From 5494490c40e494c72eb8ed86fb4ed020d7862cca Mon Sep 17 00:00:00 2001
From: Alexis Sellier <alexis@radicle.xyz>
Date: Wed, 2 Nov 2022 14:11:07 +0100
Subject: [PATCH] crypto: implement an OpenSSH keystore

This will become the primary keystore.

Signed-off-by: Alexis Sellier <alexis@radicle.xyz>
---
 Cargo.lock                         | 485 ++++++++++++++++++++++++++++-
 radicle-crypto/Cargo.toml          |  12 +-
 radicle-crypto/src/ssh.rs          |   1 +
 radicle-crypto/src/ssh/keystore.rs | 108 +++++++
 4 files changed, 597 insertions(+), 9 deletions(-)
 create mode 100644 radicle-crypto/src/ssh/keystore.rs

diff --git a/Cargo.lock b/Cargo.lock
index 89f4aa26..ac099405 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -8,6 +8,17 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aes"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "433cfd6710c9986c576a25ca913c39d66a6474107b406f34f91d4a8923395241"
+dependencies = [
+ "cfg-if",
+ "cipher",
+ "cpufeatures",
+]
+
 [[package]]
 name = "android_system_properties"
 version = "0.1.5"
@@ -129,12 +140,35 @@ version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4cbbc9d0964165b47557570cce6c952866c2678457aca742aafc9fb771d30270"
 
+[[package]]
+name = "base16ct"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "349a06037c7bf932dd7e7d1f653678b2038b9ad46a74102f1fc7bd7872678cce"
+
 [[package]]
 name = "base64"
 version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
 
+[[package]]
+name = "base64ct"
+version = "1.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b645a089122eccb6111b4f81cbc1a49f5900ac4666bb93ac027feaecf15607bf"
+
+[[package]]
+name = "bcrypt-pbkdf"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3806a8db60cf56efee531616a34a6aaa9a114d6da2add861b0fa4a188881b2c7"
+dependencies = [
+ "blowfish",
+ "pbkdf2",
+ "sha2 0.10.6",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -197,6 +231,16 @@ dependencies = [
  "siphasher",
 ]
 
+[[package]]
+name = "blowfish"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e412e2cd0f2b2d93e02543ceae7917b3c70331573df19ee046bcbc35e45e87d7"
+dependencies = [
+ "byteorder",
+ "cipher",
+]
+
 [[package]]
 name = "bumpalo"
 version = "3.11.0"
@@ -266,6 +310,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "const-oid"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "722e23542a15cea1f65d4a1419c4cfd7a26706c70871a13a04238ca3f40f1661"
+
 [[package]]
 name = "constant_time_eq"
 version = "0.1.5"
@@ -315,6 +365,18 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crypto-bigint"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ef2b4b23cddf68b89b8f8069890e8c270d54e2d5fe1b143820234805e4cb17ef"
+dependencies = [
+ "generic-array",
+ "rand_core 0.6.4",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "crypto-common"
 version = "0.1.6"
@@ -331,6 +393,28 @@ version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f3b7eb4404b8195a9abb6356f4ac07d8ba267045c8d6d220ac4dc992e6cc75df"
 
+[[package]]
+name = "ctr"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0369ee1ad671834580515889b80f2ea915f23b8be8d0daa4bbaf2ac5c7590835"
+dependencies = [
+ "cipher",
+]
+
+[[package]]
+name = "curve25519-dalek"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b9fdf9972b2bd6af2d913799d9ebc165ea4d2e65878e329d9c6b372c4491b61"
+dependencies = [
+ "byteorder",
+ "digest 0.9.0",
+ "rand_core 0.5.1",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.3.2"
@@ -357,6 +441,17 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "der"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13dd2ae565c0a381dde7fade45fce95984c568bdcb4700a4fdbe3175e0380b2f"
+dependencies = [
+ "const-oid",
+ "pem-rfc7468",
+ "zeroize",
+]
+
 [[package]]
 name = "digest"
 version = "0.9.0"
@@ -373,10 +468,32 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "adfbc57365a37acbd2ebf2b64d7e69bb766e2fea813521ed536f5d0520dcf86c"
 dependencies = [
  "block-buffer 0.10.3",
+ "const-oid",
  "crypto-common",
  "subtle",
 ]
 
+[[package]]
+name = "ecdsa"
+version = "0.14.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "413301934810f597c1d19ca71c8710e99a3f1ba28a0d2ebc01551a2daeea3c5c"
+dependencies = [
+ "der",
+ "elliptic-curve",
+ "rfc6979",
+ "signature",
+]
+
+[[package]]
+name = "ed25519"
+version = "1.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e9c280362032ea4203659fc489832d0204ef09f247a0506f170dafcac08c369"
+dependencies = [
+ "signature",
+]
+
 [[package]]
 name = "ed25519-compact"
 version = "1.0.15"
@@ -384,7 +501,40 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bee9df587982575886a8682edcee11877894349a805f25629c27f63abe3e9ae8"
 dependencies = [
  "ct-codecs",
- "getrandom",
+ "getrandom 0.2.7",
+]
+
+[[package]]
+name = "ed25519-dalek"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c762bae6dcaf24c4c84667b8579785430908723d5c889f469d76a41d59cc7a9d"
+dependencies = [
+ "curve25519-dalek",
+ "ed25519",
+ "rand 0.7.3",
+ "serde",
+ "sha2 0.9.9",
+ "zeroize",
+]
+
+[[package]]
+name = "elliptic-curve"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7bb888ab5300a19b8e5bceef25ac745ad065f3c9f7efc6de1b91958110891d3"
+dependencies = [
+ "base16ct",
+ "crypto-bigint",
+ "der",
+ "digest 0.10.5",
+ "ff",
+ "generic-array",
+ "group",
+ "rand_core 0.6.4",
+ "sec1",
+ "subtle",
+ "zeroize",
 ]
 
 [[package]]
@@ -396,6 +546,16 @@ dependencies = [
  "instant",
 ]
 
+[[package]]
+name = "ff"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d013fc25338cc558c5c2cfbad646908fb23591e2404481826742b651c9af7160"
+dependencies = [
+ "rand_core 0.6.4",
+ "subtle",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.24"
@@ -470,6 +630,17 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.9.0+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.7"
@@ -526,6 +697,17 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "group"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5dfbfb3a6cfbd390d5c9564ab283a0349b9b9fcd46a706c1eb10e0db70bfbac7"
+dependencies = [
+ "ff",
+ "rand_core 0.6.4",
+ "subtle",
+]
+
 [[package]]
 name = "h2"
 version = "0.3.14"
@@ -719,6 +901,9 @@ name = "lazy_static"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+dependencies = [
+ "spin",
+]
 
 [[package]]
 name = "lexopt"
@@ -744,6 +929,12 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "libm"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "292a948cd991e376cf75541fe5b97a1081d713c618b4f1b9500f8844e49eb565"
+
 [[package]]
 name = "libz-sys"
 version = "1.1.8"
@@ -882,6 +1073,23 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num-bigint-dig"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "566d173b2f9406afbc5510a90925d5a2cd80cae4605631f1212303df265de011"
+dependencies = [
+ "byteorder",
+ "lazy_static",
+ "libm",
+ "num-integer",
+ "num-iter",
+ "num-traits",
+ "rand 0.8.5",
+ "smallvec",
+ "zeroize",
+]
+
 [[package]]
 name = "num-integer"
 version = "0.1.45"
@@ -892,6 +1100,17 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-iter"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d03e6c028c5dc5cac6e2dec0efda81fc887605bb3d884578bb6d6bf7514e252"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.15"
@@ -899,6 +1118,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
 dependencies = [
  "autocfg",
+ "libm",
 ]
 
 [[package]]
@@ -949,6 +1169,28 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
+[[package]]
+name = "p256"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51f44edd08f51e2ade572f141051021c5af22677e42b7dd28a88155151c33594"
+dependencies = [
+ "ecdsa",
+ "elliptic-curve",
+ "sha2 0.10.6",
+]
+
+[[package]]
+name = "p384"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfc8c5bf642dde52bb9e87c0ecd8ca5a76faac2eeed98dedb7c717997e1080aa"
+dependencies = [
+ "ecdsa",
+ "elliptic-curve",
+ "sha2 0.10.6",
+]
+
 [[package]]
 name = "pbkdf2"
 version = "0.11.0"
@@ -958,6 +1200,15 @@ dependencies = [
  "digest 0.10.5",
 ]
 
+[[package]]
+name = "pem-rfc7468"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d159833a9105500e0398934e205e0773f0b27529557134ecfc51c27646adac"
+dependencies = [
+ "base64ct",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.2.0"
@@ -996,6 +1247,28 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
+[[package]]
+name = "pkcs1"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eff33bdbdfc54cc98a2eca766ebdec3e1b8fb7387523d5c9c9a2891da856f719"
+dependencies = [
+ "der",
+ "pkcs8",
+ "spki",
+ "zeroize",
+]
+
+[[package]]
+name = "pkcs8"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9eca2c590a5f85da82668fa685c09ce2888b9430e83299debf1f34b65fd4a4ba"
+dependencies = [
+ "der",
+ "spki",
+]
+
 [[package]]
 name = "pkg-config"
 version = "0.3.25"
@@ -1011,6 +1284,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -1050,7 +1329,7 @@ version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "588f6378e4dd99458b60ec275b4477add41ce4fa9f64dcba6f15adccb19b50d6"
 dependencies = [
- "rand",
+ "rand 0.8.5",
 ]
 
 [[package]]
@@ -1119,8 +1398,9 @@ dependencies = [
  "serde",
  "sha2 0.10.6",
  "sqlite",
+ "ssh-key",
+ "tempfile",
  "thiserror",
- "zeroize",
 ]
 
 [[package]]
@@ -1220,13 +1500,56 @@ dependencies = [
  "radicle",
 ]
 
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom 0.1.16",
+ "libc",
+ "rand_chacha 0.2.2",
+ "rand_core 0.5.1",
+ "rand_hc",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
- "rand_core",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.5.1",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom 0.1.16",
 ]
 
 [[package]]
@@ -1235,7 +1558,16 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.7",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -1280,6 +1612,38 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "rfc6979"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88c86280f057430a52f4861551b092a01b419b8eacefc7c995eacb9dc132fe32"
+dependencies = [
+ "crypto-bigint",
+ "hmac",
+ "zeroize",
+]
+
+[[package]]
+name = "rsa"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0ecc3307be66bfb3574577895555bacfb9a37a8d5cd959444b72ff02495c618"
+dependencies = [
+ "byteorder",
+ "digest 0.10.5",
+ "num-bigint-dig",
+ "num-integer",
+ "num-iter",
+ "num-traits",
+ "pkcs1",
+ "pkcs8",
+ "rand_core 0.6.4",
+ "signature",
+ "smallvec",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.11"
@@ -1307,6 +1671,20 @@ dependencies = [
  "sha2 0.10.6",
 ]
 
+[[package]]
+name = "sec1"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3be24c1842290c45df0a7bf069e0c268a747ad05a192f2fd7dcfdbc1cba40928"
+dependencies = [
+ "base16ct",
+ "der",
+ "generic-array",
+ "pkcs8",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.145"
@@ -1397,6 +1775,16 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "signature"
+version = "1.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "74233d3b3b2f6d4b006dc19dee745e73e2a6bfb6f93607cd3b02bd5b00797d7c"
+dependencies = [
+ "digest 0.10.5",
+ "rand_core 0.6.4",
+]
+
 [[package]]
 name = "siphasher"
 version = "0.3.10"
@@ -1428,6 +1816,22 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
+
+[[package]]
+name = "spki"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67cf02bbac7a337dc36e4f5a693db6c21e7863f45070f7064577eb4367a3212b"
+dependencies = [
+ "base64ct",
+ "der",
+]
+
 [[package]]
 name = "sqlite"
 version = "0.27.0"
@@ -1458,6 +1862,38 @@ dependencies = [
  "sqlite3-src",
 ]
 
+[[package]]
+name = "ssh-encoding"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19cfdc32e0199062113edf41f344fbf784b8205a94600233c84eb838f45191e1"
+dependencies = [
+ "base64ct",
+ "pem-rfc7468",
+ "sha2 0.10.6",
+]
+
+[[package]]
+name = "ssh-key"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "288d8f5562af5a3be4bda308dd374b2c807b940ac370b5efa1c99311da91d9a1"
+dependencies = [
+ "aes",
+ "bcrypt-pbkdf",
+ "ctr",
+ "ed25519-dalek",
+ "p256",
+ "p384",
+ "rand_core 0.6.4",
+ "rsa",
+ "sec1",
+ "sha2 0.10.6",
+ "signature",
+ "ssh-encoding",
+ "zeroize",
+]
+
 [[package]]
 name = "subtle"
 version = "2.4.1"
@@ -1481,6 +1917,18 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20518fe4a4c9acf048008599e464deb21beeae3d3578418951a189c235a7a9a8"
 
+[[package]]
+name = "synstructure"
+version = "0.12.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f36bdaa60a83aca3921b5259d5400cbf5e90fc51931376a9bd4a0eb79aa7210f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "unicode-xid",
+]
+
 [[package]]
 name = "tempfile"
 version = "3.3.0"
@@ -1760,6 +2208,12 @@ dependencies = [
  "tinyvec",
 ]
 
+[[package]]
+name = "unicode-xid"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
+
 [[package]]
 name = "unsigned-varint"
 version = "0.5.1"
@@ -1805,6 +2259,12 @@ dependencies = [
  "try-lock",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "wasi"
 version = "0.10.0+wasi-snapshot-preview1"
@@ -1941,3 +2401,18 @@ name = "zeroize"
 version = "1.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c394b5bd0c6f669e7275d9c20aa90ae064cb22e75a1cad54e1b34088034b149f"
+dependencies = [
+ "zeroize_derive",
+]
+
+[[package]]
+name = "zeroize_derive"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f8f187641dad4f680d25c4bfc4225b418165984179f26ca76ec4fb6441d3a17"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "synstructure",
+]
diff --git a/radicle-crypto/Cargo.toml b/radicle-crypto/Cargo.toml
index 7aef8a24..ff5a9ab3 100644
--- a/radicle-crypto/Cargo.toml
+++ b/radicle-crypto/Cargo.toml
@@ -10,7 +10,7 @@ edition = "2021"
 
 [features]
 test = ["fastrand", "quickcheck"]
-ssh = ["base64", "radicle-ssh", "sha2"]
+ssh = ["base64", "radicle-ssh", "sha2", "ssh-key"]
 
 [dependencies]
 ed25519-compact = { version = "1.0.12", features = ["pem"] }
@@ -28,6 +28,12 @@ optional = true
 version = "0.1"
 optional = true
 
+[dependencies.ssh-key]
+version = "0.5.1"
+default-features = false
+features = ["std", "encryption", "rand_core", "getrandom"]
+optional = true
+
 [dependencies.quickcheck]
 version = "1"
 default-features = false
@@ -47,9 +53,7 @@ optional = true
 version = "0.13"
 optional = true
 
-
 [dev-dependencies]
-fastrand = { version = "1.8.0" }
 quickcheck_macros = { version = "1", default-features = false }
 quickcheck = { version = "1", default-features = false }
-zeroize = { version = "1.5.7" }
+tempfile = { version = "3.3.0" }
diff --git a/radicle-crypto/src/ssh.rs b/radicle-crypto/src/ssh.rs
index b06c9a6f..9b969e4f 100644
--- a/radicle-crypto/src/ssh.rs
+++ b/radicle-crypto/src/ssh.rs
@@ -1,4 +1,5 @@
 pub mod agent;
+pub mod keystore;
 
 use std::io;
 
diff --git a/radicle-crypto/src/ssh/keystore.rs b/radicle-crypto/src/ssh/keystore.rs
new file mode 100644
index 00000000..4d7e8167
--- /dev/null
+++ b/radicle-crypto/src/ssh/keystore.rs
@@ -0,0 +1,108 @@
+use std::path::{Path, PathBuf};
+
+use thiserror::Error;
+
+use crate::{KeyPair, PublicKey, SecretKey};
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("ssh keygen: {0}")]
+    Ssh(#[from] ssh_key::Error),
+    #[error("invalid key type, expected ed25519 key")]
+    InvalidKeyType,
+    #[error("keystore already initialized")]
+    AlreadyInitialized,
+}
+
+/// Stores keys on disk, in OpenSSH format.
+#[derive(Debug)]
+pub struct Keystore {
+    path: PathBuf,
+}
+
+impl Keystore {
+    /// Create a new keystore pointing to the given path. Use [`Keystore::init`] to initialize.
+    pub fn new<P: AsRef<Path>>(path: &P) -> Self {
+        Self {
+            path: path.as_ref().to_path_buf(),
+        }
+    }
+
+    /// Initialize a keystore by generate a key pair and storing the secret and public keys
+    /// at the given path.
+    ///
+    /// The comment is associated with the private key.
+    /// The passphrase is used to encrypt the private key.
+    ///
+    pub fn init(self, comment: &str, passphrase: &str) -> Result<Self, Error> {
+        let pair = KeyPair::generate();
+        let pair = ssh_key::private::Ed25519Keypair::from_bytes(&*pair)?;
+        let pair = ssh_key::private::KeypairData::Ed25519(pair);
+        let secret = ssh_key::PrivateKey::new(pair, comment)?;
+        let secret = secret.encrypt(ssh_key::rand_core::OsRng, passphrase)?;
+        let public = secret.public_key();
+        let path = self.path.join("radicle");
+
+        if path.exists() {
+            return Err(Error::AlreadyInitialized);
+        }
+
+        secret.write_openssh_file(&path, ssh_key::LineEnding::default())?;
+        public.write_openssh_file(&path.with_extension("pub"))?;
+
+        Ok(self)
+    }
+
+    /// Load the public key from the store. Returns `None` if it wasn't found.
+    pub fn public_key(&self) -> Result<Option<PublicKey>, Error> {
+        let path = self.path.join("radicle.pub");
+        if !path.exists() {
+            return Ok(None);
+        }
+
+        let public = ssh_key::PublicKey::read_openssh_file(&path)?;
+        match public.key_data() {
+            ssh_key::public::KeyData::Ed25519(ssh_key::public::Ed25519PublicKey(data)) => {
+                Ok(Some(PublicKey::from(*data)))
+            }
+            _ => Err(Error::InvalidKeyType),
+        }
+    }
+
+    /// Load the secret key from the store, decrypting it with the given passphrase.
+    /// Returns `None` if it wasn't found.
+    pub fn secret_key(&self, passphrase: &str) -> Result<Option<SecretKey>, Error> {
+        let path = self.path.join("radicle");
+        if !path.exists() {
+            return Ok(None);
+        }
+
+        let encrypted = ssh_key::PrivateKey::read_openssh_file(&path)?;
+        let secret = encrypted.decrypt(passphrase)?;
+
+        match secret.key_data() {
+            ssh_key::private::KeypairData::Ed25519(pair) => {
+                Ok(Some(SecretKey::new(pair.to_bytes())))
+            }
+            _ => Err(Error::InvalidKeyType),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_init() {
+        let tmp = tempfile::tempdir().unwrap();
+        let store = Keystore::new(&tmp.path());
+
+        let store = store.init("test", "hunter").unwrap();
+        let public = store.public_key().unwrap().unwrap();
+        let secret = store.secret_key("hunter").unwrap().unwrap();
+
+        assert_eq!(PublicKey::from(secret.public_key()), public);
+        store.secret_key("blunder").unwrap_err(); // Wrong passphrase.
+    }
+}