Add SRAM PUF (Physically Unclonable Function) support to wolfCrypt. Derives device-unique cryptographic keys from the power-on state of SRAM memory using a BCH(127,64,t=10) fuzzy extractor with HKDF key derivation.
- **wolfCrypt PUF API** (`wolfcrypt/src/puf.c`, `wolfssl/wolfcrypt/puf.h`)
- `wc_PufInit`, `wc_PufReadSram`, `wc_PufEnroll`, `wc_PufReconstruct`
- `wc_PufDeriveKey` (HKDF-SHA256), `wc_PufGetIdentity` (SHA-256 device fingerprint)
- `wc_PufZeroize` (secure context cleanup)
- `wc_PufSetTestData` (synthetic SRAM for testing without hardware)
- **BCH(127,64,t=10) error-correcting codec** - corrects up to 10 bit flips per 127-bit codeword across 16 codewords
- **`WC_PUF_SHA3` build option** - select SHA3-256 instead of SHA-256 for identity hash and HKDF (default: SHA-256)
- **Precomputed GF(2^7) tables** - `const` arrays in `.rodata` (no runtime init, thread-safe, flash-resident on embedded)
- `./configure --enable-puf` (auto-enables HKDF dependency)
- CMake: `WOLFSSL_PUF=yes`
- `WOLFSSL_USER_SETTINGS`: define `WOLFSSL_PUF` and `WOLFSSL_PUF_SRAM`
- See wolfssl-examples/puf for example implementation on STM32 NUCLEO-H563ZI (Cortex-M33, STM32H563ZI)
- Supports test mode (synthetic SRAM)
- Builds to ~13KB `.elf`
- Tested on NUCLEO-H563ZI: enrollment, noisy reconstruction, key derivation all pass
- `.github/workflows/puf.yml`: host build + test workflow for PUF feature
- Doxygen API docs for all 8 public functions
- PUF group added to `doxygen_groups.h`
Add implementation of SRTP KDF and SRTCP KDF.
One shot APIs compatible with SP 800-135 and ACVP testing.
Tests added to test.c.
Benchmarking added.
Doxygen added.
* This PR resolves issues with using TLS client authentication (mutual auth) with crypto callbacks. The TLS client auth will not be sent without a private key being set. The solution is to allow setting a public key only if crypto callbacks is enabled and a devId is set.
* Fix to allow using crypto callbacks with TLS mutual authentication where a private key is not available.
* Fix for ED25519 sign when only a private key is loaded.
* Fix to enable crypto callbacks for ED25519 and Curve25519 in TLS by using the _ex init functions.
* Fix for wc_PemToDer return code where a PKCS8 header does not exist.
* Remove duplicate logs in DoCertificateVerify.
* Doxygen API updates: Added crypto callback help and updated use_PrivateKey with info about public key use.
* * Added crypto callback tests for TLS client and server with mutual auth for RSA, ECC and ED25519.
* Enhanced the API unit test TLS code to allow setting CA, cert and key.
* Revert ED25519 changes. Opt to calculate public key directly when required for signing in the TLS crypto callback test. Build configuration fixes.
* Fix to use proper devId in `ProcessBufferTryDecode`.
* Various build fixes due to changes in PR. G++ issue with `missing-field-initializers`. Unused api.c func with DTLS and session export. Duplicate `eccKeyPubFile` def.
* Added crypto callback TLS tests at WOLFSSL object level. Fix for ED25519/ED448 with client mutual auth where the private key is not set till WOLFSSL object. Fix issues with `wolfSSL_CTX_GetDevId` where devId is set on WOLFSSL object. Enable the `_id` API's for crypto callbacks.
* Proper fix for `eccKeyPubFile` name conflict. Was causing RSA test to fail (expected DER, not PEM).