From: Praveen Palaniswamy <praveen.palaniswamy@gmail.com>
Date: Tue, 9 Dec 2025 04:39:26 +0000 (-0500)
Subject: Document EC_curve_nist2nid and EC_curve_nid2nist functions
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f541dede6360f56ec5e09e7f91a747b2e39f0ae4;p=thirdparty%2Fopenssl.git

Document EC_curve_nist2nid and EC_curve_nid2nist functions

Add documentation for EC_curve_nist2nid() and EC_curve_nid2nist()
functions which were previously undocumented. These functions convert
between OpenSSL NIDs and NIST standardized curve names (e.g., "P-256",
"P-384", "P-521" for prime field curves and "B-163", "K-233", etc.
for binary field curves).

The documentation includes:
 - Function prototypes in the SYNOPSIS section
 - Detailed descriptions explaining the purpose and behavior
 - Examples of NIST curve names
 - Return value documentation

Fixes #29180

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
MergeDate: Mon Feb  9 09:59:04 2026
(Merged from https://github.com/openssl/openssl/pull/29341)
---

diff --git a/doc/man3/EC_GROUP_new.pod b/doc/man3/EC_GROUP_new.pod
index 6c6b61af8aa..53ea2ee3b9d 100644
--- a/doc/man3/EC_GROUP_new.pod
+++ b/doc/man3/EC_GROUP_new.pod
@@ -22,7 +22,9 @@ EC_GROUP_get_curve_GFp,
 EC_GROUP_set_curve_GF2m,
 EC_GROUP_get_curve_GF2m,
 EC_get_builtin_curves,
-OSSL_EC_curve_nid2name -
+OSSL_EC_curve_nid2name,
+EC_curve_nid2nist,
+EC_curve_nist2nid -
 Functions for creating and destroying EC_GROUP objects
 
 =head1 SYNOPSIS
@@ -57,6 +59,8 @@ Functions for creating and destroying EC_GROUP objects
 
  size_t EC_get_builtin_curves(EC_builtin_curve *r, size_t nitems);
  const char *OSSL_EC_curve_nid2name(int nid);
+ const char *EC_curve_nid2nist(int nid);
+ int EC_curve_nist2nid(const char *name);
 
 The following functions have been deprecated since OpenSSL 3.0, and can be
 hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
@@ -190,6 +194,20 @@ If I<group> is NULL nothing is done.
 
 OSSL_EC_curve_nid2name() converts a curve I<nid> into the corresponding name.
 
+EC_curve_nid2nist() converts a curve I<nid> into the corresponding NIST name.
+NIST names are standardized curve names defined by NIST, such as "P-192", "P-224",
+"P-256", "P-384", and "P-521" for prime field curves, and "B-163", "B-233",
+"B-283", "B-409", "B-571", "K-163", "K-233", "K-283", "K-409", and "K-571" for
+binary field curves.
+If the curve specified by I<nid> does not have a NIST name, this function returns
+NULL.
+
+EC_curve_nist2nid() converts a NIST curve name I<name> to the corresponding NID.
+The I<name> argument should be a string containing a NIST curve name such as
+"P-256" or "B-163".
+If the name does not correspond to a known NIST curve, this function returns
+NID_undef.
+
 =head1 RETURN VALUES
 
 All EC_GROUP_new* functions return a pointer to the newly constructed group, or
@@ -203,6 +221,12 @@ EC_GROUP_get_curve_GF2m() return 1 on success or 0 on error.
 
 OSSL_EC_curve_nid2name() returns a character string constant, or NULL on error.
 
+EC_curve_nid2nist() returns a pointer to a constant string containing the NIST
+name for the specified curve, or NULL if the curve does not have a NIST name.
+
+EC_curve_nist2nid() returns the NID of the curve with the given NIST name, or
+NID_undef if the name does not correspond to a known NIST curve.
+
 =head1 SEE ALSO
 
 L<crypto(7)>, L<EC_GROUP_copy(3)>,
diff --git a/util/missingcrypto.txt b/util/missingcrypto.txt
index b0cc4e9214a..fedf86d4bf6 100644
--- a/util/missingcrypto.txt
+++ b/util/missingcrypto.txt
@@ -464,8 +464,6 @@ EC_KEY_new_method(3)
 EC_KEY_print(3)
 EC_KEY_print_fp(3)
 EC_KEY_set_default_method(3)
-EC_curve_nid2nist(3)
-EC_curve_nist2nid(3)
 EDIPARTYNAME_it(3)
 ENGINE_get_EC(3)
 ENGINE_get_default_EC(3)