EVP_SIGNATURE-ECDSA(7SSL)

📦
version 4.0.3 · 13 versions
, in ubuntu stonking

✨ EVP_SIGNATURE-ECDSA ✨

okay bestie, gather round, we're talking about EVP_SIGNATURE-ECDSA 💖 this is the EVP_PKEY ECDSA signature implementation — aka the whole entire vibe behind ECDSA signatures in OpenSSL, documented here under the manual name EVP_SIGNATURE-ECDSA(7SSL). yes she's a section 7 page, yes she's iconic, no we're not skipping anything 🎀

🌸 DESCRIPTION 🌸

So like. This page is all about support for computing ECDSA signatures. That's the whole thing. That's the assignment, and she ate 💅

If you're here for the keys rather than the signatures, run don't walk to EVP_PKEY-EC(7) — that's where all the EC key lore lives 🦋

🧚 Algorithm Names 🧚

okay so in this list, names are grouped together to signify that they're literally the same algorithm wearing multiple name outfits. the way that a single algorithm can have like nine names and still be that girl 😭

this grouping also includes the OID in canonical decimal form — which means you can fetch them if you've got nothing but a mere OID that came out in this form after a call to OBJ_obj2txt(3) ✨ (iykyk)

not me warning you that it can't be used with EVP_PKEY_sign_message_init(3) 😭 like. she said no to that one specifically. respect.
  • "ECDSA-SHA1", "ECDSA-SHA-1", "ecdsa-with-SHA1", "1.2.840.10045.4.1"
  • "ECDSA-SHA2-224", "ECDSA-SHA224", "ecdsa-with-SHA224", "1.2.840.10045.4.3.1"
  • "ECDSA-SHA2-256", "ECDSA-SHA256", "ecdsa-with-SHA256", "1.2.840.10045.4.3.2"
  • "ECDSA-SHA2-384", "ECDSA-SHA384", "ecdsa-with-SHA384", "1.2.840.10045.4.3.3"
  • "ECDSA-SHA2-512", "ECDSA-SHA512", "ecdsa-with-SHA512", "1.2.840.10045.4.3.4"
  • "ECDSA-SHA3-224", "ecdsa_with_SHA3-224", "id-ecdsa-with-sha3-224", "2.16.840.1.101.3.4.3.9"
  • "ECDSA-SHA3-256", "ecdsa_with_SHA3-256", "id-ecdsa-with-sha3-256", "2.16.840.1.101.3.4.3.10"
  • "ECDSA-SHA3-384", "ecdsa_with_SHA3-384", "id-ecdsa-with-sha3-384", "2.16.840.1.101.3.4.3.11"
  • "ECDSA-SHA3-512", "ecdsa_with_SHA3-512", "id-ecdsa-with-sha3-512", "2.16.840.1.101.3.4.3.12"

These ones up here ^^^ are ECDSA signature schemes with diverse message digest algorithms 🌈. They are all supported explicitly fetched with EVP_PKEY_sign_init_ex2(3) and EVP_PKEY_sign_message_init(3). double the fetch, double the fun 🫶

🎀 ECDSA Signature Parameters 🎀

The following signature parameters can be set using EVP_PKEY_CTX_set_params(). You may call it after EVP_PKEY_sign_init() or EVP_PKEY_verify_init(), and before calling EVP_PKEY_sign() or EVP_PKEY_verify(). timing is everything, bestie ⏰

  • "digest" (OSSL_SIGNATURE_PARAM_DIGEST) <UTF8 string>
  • "properties" (OSSL_SIGNATURE_PARAM_PROPERTIES) <UTF8 string>

okay so these two? not supported with the ECDSA signature schemes that already include a message digest algorithm. peek at "Algorithm Names" above 👀 like girl, she already has a digest, she doesn't need yours.

  • "nonce-type" (OSSL_SIGNATURE_PARAM_NONCE_TYPE) <unsigned integer>
  • "key-check" (OSSL_SIGNATURE_PARAM_FIPS_KEY_CHECK) <integer>
  • "digest-check" (OSSL_SIGNATURE_PARAM_FIPS_DIGEST_CHECK) <integer>

all three of these are described in provider-signature(7) 💜

The following signature parameters can be retrieved using EVP_PKEY_CTX_get_params(). get is get, set is set, we don't mix them up 🙈

  • "algorithm-id" (OSSL_SIGNATURE_PARAM_ALGORITHM_ID) <octet string>
  • "digest" (OSSL_SIGNATURE_PARAM_DIGEST) <UTF8 string>
  • "nonce-type" (OSSL_SIGNATURE_PARAM_NONCE_TYPE) <unsigned integer>
  • "fips-indicator" (OSSL_SIGNATURE_PARAM_FIPS_APPROVED_INDICATOR) <integer>
  • "verify-message" (OSSL_SIGNATURE_PARAM_FIPS_VERIFY_MESSAGE) <integer>

The parameters are described in provider-signature(7) — yes, again. she's thorough, she's consistent, she's the moment ✨

🔥 SEE ALSO 🔥

Copyright 2020-2026 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 of the License in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

and that's the whole page, bestie 🫶 this was EVP_SIGNATURE-ECDSA(7SSL) from OpenSSL 4.0.3, dated 2026-09-29 — go forth and sign something iconic, no cap 💖✨🌈

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