Add wasm feature and document usage

Cargo.toml

@@ -11,6 +11,7 @@ readme = "README.md"
 
 [features]
 default = ["full-native-tls", "cached-client", "tuf"]
+wasm = ["getrandom/js"]
 
 full-native-tls = ["fulcio-native-tls", "rekor-native-tls", "cosign-native-tls", "mock-client-native-tls"]
 full-rustls-tls = ["fulcio-rustls-tls", "rekor-rustls-tls", "cosign-rustls-tls", "mock-client-rustls-tls"]
@@ -28,7 +29,7 @@ oauth = []
 
 rekor-native-tls = [ "reqwest/native-tls", "rekor"]
 rekor-rustls-tls = [ "reqwest/rustls-tls", "rekor" ]
-rekor = ["dep:reqwest"]
+rekor = ["reqwest"]
 
 tuf = [ "tough", "regex" ]
 
@@ -64,7 +65,6 @@ lazy_static = "1.4.0"
 oci-distribution = { version = "0.9", default-features = false, optional = true }
 olpc-cjson = "0.1"
 openidconnect = { version = "2.3", default-features = false, features = [ "reqwest" ], optional = true}
-getrandom = { version = "0.2.8", features = ["js"] }
 p256 = "0.12"
 p384 = "0.12"
 webbrowser = "0.8.4"
@@ -73,6 +73,7 @@ picky = { version = "7.0.0-rc.3", default-features = false, features = [ "x509",
 pkcs1 = "0.4.0"
 pkcs8 = { version = "0.9.0", features = ["pem", "alloc", "pkcs5", "encryption"] }
 rand = { version = "0.8.5", features = [ "getrandom", "std" ] }
+getrandom = "0.2.8"
 regex = { version = "1.5.5", optional = true }
 reqwest = { version = "0.11", default-features = false, features = ["json", "multipart"], optional = true}
 rsa = "0.8.0"

README.md

@@ -63,6 +63,16 @@ For example, `openidconnect` can be run with the following command:
 cargo run --example openidconnect
 ```
 
+## WebAssembly/WASM support
+
+To embedded this crate in WASM modules, build it using the `wasm` cargo feature:
+
+```bash
+cargo build --no-default-features --features wasm --target wasm32-unknown-unknown
+```
+
+NOTE: The wasm32-wasi target architecture is not yet supported.
+
 ## Contributing
 
 Contributions are welcome! Please see the [contributing guidelines](CONTRIBUTING.md).