rsa_pss_rsae_sha384
rsa_pss_rsae_sha384 is RSA-PSS with SHA-384 for ordinary RSA keys. Every client we recorded offers it.
What it is
rsa_pss_rsae_sha384 (code 0x0805) is a TLS 1.3 signature scheme from RFC 8446: RSASSA-PSS with SHA-384, used with a normal rsaEncryption key. It is the SHA-384 variant of rsa_pss_rsae_sha256.
TLS 1.3 requires RSA-PSS for handshake signatures made with RSA keys, so a server with an RSA certificate signs its CertificateVerify with one of the rsa_pss_rsae schemes. Which hash it uses depends on what both sides list and on the server configuration.
SHA-384 offers a larger margin than SHA-256 but no practical benefit for typical connections. Most clients we recorded list it after the SHA-256 variant; macOS curl orders its RSA-PSS schemes from SHA-512 down to SHA-256.
Like the other rsa_pss_rsae schemes, it works with the RSA certificates that public certificate authorities issue today, so no special certificate is needed. RFC 8446 also defines a SHA-512 variant, rsa_pss_rsae_sha512, and dedicated rsa_pss_pss schemes for RSA-PSS keys.
Who sends it
Measured on 2026-10-25 against our own test server: sent by 11 of 11 clients. Position counts from 1 and ignores GREASE values.
Why it matters for fingerprinting
Every client we recorded sends it: 4th for macOS curl and Go net/http, 5th for both curl-impersonate profiles, 8th for curl_cffi, 10th for Debian curl and 16th for Python requests, httpx, Node.js fetch and Guzzle. Our Chrome capture did not record signature algorithms.
Check whether your client sends it
Open the test from your browser, or call it from your script, and look for rsa_pss_rsae_sha384 in the TLS details.
Run the TLS fingerprint test