Modes (CTR, GCM, CCM, etc.) can be supported either directly or fallback
to invoking the crypto callback with a "direct" (ECB) mode.
Software implementation and AES tables are stripped under CB_ONLY_AES.
wc_swdev gains AES support so WOLF_CRYPTO_CB_ONLY_AES builds can be
tested.
crypto find cb support added to wc_AesSetKey in order to support current
CI tests that use INVALID_DEVID.
Add WOLF_CRYPTO_CB_ONLY_SHA256: when set, the SHA-256 software.
wc_Sha256FinalRaw is reduced to a stub returning NO_VALID_DEVID, and
sha256.h force-defines WOLFSSL_NO_HASH_RAW so the constant-time TLS HMAC
path falls back to its backend-opaque variant.
Incompatible with
WOLFSSL_SHA224, which aliases the SHA-256 statics; #error guard added.
Add wc_swdev support for SHA-256 for testing.
Add a software crypto-callback device (wc_swdev) that lets the wolfcrypt
test suite run under WOLF_CRYPTO_CB_ONLY_* flags without per-test devId
plumbing. The bundle is a separately-compiled second copy of wolfcrypt
(software implementations enabled, WOLF_CRYPTO_CB_ONLY_* stripped) linked
into testwolfcrypt as a single relocatable object; every symbol is demoted
to local via objcopy --keep-global-symbol except wc_SwDev_Callback, so there
is no collision with the main libwolfssl.
A find callback routes unbound operations (devId == INVALID_DEVID) to the
swdev while letting real device IDs pass through.
wc_SwDev_Init / wc_SwDev_Cleanup hooks are wired into wolfcrypt/test/test.c.
cryptocb_test's WOLF_CRYPTO_CB_FIND and WOLF_CRYPTO_CB_ONLY_RSA blocks are
gated off under WOLFSSL_SWDEV.
Enable via --enable-swdev (requires --enable-cryptocb).
Marco Oliverio