
+
+  return err;
+}
+
+
 /* Call the agent to do a sign operation using the key identified by
-   the hex string KEYGRIP. */
+ * the hex string KEYGRIP.  If DIGESTALGO is given (DIGEST,DIGESTLEN)
+ * gives the to be signed hash created using the given algo.  If
+ * DIGESTALGO is not given (i.e. zero) (DIGEST,DIGESTALGO) give the
+ * entire data to-be-signed. */
 int
 gpgsm_agent_pksign (ctrl_t ctrl, const char *keygrip, const char *desc,
                     unsigned char *digest, size_t digestlen, int digestalgo,
@@ -277,7 +305,7 @@ gpgsm_agent_pksign (ctrl_t ctrl, const char *keygrip, const char *desc,
   inq_parm.ctrl = ctrl;
   inq_parm.ctx = agent_ctx;
 
-  if (digestlen*2 + 50 > DIM(line))
+  if (digestalgo && digestlen*2 + 50 > DIM(line))
     return gpg_error (GPG_ERR_GENERAL);
 
   rc = assuan_transact (agent_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
@@ -298,11 +326,26 @@ gpgsm_agent_pksign (ctrl_t ctrl, const char *keygrip, const char *desc,
         return rc;
     }
 
-  sprintf (line, "SETHASH %d ", digestalgo);
-  p = line + strlen (line);
-  for (i=0; i < digestlen ; i++, p += 2 )
-    sprintf (p, "%02X", digest[i]);
-  rc = assuan_transact (agent_ctx, line, NULL, NULL, NULL, NULL, NULL, NULL);
+  if (!digestalgo)
+    {
+      struct sethash_inq_parm_s sethash_inq_parm;
+
+      sethash_inq_parm.ctx = agent_ctx;
+      sethash_inq_parm.data = digest;
+      sethash_inq_parm.datalen = digestlen;
+      rc = assuan_transact (agent_ctx, "SETHASH --inquire",
+                            NULL, NULL, sethash_inq_cb, &sethash_inq_parm,
+                            NULL, NULL);
+    }
+  else
+    {
+      snprintf (line, sizeof line, "SETHASH %d ", digestalgo);
+      p = line + strlen (line);
+      for (i=0; i < digestlen ; i++, p += 2 )
+        sprintf (p, "%02X", digest[i]);
+      rc = assuan_transact (agent_ctx, line,
+                            NULL, NULL, NULL, NULL, NULL, NULL);
+    }
   if (rc)
     return rc;
 
diff --git a/sm/certcheck.c b/sm/certcheck.c
index 3dcac2ffa..3604ac788 100644
--- a/sm/certcheck.c
+++ b/sm/certcheck.c
@@ -360,6 +360,8 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert)
   int use_eddsa = 0;
   unsigned int saltlen;
 
+  /* Note that we map the 4 algos which current Libgcrypt versions are
+   * not aware of the OID.  */
   algo = gcry_md_map_name ( (algoid=ksba_cert_get_digest_algo (cert)));
   if (!algo && algoid && !strcmp (algoid, "1.2.840.113549.1.1.10"))
     use_pss = 1;
@@ -367,6 +369,14 @@ gpgsm_check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert)
     use_eddsa = 1;
   else if (algoid && !strcmp (algoid, "1.3.101.113"))
     use_eddsa = 2;
+  else if (!algo && algoid && !strcmp (algoid, "1.2.840.10045.4.3.1"))
+    algo = GCRY_MD_SHA224; /* ecdsa-with-sha224 */
+  else if (!algo && algoid && !strcmp (algoid, "1.2.840.10045.4.3.2"))
+    algo = GCRY_MD_SHA256; /* ecdsa-with-sha256 */
+  else if (!algo && algoid && !strcmp (algoid, "1.2.840.10045.4.3.3"))
+    algo = GCRY_MD_SHA384; /* ecdsa-with-sha384 */
+  else if (!algo && algoid && !strcmp (algoid, "1.2.840.10045.4.3.4"))
+    algo = GCRY_MD_SHA512; /* ecdsa-with-sha512 */
   else if (!algo)
     {
       log_error ("unknown digest algorithm '%s' used in certificate\n",
diff --git a/sm/certreqgen.c b/sm/certreqgen.c
index 3fbab2d50..e54569ac8 100644
--- a/sm/certreqgen.c
+++ b/sm/certreqgen.c
@@ -67,6 +67,7 @@
 
 #include "keydb.h"
 #include "../common/i18n.h"
+#include "../common/membuf.h"
 
 
 enum para_name
@@ -835,6 +836,8 @@ create_request (ctrl_t ctrl,
   ksba_isotime_t atime;
   int certmode = 0;
   int mdalgo;
+  membuf_t tbsbuffer;
+  membuf_t *tbsmb = NULL;
 
   err = ksba_certreq_new (&cr);
   if (err)
@@ -842,21 +845,31 @@ create_request (ctrl_t ctrl,
 
   len = gcry_sexp_canon_len (public, 0, NULL, NULL);
   if (get_pk_algo_from_canon_sexp (public, len) == GCRY_PK_EDDSA)
-    mdalgo = GCRY_MD_SHA512;
-  else if ((string = get_parameter_value (para, pHASHALGO, 0)))
-    mdalgo = gcry_md_map_name (string);
+    {
+      mdalgo = GCRY_MD_SHA512;
+      md = NULL;  /* We sign the data and not a hash.  */
+      init_membuf (&tbsbuffer, 2048);
+      tbsmb = &tbsbuffer;
+      ksba_certreq_set_hash_function
+        (cr, (void (*)(void *, const void*,size_t))put_membuf, tbsmb);
+    }
   else
-    mdalgo = GCRY_MD_SHA256;
-  rc = gcry_md_open (&md, mdalgo, 0);
-  if (rc)
     {
-      log_error ("md_open failed: %s\n", gpg_strerror (rc));
-      goto leave;
+      if ((string = get_parameter_value (para, pHASHALGO, 0)))
+        mdalgo = gcry_md_map_name (string);
+      else
+        mdalgo = GCRY_MD_SHA256;
+      rc = gcry_md_open (&md, mdalgo, 0);
+      if (rc)
+        {
+          log_error ("md_open failed: %s\n", gpg_strerror (rc));
+          goto leave;
+        }
+      if (DBG_HASHING)
+        gcry_md_debug (md, "cr.cri");
+      ksba_certreq_set_hash_function (cr, HASH_FNC, md);
     }
-  if (DBG_HASHING)
-    gcry_md_debug (md, "cr.cri");
 
-  ksba_certreq_set_hash_function (cr, HASH_FNC, md);
   ksba_certreq_set_writer (cr, writer);
 
   err = ksba_certreq_add_subject (cr, get_parameter_value (para, pNAMEDN, 0));
@@ -1150,6 +1163,7 @@ create_request (ctrl_t ctrl,
       {
         unsigned char *siginfo;
 
+
         err = transform_sigval (sigkey,
                                 gcry_sexp_canon_len (sigkey, 0, NULL, NULL),
                                 mdalgo, &siginfo, NULL);
@@ -1320,6 +1334,8 @@ create_request (ctrl_t ctrl,
           char hexgrip[41];
           unsigned char *sigval, *newsigval;
           size_t siglen;
+          void *tbsdata;
+          size_t tbsdatalen;
 
           n = gcry_sexp_canon_len (sigkey, 0, NULL, NULL);
           if (!n)
@@ -1348,11 +1364,26 @@ create_request (ctrl_t ctrl,
                     certmode? "certificate":"CSR", hexgrip);
 
           if (carddirect && !certmode)
-            rc = gpgsm_scd_pksign (ctrl, carddirect, NULL,
-                                   gcry_md_read (md, mdalgo),
-                                   gcry_md_get_algo_dlen (mdalgo),
-                                   mdalgo,
-                                   &sigval, &siglen);
+            {
+              if (tbsmb)
+                {
+                  tbsdata = get_membuf (tbsmb, &tbsdatalen);
+                  tbsmb = NULL;
+                  if (!tbsdata)
+                    rc = gpg_error_from_syserror ();
+                  else
+                    rc = gpgsm_scd_pksign (ctrl, carddirect, NULL,
+                                           tbsdata, tbsdatalen, 0,
+                                           &sigval, &siglen);
+                  xfree (tbsdata);
+                }
+              else
+                rc = gpgsm_scd_pksign (ctrl, carddirect, NULL,
+                                       gcry_md_read (md, mdalgo),
+                                       gcry_md_get_algo_dlen (mdalgo),
+                                       mdalgo,
+                                       &sigval, &siglen);
+            }
           else
             {
               char *orig_codeset;
@@ -1364,11 +1395,25 @@ create_request (ctrl_t ctrl,
                    " the passphrase for the key you just created once"
                    " more.\n"));
               i18n_switchback (orig_codeset);
-              rc = gpgsm_agent_pksign (ctrl, hexgrip, desc,
-                                       gcry_md_read(md, mdalgo),
-                                       gcry_md_get_algo_dlen (mdalgo),
-                                       mdalgo,
-                                       &sigval, &siglen);
+              if (tbsmb)
+                {
+                  tbsdata = get_membuf (tbsmb, &tbsdatalen);
+                  tbsmb = NULL;
+                  if (!tbsdata)
+                    rc = gpg_error_from_syserror ();
+                  else
+                    rc = gpgsm_agent_pksign (ctrl, hexgrip, desc,
+                                             tbsdata, tbsdatalen, 0,
+
+                                             &sigval, &siglen);
+                  xfree (tbsdata);
+                }
+              else
+                rc = gpgsm_agent_pksign (ctrl, hexgrip, desc,
+                                         gcry_md_read(md, mdalgo),
+                                         gcry_md_get_algo_dlen (mdalgo),
+                                         mdalgo,
+                                         &sigval, &siglen);
               xfree (desc);
             }
           if (rc)
@@ -1398,6 +1443,8 @@ create_request (ctrl_t ctrl,
 
 
  leave:
+  if (tbsmb)
+    xfree (get_membuf (tbsmb, NULL));
   gcry_md_close (md);
   ksba_certreq_release (cr);
   return rc;
diff --git a/sm/misc.c b/sm/misc.c
index 954529390..99f6da63c 100644
--- a/sm/misc.c
+++ b/sm/misc.c
@@ -101,7 +101,7 @@ setup_pinentry_env (void)
    function ignores missing parameters so that it can also be used to
    create an siginfo value as expected by ksba_certreq_set_siginfo.
    To create a siginfo s-expression a public-key s-expression may be
-   used instead of a sig-val.  We only support RSA for now.  */
+   used instead of a sig-val.  */
 gpg_error_t
 transform_sigval (const unsigned char *sigval, size_t sigvallen, int mdalgo,
                   unsigned char **r_newsigval, size_t *r_newsigvallen)
@@ -115,6 +115,7 @@ transform_sigval (const unsigned char *sigval, size_t sigvallen, int mdalgo,
   size_t rsa_s_len, ecc_r_len, ecc_s_len;
   const char *oid;
   gcry_sexp_t sexp;
+  const char *eddsa_curve = NULL;
 
   rsa_s = ecc_r = ecc_s = NULL;
   rsa_s_len = ecc_r_len = ecc_s_len = 0;
@@ -144,6 +145,8 @@ transform_sigval (const unsigned char *sigval, size_t sigvallen, int mdalgo,
     return gpg_error (GPG_ERR_WRONG_PUBKEY_ALGO);
   if (toklen == 3 && !memcmp ("rsa", tok, 3))
     pkalgo = GCRY_PK_RSA;
+  else if (toklen == 3 && !memcmp ("ecc", tok, 3))
+    pkalgo = GCRY_PK_ECC;
   else if (toklen == 5 && !memcmp ("ecdsa", tok, 5))
     pkalgo = GCRY_PK_ECC;
   else if (toklen == 5 && !memcmp ("eddsa", tok, 5))
@@ -191,6 +194,18 @@ transform_sigval (const unsigned char *sigval, size_t sigvallen, int mdalgo,
               *mpi_len = toklen;
             }
         }
+      else if (toklen == 5 && !memcmp (tok, "curve", 5))
+        {
+          if ((err = parse_sexp (&buf, &buflen, &depth, &tok, &toklen)))
+            return err;
+          if ((toklen == 7 && !memcmp (tok, "Ed25519", 7))
+              || (toklen == 22 && !memcmp (tok, "1.3.6.1.4.1.11591.15.1", 22))
+              || (toklen == 11 && !memcmp (tok, "1.3.101.112", 11)))
+            eddsa_curve = "1.3.101.112";
+          else if ((toklen == 5 && !memcmp (tok, "Ed448", 5))
+                   || (toklen == 11 && !memcmp (tok, "1.3.101.113", 11)))
+            eddsa_curve = "1.3.101.113";
+        }
 
       /* Skip to the end of the list. */
       last_depth2 = depth;
@@ -203,50 +218,55 @@ transform_sigval (const unsigned char *sigval, size_t sigvallen, int mdalgo,
   if (err)
     return err;
 
-  /* Map the hash algorithm to an OID.  */
-  if (mdalgo < 0 || mdalgo > (1<<15) || pkalgo < 0 || pkalgo > (1<<15))
-    return gpg_error (GPG_ERR_DIGEST_ALGO);
-
-  switch (mdalgo | (pkalgo << 16))
+  if (eddsa_curve)
+    oid = eddsa_curve;
+  else
     {
-    case GCRY_MD_SHA1 | (GCRY_PK_RSA << 16):
-      oid = "1.2.840.113549.1.1.5";  /* sha1WithRSAEncryption */
-      break;
+      /* Map the hash algorithm to an OID.  */
+      if (mdalgo < 0 || mdalgo > (1<<15) || pkalgo < 0 || pkalgo > (1<<15))
+        return gpg_error (GPG_ERR_DIGEST_ALGO);
 
-    case GCRY_MD_SHA256 | (GCRY_PK_RSA << 16):
-      oid = "1.2.840.113549.1.1.11"; /* sha256WithRSAEncryption */
-      break;
+      switch (mdalgo | (pkalgo << 16))
+        {
+        case GCRY_MD_SHA1 | (GCRY_PK_RSA << 16):
+          oid = "1.2.840.113549.1.1.5";  /* sha1WithRSAEncryption */
+          break;
 
-    case GCRY_MD_SHA384 | (GCRY_PK_RSA << 16):
-      oid = "1.2.840.113549.1.1.12"; /* sha384WithRSAEncryption */
-      break;
+        case GCRY_MD_SHA256 | (GCRY_PK_RSA << 16):
+          oid = "1.2.840.113549.1.1.11"; /* sha256WithRSAEncryption */
+          break;
 
-    case GCRY_MD_SHA512 | (GCRY_PK_RSA << 16):
-      oid = "1.2.840.113549.1.1.13"; /* sha512WithRSAEncryption */
-      break;
+        case GCRY_MD_SHA384 | (GCRY_PK_RSA << 16):
+          oid = "1.2.840.113549.1.1.12"; /* sha384WithRSAEncryption */
+          break;
 
-    case GCRY_MD_SHA224 | (GCRY_PK_ECC << 16):
-      oid = "1.2.840.10045.4.3.1"; /* ecdsa-with-sha224 */
-      break;
+        case GCRY_MD_SHA512 | (GCRY_PK_RSA << 16):
+          oid = "1.2.840.113549.1.1.13"; /* sha512WithRSAEncryption */
+          break;
 
-    case GCRY_MD_SHA256 | (GCRY_PK_ECC << 16):
-      oid = "1.2.840.10045.4.3.2"; /* ecdsa-with-sha256 */
-      break;
+        case GCRY_MD_SHA224 | (GCRY_PK_ECC << 16):
+          oid = "1.2.840.10045.4.3.1"; /* ecdsa-with-sha224 */
+          break;
 
-    case GCRY_MD_SHA384 | (GCRY_PK_ECC << 16):
-      oid = "1.2.840.10045.4.3.3"; /* ecdsa-with-sha384 */
-      break;
+        case GCRY_MD_SHA256 | (GCRY_PK_ECC << 16):
+          oid = "1.2.840.10045.4.3.2"; /* ecdsa-with-sha256 */
+          break;
 
-    case GCRY_MD_SHA512 | (GCRY_PK_ECC << 16):
-      oid = "1.2.840.10045.4.3.4"; /* ecdsa-with-sha512 */
-      break;
+        case GCRY_MD_SHA384 | (GCRY_PK_ECC << 16):
+          oid = "1.2.840.10045.4.3.3"; /* ecdsa-with-sha384 */
+          break;
 
-    case GCRY_MD_SHA512 | (GCRY_PK_EDDSA << 16):
-      oid = "1.3.101.112"; /* ed25519 */
-      break;
+        case GCRY_MD_SHA512 | (GCRY_PK_ECC << 16):
+          oid = "1.2.840.10045.4.3.4"; /* ecdsa-with-sha512 */
+          break;
 
-    default:
-      return gpg_error (GPG_ERR_DIGEST_ALGO);
+        case GCRY_MD_SHA512 | (GCRY_PK_EDDSA << 16):
+          oid = "1.3.101.112"; /* ed25519 */
+          break;
+
+        default:
+          return gpg_error (GPG_ERR_DIGEST_ALGO);
+        }
     }
 
   if (is_pubkey)