Defensive code additions for sanity checks on input arguments with Base64, PEM write, mp_read_unsigned_bin

[JacobBarthelmeh]

ZD21992

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Hardens several low-level routines against integer wrap/overflow by tightening bounds checks when parsing lengths, encoding Base64/PEM, and reading big integers.

Changes:

• Added size/argument validation to prevent overflow in Base64 encoding and PEM size calculations.
• Strengthened ASN.1 buffer bounds checks to avoid word32 wrap.
• Added defensive checks in mp_read_unsigned_bin to reject problematic input sizes.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
wolfcrypt/src/integer.c	Adds input length validation intended to prevent overflow in bit/digit calculations.
wolfcrypt/src/coding.c	Adds a guard intended to prevent Base64 encoded-size calculation from wrapping.
wolfcrypt/src/asn.c	Reworks index/length comparisons to avoid word32 addition overflow.
src/pk.c	Adds a guard against overflow in PEM buffer size calculations and rejects negative lengths.

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[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #10721

Scan targets checked: wolfcrypt-bugs, wolfcrypt-src, wolfssl-bugs, wolfssl-src

Findings: 1
1 finding(s) posted as inline comments (see file-level comments below)

This review was generated automatically by Fenrir. Findings are non-blocking.

[github-actions]

MemBrowse Memory Report

gcc-arm-cortex-m0plus

• FLASH: .text +56 B (+0.1%, 64,163 B / 262,144 B, total: 24% used)

gcc-arm-cortex-m3

• FLASH: .text +236 B (+0.2%, 122,457 B / 262,144 B, total: 47% used)

gcc-arm-cortex-m4

• FLASH: .rodata.CSWTCH.1 +4 B, .rodata.str1.1 +58 B, .text +320 B (+0.2%, 200,284 B / 262,144 B, total: 76% used)

gcc-arm-cortex-m4-crypto-only

• FLASH: .rodata.CSWTCH.1 +4 B, .rodata.str1.1 +58 B, .text +64 B (+0.1%, 174,440 B / 262,144 B, total: 67% used)

gcc-arm-cortex-m4-dtls13

• FLASH: .text +192 B (+0.1%, 180,824 B / 1,048,576 B, total: 17% used)

gcc-arm-cortex-m4-min-ecc

• FLASH: .text +64 B (+0.1%, 61,741 B / 262,144 B, total: 24% used)

gcc-arm-cortex-m4-openssl-compat

• FLASH: .rodata +56 B, .text +1,024 B (+0.1%, 770,828 B / 1,048,576 B, total: 74% used)

gcc-arm-cortex-m4-pkcs7

• FLASH: .rodata.CSWTCH.1 +4 B, .rodata.str1.1 +58 B, .text +256 B (+0.1%, 212,524 B / 262,144 B, total: 81% used)

gcc-arm-cortex-m4-pq

• FLASH: .rodata +60 B, .text +128 B (+0.1%, 279,236 B / 1,048,576 B, total: 27% used)

gcc-arm-cortex-m4-rsa-only

• FLASH: .rodata +56 B, .text +192 B (+0.1%, 324,896 B / 1,048,576 B, total: 31% used)

gcc-arm-cortex-m4-sp-math

• FLASH: .text +64 B (+0.1%, 61,741 B / 262,144 B, total: 24% used)

gcc-arm-cortex-m4-tls12

• FLASH: .text +256 B (+0.2%, 123,213 B / 262,144 B, total: 47% used)

gcc-arm-cortex-m4-tls13

• FLASH: .rodata.CSWTCH.1 +4 B, .rodata.str1.1 +58 B, .text +128 B (+0.1%, 235,918 B / 262,144 B, total: 90% used)

gcc-arm-cortex-m7

• FLASH: .rodata.CSWTCH.1 +4 B, .rodata.str1.1 +58 B, .text +256 B (+0.2%, 200,220 B / 262,144 B, total: 76% used)

gcc-arm-cortex-m7-pq

• FLASH: .rodata +60 B, .text +128 B (+0.1%, 279,812 B / 1,048,576 B, total: 27% used)

gcc-arm-cortex-m7-tls13

• FLASH: .rodata.CSWTCH.1 +4 B, .rodata.str1.1 +58 B, .text +128 B (+0.1%, 235,982 B / 262,144 B, total: 90% used)

linuxkm-pie

• Data: __patchable_function_entries +192 B (+0.8%, 25,512 B)

linuxkm-standard

• Data: __patchable_function_entries +216 B (+0.5%, 48,160 B)

stm32-sim-stm32h753

• FLASH: .text +384 B (+0.2%, 183,460 B / 2,097,152 B, total: 9% used)
  No memory changes detected for:
• gcc-arm-cortex-m4-baremetal

[JacobBarthelmeh]

Retest this please Jenkins

[JacobBarthelmeh]

Retest this please Jenkins. Apple M1 test failure unexpected disconnect while reading sideband packet