From 2817868382c143c6606670d854159f0fd2eec0d2 Mon Sep 17 00:00:00 2001
From: Marshall Pierce <marshallpierce@google.com>
Date: Wed, 12 Mar 2025 11:54:59 -0600
Subject: [PATCH] Make SigningKey::from use Self::new()

This matches https://github.com/RustCrypto/RSA/pull/472.
---
 src/pkcs1v15/signing_key.rs |  4 +--
 tests/pkcs1v15.rs           | 57 +++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/src/pkcs1v15/signing_key.rs b/src/pkcs1v15/signing_key.rs
index a354acc4..badef88b 100644
--- a/src/pkcs1v15/signing_key.rs
+++ b/src/pkcs1v15/signing_key.rs
@@ -197,10 +197,10 @@ where
 
 impl<D> From<RsaPrivateKey> for SigningKey<D>
 where
-    D: Digest,
+    D: Digest + AssociatedOid,
 {
     fn from(key: RsaPrivateKey) -> Self {
-        Self::new_unprefixed(key)
+        Self::new(key)
     }
 }
 
diff --git a/tests/pkcs1v15.rs b/tests/pkcs1v15.rs
index 2b42ed71..0960c90e 100644
--- a/tests/pkcs1v15.rs
+++ b/tests/pkcs1v15.rs
@@ -21,3 +21,60 @@ fn signature_stringify() {
     assert_eq!(format!("{:X}", signature), expected);
     assert_eq!(signature.to_string(), expected);
 }
+
+#[cfg(feature = "pem")]
+#[test]
+fn signing_key_new_same_as_from() {
+    use pkcs1::DecodeRsaPrivateKey;
+    use rsa::RsaPrivateKey;
+    use signature::{Keypair, Signer, Verifier};
+
+    // randomly generated key, hardcoded for test repeatability
+    const PRIV_KEY_PKCS1_PEM: &str = "-----BEGIN RSA PRIVATE KEY-----
+MIIEowIBAAKCAQEAwQe5brkkpxrwR/5TJ6JXsUyBzYtbEL/w8u8P6NnxQ8sL4KYp
+MzzTB6aq1gq7bieYXChg0PIWeTukGaOzZe96KxhT0GbhhYRlukktM/quRrM7nYdm
+UmXo7+KWU55kfcNOjWKADL/7qmxn6y/+kPmBg83nHdr1Mq6/pNkeHY/1CeGGECl0
+rg7gfEkssHjZw/uKafA271fX9A/q3LcAeWi7iA01PgmP28BrWb7OQoYVY71kFY11
+e919VlMh8oXsIV0nXCkYu9dR8Pzq6U4gFASK32fFkKX/djRMljEgss3kR0SWPH7t
+m5uXX1wRTJ2mRaZh/BmGweIvYCZ5y0+9ESOD1wIDAQABAoIBAAj3NuGxr8YjNi3h
+3jLlE3WkvBKz+lLY13QxLmf+V3pyn+abUSaUGKkuUJkIfpQrOqRtK7IIzIps/r5C
+ID8H1IDT7HCtlqQA9kikxXi4mAeoo4g5lcMWAK/Dsn/Hx5sfyzI99PyininYRyth
+W02YiS96DNYSKXllLHmXrBJrcVI4FqXAz5s7MezU0XYi+jeaVGEP2bd2cHfQJki/
+pLOKBvA5DGT7HbmMV7Z1qg/zcr/4Py+7qAFC5XsbQIILSMTfC45QFgs1lApnUG8H
+uIhf5lgZ8m0ouDBb/e1Q04ANtdLLI6EmrR11PwavUmvPvXuedXkv2OvnuAbiJr6g
+j0I0VaECgYEAyWf2QZrEoZLzVrInZ+VYtov1+jjgFcxW9lHuCJXtTx8hFla13Bmp
+bc8PoxWb+37jPdrOYPW0yv1sk5VeVkxOJbms0Gn8hpyI+0muQZ3jmwlS0A10T6FL
+wWECYvrxO8DCaVCQ4V+egLSDb/GMkRgHJF3Dr7g3ep7krXf2eeWILQUCgYEA9VqJ
+ijMDKw/KX6swyMe3A1nA0MlLBeseXxrwNIJenwRXCzjG3BH6oHW2MGwH0EV7sSoG
+FR6j7LZbp9I9NvRcAYU/s1qiAX3iX3KIsbZYNtEC6tKn/HClaHLZOhyuE8tjshyD
+jhK/0rhw7R5VQ1GfJhmuzvwoMFTA0fqZBQpWZCsCgYBA5WO+3dyv50bLT5pM6uR7
+5Xs7xinGPFJlCh812wFdNj2WEhiFNCuYu1hhhyv8jHUyUBehvGol4iSjJUUBb5La
+qwpZGV2KDlRBDAu/Dt3w7b8mVL9+jQ144QZA2HT0ePbrsk8Mn5/V/tQ/NMjDU8ex
+WxkbvLL7qskqb/YWbvRC9QKBgQDUJYvFpmQ36LhozmIpSZ6yU/oHzfWD0Y/6VhWa
+oZtlTeBhwJ8aDKWz9vQonFCJQns4bgjCXDMLa4aG7p+lk9a2LdwtndF1Dr8dHrCZ
+UPynsUQffTRpb5FmZd/0gnX2gafbixIpV4brkjV6of7BbaL50702Fgw99hqftVp4
+ZD7c7wKBgD7uIs6rgpaJzKbf7ejjZSjfLOgHlJhtH6Nejp8KoJRsEQI1ofWyIn7D
+eMjIuecwLapPwjY2G0/sUW61bqrxgW10wDJHPNllGsZFanzpb7x5o/7eNhzc4qNf
+Rmb665iB5fwpqmbE/hYKIn7asYQE+V0dkgt8M3qvlJJ5JJbCrJx3
+-----END RSA PRIVATE KEY-----";
+
+    let priv_key = RsaPrivateKey::from_pkcs1_pem(PRIV_KEY_PKCS1_PEM).unwrap();
+
+    let msg = b"1234";
+
+    let key_via_new = rsa::pkcs1v15::SigningKey::<sha2::Sha256>::new(priv_key.clone());
+    let key_via_from = rsa::pkcs1v15::SigningKey::<sha2::Sha256>::from(priv_key.clone());
+    let sig_via_new = key_via_new.sign(msg);
+    let sig_via_from = key_via_from.sign(msg);
+    assert_eq!(sig_via_new, sig_via_from);
+
+    // each verifies the other
+    assert!(key_via_new
+        .verifying_key()
+        .verify(msg, &sig_via_from)
+        .is_ok());
+    assert!(key_via_from
+        .verifying_key()
+        .verify(msg, &sig_via_new)
+        .is_ok());
+}