EVP_MD-SHA1(7ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

💅 EVP_MD-SHA1 — the SHA1 EVP_MD implementation (7ossl, OpenSSL, bestie)

okay so real talk: this page lives in the 7ossl manual, and it's genuinely just about one icon — SHA1 — showing up through the EVP_MD API. Let's get into it 🎀

✨ NAME ✨

EVP_MD-SHA1 — literally the SHA1 EVP_MD implementation. that's the whole vibe. 👑

🌸 DESCRIPTION 🌸

So this is the support for computing SHA1 digests through the EVP_MD API. no cap, that's the entire description. slay. ✨

🦋 Identities

This implementation is available with the FIPS provider as well as the default provider — two whole homes, main character energy fr fr. 💖

It answers to the names "SHA1" and "SHA-1". yes bestie, both spellings, pick your fighter. 🫶

🧚 Gettable Parameters

This implementation supports the common gettable parameters described over in EVP_MD-common(7). iykyk — go read that one for the deets. 🌈

💜 Settable Context Parameters

This implementation supports the following OSSL_PARAM(3) entries, and you can set them on an EVP_MD_CTX with EVP_MD_CTX_set_params(3):

  • "ssl3-ms" (OSSL_DIGEST_PARAM_SSL3_MS) <octet string> — okay so this one is set by libssl in order to calculate a signature hash for an SSLv3 CertificateVerify message as per RFC6101. and here's the important part, bestie: it is only set after all handshake messages have already been digested via OP_digest_update() calls. the parameter provides the master secret value to be added to the digest. the digest implementation should calculate the complete digest as per RFC6101 section 5.6.8. and the next call after setting this parameter should be OP_digest_final(). periodt. 💅
heads up 🫶 — that ordering is not a suggestion, it's the whole assignment: this parameter goes in after every handshake message has been digested, and OP_digest_final() is what comes next.

🔥 SEE ALSO 🔥

Copyright 2020 The OpenSSL Project Authors. All Rights Reserved. 🎀

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>. 💖

and that's the whole page, bestie — version 3.5.6, dated 2026-04-07, filed under EVP_MD-SHA1(7ossl). go digest something 🌸🦋💜

📦 where this page comes from