From 158c1deff123b9fc595f0280c17b24be9fa633e8 Mon Sep 17 00:00:00 2001
From: Peter Rabbitson <ribasushi@protocol.ai>
Date: Sat, 23 May 2020 03:37:18 +0200
Subject: [PATCH] Base36 implementation

---
 go.mod            |  1 +
 go.sum            |  2 ++
 multibase.go      | 14 +++++++++++++-
 multibase_test.go |  2 ++
 spec              |  2 +-
 5 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/go.mod b/go.mod
index 5e430ae..68d0982 100644
--- a/go.mod
+++ b/go.mod
@@ -5,4 +5,5 @@ go 1.11
 require (
 	github.com/mr-tron/base58 v1.1.0
 	github.com/multiformats/go-base32 v0.0.3
+	github.com/multiformats/go-base36 v0.1.0
 )
diff --git a/go.sum b/go.sum
index 510e3dc..8256cfd 100644
--- a/go.sum
+++ b/go.sum
@@ -2,3 +2,5 @@ github.com/mr-tron/base58 v1.1.0 h1:Y51FGVJ91WBqCEabAi5OPUz38eAx8DakuAm5svLcsfQ=
 github.com/mr-tron/base58 v1.1.0/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=
 github.com/multiformats/go-base32 v0.0.3 h1:tw5+NhuwaOjJCC5Pp82QuXbrmLzWg7uxlMFp8Nq/kkI=
 github.com/multiformats/go-base32 v0.0.3/go.mod h1:pLiuGC8y0QR3Ue4Zug5UzK9LjgbkL8NSQj0zQ5Nz/AA=
+github.com/multiformats/go-base36 v0.1.0 h1:JR6TyF7JjGd3m6FbLU2cOxhC0Li8z8dLNGQ89tUg4F4=
+github.com/multiformats/go-base36 v0.1.0/go.mod h1:kFGE83c6s80PklsHO9sRn2NCoffoRdUUOENyW/Vv6sM=
diff --git a/multibase.go b/multibase.go
index c1833b5..87b8118 100644
--- a/multibase.go
+++ b/multibase.go
@@ -7,6 +7,7 @@ import (
 
 	b58 "github.com/mr-tron/base58/base58"
 	b32 "github.com/multiformats/go-base32"
+	b36 "github.com/multiformats/go-base36"
 )
 
 // Encoding identifies the type of base-encoding that a multibase is carrying.
@@ -29,8 +30,10 @@ const (
 	Base32hexUpper    = 'V'
 	Base32hexPad      = 't'
 	Base32hexPadUpper = 'T'
-	Base58Flickr      = 'Z'
+	Base36            = 'k'
+	Base36Upper       = 'K'
 	Base58BTC         = 'z'
+	Base58Flickr      = 'Z'
 	Base64            = 'm'
 	Base64url         = 'u'
 	Base64pad         = 'M'
@@ -52,6 +55,8 @@ var EncodingToStr = map[Encoding]string{
 	'V':  "base32hexupper",
 	't':  "base32hexpad",
 	'T':  "base32hexpadupper",
+	'k':  "base36",
+	'K':  "base36upper",
 	'z':  "base58btc",
 	'Z':  "base58flickr",
 	'm':  "base64",
@@ -102,6 +107,10 @@ func Encode(base Encoding, data []byte) (string, error) {
 		return string(Base32hexPad) + base32HexLowerPad.EncodeToString(data), nil
 	case Base32hexPadUpper:
 		return string(Base32hexPadUpper) + base32HexUpperPad.EncodeToString(data), nil
+	case Base36:
+		return string(Base36) + b36.EncodeToStringLc(data), nil
+	case Base36Upper:
+		return string(Base36Upper) + b36.EncodeToStringUc(data), nil
 	case Base58BTC:
 		return string(Base58BTC) + b58.EncodeAlphabet(data, b58.BTCAlphabet), nil
 	case Base58Flickr:
@@ -149,6 +158,9 @@ func Decode(data string) (Encoding, []byte, error) {
 	case Base32hexPad, Base32hexPadUpper:
 		bytes, err := b32.HexEncoding.DecodeString(data[1:])
 		return enc, bytes, err
+	case Base36, Base36Upper:
+		bytes, err := b36.DecodeString(data[1:])
+		return enc, bytes, err
 	case Base58BTC:
 		bytes, err := b58.DecodeAlphabet(data[1:], b58.BTCAlphabet)
 		return Base58BTC, bytes, err
diff --git a/multibase_test.go b/multibase_test.go
index 4c75036..12f24da 100644
--- a/multibase_test.go
+++ b/multibase_test.go
@@ -36,6 +36,8 @@ var encodedSamples = map[Encoding]string{
 	Base32hexUpper:    "V8HIM6PBEEHP62R39F9II0PBMCLP7IT38D5N6E89144",
 	Base32hexPad:      "t8him6pbeehp62r39f9ii0pbmclp7it38d5n6e89144======",
 	Base32hexPadUpper: "T8HIM6PBEEHP62R39F9II0PBMCLP7IT38D5N6E89144======",
+	Base36:            "km552ng4dabi4neu1oo8l4i5mndwmpc3mkukwtxy9",
+	Base36Upper:       "KM552NG4DABI4NEU1OO8L4I5MNDWMPC3MKUKWTXY9",
 	Base58BTC:         "z36UQrhJq9fNDS7DiAHM9YXqDHMPfr4EMArvt",
 	Base58Flickr:      "Z36tpRGiQ9Endr7dHahm9xwQdhmoER4emaRVT",
 	Base64:            "mRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchISE",
diff --git a/spec b/spec
index 54f897a..3806057 160000
--- a/spec
+++ b/spec
@@ -1 +1 @@
-Subproject commit 54f897a5032fc35d2ae50477c2918da715b43efb
+Subproject commit 3806057e6f6c09c7cc0a6dc14de22fa50c9e0b51