move mpint/mpz conversion into separate file

these functions need linking against libgmp

3 files changed, 63 insertions, 37 deletions

diff --git a/Makefile b/Makefile
index 3747a03..644b055 100644
--- a/Makefile
+++ b/Makefile
@@ -33,6 +33,8 @@ ssh-agent-filter: ssh-agent-filter.o
 
 ssh-agent-filter.o: ssh-agent-filter.C rfc4251.h ssh-agent.h version.h
 
+rfc4251_gmp.o: rfc4251_gmp.C rfc4251.h
+
 version.h:
 	test ! -d .git || git describe | sed 's/^.*$$/#define SSH_AGENT_FILTER_VERSION "ssh-agent-filter \0"/' > $@
 
diff --git a/rfc4251.h b/rfc4251.h
index 7f68407..80723a9 100644
--- a/rfc4251.h
+++ b/rfc4251.h
@@ -176,32 +176,6 @@ rfc4251string::rfc4251string (std::vector<std::string> const & v) {
 	}
 }
 
-rfc4251string::rfc4251string (mpz_srcptr x) {
-	if (mpz_sgn(x) == 0)
-		return;
-
-	auto const import_positive = [] (mpz_srcptr x, std::vector<char> & value) {
-		size_t bits{mpz_sizeinbase(x, 2)};
-		size_t bytes{(bits + 7) / 8};
-		size_t extrabyte{(bits % 8) == 0}; // need extra byte if MSB is 1 to keep it non-negative
-		if (bytes + extrabyte > std::numeric_limits<uint32_t>::max())
-			throw std::length_error{"32-bit limit for rfc4251string exceeded"};
-		value.resize(bytes + extrabyte);
-		value[0] = 0;
-		mpz_export(value.data() + extrabyte, nullptr, 1, 1, 1, 0, x);
-	};
-	if (mpz_sgn(x) == 1)
-		import_positive(x, value);
-	else {
-		// handle two's complement: add 1, invert all bits
-		mpz_class tmp{x};
-		tmp += 1;
-		import_positive(tmp.get_mpz_t(), value);
-		for (auto & i : value)
-			i ^= 0xff;
-	}
-}
-
 rfc4251string::operator std::vector<std::string> () const {
 	std::vector<std::string> ret;
 	auto name_start = value.begin();
@@ -219,17 +193,6 @@ rfc4251string::operator std::vector<std::string> () const {
 	return ret;
 }
 
-rfc4251string::operator mpz_class () const {
-	mpz_class ret;
-	mpz_import(ret.get_mpz_t(), value.size(), 1, 1, 1, 0, value.data());
-	if (mpz_sizeinbase(ret.get_mpz_t(), 2) == value.size() * 8) { // negative
-		mpz_com(ret.get_mpz_t(), ret.get_mpz_t());
-		ret += 1;
-		mpz_neg(ret.get_mpz_t(), ret.get_mpz_t());
-	}
-	return ret;
-}
-
 inline std::istream & operator>> (std::istream & is, rfc4251string & s) {
 	s.value.clear();
 	rfc4251uint32 len;
diff --git a/rfc4251_gmp.C b/rfc4251_gmp.C
new file mode 100644
index 0000000..d3a664e
--- /dev/null
+++ b/rfc4251_gmp.C
@@ -0,0 +1,61 @@
+/*
+ * rfc4251_gmp.C -- implements mpint/gmp conversions for rfc4251string
+ *
+ * these functions need linking against libgmp
+ *
+ * Copyright (C) 2013 Timo Weingärtner <timo@tiwe.de>
+ *
+ * This file is part of ssh-agent-filter.
+ *
+ * ssh-agent-filter 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * ssh-agent-filter 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with ssh-agent-filter.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "rfc4251.h"
+
+rfc4251string::rfc4251string (mpz_srcptr x) {
+	if (mpz_sgn(x) == 0)
+		return;
+
+	auto const import_positive = [] (mpz_srcptr x, std::vector<char> & value) {
+		size_t bits{mpz_sizeinbase(x, 2)};
+		size_t bytes{(bits + 7) / 8};
+		size_t extrabyte{(bits % 8) == 0}; // need extra byte if MSB is 1 to keep it non-negative
+		if (bytes + extrabyte > std::numeric_limits<uint32_t>::max())
+			throw std::length_error{"32-bit limit for rfc4251string exceeded"};
+		value.resize(bytes + extrabyte);
+		value[0] = 0;
+		mpz_export(value.data() + extrabyte, nullptr, 1, 1, 1, 0, x);
+	};
+	if (mpz_sgn(x) == 1)
+		import_positive(x, value);
+	else {
+		// handle two's complement: add 1, invert all bits
+		mpz_class tmp{x};
+		tmp += 1;
+		import_positive(tmp.get_mpz_t(), value);
+		for (auto & i : value)
+			i ^= 0xff;
+	}
+}
+
+rfc4251string::operator mpz_class () const {
+	mpz_class ret;
+	mpz_import(ret.get_mpz_t(), value.size(), 1, 1, 1, 0, value.data());
+	if (mpz_sizeinbase(ret.get_mpz_t(), 2) == value.size() * 8) { // negative
+		mpz_com(ret.get_mpz_t(), ret.get_mpz_t());
+		ret += 1;
+		mpz_neg(ret.get_mpz_t(), ret.get_mpz_t());
+	}
+	return ret;
+}