sign: init

Signed-off-by: Jack Leightcap <jack.leightcap@trailofbits.com>
Signed-off-by: Andrew Pan <andrew.pan@trailofbits.com>
Co-authored-by: Jack Leightcap <jack.leightcap@trailofbits.com>

Cargo.toml

@@ -9,7 +9,7 @@ readme = "README.md"
 repository = "https://github.com/sigstore/sigstore-rs"
 
 [features]
-default = ["full-native-tls", "cached-client", "tuf"]
+default = ["full-native-tls", "cached-client", "tuf", "sign"]
 wasm = ["getrandom/js"]
 
 full-native-tls = [
@@ -42,6 +42,8 @@ rekor = ["reqwest"]
 
 tuf = ["tough", "regex"]
 
+sign = []
+
 cosign-native-tls = [
   "oci-distribution/native-tls",
   "cert",
@@ -72,7 +74,7 @@ async-trait = "0.1.52"
 base64 = "0.21.0"
 cached = { version = "0.46.0", optional = true, features = ["async"] }
 cfg-if = "1.0.0"
-chrono = { version = "0.4.27", default-features = false }
+chrono = { version = "0.4.27", default-features = false, features = ["serde"] }
 const-oid = "0.9.1"
 digest = { version = "0.10.3", default-features = false }
 ecdsa = { version = "0.16.7", features = ["pkcs8", "digest", "der", "signing"] }
@@ -88,10 +90,7 @@ openidconnect = { version = "3.0", default-features = false, features = [
 p256 = "0.13.2"
 p384 = "0.13"
 webbrowser = "0.8.4"
-pem = "3.0"
-picky = { version = "7.0.0-rc.8", default-features = false, features = [
-  "x509",
-] }
+pem = { version = "3.0", features = ["serde"] }
 pkcs1 = { version = "0.7.5", features = ["std"] }
 pkcs8 = { version = "0.10.2", features = [
   "pem",
@@ -113,17 +112,20 @@ serde_json = "1.0.79"
 serde_with = { version = "3.4.0", features = ["base64"] }
 sha2 = { version = "0.10.6", features = ["oid"] }
 signature = { version = "2.0" }
+sigstore_protobuf_specs = "0.1.0-rc.2"
 thiserror = "1.0.30"
 tokio = { version = "1.17.0", features = ["rt"] }
 tough = { version = "0.14", features = ["http"], optional = true }
 tracing = "0.1.31"
 url = "2.2.2"
-x509-cert = { version = "0.2.2", features = ["pem", "std"] }
+x509-cert = { version = "0.2.2", features = ["builder", "pem", "std"] }
 crypto_secretbox = "0.1.1"
 zeroize = "1.5.7"
 rustls-webpki = { version = "0.102.0-alpha.4", features = ["alloc"] }
 rustls-pki-types = { version = "0.2.1", features = ["std"] }
 serde_repr = "0.1.16"
+hex = "0.4.3"
+json-syntax = { version = "0.9.6", features = ["canonicalize", "serde"] }
 
 [dev-dependencies]
 anyhow = { version = "1.0", features = ["backtrace"] }
@@ -137,7 +139,6 @@ serial_test = "2.0.0"
 tempfile = "3.3.0"
 testcontainers = "0.15"
 tracing-subscriber = { version = "0.3.9", features = ["env-filter"] }
-hex = "0.4.3"
 
 # cosign example mappings
 

src/bundle/mod.rs

@@ -0,0 +1,54 @@
+// Copyright 2023 The Sigstore Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Useful types for Sigstore bundles.
+
+use std::fmt::Display;
+
+pub use sigstore_protobuf_specs::Bundle;
+
+// Known Sigstore bundle media types.
+#[derive(Clone, Copy, Debug)]
+pub enum Version {
+    Bundle0_1,
+    Bundle0_2,
+}
+
+impl TryFrom<&str> for Version {
+    type Error = ();
+
+    fn try_from(value: &str) -> Result<Self, Self::Error> {
+        match value {
+            "application/vnd.dev.sigstore.bundle+json;version=0.1" => Ok(Version::Bundle0_1),
+            "application/vnd.dev.sigstore.bundle+json;version=0.2" => Ok(Version::Bundle0_2),
+            _ => Err(()),
+        }
+    }
+}
+
+impl From<Version> for &str {
+    fn from(value: Version) -> Self {
+        match value {
+            Version::Bundle0_1 => "application/vnd.dev.sigstore.bundle+json;version=0.1",
+            Version::Bundle0_2 => "application/vnd.dev.sigstore.bundle+json;version=0.2",
+        }
+    }
+}
+
+impl Display for Version {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str((*self).into())?;
+        Ok(())
+    }
+}

src/crypto/verification.rs

@@ -0,0 +1,12 @@
+use rustls_pki_types::CertificateDer;
+use webpki::TrustAnchor;
+
+/// Machinery for Sigstore end entity certificate verification.
+struct CertificateVerificationContext<'a> {
+    pub trust_anchors: Vec<TrustAnchor<'a>>,
+    pub intermediate_certs: Vec<CertificateDer<'a>>,
+}
+
+impl CertificateVerificationContext<'_> {
+    pub fn new() {}
+}

src/crypto/verification_key.rs

@@ -18,7 +18,7 @@ use const_oid::db::rfc5912::{ID_EC_PUBLIC_KEY, RSA_ENCRYPTION};
 use ed25519::pkcs8::DecodePublicKey as ED25519DecodePublicKey;
 use rsa::{pkcs1v15, pss};
 use sha2::{Digest, Sha256, Sha384};
-use signature::{DigestVerifier, Verifier};
+use signature::{hazmat::PrehashVerifier, DigestVerifier, Verifier};
 use std::convert::TryFrom;
 use x509_cert::{der::referenced::OwnedToRef, spki::SubjectPublicKeyInfoOwned};
 
@@ -329,6 +329,68 @@ impl CosignVerificationKey {
             }
         }
     }
+
+    /// Verify the signature provided has been actually generated by the given key
+    /// when signing the provided prehashed message.
+    pub fn verify_prehash(&self, signature: Signature, msg: &[u8]) -> Result<()> {
+        let sig = match signature {
+            Signature::Raw(data) => data.to_owned(),
+            Signature::Base64Encoded(data) => BASE64_STD_ENGINE.decode(data)?,
+        };
+
+        match self {
+            CosignVerificationKey::RSA_PSS_SHA256(inner) => {
+                let sig = pss::Signature::try_from(sig.as_slice())?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            CosignVerificationKey::RSA_PSS_SHA384(inner) => {
+                let sig = pss::Signature::try_from(sig.as_slice())?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            CosignVerificationKey::RSA_PSS_SHA512(inner) => {
+                let sig = pss::Signature::try_from(sig.as_slice())?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            CosignVerificationKey::RSA_PKCS1_SHA256(inner) => {
+                let sig = pkcs1v15::Signature::try_from(sig.as_slice())?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            CosignVerificationKey::RSA_PKCS1_SHA384(inner) => {
+                let sig = pkcs1v15::Signature::try_from(sig.as_slice())?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            CosignVerificationKey::RSA_PKCS1_SHA512(inner) => {
+                let sig = pkcs1v15::Signature::try_from(sig.as_slice())?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            // ECDSA signatures are encoded in der.
+            CosignVerificationKey::ECDSA_P256_SHA256_ASN1(inner) => {
+                let sig = ecdsa::Signature::from_der(&sig)?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            CosignVerificationKey::ECDSA_P384_SHA384_ASN1(inner) => {
+                let sig = ecdsa::Signature::from_der(&sig)?;
+                inner
+                    .verify_prehash(msg, &sig)
+                    .map_err(|_| SigstoreError::PublicKeyVerificationError)
+            }
+            _ => unimplemented!("Ed25519 doesn't implement verify_prehash"),
+        }
+    }
 }
 
 #[cfg(test)]

src/errors.rs

@@ -52,6 +52,9 @@ pub enum SigstoreError {
     #[error("invalid key format: {error}")]
     InvalidKeyFormat { error: String },
 
+    #[error("Unable to parse identity token: {0}")]
+    IdentityTokenError(&'static str),
+
     #[error("unmatched key type {key_typ} and signing scheme {scheme}")]
     UnmatchedKeyAndSigningScheme { key_typ: String, scheme: String },
 
@@ -70,6 +73,9 @@ pub enum SigstoreError {
     #[error("Public key verification error")]
     PublicKeyVerificationError,
 
+    #[error("X.509 certificate version is not V3")]
+    CertificateUnsupportedVersionError,
+
     #[error("Certificate validity check failed: cannot be used before {0}")]
     CertificateValidityError(String),
 
@@ -103,6 +109,12 @@ pub enum SigstoreError {
     #[error("Certificate pool error: {0}")]
     CertificatePoolError(&'static str),
 
+    #[error("Signing session expired")]
+    ExpiredSigningSession(),
+
+    #[error("Fulcio request unsuccessful: {0}")]
+    FulcioClientError(&'static str),
+
     #[error("Cannot fetch manifest of {image}: {error}")]
     RegistryFetchManifestError { image: String, error: String },
 
@@ -115,9 +127,18 @@ pub enum SigstoreError {
     #[error("Cannot push {image}: {error}")]
     RegistryPushError { image: String, error: String },
 
+    #[error("Rekor request unsuccessful: {0}")]
+    RekorClientError(String),
+
+    #[error(transparent)]
+    ReqwestError(#[from] reqwest::Error),
+
     #[error("OCI reference not valid: {reference}")]
     OciReferenceNotValidError { reference: String },
 
+    #[error("Sigstore bundle malformed: {0}")]
+    SigstoreBundleMalformedError(String),
+
     #[error("Layer doesn't have Sigstore media type")]
     SigstoreMediaTypeNotFoundError,
 
@@ -155,6 +176,9 @@ pub enum SigstoreError {
     #[error("{0}")]
     VerificationConstraintError(String),
 
+    #[error("{0}")]
+    VerificationMaterialError(String),
+
     #[error("{0}")]
     ApplyConstraintError(String),
 
@@ -214,4 +238,10 @@ pub enum SigstoreError {
 
     #[error(transparent)]
     Ed25519PKCS8Error(#[from] ed25519_dalek::pkcs8::spki::Error),
+
+    #[error(transparent)]
+    X509ParseError(#[from] x509_cert::der::Error),
+
+    #[error(transparent)]
+    X509BuilderError(#[from] x509_cert::builder::Error),
 }