(rsa_keypair_to_openpgp): New file, new function.

Rev: src/nettle/rsa.h:1.13
Rev: src/nettle/rsa2openpgp.c:1.1

rsa.h

@@ -5,7 +5,7 @@
 
 /* nettle, low-level cryptographics library
  *
- * Copyright (C) 2001 Niels Mller
+ * Copyright (C) 2001, 2002 Niels Mller
  *  
  * The nettle library is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -234,4 +234,12 @@ rsa_keypair_from_sexp(struct rsa_public_key *pub,
 		      unsigned length, const uint8_t *expr);
 
 
+/* OpenPGP format. Experimental interface, subject to change. */
+int
+rsa_keypair_to_openpgp(struct nettle_buffer *buffer,
+		       const struct rsa_public_key *pub,
+		       const struct rsa_private_key *priv,
+		       /* A single user id. NUL-terminated utf8. */
+		       const char userid);
+
 #endif /* NETTLE_RSA_H_INCLUDED */

rsa2openpgp.c

+/* rsa2openpgp.c
+ *
+ * Converting rsa keys to OpenPGP format.
+ */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2001, 2002 Niels Mller
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#if WITH_PUBLIC_KEY
+
+#include "rsa.h"
+
+#include "buffer.h"
+#include "pgp.h"
+
+#include <time.h>
+
+
+/* According to RFC 2440, a public key consists of the following packets:
+ *
+ * Public key packet
+ *
+ * Zero or more revocation signatures
+ *
+ * One or more User ID packets
+ *
+ * After each User ID packet, zero or more signature packets
+ *
+ * Zero or more Subkey packets
+ *
+ * After each Subkey packet, one signature packet, optionally a
+ * revocation.
+ *
+ * Currently, we generate a public key packet, a single user id, and a
+ * signature. */
+ */
+int
+rsa_keypair_to_openpgp(struct nettle_buffer *buffer,
+		       const struct rsa_public_key *pub,
+		       const struct rsa_private_key *priv,
+		       /* A single user id. NUL-terminated utf8. */
+		       const char userid)
+{
+  time_t now = time(NULL);
+
+  unsigned key_start;
+  unsigned key_length;
+  unsigned userid_start;
+  
+  struct sha1_ctx key_hash;
+  struct sha1_ctx signature_hash;
+  uint8_t fingerprint[SHA1_DIGEST_SIZE];
+  
+  mpz_t s;
+  
+  key_start = buffer->size;
+  
+  if (!pgp_put_public_rsa_key(buffer, pub, now))
+    return 0;
+
+  /* userid packet */
+  userid_start = buffer->size;
+  if (!pgp_put_userid(buffer, strlen(userid), userid))
+    return 0;
+
+  /* FIXME: We hash the key first, and then the user id. Is this right? */
+  sha1_init(&key_hash);
+  sha1_update(&key_hash,
+	      userid_start - key_start,
+	      buffer->contents + key_start);
+
+  signature_hash = key_hash;
+  sha1_digest(&key_hash, fingerprint, sizeof(fingerprint));
+
+  sha1_update(&signature_hash,
+	      buffer->size - userid_start,
+	      buffer->contents + userid_start);
+  
+  return pgp_put_rsa_sha1_signature(buffer,
+				    priv,
+				    fingerprint + SHA1_DIGEST_SIZE - 8,
+				    PGP_SIGN_CERTIFICATION,
+				    signature_hash);
+}
+#endif /* WITH_PUBLIC_KEY */