commit 3e013d432d2bdfdc327702b6f0b9e2a34526f906
Author: WeebDataHoarder <57538841+WeebDataHoarder@users.noreply.github.com>
Date:   Sat May 27 17:37:14 2023 +0200

    Initial commit, imported from https://git.gammaspectra.live/P2Pool/moneroutil commit 7b24ed2d11ce3f88ca88247778296d60a6129319

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..c6cddb9
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,8 @@
+Monero Utilities
+Copyright (c) 2013 Go Authors
+Copyright (c) 2017 Paxos
+
+Portion of the code is Go Author's property, licensed under the BSD-3 license
+Portion of the code is Paxos's property, licensed under the MIT license
+
+const.go and edwards25519.go are licensed under BSD-3 (see LICENSE-BSD), all other files are licensed under MIT (see LICENSE-MIT).
diff --git a/LICENSE-BSD b/LICENSE-BSD
new file mode 100644
index 0000000..7e33363
--- /dev/null
+++ b/LICENSE-BSD
@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * 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.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT
+OWNER 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.
diff --git a/LICENSE-MIT b/LICENSE-MIT
new file mode 100644
index 0000000..9c743d0
--- /dev/null
+++ b/LICENSE-MIT
@@ -0,0 +1,25 @@
+Monero Utilities
+Copyright (c) 2017, Paxos <jimmy.song@paxos.com>
+
+Permission is hereby granted, free of charge, to any 
+person obtaining a copy of this software and associated 
+documentation files (the "Software"), to deal in the 
+Software without restriction, including without 
+limitation the rights to use, copy, modify, merge, 
+publish, distribute, sublicense, and/or sell copies of 
+the Software, and to permit persons to whom the Software 
+is furnished to do so, subject to the following 
+conditions:
+
+The above copyright notice and this permission notice 
+shall be included in all copies or substantial portions 
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
+KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 
+WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 
+PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS 
+OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT 
+OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH 
+THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\ No newline at end of file
diff --git a/base58.go b/base58.go
new file mode 100644
index 0000000..fda5204
--- /dev/null
+++ b/base58.go
@@ -0,0 +1,133 @@
+package base58
+
+import (
+	"encoding/binary"
+)
+
+const base58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
+
+const reverseBase58 =
+//               0   1   2   3   4   5   6   7   8   9   a   b   c   d   e   f */
+/* 00 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* 10 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* 20 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* 30 */ "\xff\x00\x01\x02\x03\x04\x05\x06\x07\x08\xff\xff\xff\xff\xff\xff" +
+	/* 40 */ "\xff\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\xff\x11\x12\x13\x14\x15\xff" +
+	/* 50 */ "\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\xff\xff\xff\xff\xff" +
+	/* 60 */ "\xff\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\xff\x2c\x2d\x2e" +
+	/* 70 */ "\x2f\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\xff\xff\xff\xff\xff" +
+	/* 80 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* 90 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* a0 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* b0 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* c0 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* d0 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* e0 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" +
+	/* f0 */ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
+
+func encodeChunk(raw []byte, buf []byte) []byte {
+	intToDecode := binary.BigEndian.Uint64(raw[:])
+
+	for intToDecode > 0 {
+		buf = append(buf, base58[intToDecode%58])
+		intToDecode /= 58
+	}
+	for len(buf) < 11 {
+		buf = append(buf, '1')
+	}
+	for i, j := 0, len(buf)-1; i < j; i, j = i+1, j-1 {
+		buf[i], buf[j] = buf[j], buf[i]
+	}
+	return buf
+}
+func encodeChunkTail(raw []byte, buf []byte) []byte {
+	var data [8]byte
+	copy(data[8-len(raw):], raw)
+
+	intToDecode := binary.BigEndian.Uint64(data[:])
+
+	for intToDecode > 0 {
+		buf = append(buf, base58[intToDecode%58])
+		intToDecode /= 58
+	}
+	for len(buf) < 7 {
+		buf = append(buf, '1')
+	}
+	for i, j := 0, len(buf)-1; i < j; i, j = i+1, j-1 {
+		buf[i], buf[j] = buf[j], buf[i]
+	}
+	return buf
+}
+
+func decodeChunk(buf []byte, encoded string) []byte {
+	var intResult uint64
+	currentMultiplier := uint64(1)
+	for i := len(encoded) - 1; i >= 0; i-- {
+		intResult += currentMultiplier * uint64(reverseBase58[encoded[i]])
+		// this can overflow, but only on the last iteration when i == 0 when all data is valid
+		currentMultiplier *= 58
+	}
+
+	var result [8]byte
+	binary.BigEndian.PutUint64(result[:], intResult)
+	switch len(encoded) {
+	case 0:
+		return append(buf, result[8:]...)
+	case 2:
+		return append(buf, result[7:]...)
+	case 3:
+		return append(buf, result[6:]...)
+	case 5:
+		return append(buf, result[5:]...)
+	case 6:
+		return append(buf, result[4:]...)
+	case 7:
+		return append(buf, result[3:]...)
+	case 9:
+		return append(buf, result[2:]...)
+	case 10:
+		return append(buf, result[1:]...)
+	case 11:
+		return append(buf, result[:]...)
+	default:
+	}
+	return nil
+}
+
+func Encode(data ...[]byte) string {
+	//preallocate common case
+	combined := make([]byte, 0, 96)
+	for _, item := range data {
+		combined = append(combined, item...)
+	}
+
+	result := make([]byte, 0, len(combined)*2)
+	buf := make([]byte, 0, len(combined)*2)
+	length := len(combined)
+	rounds := length / 8
+	for i := 0; i < rounds; i++ {
+		result = append(result, encodeChunk(combined[i*8:(i+1)*8], buf[:0])...)
+	}
+	if length%8 > 0 {
+		result = append(result, encodeChunkTail(combined[rounds*8:], buf[:0])...)
+	}
+	return string(result)
+}
+
+func Decode(data string) (result []byte) {
+	//common case
+	return DecodePreAllocated(make([]byte, 0, 69), data)
+}
+
+func DecodePreAllocated(buf []byte, data string) (result []byte) {
+	result = buf
+	length := len(data)
+	rounds := length / 11
+	for i := 0; i < rounds; i++ {
+		result = decodeChunk(result, data[i*11:i*11+11])
+	}
+	if length%11 > 0 {
+		result = decodeChunk(result, data[rounds*11:])
+	}
+	return
+}
diff --git a/base58_test.go b/base58_test.go
new file mode 100644
index 0000000..fe2b982
--- /dev/null
+++ b/base58_test.go
@@ -0,0 +1,16 @@
+package base58
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestEncodeDecodeMoneroBase58Bounds(t *testing.T) {
+	data := make([]byte, 2048)
+	for i := range data {
+		data[i] = 0xff
+	}
+	if bytes.Compare(Decode(Encode(data)), data) != 0 {
+		t.Fatal()
+	}
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..cf6ba00
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module git.gammaspectra.live/P2Pool/monero-base58
+
+go 1.20