Two follow-ups raised by Copilot review on PR #10247:
src/pk_rsa.c: Make derAllocSz a word32 instead of int and only assign
it after a successful XMALLOC, so the cleanup path can never call
ForceZero with a wrapped-around size derived from a negative derSz.
src/pk.c: Capture allocSz at the XMALLOC call site (and clear it back
to 0 on allocation failure) so the relationship between the buffer
allocation and the recorded size is explicit and cannot drift if the
surrounding control flow changes.
F-2148
The prior fix zeroed the computed DER staging area, but PEM output from
wc_DerToPemEx fills most of the buffer and overlaps that region,
corrupting the valid PEM. Preserve the allocation size and zero only
the bytes beyond the actual PEM length, or the whole buffer on failure.
F-2148
pem_write_mem_pkcs8privatekey stages the PKCS#8 DER encoded private key
at the tail of the PEM buffer, then writes the shorter PEM output at
the head of the same buffer. The DER tail is not overwritten, leaking
the plaintext private key to heap memory after the callers free. Zero
the DER staging area before returning.
F-2147
The error path in wolfSSL_i2d_ECPrivateKey could free an EC private key
DER staging buffer that may contain a partial private scalar. Zeroize
before XFREE.
F-2146
wolfSSL_d2i_RSAPrivateKey_bio read PKCS#1-encoded RSA private key DER
from a BIO into a heap buffer and freed it without ForceZero. Zeroize
before XFREE on both success and error paths.
F-2145
wolfSSL_CTX_use_RSAPrivateKey staged the RSA private key DER (PKCS#1:
n, e, d, p, q, dP, dQ, qInv) in a heap buffer and freed it without
ForceZero. Zeroize before XFREE.
F-2144
SetStaticEphemeralKey loaded a private key file into keyBuf and freed it
without ForceZero. Static ephemeral keys are long-lived, so zeroize the
buffer before XFREE.
F-2143
ssl_SetWatchKey_file loaded a private key file into a heap buffer and
freed it without ForceZero on both error and success paths. Zeroize
before XFREE.
F-2142
wolfSSL_RSA_To_Der could free a buffer holding RSA private key material
when the DER encoding step failed. Record the allocation size and
ForceZero the buffer before XFREE on the private key path.
F-2140
wolfSSL_PEM_write_mem_DSAPrivateKey serializes the DSA private key to a
heap DER buffer and freed it on five paths without ForceZero. Zeroize
the buffer before each XFREE.
F-2139
Previously the plaintext private key DER buffer was freed via XFREE
without a preceding ForceZero when no password encryption was requested.
Track the actual allocation size and zeroize the buffer before release.
* Fix OOB heap reads via TLSX_ExtractEch() by preemptively rejecting oversized
SNI names in TLSX_UseSNI().
* In TLSX_EchChangeSNI(), don't attempt to truncate if an oversized name is
seen, just return error.
* Move definition of WOLFSSL_HOST_NAME_MAX to an ungated context in ssl.h, and
use it consistently in tls.c, eliminating the duplicative
WOLFSSL_HOST_NAME_MAX.
1. sp_cond_swap_ct_ex (line ~5524) — XOR typo: b->sign ^= b->sign always
zeroed the sign. Fixed to b->sign ^= t->sign to correctly swap signs.
2. sp_mod_d (line ~7271) — Negative modulo correction was applied even
when the remainder was 0. Added (*r != 0) guard to avoid producing d
instead of 0.
3. sp_lshb (line ~8444) — Left-shift size check was off. Refactored to
correctly distinguish between pure-digit shifts and bit-within-digit
shifts when checking if the result fits, using separate overflow checks
for each case.
4. _sp_mulmod_tmp (line ~12160) — Zero inputs caused an allocation of
size 0, which is problematic. Added an early path: if either operand is
zero, set result to zero and skip the allocation/multiply entirely.
5. sp_mod_2d — copy path (line ~14762) — XMEMCPY copied digits *
SP_WORD_SIZEOF bytes but a may have fewer than digits used digits. Fixed
to copy min(a->used, digits) digits to avoid reading uninitialized
memory.
6. sp_mod_2d — negation loop (line ~14782) — Negation loop iterated
over r->used, which could exceed digits. Fixed to loop over min(r->used,
digits).
7. _sp_sqrmod (line ~17314) — Same zero-input issue as _sp_mulmod_tmp.
Added early zero path to skip the allocation/squaring when input is
zero.
8. sp_lcm (line ~19838) — Typo in sign check: b->sign >= MP_NEG
(comparing against a value that is 1, so >= 1 would also match MP_ZPOS)
changed to b->sign == MP_NEG.
Juliusz Sosinowicz
Reda Chouk
Sean Parkinson
Brett Nicholas
David Garske
Daniel Pouzzner
Jeremiah Mackey
night1rider
Eric Blankenhorn