> If it's just as simple, this might be the right place/time to use sha256 > for this sort of thing.
Again, I did not look into this in detail, but CSRs I generated recently with openssl seem to use "SHA1 with RSA encryption" for the signature: Certificate Request: Data: Version: 0 (0x0) Subject: C=ZA, L=Kestell, ST=Free State, O=Proxima Research & Development, OU=Public Internet Services, CN=serendipity.proxima.alt.za/emailAddress=ad...@proxima.alt.za Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (1024 bit) Modulus: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx Exponent: 65537 (0x10001) Attributes: a0:00 Signature Algorithm: sha1WithRSAEncryption xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx: xx:xx That was what I thought would take some effort to get right in x509.c Lucio.