Fix GetSafeContent to check length#10018
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dgarske merged 2 commits intowolfSSL:masterfrom Mar 20, 2026
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Pull request overview
Adds a defensive bounds check in PKCS#12 parsing to prevent an unsigned underflow when an encoded OID exceeds the declared ContentInfo SEQUENCE length, and introduces a regression test for the crafted input case.
Changes:
- Add a post-
GetObjectId()bounds check inGetSafeContent()to reject OIDs longer than the declared SEQUENCE length. - Add a new API test exercising the OID-length vs SEQUENCE-length underflow scenario.
- Register the new test in the PKCS#12 API test declarations.
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.
| File | Description |
|---|---|
| wolfcrypt/src/pkcs12.c | Adds bounds validation to prevent size underflow during ContentInfo parsing. |
| tests/api/test_pkcs12.h | Registers the new regression test in the PKCS#12 test list. |
| tests/api/test_pkcs12.c | Adds a crafted DER test case to ensure the parser rejects the underflow scenario. |
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Fix confirmed by reporter |
dgarske
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Mar 20, 2026
TristanInSec
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to TristanInSec/wolfssl
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Apr 15, 2026
Bound GetObjectId() by the ContentInfo SEQUENCE end (curIdx + curSz) instead of the full buffer size. This prevents the OID TLV from being parsed past the SEQUENCE boundary in the first place, complementing the post-check added in PR wolfSSL#10018. Previously, GetObjectId received (word32)size as maxIdx, allowing it to read OID data beyond the ContentInfo SEQUENCE. The post-check then caught this after the fact. With this change, GetObjectId itself rejects an OID that would exceed the SEQUENCE, so the over-read never occurs.
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Description
Added bounds check after GetObjectId() in GetSafeContent() to verify the OID didn't consume more bytes than the ContentInfo SEQUENCE declared. Returns ASN_PARSE_E if (localIdx - curIdx) > (word32)curSz, preventing the unsigned integer underflow in the ci->dataSz calculation.
Credit to
Muhammad Arya Arjuna (pelioro)for reporting this issue and confirming the fix.Fixes zd21389
Testing
Added
test_wc_d2i_PKCS12_oid_underflowChecklist