broken-csr-validation
This repository is for keeping track of a number of software tools/libraries/packages that do not fully respect RFC2986 in verifying the signature on Certificate Signing Requests (CSRs) -- at least, this is my opinion. I may be wrong, but I am still waiting to see a sound counter-argument.
Most software capable of parsing CSRs do not check how a CSR is encoded (whether DER or BER): they just check that the signature was computed over the certificationRequestInfo element "AS IS" (as it appears in the CSR). This assumption is wrong, as a BER-encoded CSR (which is legitimate, although unfrequent) requires a more complex treatment. RFC2986, in fact, requires DER-encoding the certificationRequestInfo component prior to signing it, and consequently the same processing should be done on verifying the signature by any software which offers a CSR verification function. In practice, some do and some don't, leading to interoperability problems.
In the following table, a Result "OK" means that the software gives what I consider the correct result (such as "Failed", "Invalid" or the likes) on verifying a wrong signature, where wrong means cryptographically correct, but computed over the wrong data (as explained above).
Examples of CSRs carrying a wrong signature can be found in the "data" folder.
| Environment | Software | Version | Result | Bug report |
|---|---|---|---|---|
| .NET | BouncyCastle C# | 1.8.2 | KO | |
| .NET | BouncyCastle C# | 1.9.0 | KO | |
| Java | BouncyCastle Java | 1.46 | KO | |
| Java | BouncyCastle Java | 1.64 | OK | |
| Java | Oracle JRE/JDK (sun.security.pkcs10.PKCS10) | 1.8.0_311 | KO | |
| Java | OpenJDK (sun.security.pkcs10.PKCS10) | 11.0.11 | KO | |
| Java | Oracle Security Developer Tools | 19.3 | OK | |
| Javascript | PKI.js | ... | KO | |
| Javascript | forge | 0.7.0 | KO | |
| Linux | GnuTLS (certtool) | 3.5.18 | OK | |
| Linux | Golang (crypto/x509) | 1.17.1 | KO | golang/go#49519 |
| Linux | OpenSSL | 1.1.1 | KO | |
| Windows 10 | CertEnroll.dll | 10.0.19041.746 | KO | |
| Windows 10 | CertUtil.exe | 10.0.19041.1 | KO | |
| Windows 10 | OpenSSL | 3.0.0 | KO | openssl/openssl#17010 |
| Windows 10 | PKISolutions' PowerShell PKI Module | 3.7 | KO | PKISolutions/PSPKI#162 |