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

[Thomas Huth <thuth@redhat.com>]

On 29/07/2026 17.51, Paul Louvel wrote:
> Add the parameters for the NIST P224 curve and define a new curve ID for
> it. Make the curve available in ecc_get_curve().

May I ask: Who's going to consume this?

  Thomas

> Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
> ---
>   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
> 
>