Add signed-length validation to d2i, PEM, and buffer-load APIs#10207
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ColtonWilley wants to merge 2 commits intowolfSSL:masterfrom
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Add signed-length validation to d2i, PEM, and buffer-load APIs#10207ColtonWilley wants to merge 2 commits intowolfSSL:masterfrom
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…er loaders Reject negative signed lengths before they are cast to unsigned (word32/size_t), preventing heap buffer over-reads and oversized allocations. Covers d2i_* OpenSSL compat wrappers, ProcessBuffer, PemToDer, certgen helpers, and CRL buffer paths.
Add `*pp == NULL` checks to three d2i wrappers to prevent NULL deref on public OpenSSL-compat APIs: - d2i_evp_pkey (reachable via wolfSSL_d2i_PublicKey/PrivateKey) - wolfSSL_d2i_OCSP_RESPONSE - wolfSSL_d2i_ECDSA_SIG (template-ASN crash) Also add regression tests for the existing PR fixes: ProcessBuffer negative-size, PemToDer family negative-pemSz, GetCRLInfo negative-sz, and wc_Set*Buffer derSz<0.
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Internal security review found that ~25 public API entry points accept signed
length parameters (long/int) and cast them to word32 or size_t without rejecting
negative values first. A negative length wraps to a huge unsigned value, giving
ASN.1 parsers and memcpy calls a bogus bound.
Three main areas fixed:
len <= 0 guards before the (word32) casts
entry points and all PEM conversion paths respectively
negative derSz before forwarding to wc_SetCert_LoadDer
Also fixes an integer overflow in wolfSSL_ASN1_STRING_set where sz == INT_MAX
caused sz + 1 to wrap, bypassing the buffer size check.
8 locations were audited and confirmed already safe (existing guards catch
negatives). Those are left unchanged.
Still needs additional testing, PR up early for duplicate detection on vulnerability reports.