- wo_rsa_pkcs1_sha256_verify + wo_rsa_pss_sha256_verify (SHA-256), for the
server cert chain and TLS 1.3 CertificateVerify
- bignum: Montgomery multiply (CIOS, 64-bit limbs, __int128), modexp with the
public exponent (R^2 via 128k modular doublings, no division); MGF1-SHA256
- verification is public data only -> NOT constant-time by design (correct and
much simpler than a private-key op)
- assumes a full-length modulus for PSS emBits (standard RSA-2048/3072/4096)
- VERIFIED against python cryptography RSA-2048 vectors (PKCS#1 v1.5 + PSS,
salt 32); tamper + wrong-hash rejected; test_crypto 66/0; ASan/UBSan clean;
battery green
- internal C, no builtin/compiler change. Remaining in D: ECDSA-P256 (D2)
(cherry picked from commit 9118177fbfd03eff9757defea6931afdd68830c4)
shoney.arickathil
d0bd66c704