X509_NAME_oneline: escape '/', '+' and '\' inside attribute values

[aidankeefe2022]

A single attribute whose value contains the RDN separator rendered byte-identical to a name made of several attributes: CN="foo/O=bar" and CN=foo, O=bar both came out as "/CN=foo/O=bar". X509_NAME_cmp() compares this string, so the two names compared equal, and so did the issuer checks built on it.

Description

Add X509CertEscapeName(), which prefixes every '', '/' and '+' in a value with '', and use it wherever the one-line form is built:

• GetRDN() and GetCertName(), which build the DecodedCert subject and issuer strings. The WC_ASN_NAME_MAX check now uses the escaped length.
• AddAllEntry() and RebuildFullName(), which rebuild the string from the X509_NAME entries. The sizing pass skips entries with no value.

OpenSSL 3 escapes '/' and '+'. '' is escaped here as well: otherwise CN="foo", O=bar still renders as CN="foo/O=bar" does, and CN="a+b" as CN="a+b" does. A value containing '' therefore renders differently than it does in OpenSSL.

This changes the strings from wolfSSL_X509_NAME_oneline(), wc_GetDecodedCertSubject() and wc_GetDecodedCertIssuer() for values containing these characters, and so the caSubject that wc_OcspResponder_AddSigner() expects. Document the escaping for each.

Fixes zd#

Testing

test_wolfSSL_X509_NAME_oneline_escape covers names built from entries and names parsed from a signed certificate, that X509_NAME_dup() does not escape twice, and a value long enough that escaping doubles it.

Checklist

• added tests
• updated/added doxygen

[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #11446

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

Findings: 4
4 finding(s) posted as inline comments (see file-level comments below)

This review was generated automatically by Fenrir. Reported findings require changes before merge.

[github-actions]

MemBrowse Memory Report

gcc-arm-cortex-m0plus

• FLASH: .text +88 B (+0.1%, 67,047 B / 262,144 B, total: 26% used)

gcc-arm-cortex-m3

• FLASH: .text +64 B (+0.1%, 125,839 B / 262,144 B, total: 48% used)

gcc-arm-cortex-m4

• FLASH: .text +64 B (+0.0%, 205,021 B / 262,144 B, total: 78% used)

gcc-arm-cortex-m4-baremetal

• FLASH: .text +64 B (+0.1%, 69,539 B / 262,144 B, total: 27% used)

gcc-arm-cortex-m4-crypto-only

• FLASH: .text +64 B (+0.0%, 178,968 B / 262,144 B, total: 68% used)

gcc-arm-cortex-m4-dtls13

• FLASH: .text +64 B (+0.0%, 187,324 B / 1,048,576 B, total: 18% used)

gcc-arm-cortex-m4-min-ecc

• FLASH: .text +64 B (+0.1%, 64,389 B / 262,144 B, total: 25% used)

gcc-arm-cortex-m4-openssl-compat

• FLASH: .text +64 B (+0.0%, 783,908 B / 1,048,576 B, total: 75% used)

gcc-arm-cortex-m4-pkcs7

• FLASH: .text +64 B (+0.0%, 217,692 B / 262,144 B, total: 83% used)

gcc-arm-cortex-m4-pq

• FLASH: .text +64 B (+0.0%, 302,152 B / 1,048,576 B, total: 29% used)

gcc-arm-cortex-m4-sp-math

• FLASH: .text +64 B (+0.1%, 64,389 B / 262,144 B, total: 25% used)

gcc-arm-cortex-m4-tls12

• FLASH: .text +64 B (+0.1%, 126,643 B / 262,144 B, total: 48% used)

gcc-arm-cortex-m4-tls13

• FLASH: .text +64 B (+0.0%, 242,703 B / 262,144 B, total: 93% used)

gcc-arm-cortex-m7

• FLASH: .text +64 B (+0.0%, 205,021 B / 262,144 B, total: 78% used)

gcc-arm-cortex-m7-pq

• FLASH: .text +64 B (+0.0%, 303,112 B / 1,048,576 B, total: 29% used)

gcc-arm-cortex-m7-tls13

• FLASH: .text +64 B (+0.0%, 242,703 B / 262,144 B, total: 93% used)

linuxkm-pie

• Data: __patchable_function_entries +24 B (+0.1%, 27,096 B)

linuxkm-standard

• Data: __patchable_function_entries +16 B (+0.0%, 49,888 B)

stm32-sim-stm32h753

• FLASH: .text -384 B (-0.2%, 188,220 B / 2,097,152 B, total: 9% used)
  No memory changes detected for:
• gcc-arm-cortex-m4-rsa-only

[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #11446

Fenrir already completed a review of this PR at commit 8c3db19c5b5f (run 2502); its findings are the review threads on the PR. Push new commits to get a re-review of what changed, or comment @wolfSSL-Fenrir-bot review force to run the full review again at this commit.