1 files changed, 186 insertions, 0 deletions
diff --git a/src/sshagent/ASN1Key.cpp b/src/sshagent/ASN1Key.cpp
new file mode 100644
index 000000000..c46b8fa0b
--- /dev/null
+++ b/src/sshagent/ASN1Key.cpp
@@ -0,0 +1,186 @@
+/*
+ *  Copyright (C) 2018 Toni Spets <toni.spets@iki.fi>
+ *  Copyright (C) 2018 KeePassXC Team <team@keepassxc.org>
+ *
+ *  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 or (at your option)
+ *  version 3 of the License.
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ASN1Key.h"
+#include <gcrypt.h>
+
+namespace {
+    constexpr quint8 TAG_INT         = 0x02;
+    constexpr quint8 TAG_SEQUENCE    = 0x30;
+    constexpr quint8 KEY_ZERO        = 0x0;
+
+    bool nextTag(BinaryStream& stream, quint8& tag, quint32& len)
+    {
+        stream.read(tag);
+
+        quint8 lenByte;
+        stream.read(lenByte);
+
+        if (lenByte & 0x80) {
+            quint32 bytes = lenByte & ~0x80;
+            if (bytes == 1) {
+                stream.read(lenByte);
+                len = lenByte;
+            } else if (bytes == 2) {
+                quint16 lenShort;
+                stream.read(lenShort);
+                len = lenShort;
+            } else if (bytes == 4) {
+                stream.read(len);
+            } else {
+                return false;
+            }
+        } else {
+            len = lenByte;
+        }
+
+        return true;
+    }
+
+    bool parseHeader(BinaryStream& stream, quint8 wantedType)
+    {
+        quint8 tag;
+        quint32 len;
+
+        nextTag(stream, tag, len);
+
+        if (tag != TAG_SEQUENCE) {
+            return false;
+        }
+
+        nextTag(stream, tag, len);
+
+        if (tag != TAG_INT || len != 1) {
+            return false;
+        }
+
+        quint8 keyType;
+        stream.read(keyType);
+
+        return (keyType == wantedType);
+    }
+
+    bool readInt(BinaryStream& stream, QByteArray& target)
+    {
+        quint8 tag;
+        quint32 len;
+
+        nextTag(stream, tag, len);
+
+        if (tag != TAG_INT) {
+            return false;
+        }
+
+        target.resize(len);
+        stream.read(target);
+        return true;
+    }
+
+    QByteArray calculateIqmp(QByteArray& bap, QByteArray& baq)
+    {
+        gcry_mpi_t u, p, q;
+        QByteArray iqmp_hex;
+
+        u = gcry_mpi_snew(bap.length() * 8);
+        gcry_mpi_scan(&p, GCRYMPI_FMT_HEX, bap.toHex().data(), 0, nullptr);
+        gcry_mpi_scan(&q, GCRYMPI_FMT_HEX, baq.toHex().data(), 0, nullptr);
+
+        mpi_invm(u, q, p);
+
+        iqmp_hex.resize((bap.length() + 1) * 2);
+        gcry_mpi_print(GCRYMPI_FMT_HEX, reinterpret_cast<unsigned char*>(iqmp_hex.data()), iqmp_hex.length(), nullptr, u);
+
+        gcry_mpi_release(u);
+        gcry_mpi_release(p);
+        gcry_mpi_release(q);
+
+        return QByteArray::fromHex(iqmp_hex);
+    }
+}
+
+bool ASN1Key::parseDSA(QByteArray& ba, OpenSSHKey& key)
+{
+    BinaryStream stream(&ba);
+
+    if (!parseHeader(stream, KEY_ZERO)) {
+        return false;
+    }
+
+    QByteArray p,q,g,y,x;
+    readInt(stream, p);
+    readInt(stream, q);
+    readInt(stream, g);
+    readInt(stream, y);
+    readInt(stream, x);
+
+    QList<QByteArray> publicData;
+    publicData.append(p);
+    publicData.append(q);
+    publicData.append(g);
+    publicData.append(y);
+
+    QList<QByteArray> privateData;
+    privateData.append(p);
+    privateData.append(q);
+    privateData.append(g);
+    privateData.append(y);
+    privateData.append(x);
+
+    key.setType("ssh-dss");
+    key.setPublicData(publicData);
+    key.setPrivateData(privateData);
+    key.setComment("");
+    return true;
+}
+
+bool ASN1Key::parseRSA(QByteArray& ba, OpenSSHKey& key)
+{
+    BinaryStream stream(&ba);
+
+    if (!parseHeader(stream, KEY_ZERO)) {
+        return false;
+    }
+
+    QByteArray n,e,d,p,q,dp,dq,qinv;
+    readInt(stream, n);
+    readInt(stream, e);
+    readInt(stream, d);
+    readInt(stream, p);
+    readInt(stream, q);
+    readInt(stream, dp);
+    readInt(stream, dq);
+    readInt(stream, qinv);
+
+    QList<QByteArray> publicData;
+    publicData.append(e);
+    publicData.append(n);
+
+    QList<QByteArray> privateData;
+    privateData.append(n);
+    privateData.append(e);
+    privateData.append(d);
+    privateData.append(calculateIqmp(p, q));
+    privateData.append(p);
+    privateData.append(q);
+
+    key.setType("ssh-rsa");
+    key.setPublicData(publicData);
+    key.setPrivateData(privateData);
+    key.setComment("");
+    return true;
+}