redirect base64 skylink to base32 subdomain

docker/nginx/conf.d/include/location-skylink

@@ -7,7 +7,7 @@ limit_conn downloads_by_ip 100; # ddos protection: max 100 downloads at a time
 
 # ensure that skylink that we pass around is base64 encoded (transform base32 encoded ones)
 # this is important because we want only one format in cache keys and logs
-set_by_lua_block $skylink { return require("skynet.skylink").parse(ngx.var.skylink) }
+set_by_lua_block $skylink { return require("skynet.skylink").base64(ngx.var.skylink) }
 
 # $skylink_v1 and $skylink_v2 variables default to the same value but in case the requested skylink was:
 # a) skylink v1 - it would not matter, no additional logic is executed

docker/nginx/conf.d/server/server.api

@@ -352,7 +352,13 @@ location ~ "^/(([a-zA-Z0-9-_]{46}|[a-z0-9]{55})(/.*)?)$" {
     set $skylink $2;
     set $path $3;
 
-    include /etc/nginx/conf.d/include/location-skylink;
+    rewrite_by_lua_block {
+        local skynet_skylink = require("skynet.skylink")
+        local base32_skylink = skynet_skylink.base32(ngx.var.skylink)
+        local base32_url = ngx.var.scheme .. "://" .. base32_skylink .. "." .. ngx.var.skynet_portal_domain .. ngx.var.path
+
+        return ngx.redirect(base32_url, ngx.HTTP_MOVED_PERMANENTLY)
+    }
 }
 
 location ~ "^/file/(([a-zA-Z0-9-_]{46}|[a-z0-9]{55})(/.*)?)$" {

docker/nginx/conf.d/server/server.dnslink

@@ -37,7 +37,7 @@ location / {
             ngx.var.skylink = cache_value
         end
 
-        ngx.var.skylink = require("skynet.skylink").parse(ngx.var.skylink)
+        ngx.var.skylink = require("skynet.skylink").base64(ngx.var.skylink)
         ngx.var.skylink_v1 = ngx.var.skylink
         ngx.var.skylink_v2 = ngx.var.skylink
     }

docker/nginx/libs/skynet/skylink.lua

@@ -3,10 +3,13 @@ local _M = {}
 local basexx = require("basexx")
 local hasher = require("hasher")
 
+-- use lowercase alphabet since our skylinks are part of urls
+local base32_alphabet = "0123456789abcdefghijklmnopqrstuv"
+
 -- parse any skylink and return base64 version
-function _M.parse(skylink)
+function _M.base64(skylink)
     if string.len(skylink) == 55 then
-        local decoded = basexx.from_basexx(string.upper(skylink), "0123456789ABCDEFGHIJKLMNOPQRSTUV", 5)
+        local decoded = basexx.from_basexx(string.lower(skylink), base32_alphabet, 5)
 
         return basexx.to_url64(decoded)
     end
@@ -14,10 +17,21 @@ function _M.parse(skylink)
     return skylink
 end
 
+-- parse any skylink and return base32 version
+function _M.base32(skylink)
+    if string.len(skylink) == 46 then
+        local decoded = basexx.from_url64(skylink)
+
+        return basexx.to_basexx(decoded, base32_alphabet, 5)
+    end
+
+    return skylink
+end
+
 -- hash skylink into 32 bytes hash used in blocklist
 function _M.hash(skylink)
     -- ensure that the skylink is base64 encoded
-    local base64Skylink = _M.parse(skylink)
+    local base64Skylink = _M.base64(skylink)
 
     -- decode skylink from base64 encoding
     local rawSkylink = basexx.from_url64(base64Skylink)

docker/nginx/libs/skynet/skylink.spec.lua

@@ -1,15 +1,28 @@
 local skynet_skylink = require("skynet.skylink")
 
-describe("parse", function()
+describe("base64", function()
    local base32 = "0404dsjvti046fsua4ktor9grrpe76erq9jot9cvopbhsvsu76r4r30"
    local base64 = "AQBG8n_sgEM_nlEp3G0w3vLjmdvSZ46ln8ZXHn-eObZNjA"
 
    it("should return unchanged base64 skylink", function()
-      assert.is.same(skynet_skylink.parse(base64), base64)
+      assert.is.same(skynet_skylink.base64(base64), base64)
    end)
    
    it("should transform base32 skylink into base64", function()
-      assert.is.same(skynet_skylink.parse(base32), base64)
+      assert.is.same(skynet_skylink.base64(base32), base64)
+   end)
+end)
+
+describe("base32", function()
+   local base32 = "0404dsjvti046fsua4ktor9grrpe76erq9jot9cvopbhsvsu76r4r30"
+   local base64 = "AQBG8n_sgEM_nlEp3G0w3vLjmdvSZ46ln8ZXHn-eObZNjA"
+
+   it("should return unchanged base32 skylink", function()
+      assert.is.same(skynet_skylink.base32(base32), base32)
+   end)
+   
+   it("should transform base64 skylink into base32", function()
+      assert.is.same(skynet_skylink.base32(base64), base32)
    end)
 end)