Document PQC parameter encryption in example READMEs

examples/README.md

@@ -8,6 +8,8 @@ The PKCS #7 and TLS examples require generating CSR's and signing them using a t
 
 To enable parameter encryption use `-aes` for AES-CFB mode or `-xor` for XOR mode. Only some TPM commands / responses support parameter encryption. If the TPM2_ API has .flags `CMD_FLAG_ENC2` or `CMD_FLAG_DEC2` set then the command will use parameter encryption / decryption.
 
+On a v1.85 PQC capable TPM the parameter encryption session can also be keyed with a post-quantum primary: pass `-mlkem` to salt the session with an ML-KEM key or `-mldsa` to bind it to an ML-DSA key (`keygen` uses `-paramkey=mlkem|mldsa` since `-mlkem`/`-mldsa` there select the child key). See "Parameter Encryption" below.
+
 There are some vendor specific examples, like the TPM 2.0 extra GPIO examples for ST33 and NPCT75x.
 
 ## Native API Test
@@ -90,6 +92,17 @@ This behavior depends on the `sessionAttributes`:
 
 Either one can be set separately or both can be set in one authorization session. This is up to the user (developer).
 
+### Post-quantum session keys (v1.85)
+
+The parameter encryption session can be keyed with a post-quantum primary instead of an RSA/ECC storage key. ML-KEM is decrypt capable and is used as the session salt key; ML-DSA is sign only and is used as the session bind key. The RSA/ECC storage key (where one is needed, such as the parent of a created child) is unchanged. `wrap_test`, `pcr/quote`, and `nvram/store` and `nvram/counter` accept `-mlkem[=512|768|1024]` and `-mldsa[=44|65|87]`; `keygen` uses `-paramkey=mlkem[=...]` / `-paramkey=mldsa[=...]` because `-mlkem`/`-mldsa` there select the child key. This requires a v1.85 PQC capable TPM.
+
+```sh
+./examples/wrap/wrap_test -aes -mlkem=768
+./examples/pcr/quote 16 quote.blob -ecc -xor -mldsa=65
+./examples/nvram/counter -aes -mldsa=65
+./examples/keygen/keygen keyblob.bin -ecc -aes -paramkey=mlkem=768
+```
+
 ## CSR
 
 Generates a Certificate Signing Request for building a certificate based on a TPM key pair.

examples/pqc/README.md

@@ -126,3 +126,49 @@ by loading it back:
 A successful load prints `Loaded key to 0x80000000`. The full 18-way
 matrix (three variants x three parameter sets) is exercised by
 `examples/run_examples.sh` when v1.85 is detected in `config.h`.
+
+### PQC keys for parameter encryption
+
+A post-quantum primary can key a TPM 2.0 parameter-encryption session:
+ML-KEM (decrypt capable) is used as the session salt key and ML-DSA
+(sign only) as the session bind key. The session protects the command's
+first sized parameter the same way an RSA/ECC salted session does. Any
+RSA/ECC storage key the example needs (for example the parent of a
+created child) is unchanged.
+
+Note on ML-DSA confidentiality: parameter-encryption confidentiality comes
+from the session key, which a bound session derives from the bind entity's
+authValue (TPM 2.0 Library Part 1, Salted Session). A sign-only ML-DSA key
+cannot exchange a salt, and the example's bind authValue is a public
+constant, so an ML-DSA bind alone provides session binding but no
+confidentiality against a bus observer. To keep the advertised encryption
+real, the helper additionally creates a transient SRK and uses it as the
+asymmetric salt for the ML-DSA session: confidentiality comes from the
+encrypted salt while the ML-DSA key supplies the binding. A real deployment
+that relies on a bare bound session for confidentiality must use a bind
+entity whose authValue is secret and was not sent in cleartext.
+
+`wrap_test`, `pcr/quote`, and `nvram/store` and `nvram/counter` take
+`-mlkem[=512|768|1024]` and `-mldsa[=44|65|87]`. `keygen` uses
+`-paramkey=mlkem[=...]` / `-paramkey=mldsa[=...]` because its `-mlkem` /
+`-mldsa` already select the child key algorithm.
+
+```
+./examples/wrap/wrap_test -aes -mlkem=768
+./examples/pcr/quote 16 quote.blob -ecc -xor -mldsa=65
+./examples/nvram/counter -aes -mldsa=65
+./examples/keygen/keygen keyblob.bin -ecc -aes -paramkey=mlkem=768
+```
+
+ML-KEM is a restricted decryption (salt) key, which requires a symmetric
+definition; the example helper sets AES-128-CFB on it (a TPM rejects a
+restricted key with no symmetric algorithm via `TPM_RC_SYMMETRIC`).
+
+### `create_primary` ML-DSA primary
+
+`examples/keygen/create_primary` can create an ML-DSA primary key:
+
+```
+./examples/keygen/create_primary -mldsa            # default MLDSA-65
+./examples/keygen/create_primary -mldsa=87 -oh
+```