diff --git a/legacy-shim/.gitignore b/legacy-shim/.gitignore
new file mode 100644
index 0000000..4fffb2f
--- /dev/null
+++ b/legacy-shim/.gitignore
@@ -0,0 +1,2 @@
+/target
+/Cargo.lock
diff --git a/legacy-shim/Cargo.lock b/legacy-shim/Cargo.lock
new file mode 100644
index 0000000..3a10466
--- /dev/null
+++ b/legacy-shim/Cargo.lock
@@ -0,0 +1,25 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "serde"
+version = "1.0.133"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97565067517b60e2d1ea8b268e59ce036de907ac523ad83a0475da04e818989a"
+
+[[package]]
+name = "sha1"
+version = "0.6.1"
+dependencies = [
+ "sha1_smol",
+]
+
+[[package]]
+name = "sha1_smol"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
+dependencies = [
+ "serde",
+]
diff --git a/legacy-shim/Cargo.toml b/legacy-shim/Cargo.toml
new file mode 100644
index 0000000..edb2c3b
--- /dev/null
+++ b/legacy-shim/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+name = "sha1"
+version = "0.6.1"
+authors = ["Armin Ronacher <armin.ronacher@active-4.com>"]
+keywords = ["sha1"]
+description = "Minimal dependency free implementation of SHA1 for Rust."
+license = "BSD-3-Clause"
+repository = "https://github.com/mitsuhiko/sha1-smol"
+edition = "2018"
+
+[features]
+std = ["sha1_smol/std"]
+serde = ["sha1_smol/serde"]
+
+[dependencies]
+sha1_smol = "1.0.0"
+
+[package.metadata.docs.rs]
+all-features = true
diff --git a/legacy-shim/LICENSE b/legacy-shim/LICENSE
new file mode 120000
index 0000000..ea5b606
--- /dev/null
+++ b/legacy-shim/LICENSE
@@ -0,0 +1 @@
+../LICENSE
\ No newline at end of file
diff --git a/legacy-shim/README.md b/legacy-shim/README.md
new file mode 120000
index 0000000..32d46ee
--- /dev/null
+++ b/legacy-shim/README.md
@@ -0,0 +1 @@
+../README.md
\ No newline at end of file
diff --git a/legacy-shim/src/lib.rs b/legacy-shim/src/lib.rs
new file mode 100644
index 0000000..974d484
--- /dev/null
+++ b/legacy-shim/src/lib.rs
@@ -0,0 +1,38 @@
+//! A minimal implementation of SHA1 for rust.
+//!
+//! This implementation supports no_std which is the default mode.  The
+//! following features are available and can be optionally enabled:
+//!
+//! * ``serde``: when enabled the `Digest` type can be serialized.
+//! * ``std``: when enabled errors from this library implement `std::error::Error`
+//!   and the `hexdigest` shortcut becomes available.
+//!
+//! **Note:** future versions of this crate with the old code are now under
+//! `sha1_smol`, the `sha1` crate name with versions beyond the 0.6 line now
+//! refer to the `RustCrypto` implementation.
+//!
+//! ## Example
+//!
+//! ```rust
+//! # fn main() {
+//!
+//! let mut m = sha1_smol::Sha1::new();
+//! m.update(b"Hello World!");
+//! assert_eq!(m.digest().to_string(),
+//!            "2ef7bde608ce5404e97d5f042f95f89f1c232871");
+//! # }
+//! ```
+//!
+//! The sha1 object can be updated multiple times.  If you only need to use
+//! it once you can also use shortcuts (requires std):
+//!
+//! ```
+//! # trait X { fn hexdigest(&self) -> &'static str { "2ef7bde608ce5404e97d5f042f95f89f1c232871" }}
+//! # impl X for sha1_smol::Sha1 {}
+//! # fn main() {
+//! assert_eq!(sha1_smol::Sha1::from("Hello World!").hexdigest(),
+//!            "2ef7bde608ce5404e97d5f042f95f89f1c232871");
+//! # }
+//! ```
+
+pub use sha1_smol::*;