diff --git a/Cargo.lock b/Cargo.lock
index fba3685..f6abd01 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -63,6 +63,8 @@ version = "0.1.0"
 dependencies = [
  "atomicwrites 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sha-1 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sha2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ssri 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.0.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 9b119be..6e45c9a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,3 +9,5 @@ ssri = "1.1.0"
 hex = "0.3.2"
 atomicwrites = "0.2.2"
 tempfile = "3.0.8"
+sha-1 = "0.8.1"
+sha2 = "0.8.0"