version 3.0

ssh/ssh_server_host_key.cc

@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2012 Juli Mallett. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+
+#include <common/buffer.h>
+
+#include <crypto/crypto_hash.h>
+
+#include <ssh/ssh_algorithm_negotiation.h>
+#include <ssh/ssh_protocol.h>
+#include <ssh/ssh_server_host_key.h>
+#include <ssh/ssh_session.h>
+
+namespace {
+	class RSAServerHostKey : public SSH::ServerHostKey {
+		LogHandle log_;
+		SSH::Session *session_; 
+		RSA *rsa_;
+
+	public:
+		RSAServerHostKey(SSH::Session *session, RSA *rsa)
+		: SSH::ServerHostKey("ssh-rsa"),
+		  log_("/ssh/serverhostkey/rsa"),
+		  session_(session),
+		  rsa_(rsa)
+		{
+			ASSERT(log_, rsa != NULL || session->role_ == SSH::ClientRole);
+		}
+
+		~RSAServerHostKey()
+		{ }
+
+		SSH::ServerHostKey *clone(void) const
+		{
+			if (session_->role_ == SSH::ClientRole) {
+				if (rsa_ != NULL)
+					return (new RSAServerHostKey(session_, RSAPublicKey_dup(rsa_)));
+				else
+					return (new RSAServerHostKey(session_, NULL));
+			} else {
+				return (new RSAServerHostKey(session_, RSAPrivateKey_dup(rsa_)));
+			}
+		}
+
+		bool decode_public_key(Buffer *in)
+		{
+			ASSERT(log_, session_->role_ == SSH::ClientRole);
+			ASSERT(log_, rsa_ == NULL);
+			Buffer tag;
+			if (!SSH::String::decode(&tag, in))
+				return (false);
+			if (!tag.equal("ssh-rsa"))
+				return (false);
+			rsa_ = RSA_new();
+			if (rsa_ == NULL)
+				return (false);
+			if (!SSH::MPInt::decode(&rsa_->e, in))
+				return (false);
+			if (!SSH::MPInt::decode(&rsa_->n, in))
+				return (false);
+			return (true);
+		}
+
+		void encode_public_key(Buffer *out) const
+		{
+			SSH::String::encode(out, Buffer("ssh-rsa"));
+			SSH::MPInt::encode(out, rsa_->e);
+			SSH::MPInt::encode(out, rsa_->n);
+		}
+
+		bool sign(Buffer *out, const Buffer *in) const
+		{
+			ASSERT(log_, session_->role_ == SSH::ServerRole);
+
+			Buffer hash;
+			if (!CryptoHash::hash(CryptoHash::SHA1, &hash, in))
+				return (false);
+
+			uint8_t m[hash.length()];
+			hash.moveout(m, sizeof m);
+			uint8_t signature[RSA_size(rsa_)];
+			unsigned signature_length = sizeof signature;
+			int rv = RSA_sign(NID_sha1, m, sizeof m, signature, &signature_length, rsa_);
+			if (rv == 0)
+				return (false);
+			SSH::String::encode(out, Buffer("ssh-rsa"));
+			SSH::String::encode(out, Buffer(signature, signature_length));
+			return (true);
+		}
+
+		bool verify(const Buffer *signature, const Buffer *message) const
+		{
+			ASSERT(log_, session_->role_ == SSH::ClientRole);
+
+			Buffer hash;
+			if (!CryptoHash::hash(CryptoHash::SHA1, &hash, message))
+				return (false);
+
+			Buffer in;
+			in.append(signature);
+			Buffer tag;
+			if (!SSH::String::decode(&tag, &in))
+				return (false);
+			if (!tag.equal("ssh-rsa"))
+				return (false);
+			Buffer sig;
+			if (!SSH::String::decode(&sig, &in))
+				return (false);
+
+			uint8_t m[hash.length()];
+			hash.moveout(m, sizeof m);
+			uint8_t sigbuf[sig.length()];
+			sig.moveout(sigbuf, sig.length());
+			int rv = RSA_verify(NID_sha1, m, sizeof m, sigbuf, sizeof sigbuf, rsa_);
+			if (rv == 0)
+				return (false);
+			return (true);
+		}
+
+		static RSAServerHostKey *open(SSH::Session *session, FILE *file)
+		{
+			RSA *rsa;
+
+			ASSERT("/ssh/serverhostkey/rsa/open", session->role_ == SSH::ServerRole);
+
+			rsa = PEM_read_RSAPrivateKey(file, NULL, NULL, NULL);
+			if (rsa == NULL)
+				return (NULL);
+
+			return (new RSAServerHostKey(session, rsa));
+		}
+	};
+}
+
+void
+SSH::ServerHostKey::add_client_algorithms(SSH::Session *session)
+{
+	ASSERT("/ssh/serverhostkey/client", session->role_ == SSH::ClientRole);
+	session->algorithm_negotiation_->add_algorithm(new RSAServerHostKey(session, NULL));
+}
+
+SSH::ServerHostKey *
+SSH::ServerHostKey::server(SSH::Session *session, const std::string& keyfile)
+{
+	SSH::ServerHostKey *key;
+	FILE *file;
+
+	ASSERT("/ssh/serverhostkey/server", session->role_ == SSH::ServerRole);
+
+	file = fopen(keyfile.c_str(), "r");
+	if (file == NULL)
+		return (NULL);
+	
+	key = RSAServerHostKey::open(session, file);
+	if (key == NULL) {
+		fclose(file);
+		return (NULL);
+	}
+
+	fclose(file);
+
+	return (key);
+}