Software / code / prosody
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util/datamapper.lua @ 13801:a5d5fefb8b68 13.0
mod_tls: Enable Prosody's certificate checking for incoming s2s connections (fixes #1916) (thanks Damian, Zash)
Various options in Prosody allow control over the behaviour of the certificate
verification process For example, some deployments choose to allow falling
back to traditional "dialback" authentication (XEP-0220), while others verify
via DANE, hard-coded fingerprints, or other custom plugins.
Implementing this flexibility requires us to override OpenSSL's default
certificate verification, to allow Prosody to verify the certificate itself,
apply custom policies and make decisions based on the outcome.
To enable our custom logic, we have to suppress OpenSSL's default behaviour of
aborting the connection with a TLS alert message. With LuaSec, this can be
achieved by using the verifyext "lsec_continue" flag.
We also need to use the lsec_ignore_purpose flag, because XMPP s2s uses server
certificates as "client" certificates (for mutual TLS verification in outgoing
s2s connections).
Commit 99d2100d2918 moved these settings out of the defaults and into mod_s2s,
because we only really need these changes for s2s, and they should be opt-in,
rather than automatically applied to all TLS services we offer.
That commit was incomplete, because it only added the flags for incoming
direct TLS connections. StartTLS connections are handled by mod_tls, which was
not applying the lsec_* flags. It previously worked because they were already
in the defaults.
This resulted in incoming s2s connections with "invalid" certificates being
aborted early by OpenSSL, even if settings such as `s2s_secure_auth = false`
or DANE were present in the config.
Outgoing s2s connections inherit verify "none" from the defaults, which means
OpenSSL will receive the cert but will not terminate the connection when it is
deemed invalid. This means we don't need lsec_continue there, and we also
don't need lsec_ignore_purpose (because the remote peer is a "server").
Wondering why we can't just use verify "none" for incoming s2s? It's because
in that mode, OpenSSL won't request a certificate from the peer for incoming
connections. Setting verify "peer" is how you ask OpenSSL to request a
certificate from the client, but also what triggers its built-in verification.
| author | Matthew Wild <mwild1@gmail.com> |
|---|---|
| date | Tue, 01 Apr 2025 17:26:56 +0100 |
| parent | 12975:d10957394a3c |
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-- This file is generated from teal-src/util/datamapper.lua if not math.type then require("prosody.util.mathcompat") end local st = require("prosody.util.stanza"); local pointer = require("prosody.util.jsonpointer"); local schema_t = {} local function toboolean(s) if s == "true" or s == "1" then return true elseif s == "false" or s == "0" then return false elseif s then return true end end local function totype(t, s) if not s then return nil end if t == "string" then return s elseif t == "boolean" then return toboolean(s) elseif t == "number" or t == "integer" then return tonumber(s) end end local value_goes = {} local function resolve_schema(schema, root) if type(schema) == "table" then if schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then return pointer.resolve(root, schema["$ref"]:sub(2)) end end return schema end local function guess_schema_type(schema) local schema_types = schema.type if type(schema_types) == "string" then return schema_types elseif schema_types ~= nil then error("schema has unsupported 'type' property") elseif schema.properties then return "object" elseif schema.items then return "array" end return "string" end local function unpack_propschema(propschema, propname, current_ns) local proptype = "string" local value_where = propname and "in_text_tag" or "in_text" local name = propname local namespace local prefix local single_attribute local enums if type(propschema) == "table" then proptype = guess_schema_type(propschema); elseif type(propschema) == "string" then error("schema as string is not supported: " .. propschema .. " {" .. current_ns .. "}" .. propname) end if proptype == "object" or proptype == "array" then value_where = "in_children" end if type(propschema) == "table" then local xml = propschema.xml if xml then if xml.name then name = xml.name end if xml.namespace and xml.namespace ~= current_ns then namespace = xml.namespace end if xml.prefix then prefix = xml.prefix end if proptype == "array" and xml.wrapped then value_where = "in_wrapper" elseif xml.attribute then value_where = "in_attribute" elseif xml.text then value_where = "in_text" elseif xml.x_name_is_value then value_where = "in_tag_name" elseif xml.x_single_attribute then single_attribute = xml.x_single_attribute value_where = "in_single_attribute" end end if propschema["const"] then enums = {propschema["const"]} elseif propschema["enum"] then enums = propschema["enum"] end end return proptype, value_where, name, namespace, prefix, single_attribute, enums end local parse_object local parse_array local function extract_value(s, value_where, proptype, name, namespace, prefix, single_attribute, enums) if value_where == "in_tag_name" then local c if proptype == "boolean" then c = s:get_child(name, namespace); elseif enums and proptype == "string" then for i = 1, #enums do c = s:get_child(enums[i], namespace); if c then break end end else c = s:get_child(nil, namespace); end if c then return c.name end elseif value_where == "in_attribute" then local attr = name if prefix then attr = prefix .. ":" .. name elseif namespace and namespace ~= s.attr.xmlns then attr = namespace .. "\1" .. name end return s.attr[attr] elseif value_where == "in_text" then return s:get_text() elseif value_where == "in_single_attribute" then local c = s:get_child(name, namespace) return c and c.attr[single_attribute] elseif value_where == "in_text_tag" then return s:get_child_text(name, namespace) end end function parse_object(schema, s, root) local out = {} schema = resolve_schema(schema, root) if type(schema) == "table" and schema.properties then for prop, propschema in pairs(schema.properties) do propschema = resolve_schema(propschema, root) local proptype, value_where, name, namespace, prefix, single_attribute, enums = unpack_propschema(propschema, prop, s.attr.xmlns) if value_where == "in_children" and type(propschema) == "table" then if proptype == "object" then local c = s:get_child(name, namespace) if c then out[prop] = parse_object(propschema, c, root); end elseif proptype == "array" then local a = parse_array(propschema, s, root); if a and a[1] ~= nil then out[prop] = a; end else error("unreachable") end elseif value_where == "in_wrapper" and type(propschema) == "table" and proptype == "array" then local wrapper = s:get_child(name, namespace); if wrapper then out[prop] = parse_array(propschema, wrapper, root); end else local value = extract_value(s, value_where, proptype, name, namespace, prefix, single_attribute, enums) out[prop] = totype(proptype, value) end end end return out end function parse_array(schema, s, root) local itemschema = resolve_schema(schema.items, root); local proptype, value_where, child_name, namespace, prefix, single_attribute, enums = unpack_propschema(itemschema, nil, s.attr.xmlns) local attr_name if value_where == "in_single_attribute" then value_where = "in_attribute"; attr_name = single_attribute; end local out = {} if proptype == "object" then if type(itemschema) == "table" then for c in s:childtags(child_name, namespace) do table.insert(out, parse_object(itemschema, c, root)); end else error("array items must be schema object") end elseif proptype == "array" then if type(itemschema) == "table" then for c in s:childtags(child_name, namespace) do table.insert(out, parse_array(itemschema, c, root)); end end else for c in s:childtags(child_name, namespace) do local value = extract_value(c, value_where, proptype, attr_name or child_name, namespace, prefix, single_attribute, enums) table.insert(out, totype(proptype, value)); end end return out end local function parse(schema, s) local s_type = guess_schema_type(schema) if s_type == "object" then return parse_object(schema, s, schema) elseif s_type == "array" then return parse_array(schema, s, schema) else error("top-level scalars unsupported") end end local function toxmlstring(proptype, v) if proptype == "string" and type(v) == "string" then return v elseif proptype == "number" and type(v) == "number" then return string.format("%g", v) elseif proptype == "integer" and type(v) == "number" then return string.format("%d", v) elseif proptype == "boolean" then return v and "1" or "0" end end local unparse local function unparse_property(out, v, proptype, propschema, value_where, name, namespace, current_ns, prefix, single_attribute, root) if value_where == "in_attribute" then local attr = name if prefix then attr = prefix .. ":" .. name elseif namespace and namespace ~= current_ns then attr = namespace .. "\1" .. name end out.attr[attr] = toxmlstring(proptype, v) elseif value_where == "in_text" then out:text(toxmlstring(proptype, v)) elseif value_where == "in_single_attribute" then assert(single_attribute) local propattr = {} if namespace and namespace ~= current_ns then propattr.xmlns = namespace end propattr[single_attribute] = toxmlstring(proptype, v) out:tag(name, propattr):up(); else local propattr if namespace ~= current_ns then propattr = {xmlns = namespace} end if value_where == "in_tag_name" then if proptype == "string" and type(v) == "string" then out:tag(v, propattr):up(); elseif proptype == "boolean" and v == true then out:tag(name, propattr):up(); end elseif proptype == "object" and type(propschema) == "table" and type(v) == "table" then local c = unparse(propschema, v, name, namespace, nil, root); if c then out:add_direct_child(c); end elseif proptype == "array" and type(propschema) == "table" and type(v) == "table" then if value_where == "in_wrapper" then local c = unparse(propschema, v, name, namespace, nil, root); if c then out:add_direct_child(c); end else unparse(propschema, v, name, namespace, out, root); end else out:text_tag(name, toxmlstring(proptype, v), propattr) end end end function unparse(schema, t, current_name, current_ns, ctx, root) if root == nil then root = schema end if schema.xml then if schema.xml.name then current_name = schema.xml.name end if schema.xml.namespace then current_ns = schema.xml.namespace end end local out = ctx or st.stanza(current_name, {xmlns = current_ns}) local s_type = guess_schema_type(schema) if s_type == "object" then for prop, propschema in pairs(schema.properties) do propschema = resolve_schema(propschema, root) local v = t[prop] if v ~= nil then local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(propschema, prop, current_ns) unparse_property(out, v, proptype, propschema, value_where, name, namespace, current_ns, prefix, single_attribute, root) end end return out elseif s_type == "array" then local itemschema = resolve_schema(schema.items, root) local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(itemschema, current_name, current_ns) for _, item in ipairs(t) do unparse_property(out, item, proptype, itemschema, value_where, name, namespace, current_ns, prefix, single_attribute, root) end return out end end return {parse = parse; unparse = unparse}