Imported Upstream version 5.1.1

1 files changed, 125 insertions, 0 deletions

diff --git a/src/libstrongswan/plugins/sshkey/sshkey_encoder.c b/src/libstrongswan/plugins/sshkey/sshkey_encoder.c
new file mode 100644
index 000000000..d423671bd
--- /dev/null
+++ b/src/libstrongswan/plugins/sshkey/sshkey_encoder.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2013 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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 General Public License
+ * for more details.
+ */
+
+#include "sshkey_encoder.h"
+
+#include <asn1/asn1.h>
+#include <asn1/oid.h>
+#include <bio/bio_writer.h>
+
+#define ECDSA_PREFIX "ecdsa-sha2-"
+
+/**
+ * Write an EC domain parameter identifier as defined in RFC 5656
+ */
+static void write_ec_identifier(bio_writer_t *writer, char *prefix, int oid,
+								chunk_t enc)
+{
+	char *curve, identifier[128];
+
+	switch (oid)
+	{
+		case OID_PRIME256V1:
+			curve = strdup("nistp256");
+			break;
+		case OID_SECT384R1:
+			curve = strdup("nistp384");
+			break;
+		case OID_SECT521R1:
+			curve = strdup("nistp521");
+			break;
+		default:
+			curve = asn1_oid_to_string(enc);
+			break;
+	}
+	if (curve && snprintf(identifier, sizeof(identifier), "%s%s", prefix,
+						  curve) < sizeof(identifier))
+	{
+		writer->write_data32(writer, chunk_from_str(identifier));
+	}
+	free(curve);
+}
+
+/**
+ * Encode the public key as Base64 encoded SSH key blob
+ */
+static bool build_public_key(chunk_t *encoding, va_list args)
+{
+	bio_writer_t *writer;
+	chunk_t n, e;
+
+	if (cred_encoding_args(args, CRED_PART_RSA_MODULUS, &n,
+						   CRED_PART_RSA_PUB_EXP, &e, CRED_PART_END))
+	{
+		writer = bio_writer_create(0);
+		writer->write_data32(writer, chunk_from_str("ssh-rsa"));
+
+		writer->write_data32(writer, e);
+		writer->write_data32(writer, n);
+		*encoding = chunk_to_base64(writer->get_buf(writer), NULL);
+		writer->destroy(writer);
+		return TRUE;
+	}
+	else if (cred_encoding_args(args, CRED_PART_ECDSA_PUB_ASN1_DER, &n,
+								CRED_PART_END))
+	{
+		chunk_t params, alg, q;
+		int oid;
+
+		/* parse subjectPublicKeyInfo */
+		if (asn1_unwrap(&n, &n) != ASN1_SEQUENCE)
+		{
+			return FALSE;
+		}
+		oid = asn1_parse_algorithmIdentifier(n, 1, &params);
+		if (oid != OID_EC_PUBLICKEY ||
+			asn1_unwrap(&params, &params) != ASN1_OID)
+		{
+			return FALSE;
+		}
+		oid = asn1_known_oid(params);
+		if (oid == OID_UNKNOWN)
+		{
+			return FALSE;
+		}
+		if (asn1_unwrap(&n, &alg) != ASN1_SEQUENCE ||
+			asn1_unwrap(&n, &q) != ASN1_BIT_STRING)
+		{
+			return FALSE;
+		}
+		writer = bio_writer_create(0);
+		write_ec_identifier(writer, ECDSA_PREFIX, oid, params);
+		write_ec_identifier(writer, "", oid, params);
+
+		q = chunk_skip_zero(q);
+		writer->write_data32(writer, q);
+		*encoding = chunk_to_base64(writer->get_buf(writer), NULL);
+		writer->destroy(writer);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+bool sshkey_encoder_encode(cred_encoding_type_t type, chunk_t *encoding,
+						   va_list args)
+{
+	switch (type)
+	{
+		case PUBKEY_SSHKEY:
+			return build_public_key(encoding, args);
+		default:
+			return FALSE;
+	}
+}