diff --git a/bin/acme b/bin/acme
index 5c7cd30..e05a49f 100755
--- a/bin/acme
+++ b/bin/acme
@@ -14,7 +14,7 @@ require __DIR__ . "/../vendor/autoload.php";
 $commands = [
     "setup",
     "issue",
-    "renew",
+    "check",
     "revoke",
 ];
 
@@ -53,7 +53,14 @@ if (count($argv) === 1 || in_array($argv[1], ["h", "-h", "help", "--help"], true
 }
 
 if (!in_array($argv[1], $commands)) {
-    $climate->error("Unknown command '{$argv[1]}', use --help for a list of available commands.");
+    $climate->error("Unknown command '{$argv[1]}'. Use --help for a list of available commands.");
+
+    $suggestion = \Kelunik\AcmeClient\suggestCommand($argv[1], $commands);
+
+    if ($suggestion) {
+        $climate->br()->info("    Did you mean '$suggestion'?")->br();
+    }
+
     exit(1);
 }
 
@@ -70,6 +77,7 @@ try {
 } catch (Exception $e) {
     if (count($argv) === 3 && in_array($argv[2], ["h", "-h", "--help", "help"], true)) {
         $climate->usage(["bin/acme {$argv[1]}"]);
+        $climate->br();
         exit(0);
     } else {
         $climate->error($e->getMessage());
@@ -77,12 +85,6 @@ try {
     }
 }
 
-if (posix_geteuid() !== 0) { // TODO: Windows?
-    $climate->error("Please run this script as root.");
-
-    exit(1);
-}
-
 $handler = new StreamHandler("php://stdout", Logger::DEBUG);
 $handler->setFormatter(new ColoredLineFormatter(new LoggerColorScheme, null, null, true, true));
 
diff --git a/composer.json b/composer.json
index 776396d..d025657 100644
--- a/composer.json
+++ b/composer.json
@@ -6,13 +6,14 @@
         "bramus/monolog-colored-line-formatter": "^2",
         "ext-posix": "*",
         "ext-openssl": "*",
-        "kelunik/acme": "^0.2",
-        "kelunik/certificate": "^0.2",
+        "kelunik/acme": "^0.3",
+        "kelunik/certificate": "^1",
         "league/climate": "^3",
         "monolog/monolog": "^1.17",
         "php": ">=5.5",
         "psr/log": "^1",
-        "rdlowrey/auryn": "^1"
+        "rdlowrey/auryn": "^1",
+        "webmozart/assert": "^1"
     },
     "license": "MIT",
     "authors": [
@@ -26,6 +27,12 @@
     "autoload": {
         "psr-4": {
             "Kelunik\\AcmeClient\\": "src"
-        }
+        },
+        "files": [
+            "src/functions.php"
+        ]
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^5"
     }
 }
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..cda635b
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<phpunit backupGlobals="false"
+         backupStaticAttributes="false"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false"
+         syntaxCheck="false"
+         bootstrap="./vendor/autoload.php">
+    <php>
+        <ini name="memory_limit" value="1G"/>
+        <ini name="error_reporting" value="-1"/>
+    </php>
+
+    <testsuites>
+        <testsuite name="Tests">
+            <directory>./test</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist>
+            <directory>./src/</directory>
+        </whitelist>
+    </filter>
+</phpunit>
\ No newline at end of file
diff --git a/src/Commands/Check.php b/src/Commands/Check.php
new file mode 100644
index 0000000..6a3de7b
--- /dev/null
+++ b/src/Commands/Check.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace Kelunik\AcmeClient\Commands;
+
+use Kelunik\Certificate\Certificate;
+use League\CLImate\Argument\Manager;
+use Psr\Log\LoggerInterface;
+
+class Check implements Command {
+    private $logger;
+
+    public function __construct(LoggerInterface $logger) {
+        $this->logger = $logger;
+    }
+
+    public function execute(Manager $args) {
+        return \Amp\resolve($this->doExecute($args));
+    }
+
+    /**
+     * @param Manager $args
+     * @return \Generator
+     */
+    private function doExecute(Manager $args) {
+        $path = $args->get("cert");
+
+        if (!realpath($path)) {
+            throw new \RuntimeException("Certificate doesn't exist: '{$path}'");
+        }
+
+        $pem = (yield \Amp\File\get($path));
+        $cert = new Certificate($pem);
+
+        $this->logger->info("Certificate is valid until " . date("d.m.Y", $cert->getValidTo()));
+
+        if ($cert->getValidTo() > time() + $args->get("ttl") * 24 * 60 * 60) {
+            exit(0);
+        }
+
+        $this->logger->warning("Certificate is going to expire within the specified " . $args->get("ttl") . " days.");
+
+        exit(1);
+    }
+
+    public static function getDefinition() {
+        return [
+            "cert" => [
+                "longPrefix" => "cert",
+                "prefix" => "c",
+                "description" => "Certificate to check.",
+                "required" => true,
+            ],
+            "ttl" => [
+                "longPrefix" => "ttl",
+                "description" => "Minimum valid time in days.",
+                "defaultValue" => 30,
+                "castTo" => "int",
+            ],
+        ];
+    }
+}
\ No newline at end of file
diff --git a/src/Commands/Issue.php b/src/Commands/Issue.php
index 349516a..0c1dda4 100644
--- a/src/Commands/Issue.php
+++ b/src/Commands/Issue.php
@@ -29,15 +29,30 @@ class Issue implements Command {
     }
 
     private function doExecute(Manager $args) {
-        $domains = array_map("trim", explode(",", $args->get("domains")));
-        yield \Amp\resolve($this->checkDnsRecords($domains));
+        if (strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN') {
+            if (posix_geteuid() !== 0) {
+                $processUser = posix_getpwnam(posix_geteuid());
+                $currentUsername = $processUser["name"];
+                $user = $args->get("user") ?: $currentUsername;
 
-        $user = $args->get("user") ?: "www-data";
+                if ($currentUsername !== $user) {
+                    throw new AcmeException("Running this script with --user only works as root!");
+                }
+            } else {
+                $user = $args->get("user") ?: "www-data";
+            }
+        }
+
+        $domains = array_map("trim", explode(":", $args->get("domains")));
+        yield \Amp\resolve($this->checkDnsRecords($domains));
 
         $keyStore = new KeyStore(dirname(dirname(__DIR__)) . "/data");
 
-        $keyPair = (yield $keyStore->get("account/key.pem"));
-        $acme = new AcmeService(new AcmeClient(\Kelunik\AcmeClient\getServer(), $keyPair), $keyPair);
+        $server = \Kelunik\AcmeClient\resolveServer($args->get("server"));
+        $keyFile = \Kelunik\AcmeClient\serverToKeyname($server);
+
+        $keyPair = (yield $keyStore->get("accounts/{$keyFile}.pem"));
+        $acme = new AcmeService(new AcmeClient($server, $keyPair));
 
         foreach ($domains as $domain) {
             list($location, $challenges) = (yield $acme->requestChallenges($domain));
@@ -51,11 +66,11 @@ class Issue implements Command {
             $token = $challenge->token;
 
             if (!preg_match("#^[a-zA-Z0-9-_]+$#", $token)) {
-                throw new AcmeException("Protocol Violation: Invalid Token!");
+                throw new AcmeException("Protocol violation: Invalid Token!");
             }
 
             $this->logger->debug("Generating payload...");
-            $payload = $acme->generateHttp01Payload($token);
+            $payload = $acme->generateHttp01Payload($token, $keyPair);
 
             $this->logger->info("Providing payload at http://{$domain}/.well-known/acme-challenge/{$token}");
             $docRoot = rtrim(str_replace("\\", "/", $args->get("path")), "/");
@@ -63,9 +78,9 @@ class Issue implements Command {
             $challengeStore = new ChallengeStore($docRoot);
 
             try {
-                $challengeStore->put($token, $payload, $user);
+                $challengeStore->put($token, $payload, isset($user) ? $user : null);
 
-                yield $acme->selfVerify($domain, $token, $payload);
+                yield $acme->verifyHttp01Challenge($domain, $token, $payload);
                 $this->logger->info("Successfully self-verified challenge.");
 
                 yield $acme->answerChallenge($challenge->uri, $payload);
@@ -87,7 +102,7 @@ class Issue implements Command {
         }
 
         $path = "certs/" . reset($domains) . "/key.pem";
-        $bits = $args->get("bits") ?: 2048;
+        $bits = $args->get("bits");
 
         try {
             $keyPair = (yield $keyStore->get($path));
@@ -153,23 +168,28 @@ class Issue implements Command {
 
     public static function getDefinition() {
         return [
+            "server" => [
+                "prefix" => "s",
+                "longPrefix" => "server",
+                "description" => "Server to use for issuance, see also 'bin/acme setup'.",
+                "required" => true,
+            ],
             "domains" => [
                 "prefix" => "d",
                 "longPrefix" => "domains",
-                "description" => "Comma separated list of domains to request a certificate for.",
+                "description" => "Colon separated list of domains to request a certificate for.",
                 "required" => true,
             ],
             "path" => [
                 "prefix" => "p",
                 "longPrefix" => "path",
-                "description" => "Absolute path to the document root of these domains.",
+                "description" => "Colon separated list of paths to the document roots. The last one will be used for all remaining ones if fewer than the amount of domains is given.",
                 "required" => true,
             ],
             "user" => [
                 "prefix" => "u",
                 "longPrefix" => "user",
                 "description" => "User running the web server.",
-                "defaultValue" => "www-data",
             ],
             "bits" => [
                 "longPrefix" => "bits",
diff --git a/src/Commands/Renew.php b/src/Commands/Renew.php
deleted file mode 100644
index c43e4c2..0000000
--- a/src/Commands/Renew.php
+++ /dev/null
@@ -1,86 +0,0 @@
-<?php
-
-namespace Kelunik\AcmeClient\Commands;
-
-use Amp\Process;
-use Kelunik\Certificate\Certificate;
-use League\CLImate\Argument\Manager;
-use Psr\Log\LoggerInterface;
-
-class Renew implements Command {
-    private $logger;
-
-    public function __construct(LoggerInterface $logger) {
-        $this->logger = $logger;
-    }
-
-    public function execute(Manager $args) {
-        return \Amp\resolve($this->doExecute($args));
-    }
-
-    private function doExecute(Manager $args) {
-        $path = dirname(dirname(__DIR__)) . "/data/certs";
-
-        if (!realpath($path)) {
-            throw new \RuntimeException("Certificate path doesn't exist: '{$path}'");
-        }
-
-        $domains = (yield \Amp\File\scandir($path));
-        $promises = [];
-
-        foreach ($domains as $domain) {
-            $pem = (yield \Amp\File\get($path . "/" . $domain . "/cert.pem"));
-            $cert = new Certificate($pem);
-
-            if ($cert->getValidTo() > time() + 30 * 24 * 60 * 60) {
-                $this->logger->info("Certificate for " . implode(",", $cert->getNames()) . " is still valid for more than 30 days.");
-
-                continue;
-            }
-
-            $json = (yield \Amp\File\get($path . "/" . $domain . "/config.json"));
-            $config = json_decode($json);
-
-            $command = [
-                PHP_BINARY,
-                dirname(dirname(__DIR__)) . "/bin/acme",
-                "issue",
-                "-d",
-                implode(",", $config->domains),
-                "-p",
-                $config->path,
-                "-u",
-                $config->user,
-            ];
-
-            $command = array_map("escapeshellarg", $command);
-            $command = implode(" ", $command);
-
-            $promises[] = \Amp\pipe((new Process($command))->exec()->watch(function ($update) {
-                list($type, $data) = $update;
-
-                if ($type === "err") {
-                    $this->logger->error($data);
-                } else {
-                    $this->logger->info($data);
-                }
-            }), function ($result) use ($command) {
-                $result->command = $command;
-
-                return $result;
-            });
-        }
-
-        $results = (yield \Amp\all($promises));
-
-        foreach ($results as $result) {
-            if ($result->exit !== 0) {
-                throw new \RuntimeException("Invalid exit code: " . $result->exit . " (" . $result->command . ")");
-            }
-        }
-    }
-
-    public static function getDefinition() {
-        return [];
-    }
-}
\ No newline at end of file
diff --git a/src/Commands/Revoke.php b/src/Commands/Revoke.php
index 7bdcc31..c74f62e 100644
--- a/src/Commands/Revoke.php
+++ b/src/Commands/Revoke.php
@@ -26,14 +26,13 @@ class Revoke implements Command {
     }
 
     private function doExecute(Manager $args) {
-        if (posix_geteuid() !== 0) {
-            throw new AcmeException("Please run this script as root!");
-        }
-
         $keyStore = new KeyStore(dirname(dirname(__DIR__)) . "/data");
 
-        $keyPair = (yield $keyStore->get("account/key.pem"));
-        $acme = new AcmeService(new AcmeClient(\Kelunik\AcmeClient\getServer(), $keyPair), $keyPair);
+        $server = $args->get("server");
+        $keyFile = \Kelunik\AcmeClient\serverToKeyname($server);
+
+        $keyPair = (yield $keyStore->get("accounts/{$keyFile}.pem"));
+        $acme = new AcmeService(new AcmeClient($server, $keyPair), $keyPair);
 
         $this->logger->info("Revoking certificate ...");
 
@@ -57,6 +56,12 @@ class Revoke implements Command {
 
     public static function getDefinition() {
         return [
+            "server" => [
+                "prefix" => "s",
+                "longPrefix" => "server",
+                "description" => "",
+                "required" => true,
+            ],
             "name" => [
                 "longPrefix" => "name",
                 "description" => "Common name of the certificate to be revoked.",
diff --git a/src/Commands/Setup.php b/src/Commands/Setup.php
index 038deb5..ff25e55 100644
--- a/src/Commands/Setup.php
+++ b/src/Commands/Setup.php
@@ -34,15 +34,9 @@ class Setup implements Command {
         yield \Amp\resolve($this->checkEmail($email));
 
         $server = $args->get("server");
-        $protocol = substr($server, 0, strpos("://", $server));
+        $keyFile = \Kelunik\AcmeClient\serverToKeyname($server);
 
-        if (!$protocol || $protocol === $server) {
-            $server = "https://" . $server;
-        } elseif ($protocol !== "https") {
-            throw new \InvalidArgumentException("Invalid protocol, only https is allowed!");
-        }
-
-        $path = "account/key.pem";
+        $path = "accounts/{$keyFile}.pem";
         $bits = 4096;
 
         $keyStore = new KeyStore(dirname(dirname(__DIR__)) . "/data");
diff --git a/src/Config.php b/src/Config.php
deleted file mode 100644
index 112bc92..0000000
--- a/src/Config.php
+++ /dev/null
@@ -1,15 +0,0 @@
-<?php
-
-namespace Kelunik\AcmeClient;
-
-class Config {
-    private $config;
-
-    public function __construct(array $config) {
-        $this->config = $config;
-    }
-
-    public function get($key) {
-        return isset($this->config[$key]) ? $this->config[$key] : null;
-    }
-}
\ No newline at end of file
diff --git a/src/Stores/CertificateStore.php b/src/Stores/CertificateStore.php
index 607f717..738c618 100644
--- a/src/Stores/CertificateStore.php
+++ b/src/Stores/CertificateStore.php
@@ -5,6 +5,7 @@ namespace Kelunik\AcmeClient\Stores;
 use Amp\File\FilesystemException;
 use InvalidArgumentException;
 use Kelunik\Certificate\Certificate;
+use Webmozart\Assert\Assert;
 
 class CertificateStore {
     private $root;
@@ -43,38 +44,29 @@ class CertificateStore {
             $path = $this->root . "/" . $commonName;
             $realpath = realpath($path);
 
-            if (!$realpath && !mkdir($path, 0770, true)) {
+            if (!$realpath && !mkdir($path, 0775, true)) {
                 throw new FilesystemException("Couldn't create certificate directory: '{$path}'");
             }
 
             yield \Amp\File\put($path . "/cert.pem", $certificates[0]);
-            yield \Amp\File\chown($path . "/cert.pem", 0, 0);
-            yield \Amp\File\chmod($path . "/cert.pem", 0640);
+            yield \Amp\File\chmod($path . "/cert.pem", 0644);
 
             yield \Amp\File\put($path . "/fullchain.pem", implode("\n", $certificates));
-            yield \Amp\File\chown($path . "/fullchain.pem", 0, 0);
-            yield \Amp\File\chmod($path . "/fullchain.pem", 0640);
+            yield \Amp\File\chmod($path . "/fullchain.pem", 0644);
 
             yield \Amp\File\put($path . "/chain.pem", implode("\n", $chain));
-            yield \Amp\File\chown($path . "/chain.pem", 0, 0);
-            yield \Amp\File\chmod($path . "/chain.pem", 0640);
+            yield \Amp\File\chmod($path . "/chain.pem", 0644);
         } catch (FilesystemException $e) {
             throw new CertificateStoreException("Couldn't save certificates for '{$commonName}'", 0, $e);
         }
     }
 
     public function delete($name) {
-        if (!is_string($name)) {
-            throw new InvalidArgumentException(sprintf("\$name must be of type string, %s given.", gettype($name)));
-        }
-
         return \Amp\resolve($this->doDelete($name));
     }
 
     private function doDelete($name) {
-        if (!is_string($name)) {
-            throw new InvalidArgumentException(sprintf("\$name must be of type string, %s given.", gettype($name)));
-        }
+        Assert::string($name, "Name must be a string. Got: %s");
 
         foreach ((yield \Amp\File\scandir($this->root . "/" . $name)) as $file) {
             yield \Amp\File\unlink($this->root . "/" . $name . "/" . $file);
diff --git a/src/Stores/ChallengeStore.php b/src/Stores/ChallengeStore.php
index 9d222d7..b9a9b1e 100644
--- a/src/Stores/ChallengeStore.php
+++ b/src/Stores/ChallengeStore.php
@@ -2,9 +2,8 @@
 
 namespace Kelunik\AcmeClient\Stores;
 
-use Amp\Promise;
-use Generator;
 use InvalidArgumentException;
+use Webmozart\Assert\Assert;
 
 class ChallengeStore {
     private $docroot;
@@ -17,34 +16,14 @@ class ChallengeStore {
         $this->docroot = rtrim(str_replace("\\", "/", $docroot), "/");
     }
 
-    public function put($token, $payload, $user) {
-        if (!is_string($token)) {
-            throw new InvalidArgumentException(sprintf("\$token must be of type string, %s given.", gettype($token)));
-        }
-
-        if (!is_string($payload)) {
-            throw new InvalidArgumentException(sprintf("\$payload must be of type string, %s given.", gettype($payload)));
-        }
-
-        if (!is_string($user)) {
-            throw new InvalidArgumentException(sprintf("\$user must be of type string, %s given.", gettype($user)));
-        }
-
+    public function put($token, $payload, $user = null) {
         return \Amp\resolve($this->doPut($token, $payload, $user));
     }
 
-    private function doPut($token, $payload, $user) {
-        if (!is_string($token)) {
-            throw new InvalidArgumentException(sprintf("\$token must be of type string, %s given.", gettype($token)));
-        }
-
-        if (!is_string($payload)) {
-            throw new InvalidArgumentException(sprintf("\$payload must be of type string, %s given.", gettype($payload)));
-        }
-
-        if (!is_string($user)) {
-            throw new InvalidArgumentException(sprintf("\$user must be of type string, %s given.", gettype($user)));
-        }
+    private function doPut($token, $payload, $user = null) {
+        Assert::string($token, "Token must be a string. Got: %s");
+        Assert::string($payload, "Payload must be a string. Got: %s");
+        Assert::nullOrString($user, "User must be a string or null. Got: %s");
 
         $path = $this->docroot . "/.well-known/acme-challenge";
         $realpath = realpath($path);
@@ -53,36 +32,36 @@ class ChallengeStore {
             throw new ChallengeStoreException("Document root doesn't exist: '{$this->docroot}'");
         }
 
-        if (!$realpath && !@mkdir($path, 0770, true)) {
+        if (!$realpath && !@mkdir($path, 0755, true)) {
             throw new ChallengeStoreException("Couldn't create public directory to serve the challenges: '{$path}'");
         }
 
-        if (!$userInfo = posix_getpwnam($user)) {
-            throw new ChallengeStoreException("Unknown user: '{$user}'");
+        if ($user) {
+            if (!$userInfo = posix_getpwnam($user)) {
+                throw new ChallengeStoreException("Unknown user: '{$user}'");
+            }
         }
 
-        // TODO: Make async, see https://github.com/amphp/file/issues/6
-        chown($this->docroot . "/.well-known", $userInfo["uid"]);
-        chown($this->docroot . "/.well-known/acme-challenge", $userInfo["uid"]);
+        if (isset($userInfo)) {
+            yield \Amp\File\chown($this->docroot . "/.well-known", $userInfo["uid"], -1);
+            yield \Amp\File\chown($this->docroot . "/.well-known/acme-challenge", $userInfo["uid"], -1);
+        }
 
         yield \Amp\File\put("{$path}/{$token}", $payload);
 
-        chown("{$path}/{$token}", $userInfo["uid"]);
-        chmod("{$path}/{$token}", 0660);
+        if (isset($userInfo)) {
+            yield \Amp\File\chown("{$path}/{$token}", $userInfo["uid"], -1);
+        }
+
+        yield \Amp\File\chmod("{$path}/{$token}", 0644);
     }
 
     public function delete($token) {
-        if (!is_string($token)) {
-            throw new InvalidArgumentException(sprintf("\$token must be of type string, %s given.", gettype($token)));
-        }
-
         return \Amp\resolve($this->doDelete($token));
     }
 
     private function doDelete($token) {
-        if (!is_string($token)) {
-            throw new InvalidArgumentException(sprintf("\$token must be of type string, %s given.", gettype($token)));
-        }
+        Assert::string($token, "Token must be a string. Got: %s");
 
         $path = $this->docroot . "/.well-known/acme-challenge/{$token}";
         $realpath = realpath($path);
diff --git a/src/Stores/KeyStore.php b/src/Stores/KeyStore.php
index 9bbe776..d1711f8 100644
--- a/src/Stores/KeyStore.php
+++ b/src/Stores/KeyStore.php
@@ -67,7 +67,7 @@ class KeyStore {
 
         try {
             // TODO: Replace with async version once available
-            mkdir(dirname($file), 0770, true);
+            mkdir(dirname($file), 0755, true);
 
             yield \Amp\File\put($file, $keyPair->getPrivate());
             yield \Amp\File\chmod($file, 0600);
diff --git a/src/functions.php b/src/functions.php
new file mode 100644
index 0000000..c63217e
--- /dev/null
+++ b/src/functions.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace Kelunik\AcmeClient;
+
+use Webmozart\Assert\Assert;
+
+function suggestCommand($badCommand, array $commands, $suggestThreshold = 70) {
+    Assert::string($badCommand, "Bad command must be a string. Got: %s");
+    Assert::integer($suggestThreshold, "Suggest threshold must be an integer. Got: %s");
+
+    $badCommand = strtolower($badCommand);
+
+    $bestMatch = "";
+    $bestMatchPercentage = 0;
+    $byRefPercentage = 0;
+
+    foreach ($commands as $command) {
+        \similar_text($badCommand, strtolower($command), $byRefPercentage);
+
+        if ($byRefPercentage > $bestMatchPercentage) {
+            $bestMatchPercentage = $byRefPercentage;
+            $bestMatch = $command;
+        }
+    }
+
+    return $bestMatchPercentage >= $suggestThreshold ? $bestMatch : "";
+}
+
+function resolveServer($uri) {
+    Assert::string($uri, "URI must be a string. Got: %s");
+
+    $shortcuts = [
+        "letsencrypt" => "https://acme-v01.api.letsencrypt.org/directory",
+        "letsencrypt:production" => "https://acme-v01.api.letsencrypt.org/directory",
+        "letsencrypt:staging" => "https://acme-staging.api.letsencrypt.org/directory",
+    ];
+
+    if (isset($shortcuts[$uri])) {
+        return $shortcuts[$uri];
+    }
+
+    $protocol = substr($uri, 0, strpos($uri, "://"));
+
+    if (!$protocol || $protocol === $uri) {
+        return "https://{$uri}";
+    } else {
+        return $uri;
+    }
+}
+
+function serverToKeyname($server) {
+    $keyFile = str_replace("/", ".", $server);
+    $keyFile = preg_replace("[^a-z0-9._-]", "", $keyFile);
+    $keyFile = preg_replace("\\.+", ".", $keyFile);
+
+    return $keyFile;
+}
\ No newline at end of file
diff --git a/test/FunctionsTest.php b/test/FunctionsTest.php
new file mode 100644
index 0000000..f48c771
--- /dev/null
+++ b/test/FunctionsTest.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Kelunik\AcmeClient;
+
+class FunctionsTest extends \PHPUnit_Framework_TestCase {
+    public function testResolveServer() {
+        $this->assertSame("https://acme-v01.api.letsencrypt.org/directory", resolveServer("letsencrypt"));
+        $this->assertSame("https://acme-v01.api.letsencrypt.org/directory", resolveServer("letsencrypt:production"));
+        $this->assertSame("https://acme-staging.api.letsencrypt.org/directory", resolveServer("letsencrypt:staging"));
+        $this->assertSame("https://acme-v01.api.letsencrypt.org/directory", resolveServer("acme-v01.api.letsencrypt.org/directory"));
+        $this->assertSame("https://acme-v01.api.letsencrypt.org/directory", resolveServer("https://acme-v01.api.letsencrypt.org/directory"));
+    }
+
+    public function testSuggestCommand() {
+        $this->assertSame("acme", suggestCommand("acme!", ["acme"]));
+        $this->assertSame("", suggestCommand("issue", ["acme"]));
+    }
+}
\ No newline at end of file