From 6399892bf2c53fc3701438c752718638baff8e27 Mon Sep 17 00:00:00 2001
From: Marvin W <git@larma.de>
Date: Fri, 14 May 2021 19:26:05 +0200
Subject: Move crypto-vala to shared library

---
 crypto-vala/src/cipher_converter.vala | 102 ++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 crypto-vala/src/cipher_converter.vala

(limited to 'crypto-vala/src/cipher_converter.vala')

diff --git a/crypto-vala/src/cipher_converter.vala b/crypto-vala/src/cipher_converter.vala
new file mode 100644
index 00000000..b2b52c5a
--- /dev/null
+++ b/crypto-vala/src/cipher_converter.vala
@@ -0,0 +1,102 @@
+using GLib;
+
+namespace Crypto {
+public abstract class SymmetricCipherConverter : Converter, Object {
+    internal SymmetricCipher cipher;
+    internal size_t attached_taglen;
+
+    public abstract ConverterResult convert(uint8[] inbuf, uint8[] outbuf, ConverterFlags flags, out size_t bytes_read, out size_t bytes_written) throws IOError;
+
+    public uint8[] get_tag(size_t taglen) throws Error {
+        return cipher.get_tag(taglen);
+    }
+
+    public void check_tag(uint8[] tag) throws Error {
+        cipher.check_tag(tag);
+    }
+
+    public void reset() {
+        try {
+            cipher.reset();
+        } catch (Crypto.Error e) {
+            warning(@"$(e.domain) error while resetting cipher: $(e.message)");
+        }
+    }
+}
+
+public class SymmetricCipherEncrypter : SymmetricCipherConverter {
+    public SymmetricCipherEncrypter(owned SymmetricCipher cipher, size_t attached_taglen = 0) {
+        this.cipher = (owned) cipher;
+        this.attached_taglen = attached_taglen;
+    }
+
+    public override ConverterResult convert(uint8[] inbuf, uint8[] outbuf, ConverterFlags flags, out size_t bytes_read, out size_t bytes_written) throws IOError {
+        if (inbuf.length > outbuf.length) {
+            throw new IOError.NO_SPACE("CipherConverter needs at least the size of input as output space");
+        }
+        if ((flags & ConverterFlags.INPUT_AT_END) != 0 && inbuf.length + attached_taglen > outbuf.length) {
+            throw new IOError.NO_SPACE("CipherConverter needs additional output space to attach tag");
+        }
+        try {
+            if (inbuf.length > 0) {
+                cipher.encrypt(outbuf, inbuf);
+            }
+            bytes_read = inbuf.length;
+            bytes_written = inbuf.length;
+            if ((flags & ConverterFlags.INPUT_AT_END) != 0) {
+                if (attached_taglen > 0) {
+                    Memory.copy((uint8*)outbuf + inbuf.length, get_tag(attached_taglen), attached_taglen);
+                    bytes_written = inbuf.length + attached_taglen;
+                }
+                return ConverterResult.FINISHED;
+            }
+            if ((flags & ConverterFlags.FLUSH) != 0) {
+                return ConverterResult.FLUSHED;
+            }
+            return ConverterResult.CONVERTED;
+        } catch (Crypto.Error e) {
+            throw new IOError.FAILED(@"$(e.domain) error while decrypting: $(e.message)");
+        }
+    }
+}
+
+public class SymmetricCipherDecrypter : SymmetricCipherConverter {
+    public SymmetricCipherDecrypter(owned SymmetricCipher cipher, size_t attached_taglen = 0) {
+        this.cipher = (owned) cipher;
+        this.attached_taglen = attached_taglen;
+    }
+
+    public override ConverterResult convert(uint8[] inbuf, uint8[] outbuf, ConverterFlags flags, out size_t bytes_read, out size_t bytes_written) throws IOError {
+        if (inbuf.length > outbuf.length + attached_taglen) {
+            throw new IOError.NO_SPACE("CipherConverter needs at least the size of input as output space");
+        }
+        if ((flags & ConverterFlags.INPUT_AT_END) != 0 && inbuf.length < attached_taglen) {
+            throw new IOError.PARTIAL_INPUT("CipherConverter needs additional input to read tag");
+        } else if ((flags & ConverterFlags.INPUT_AT_END) == 0 && inbuf.length < attached_taglen + 1) {
+            throw new IOError.PARTIAL_INPUT("CipherConverter needs additional input to make sure to not accidentally read tag");
+        }
+        try {
+            inbuf.length -= (int) attached_taglen;
+            if (inbuf.length > 0) {
+                cipher.decrypt(outbuf, inbuf);
+            }
+            bytes_read = inbuf.length;
+            bytes_written = inbuf.length;
+            inbuf.length += (int) attached_taglen;
+            if ((flags & ConverterFlags.INPUT_AT_END) != 0) {
+                if (attached_taglen > 0) {
+                    check_tag(inbuf[(inbuf.length - attached_taglen):inbuf.length]);
+                    bytes_read = inbuf.length;
+                }
+                return ConverterResult.FINISHED;
+            }
+            if ((flags & ConverterFlags.FLUSH) != 0) {
+                return ConverterResult.FLUSHED;
+            }
+            return ConverterResult.CONVERTED;
+        } catch (Crypto.Error e) {
+            throw new IOError.FAILED(@"$(e.domain) error while decrypting: $(e.message)");
+        }
+    }
+}
+}
-- 
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