[PATCH] crypto: ecc - Add NIST P224 curve parameters

Paul Louvel <[email protected]> Wed, 29 Jul 2026 17:51:04 +0200
Newsgroups org.kernel.vger.linux-crypto,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
Add the parameters for the NIST P224 curve and define a new curve ID for
it. Make the curve available in ecc_get_curve().

Signed-off-by: Paul Louvel <[email protected]>
---
 crypto/ecc.c            |  2 ++
 crypto/ecc_curve_defs.h | 27 +++++++++++++++++++++++++++
 include/crypto/ecdh.h   |  7 ++++---
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/crypto/ecc.c b/crypto/ecc.c
index 6eb4d97a5f0d..6aa007420ab4 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -56,6 +56,8 @@ const struct ecc_curve *ecc_get_curve(unsigned int curve_id)
 	/* In FIPS mode only allow P256 and higher */
 	case ECC_CURVE_NIST_P192:
 		return fips_enabled ? NULL : &nist_p192;
+	case ECC_CURVE_NIST_P224:
+		return &nist_p224;
 	case ECC_CURVE_NIST_P256:
 		return &nist_p256;
 	case ECC_CURVE_NIST_P384:
diff --git a/crypto/ecc_curve_defs.h b/crypto/ecc_curve_defs.h
index 0ecade7d02f5..c67b73f2cd5a 100644
--- a/crypto/ecc_curve_defs.h
+++ b/crypto/ecc_curve_defs.h
@@ -29,6 +29,33 @@ static struct ecc_curve nist_p192 = {
 	.b = nist_p192_b
 };
 
+/* NIST P-224: a = p - 3 */
+static u64 nist_p224_g_x[] = { 0x115c1d21ull, 0x56c21122343280d6ull,
+			       0x321390b94a03c1d3ull, 0xb70e0cbd6bb4bf7full };
+static u64 nist_p224_g_y[] = { 0x85007e34ull, 0x5a07476444d58199ull,
+			       0x4c22dfe6cd4375a0ull, 0xbd376388b5f723fbull };
+static u64 nist_p224_p[] = { 0x00000001ull, 0x0000000000000000ull,
+			     0xffffffffffffffffull, 0xffffffffffffffffull };
+static u64 nist_p224_n[] = { 0x5c5c2a3dull, 0xe0b8f03e13dd2945ull,
+			     0xffffffffffff16a2ull, 0xffffffffffffffffull };
+static u64 nist_p224_a[] = { 0xfffffffeull, 0xffffffffffffffffull,
+			     0xfffffffffffffffeull, 0xffffffffffffffffull };
+static u64 nist_p224_b[] = { 0x2355ffb4ull, 0xd7bfd8ba270b3943ull,
+			     0xf54132565044b0b7ull, 0xb4050a850c04b3abull };
+static struct ecc_curve nist_p224 = {
+	.name = "nist_224",
+	.nbits = 224,
+	.g = {
+		.x = nist_p224_g_x,
+		.y = nist_p224_g_y,
+		.ndigits = 4,
+	},
+	.p = nist_p224_p,
+	.n = nist_p224_n,
+	.a = nist_p224_a,
+	.b = nist_p224_b
+};
+
 /* NIST P-256: a = p - 3 */
 static u64 nist_p256_g_x[] = { 0xF4A13945D898C296ull, 0x77037D812DEB33A0ull,
 				0xF8BCE6E563A440F2ull, 0x6B17D1F2E12C4247ull };
diff --git a/include/crypto/ecdh.h b/include/crypto/ecdh.h
index 9784ecdd2fb4..07e0d3058f5f 100644
--- a/include/crypto/ecdh.h
+++ b/include/crypto/ecdh.h
@@ -24,9 +24,10 @@
 
 /* Curves IDs */
 #define ECC_CURVE_NIST_P192	0x0001
-#define ECC_CURVE_NIST_P256	0x0002
-#define ECC_CURVE_NIST_P384	0x0003
-#define ECC_CURVE_NIST_P521	0x0004
+#define ECC_CURVE_NIST_P224	0x0002
+#define ECC_CURVE_NIST_P256	0x0003
+#define ECC_CURVE_NIST_P384	0x0004
+#define ECC_CURVE_NIST_P521	0x0005
 
 /**
  * struct ecdh - define an ECDH private key

---
base-commit: f5098b6bae761e346ebcd9da7f95622c04733cff
change-id: 20260729-add-nist-p224-curve-8612b49d6ba2

Best regards,
--  
Paul Louvel, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com