diff --git a/Cargo.lock b/Cargo.lock
index 29dbb3e..059013e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -184,6 +184,7 @@ dependencies = [
  "serde_derive 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "sha2 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "version-compare 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -949,6 +950,11 @@ name = "vec_map"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "version-compare"
+version = "0.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "version_check"
 version = "0.1.3"
@@ -1107,6 +1113,7 @@ dependencies = [
 "checksum uuid 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "bcc7e3b898aa6f6c08e5295b6c89258d1331e9ac578cc992fb818759951bdc22"
 "checksum vcpkg 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9e0a7d8bed3178a8fb112199d466eeca9ed09a14ba8ad67718179b4fd5487d0b"
 "checksum vec_map 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "887b5b631c2ad01628bbbaa7dd4c869f80d3186688f8d0b6f58774fbe324988c"
+"checksum version-compare 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "78068add8bf1e4d37d13fa5867182fe4c03f8e525c831053733f83aaba942d37"
 "checksum version_check 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "6b772017e347561807c1aa192438c5fd74242a670a6cffacc40f2defd1dc069d"
 "checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "04e3bd221fcbe8a271359c04f21a76db7d0c6028862d1bb5512d85e1e2eb5bb3"
diff --git a/Cargo.toml b/Cargo.toml
index b39b62f..29f6f2f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,3 +17,4 @@ serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 sha2 = "0.7"
+version-compare = "0.0"
diff --git a/src/b64.rs b/src/b64.rs
new file mode 100644
index 0000000..d02eb04
--- /dev/null
+++ b/src/b64.rs
@@ -0,0 +1,19 @@
+//! A simple module for encoding or decoding a base64 string from or to a
+//! byte array.
+//!
+//! This module uses an URL-safe scheme, and doesn't add additional padding
+//! to the encoded strings.
+
+extern crate base64;
+
+use self::base64::DecodeError;
+
+/// Encode the given byte slice using base64, in an URL-safe manner.
+pub fn encode(input: &[u8]) -> String {
+    base64::encode_config(input, base64::URL_SAFE_NO_PAD)
+}
+
+/// Decode the given string as base64, in an URL-safe manner.
+pub fn decode(input: &str) -> Result<Vec<u8>, DecodeError> {
+    base64::decode_config(input, base64::URL_SAFE_NO_PAD)
+}
diff --git a/src/main.rs b/src/main.rs
index dc0d687..3fd4fe4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,3 @@
-extern crate base64;
 extern crate clap;
 extern crate hkdf;
 extern crate hyper;
@@ -12,6 +11,7 @@ extern crate serde_derive;
 extern crate serde_json;
 extern crate sha2;
 
+mod b64;
 mod reader;
 
 use std::fmt;
@@ -124,7 +124,7 @@ fn main() {
 
     // Make the request
     let mut res = client.post("http://localhost:8080/api/upload")
-        .header(Authorization(format!("send-v1 {}", base64_encode(&auth_key))))
+        .header(Authorization(format!("send-v1 {}", b64::encode(&auth_key))))
         .header(XFileMetadata::from(&metadata))
         .multipart(form)
         .send()
@@ -136,7 +136,7 @@ fn main() {
     // Print the response
     let url = upload_res.download_url(&secret);
     println!("Response: {:#?}", upload_res);
-    println!("Secret key: {}", base64_encode(&secret));
+    println!("Secret key: {}", b64::encode(&secret));
     println!("Download URL: {}", url);
 
     // Open the URL in the browser
@@ -285,11 +285,6 @@ impl UploadResponse {
     ///
     /// The secret bytes must be passed to `secret`.
     pub fn download_url(&self, secret: &[u8]) -> String {
-        format!("{}#{}", self.url, base64_encode(secret))
+        format!("{}#{}", self.url, b64::encode(secret))
     }
 }
-
-/// Encode the given byte slice using base64, in an URL-safe manner.
-fn base64_encode(input: &[u8]) -> String {
-    base64::encode_config(input, base64::URL_SAFE_NO_PAD)
-}