EVP_MD-SHA1(7ossl)

📦 version 3.5.0, in opensuse-leap 16.0

💖 NAME 💖

EVP_MD-SHA1 — literally The SHA1 EVP_MD implementation. That’s the whole name, bestie, no cap.

✨ DESCRIPTION ✨

Support for computing SHA1 digests through the EVP_MD API. Slay.

🪪 Identities

This implementation is available with the FIPS provider as well as the default provider, and is identified with the names "SHA1" and "SHA-1". Iconic behavior, honestly.

📦 Gettable Parameters

This implementation supports the common gettable parameters described in EVP_MD-common(7). That’s the whole vibe — go peek over there 🫶.

🎛️ Settable Context Parameters

This implementation supports the following OSSL_PARAM(3) entries, settable for an EVP_MD_CTX with EVP_MD_CTX_set_params(3):

  • "ssl3-ms" (OSSL_DIGEST_PARAM_SSL3_MS) — <octet string> 🦋

Okay so this parameter is set by libssl in order to calculate a signature hash for an SSLv3 CertificateVerify message as per RFC6101. 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. The next call after setting this parameter should be OP_digest_final().

Bestie, lowkey important: that last line is not a suggestion for a fun little detour — after setting this parameter, the next call should be OP_digest_final() 💅.

👀 SEE ALSO 👀

Go read these too, bestie:

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>.

That’s the whole page, bestie — OpenSSL 3.5.0, dated 2026-09-25, signing off as EVP_MD-SHA1(7ossl) 💅✨

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