From 498f9e0b0b87e6d497b235474c0db669076d73ff Mon Sep 17 00:00:00 2001
From: Bryan Newbold <bnewbold@robocracy.org>
Date: Thu, 3 Nov 2022 17:29:27 -0700
Subject: start adding ucan support

---
 Cargo.lock                     | 423 ++++++++++++++++++++++++++++++++++++++++-
 adenosine-pds/Cargo.toml       |   4 +
 adenosine-pds/src/ucan_p256.rs |  91 +++++++++
 3 files changed, 514 insertions(+), 4 deletions(-)
 create mode 100644 adenosine-pds/src/ucan_p256.rs

diff --git a/Cargo.lock b/Cargo.lock
index df42992..1721692 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -35,7 +35,9 @@ name = "adenosine-pds"
 version = "0.1.0-dev.0"
 dependencies = [
  "anyhow",
+ "async-trait",
  "bcrypt",
+ "bs58",
  "data-encoding",
  "futures",
  "ipfs-sqlite-block-store",
@@ -57,6 +59,7 @@ dependencies = [
  "sha256",
  "structopt",
  "tokio",
+ "ucan",
 ]
 
 [[package]]
@@ -171,6 +174,119 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d92bec98840b8f03a5ff5413de5293bfcd8bf96467cf5452609f939ec6f5de16"
 
+[[package]]
+name = "async-channel"
+version = "1.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e14485364214912d3b19cc3435dde4df66065127f05fa0d75c712f36f12c2f28"
+dependencies = [
+ "concurrent-queue",
+ "event-listener",
+ "futures-core",
+]
+
+[[package]]
+name = "async-executor"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "871f9bb5e0a22eeb7e8cf16641feb87c9dc67032ccf8ff49e772eb9941d3a965"
+dependencies = [
+ "async-task",
+ "concurrent-queue",
+ "fastrand",
+ "futures-lite",
+ "once_cell",
+ "slab",
+]
+
+[[package]]
+name = "async-global-executor"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1b6f5d7df27bd294849f8eec66ecfc63d11814df7a4f5d74168a2394467b776"
+dependencies = [
+ "async-channel",
+ "async-executor",
+ "async-io",
+ "async-lock",
+ "blocking",
+ "futures-lite",
+ "once_cell",
+]
+
+[[package]]
+name = "async-io"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8121296a9f05be7f34aa4196b1747243b3b62e048bb7906f644f3fbfc490cf7"
+dependencies = [
+ "async-lock",
+ "autocfg",
+ "concurrent-queue",
+ "futures-lite",
+ "libc",
+ "log",
+ "parking",
+ "polling",
+ "slab",
+ "socket2",
+ "waker-fn",
+ "winapi",
+]
+
+[[package]]
+name = "async-lock"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8101efe8695a6c17e02911402145357e718ac92d3ff88ae8419e84b1707b685"
+dependencies = [
+ "event-listener",
+ "futures-lite",
+]
+
+[[package]]
+name = "async-recursion"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2cda8f4bcc10624c4e85bc66b3f452cca98cfa5ca002dc83a16aad2367641bea"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "async-std"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62565bb4402e926b29953c785397c6dc0391b7b446e45008b0049eb43cec6f5d"
+dependencies = [
+ "async-channel",
+ "async-global-executor",
+ "async-io",
+ "async-lock",
+ "crossbeam-utils",
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-lite",
+ "gloo-timers",
+ "kv-log-macro",
+ "log",
+ "memchr",
+ "once_cell",
+ "pin-project-lite",
+ "pin-utils",
+ "slab",
+ "wasm-bindgen-futures",
+]
+
+[[package]]
+name = "async-task"
+version = "4.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a40729d2133846d9ed0ea60a8b9541bccddab49cd30f0715a1da672fe9a2524"
+
 [[package]]
 name = "async-trait"
 version = "0.1.58"
@@ -206,6 +322,12 @@ dependencies = [
  "system-deps 6.0.3",
 ]
 
+[[package]]
+name = "atomic-waker"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "065374052e7df7ee4047b1160cca5e1467a12351a40b3da123c870ba0b8eda2a"
+
 [[package]]
 name = "attohttpc"
 version = "0.22.0"
@@ -355,6 +477,20 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "blocking"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c6ccb65d468978a086b69884437ded69a90faab3bbe6e67f242173ea728acccc"
+dependencies = [
+ "async-channel",
+ "async-task",
+ "atomic-waker",
+ "fastrand",
+ "futures-lite",
+ "once_cell",
+]
+
 [[package]]
 name = "blowfish"
 version = "0.9.1"
@@ -386,6 +522,12 @@ dependencies = [
  "alloc-stdlib",
 ]
 
+[[package]]
+name = "bs58"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "771fe0050b883fcc3ea2359b1a96bcfbc090b7116eae7c3c512c7a083fdf23d3"
+
 [[package]]
 name = "bstr"
 version = "0.2.17"
@@ -435,6 +577,12 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec8a7b6a70fde80372154c65702f00a0f56f3e1c36abbc6c440484be248856db"
 
+[[package]]
+name = "cache-padded"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1db59621ec70f09c5e9b597b220c7a2b43611f4710dc03ceb8748637775692c"
+
 [[package]]
 name = "cached"
 version = "0.30.0"
@@ -554,6 +702,7 @@ dependencies = [
  "multibase",
  "multihash",
  "serde",
+ "serde_bytes",
  "unsigned-varint",
 ]
 
@@ -697,6 +846,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "concurrent-queue"
+version = "1.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af4780a44ab5696ea9e28294517f1fffb421a83a25af521333c838635509db9c"
+dependencies = [
+ "cache-padded",
+]
+
 [[package]]
 name = "const-oid"
 version = "0.9.0"
@@ -1067,6 +1225,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "discard"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "212d0f5754cb6769937f4501cc0e67f4f4483c8d2c3e1e922ee9edbe4ab4c7c0"
+
 [[package]]
 name = "dispatch"
 version = "0.2.0"
@@ -1167,6 +1331,12 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "event-listener"
+version = "2.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0206175f82b8d6bf6652ff7d71a1e27fd2e4efde587fd368662814d6ec1d9ce0"
+
 [[package]]
 name = "fallible-iterator"
 version = "0.2.0"
@@ -1344,6 +1514,21 @@ version = "0.3.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "00f5fb52a06bdcadeb54e8d3671f8888a39697dcb0b81b23b55174030427f4eb"
 
+[[package]]
+name = "futures-lite"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7694489acd39452c77daa48516b894c153f192c3578d5a839b62c58099fcbf48"
+dependencies = [
+ "fastrand",
+ "futures-core",
+ "futures-io",
+ "memchr",
+ "parking",
+ "pin-project-lite",
+ "waker-fn",
+]
+
 [[package]]
 name = "futures-macro"
 version = "0.3.25"
@@ -1507,8 +1692,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c05aeb6a22b8f62540c194aac980f2115af067bfe15a0734d7277a768d396b31"
 dependencies = [
  "cfg-if",
+ "js-sys",
  "libc",
  "wasi 0.11.0+wasi-snapshot-preview1",
+ "wasm-bindgen",
 ]
 
 [[package]]
@@ -1605,6 +1792,18 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "gloo-timers"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fb7d06c1c8cc2a29bee7ec961009a0b2caa0793ee4900c2ffb348734ba1c8f9"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "gobject-sys"
 version = "0.15.10"
@@ -2004,6 +2203,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"
 dependencies = [
  "cfg-if",
+ "js-sys",
+ "stdweb",
+ "wasm-bindgen",
+ "web-sys",
 ]
 
 [[package]]
@@ -2205,6 +2408,15 @@ dependencies = [
  "selectors",
 ]
 
+[[package]]
+name = "kv-log-macro"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0de8b303297635ad57c9f5059fd9cee7a47f8e8daa09df0fcd07dd39fb22977f"
+dependencies = [
+ "log",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -2282,6 +2494,7 @@ dependencies = [
  "core2",
  "multibase",
  "multihash",
+ "serde",
  "thiserror",
 ]
 
@@ -2364,6 +2577,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
 dependencies = [
  "cfg-if",
+ "value-bag",
 ]
 
 [[package]]
@@ -2519,6 +2733,8 @@ dependencies = [
  "core2",
  "digest 0.10.5",
  "multihash-derive",
+ "serde",
+ "serde-big-array",
  "sha2 0.10.6",
  "sha3",
  "unsigned-varint",
@@ -2948,6 +3164,12 @@ dependencies = [
  "system-deps 6.0.3",
 ]
 
+[[package]]
+name = "parking"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "427c3892f9e783d91cc128285287e70a59e206ca452770ece88a76f7a3eddd72"
+
 [[package]]
 name = "parking_lot"
 version = "0.11.2"
@@ -3198,6 +3420,20 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "polling"
+version = "2.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab4609a838d88b73d8238967b60dd115cc08d38e2bbaf51ee1e4b695f89122e2"
+dependencies = [
+ "autocfg",
+ "cfg-if",
+ "libc",
+ "log",
+ "wepoll-ffi",
+ "winapi",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.16"
@@ -3584,7 +3820,7 @@ dependencies = [
  "serde",
  "serde_derive",
  "serde_json",
- "sha1",
+ "sha1 0.10.5",
  "threadpool",
  "time",
  "tiny_http",
@@ -3616,6 +3852,15 @@ dependencies = [
  "rusqlite",
 ]
 
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+dependencies = [
+ "semver 0.9.0",
+]
+
 [[package]]
 name = "rustc_version"
 version = "0.3.3"
@@ -3789,13 +4034,22 @@ dependencies = [
  "thin-slice",
 ]
 
+[[package]]
+name = "semver"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+dependencies = [
+ "semver-parser 0.7.0",
+]
+
 [[package]]
 name = "semver"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f301af10236f6df4160f7c3f04eec6dbc70ace82d23326abad5edee88801c6b6"
 dependencies = [
- "semver-parser",
+ "semver-parser 0.10.2",
 ]
 
 [[package]]
@@ -3807,6 +4061,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+
 [[package]]
 name = "semver-parser"
 version = "0.10.2"
@@ -3825,6 +4085,24 @@ dependencies = [
  "serde_derive",
 ]
 
+[[package]]
+name = "serde-big-array"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd31f59f6fe2b0c055371bb2f16d7f0aa7d8881676c04a55b1596d1a17cd10a4"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "serde_bytes"
+version = "0.11.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfc50e8183eeeb6178dcb167ae34a8051d63535023ae38b5d8d12beae193d37b"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "serde_derive"
 version = "1.0.147"
@@ -3924,6 +4202,15 @@ dependencies = [
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "sha1"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1da05c97445caa12d05e848c4a4fcbbea29e748ac28f7e80e9b010392063770"
+dependencies = [
+ "sha1_smol",
+]
+
 [[package]]
 name = "sha1"
 version = "0.10.5"
@@ -3935,6 +4222,12 @@ dependencies = [
  "digest 0.10.5",
 ]
 
+[[package]]
+name = "sha1_smol"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae1a47186c03a32177042e55dbc5fd5aee900b8e0069a8d70fba96a9375cd012"
+
 [[package]]
 name = "sha2"
 version = "0.9.9"
@@ -4101,6 +4394,57 @@ dependencies = [
  "loom",
 ]
 
+[[package]]
+name = "stdweb"
+version = "0.4.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d022496b16281348b52d0e30ae99e01a73d737b2f45d38fed4edf79f9325a1d5"
+dependencies = [
+ "discard",
+ "rustc_version 0.2.3",
+ "serde",
+ "serde_json",
+ "stdweb-derive",
+ "stdweb-internal-macros",
+ "stdweb-internal-runtime",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "stdweb-derive"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c87a60a40fccc84bef0652345bbbbbe20a605bf5d0ce81719fc476f5c03b50ef"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "serde",
+ "serde_derive",
+ "syn",
+]
+
+[[package]]
+name = "stdweb-internal-macros"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58fa5ff6ad0d98d1ffa8cb115892b6e69d67799f6763e162a1c9db421dc22e11"
+dependencies = [
+ "base-x",
+ "proc-macro2",
+ "quote",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "sha1 0.6.1",
+ "syn",
+]
+
+[[package]]
+name = "stdweb-internal-runtime"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "213701ba3370744dcd1a12960caa4843b3d68b4d1c0a5d575e0d65b2ee9d16c0"
+
 [[package]]
 name = "string_cache"
 version = "0.8.4"
@@ -4169,9 +4513,15 @@ version = "0.22.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f7ac893c7d471c8a21f31cfe213ec4f6d9afeed25537c772e08ef3f005f8729e"
 dependencies = [
- "strum_macros",
+ "strum_macros 0.22.0",
 ]
 
+[[package]]
+name = "strum"
+version = "0.24.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "063e6045c0e62079840579a7e47a355ae92f60eb74daaf156fb1e84ba164e63f"
+
 [[package]]
 name = "strum_macros"
 version = "0.22.0"
@@ -4184,6 +4534,19 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "strum_macros"
+version = "0.24.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e385be0d24f186b4ce2f9982191e7101bb737312ad61c1f2f984f34bcf85d59"
+dependencies = [
+ "heck 0.4.0",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn",
+]
+
 [[package]]
 name = "subtle"
 version = "2.4.1"
@@ -4480,7 +4843,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c58de036c4d2e20717024de2a3c4bf56c301f07b21bc8ef9b57189fce06f1f3b"
 dependencies = [
  "quick-xml",
- "strum",
+ "strum 0.22.0",
  "windows 0.39.0",
 ]
 
@@ -4789,6 +5152,33 @@ version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dcf81ac59edc17cc8697ff311e8f5ef2d99fcbd9817b34cec66f90b6c3dfd987"
 
+[[package]]
+name = "ucan"
+version = "0.7.0-alpha.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64f04c190573eadd24c3888253029aed61ba319261c67b1ef7f7edd16d47ef70"
+dependencies = [
+ "anyhow",
+ "async-recursion",
+ "async-std",
+ "async-trait",
+ "base64",
+ "bs58",
+ "cid",
+ "getrandom 0.2.8",
+ "instant",
+ "libipld-core",
+ "libipld-json",
+ "log",
+ "rand 0.8.5",
+ "serde",
+ "serde_json",
+ "strum 0.24.1",
+ "strum_macros 0.24.3",
+ "unsigned-varint",
+ "url",
+]
+
 [[package]]
 name = "ucd-trie"
 version = "0.1.5"
@@ -4898,6 +5288,16 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830b7e5d4d90034032940e4ace0d9a9a057e7a45cd94e6c007832e39edb82f6d"
 
+[[package]]
+name = "value-bag"
+version = "1.0.0-alpha.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2209b78d1249f7e6f3293657c9779fe31ced465df091bbd433a1cf88e916ec55"
+dependencies = [
+ "ctor",
+ "version_check",
+]
+
 [[package]]
 name = "vcpkg"
 version = "0.2.15"
@@ -4928,6 +5328,12 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
+[[package]]
+name = "waker-fn"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d5b2c62b4012a3e1eca5a7e077d13b3bf498c4073e33ccd58626607748ceeca"
+
 [[package]]
 name = "walkdir"
 version = "2.3.2"
@@ -5122,6 +5528,15 @@ dependencies = [
  "windows-metadata",
 ]
 
+[[package]]
+name = "wepoll-ffi"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d743fdedc5c64377b5fc2bc036b01c7fd642205a0d96356034ae3404d49eb7fb"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "which"
 version = "4.3.0"
diff --git a/adenosine-pds/Cargo.toml b/adenosine-pds/Cargo.toml
index 8fdc138..432e893 100644
--- a/adenosine-pds/Cargo.toml
+++ b/adenosine-pds/Cargo.toml
@@ -36,6 +36,10 @@ data-encoding = "*"
 k256 = { version = "*", features = ["ecdsa"] }
 p256 = { version = "*", features = ["ecdsa"] }
 multibase = "*"
+ucan = "0.7.0-alpha.1"
+# TODO: replace this with data-encoding or similar; this is only needed for ucan_p256 stuff
+bs58 = "*"
+async-trait = "*"
 
 [package.metadata.deb]
 maintainer = "Bryan Newbold <bnewbold@robocracy.org>"
diff --git a/adenosine-pds/src/ucan_p256.rs b/adenosine-pds/src/ucan_p256.rs
new file mode 100644
index 0000000..9fe89ed
--- /dev/null
+++ b/adenosine-pds/src/ucan_p256.rs
@@ -0,0 +1,91 @@
+/// Implement UCAN KeyMaterial trait for p256
+///
+/// This is needed because the 'ucan-key-support' crate does not include support for this key type.
+use anyhow::{anyhow, Result};
+use async_trait::async_trait;
+
+use p256::ecdsa::signature::{Signer, Verifier};
+use p256::ecdsa::{Signature, SigningKey as P256PrivateKey, VerifyingKey as P256PublicKey};
+
+use ucan::crypto::KeyMaterial;
+
+pub use ucan::crypto::{did::P256_MAGIC_BYTES, JwtSignatureAlgorithm};
+
+pub fn bytes_to_p256_key(bytes: Vec<u8>) -> Result<Box<dyn KeyMaterial>> {
+    let public_key = P256PublicKey::try_from(bytes.as_slice())?;
+    Ok(Box::new(P256KeyMaterial(public_key, None)))
+}
+
+#[derive(Clone)]
+pub struct P256KeyMaterial(pub P256PublicKey, pub Option<P256PrivateKey>);
+
+#[cfg_attr(target_arch="wasm32", async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
+impl KeyMaterial for P256KeyMaterial {
+    fn get_jwt_algorithm_name(&self) -> String {
+        JwtSignatureAlgorithm::ES256.to_string()
+    }
+
+    async fn get_did(&self) -> Result<String> {
+        let bytes = [
+            P256_MAGIC_BYTES,
+            &self.0.to_encoded_point(true).to_bytes().to_vec(),
+        ]
+        .concat();
+        Ok(format!("did:key:z{}", bs58::encode(bytes).into_string()))
+    }
+
+    async fn sign(&self, payload: &[u8]) -> Result<Vec<u8>> {
+        match self.1 {
+            Some(ref private_key) => {
+                let signature = private_key.sign(payload);
+                Ok(signature.to_vec())
+            }
+            None => Err(anyhow!("No private key; cannot sign data")),
+        }
+    }
+
+    async fn verify(&self, payload: &[u8], signature: &[u8]) -> Result<()> {
+        let signature = Signature::try_from(signature)?;
+        self.0
+            .verify(payload, &signature)
+            .map_err(|error| anyhow!("Could not verify signature: {:?}", error))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{bytes_to_p256_key, P256KeyMaterial, P256_MAGIC_BYTES};
+    use p256::ecdsa::signature::{Signer, Verifier};
+    use p256::ecdsa::{SigningKey as P256PrivateKey, VerifyingKey as P256PublicKey};
+    use ucan::{
+        builder::UcanBuilder,
+        crypto::{did::DidParser, KeyMaterial},
+        ucan::Ucan,
+    };
+
+    #[cfg_attr(not(target_arch = "wasm32"), tokio::test)]
+    async fn it_can_sign_and_verify_a_ucan() {
+        let rng = rand::thread_rng();
+        let private_key = P256PrivateKey::new(rng);
+        let public_key = P256PublicKey::from(&private_key);
+
+        let key_material = P256KeyMaterial(public_key, Some(private_key));
+        let token_string = UcanBuilder::default()
+            .issued_by(&key_material)
+            .for_audience(key_material.get_did().await.unwrap().as_str())
+            .with_lifetime(60)
+            .build()
+            .unwrap()
+            .sign()
+            .await
+            .unwrap()
+            .encode()
+            .unwrap();
+
+        let mut did_parser = DidParser::new(&[(P256_MAGIC_BYTES, bytes_to_p256_key)]);
+
+        let ucan = Ucan::try_from(token_string).unwrap();
+        ucan.check_signature(&mut did_parser).await.unwrap();
+    }
+}
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