BTW, while I still cannot find a PKCS #11 function to get the public key, I have a workaround now inside JDK. Please confirm if this is correct.
It looks like there are 3 cases in SunPKCS11 where a P11PrivateKey is created: 1. As a part of a newly generated key pair 2. Read from a PKCS11 KeyStore 3. Translated by a KeyFactory In the first 2 cases, the public key is right at side. In the 3rd case, the key material is available and I can calculate the public key. Thanks, Weijun On Dec 11, 2024, at 12:00, Wei-Jun Wang <weijun.w...@oracle.com> wrote: Hi Martin, That’s how DH works. Unfortunately, DHKEM is not simply exposing DH in KEM API. Its decapsulation function is defined as [1] def Decap(enc, skR): pkE = DeserializePublicKey(enc) dh = DH(skR, pkE) pkRm = SerializePublicKey(pk(skR)) kem_context = concat(enc, pkRm) shared_secret = ExtractAndExpand(dh, kem_context) return shared_secret Here, the DH output is fed as IKM into a HKDF and the HKDF-Expand info contains its own public key — pk(skR) — as a part. Thanks, Weijun [1] https://www.rfc-editor.org/rfc/rfc9180.html#name-dh-based-kem-dhkem On Dec 11, 2024, at 09:44, Martin Balao <mba...@redhat.com> wrote: Hi Weijun, I am not familiar to this algorithm but the typical key-exchange APIs let you generate a key pair first and, when you invoke the secret encapsulation mechanism, you use your private key + your counter-part public key. Do you think this could be the case here? Regards, Martin.- On 12/10/24 00:07, Wei-Jun Wang wrote: So are you suggesting there is no such a way? I do notice that in NSS’s own HPKE implementation, the receiver needs to provide both keys [1]: SECStatus PK11_HPKE_SetupR(HpkeContext *cx, const SECKEYPublicKey *pkR, SECKEYPrivateKey *skR, const SECItem *enc, const SECItem *info); Maybe they also don’t have a simple way to get pkR from skR. Thanks, Weijun [1] https://urldefense.com/v3/__https://github.com/nss-dev/nss/blob/e2f270997ff9364aebb688f49b7c28698b70f24d/lib/pk11wrap/pk11pub.h*L788__;Iw!!ACWV5N9M2RV99hQ!N-hg_2MBY8A7Xq5uANI019wCfwrtROskrREyxtRKa8WKXwKZEgtWe1TNH0sMsIFnn9aIkIUBUqOIp7KE$ <https://urldefense.com/v3/__https://github.com/nss-dev/nss/blob/e2f270997ff9364aebb688f49b7c28698b70f24d/lib/pk11wrap/pk11pub.h*L788__;Iw!!ACWV5N9M2RV99hQ!N-hg_2MBY8A7Xq5uANI019wCfwrtROskrREyxtRKa8WKXwKZEgtWe1TNH0sMsIFnn9aIkIUBUqOIp7KE$ > On Dec 9, 2024, at 21:27, Francisco Ferrari Bihurriet <fferr...@redhat.com> wrote: Hi Wei-Jun, As far as I know, public and private keys are different PKCS#11 objects, each one with a different CK_OBJECT_HANDLE. See for example how C_GenerateKeyPair [1] has two output parameters: CK_OBJECT_HANDLE_PTR phPublicKey amd CK_OBJECT_HANDLE_PTR phPrivateKey. NSS uses CKA_PUBLIC_KEY_INFO only when wrapping [2] / unwrapping [3] (C_WrapKey / C_UnwrapKey) RSA-PSS keys (where it stores an ASN1-encoded SubjectPublicKeyInfo with the algorithm OID and the DER encoding of the public key). Here [4] is how SunPKCS11 proceeds after calling C_GenerateKeyPair, by creating two P11Key objects for each handle (P11PublicKey and P11PrivateKey). [1]https://urldefense.com/v3/__https://docs.oasis-open.org/pkcs11/pkcs11-base/v3.0/pkcs11-base-v3.0.html*_Toc29976704__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTLO6ARjM$ <https://urldefense.com/v3/__https://docs.oasis-open.org/pkcs11/pkcs11-base/v3.0/pkcs11-base-v3.0.html*_Toc29976704__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTLO6ARjM$> [2]https://urldefense.com/v3/__https://github.com/nss-dev/nss/blob/NSS_3_101_RTM/lib/softoken/pkcs11c.c*L6038-L6039__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTT9ztKx9Y$ <https://urldefense.com/v3/__https://github.com/nss-dev/nss/blob/NSS_3_101_RTM/lib/softoken/pkcs11c.c*L6038-L6039__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTT9ztKx9Y$> [3]https://urldefense.com/v3/__https://github.com/nss-dev/nss/blob/NSS_3_101_RTM/lib/softoken/pkcs11c.c*L6604-L6605__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTdVw8oI8$ <https://urldefense.com/v3/__https://github.com/nss-dev/nss/blob/NSS_3_101_RTM/lib/softoken/pkcs11c.c*L6604-L6605__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTdVw8oI8$> [4]https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/jdk-25*1/src/jdk.crypto.cryptoki/share/classes/sun/security/pkcs11/P11KeyPairGenerator.java*L424-L431__;KyM!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTozigB-E$ <https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/jdk-25*1/src/jdk.crypto.cryptoki/share/classes/sun/security/pkcs11/P11KeyPairGenerator.java*L424-L431__;KyM!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTozigB-E$> Regards, -- Francisco On 12/10/24 01:43, Wei-Jun Wang wrote: Daniel suggested CKA_PUBLIC_KEY_INFO but it’s not available in NSS 3.101. On Dec 9, 2024, at 08:07, Wei-Jun Wang <weijun.w...@oracle.com> wrote: Hi PKCS #11 gurus, DHKEM [1] requires a function Pk(skX): The KEM public key corresponding to the KEM private key skX. "The notation pk(skX), depending on its use and the KEM and its implementation, is either the computation of the public key using the private key, or just syntax expressing the retrieval of the public key, assuming it is stored along with the private key object." For the software side, I can calculate the public key [2] from the private key. How can I do this in PKCS #11? Thanks, Weijun [1]https://urldefense.com/v3/__https://www.rfc-editor.org/rfc/rfc9180.html*name-notation__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTT0-STk6s$ <https://urldefense.com/v3/__https://www.rfc-editor.org/rfc/rfc9180.html*name-notation__;Iw!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTT0-STk6s$> [2]https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/__;!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTH8KrINU$ <https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/__;!!ACWV5N9M2RV99hQ!OmuwCcv-dJsqSgUuLEW8yqzvuB4Qwj5ay4afqgvAfvn3DiGx9lz31XjKDuAt_LABjdrwdCT8FmTTH8KrINU$> adca97b659d725b0dd320322297dcbd1b443a047/src/java.base/share/classes/ sun/security/ec/ECPrivateKeyImpl.java#L209
