[PATCH v2 14/14] crypto: ecdh - Add support for NIST P521 and add test case

From: Stefan Berger
Date: Thu Feb 15 2024 - 18:17:46 EST


Implement ecdh support with NIST P521 and add a test case from RFC5903.

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
---
crypto/ecdh.c | 34 +++++++++++++++
crypto/testmgr.c | 7 ++++
crypto/testmgr.h | 79 +++++++++++++++++++++++++++++++++++
include/crypto/internal/ecc.h | 1 +
4 files changed, 121 insertions(+)

diff --git a/crypto/ecdh.c b/crypto/ecdh.c
index e64133428552..be87832e172e 100644
--- a/crypto/ecdh.c
+++ b/crypto/ecdh.c
@@ -207,6 +207,32 @@ static struct kpp_alg ecdh_nist_p384 = {
},
};

+static int ecdh_nist_p521_init_tfm(struct crypto_kpp *tfm)
+{
+ struct ecdh_ctx *ctx = ecdh_get_ctx(tfm);
+
+ ctx->curve_id = ECC_CURVE_NIST_P521;
+ ctx->ndigits = ECC_CURVE_NIST_P521_DIGITS;
+ ctx->nbytes = DIV_ROUND_UP(521, 8);
+ ctx->msd_mask = 0x1ff;
+
+ return 0;
+}
+static struct kpp_alg ecdh_nist_p521 = {
+ .set_secret = ecdh_set_secret,
+ .generate_public_key = ecdh_compute_value,
+ .compute_shared_secret = ecdh_compute_value,
+ .max_size = ecdh_max_size,
+ .init = ecdh_nist_p521_init_tfm,
+ .base = {
+ .cra_name = "ecdh-nist-p521",
+ .cra_driver_name = "ecdh-nist-p521-generic",
+ .cra_priority = 100,
+ .cra_module = THIS_MODULE,
+ .cra_ctxsize = sizeof(struct ecdh_ctx),
+ },
+};
+
static bool ecdh_nist_p192_registered;

static int __init ecdh_init(void)
@@ -225,8 +251,15 @@ static int __init ecdh_init(void)
if (ret)
goto nist_p384_error;

+ ret = crypto_register_kpp(&ecdh_nist_p521);
+ if (ret)
+ goto nist_p521_error;
+
return 0;

+nist_p521_error:
+ crypto_unregister_kpp(&ecdh_nist_p384);
+
nist_p384_error:
crypto_unregister_kpp(&ecdh_nist_p256);

@@ -242,6 +275,7 @@ static void __exit ecdh_exit(void)
crypto_unregister_kpp(&ecdh_nist_p192);
crypto_unregister_kpp(&ecdh_nist_p256);
crypto_unregister_kpp(&ecdh_nist_p384);
+ crypto_unregister_kpp(&ecdh_nist_p521);
}

subsys_initcall(ecdh_init);
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 00f5a6cf341a..91f39f5a438b 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -5077,6 +5077,13 @@ static const struct alg_test_desc alg_test_descs[] = {
.suite = {
.kpp = __VECS(ecdh_p384_tv_template)
}
+ }, {
+ .alg = "ecdh-nist-p521",
+ .test = alg_test_kpp,
+ .fips_allowed = 1,
+ .suite = {
+ .kpp = __VECS(ecdh_p521_tv_template)
+ }
}, {
.alg = "ecdsa-nist-p192",
.test = alg_test_akcipher,
diff --git a/crypto/testmgr.h b/crypto/testmgr.h
index 9bde04be8df9..dc9a2b30b5fd 100644
--- a/crypto/testmgr.h
+++ b/crypto/testmgr.h
@@ -4468,6 +4468,85 @@ static const struct kpp_testvec ecdh_p384_tv_template[] = {
}
};

+/*
+ * NIST P521 test vectors from RFC5903
+ */
+static const struct kpp_testvec ecdh_p521_tv_template[] = {
+ {
+ .secret =
+#ifdef __LITTLE_ENDIAN
+ "\x02\x00" /* type */
+ "\x48\x00" /* len */
+ "\x42\x00" /* key_size */
+#else
+ "\x00\x02" /* type */
+ "\x00\x48" /* len */
+ "\x00\x42" /* key_size */
+#endif
+ "\x00\x37\xAD\xE9\x31\x9A\x89\xF4"
+ "\xDA\xBD\xB3\xEF\x41\x1A\xAC\xCC"
+ "\xA5\x12\x3C\x61\xAC\xAB\x57\xB5"
+ "\x39\x3D\xCE\x47\x60\x81\x72\xA0"
+ "\x95\xAA\x85\xA3\x0F\xE1\xC2\x95"
+ "\x2C\x67\x71\xD9\x37\xBA\x97\x77"
+ "\xF5\x95\x7B\x26\x39\xBA\xB0\x72"
+ "\x46\x2F\x68\xC2\x7A\x57\x38\x2D"
+ "\x4A\x52",
+ .b_public =
+ "\x00\xD0\xB3\x97\x5A\xC4\xB7\x99"
+ "\xF5\xBE\xA1\x6D\x5E\x13\xE9\xAF"
+ "\x97\x1D\x5E\x9B\x98\x4C\x9F\x39"
+ "\x72\x8B\x5E\x57\x39\x73\x5A\x21"
+ "\x9B\x97\xC3\x56\x43\x6A\xDC\x6E"
+ "\x95\xBB\x03\x52\xF6\xBE\x64\xA6"
+ "\xC2\x91\x2D\x4E\xF2\xD0\x43\x3C"
+ "\xED\x2B\x61\x71\x64\x00\x12\xD9"
+ "\x46\x0F"
+ "\x01\x5C\x68\x22\x63\x83\x95\x6E"
+ "\x3B\xD0\x66\xE7\x97\xB6\x23\xC2"
+ "\x7C\xE0\xEA\xC2\xF5\x51\xA1\x0C"
+ "\x2C\x72\x4D\x98\x52\x07\x7B\x87"
+ "\x22\x0B\x65\x36\xC5\xC4\x08\xA1"
+ "\xD2\xAE\xBB\x8E\x86\xD6\x78\xAE"
+ "\x49\xCB\x57\x09\x1F\x47\x32\x29"
+ "\x65\x79\xAB\x44\xFC\xD1\x7F\x0F"
+ "\xC5\x6A",
+ .expected_a_public =
+ "\x00\x15\x41\x7E\x84\xDB\xF2\x8C"
+ "\x0A\xD3\xC2\x78\x71\x33\x49\xDC"
+ "\x7D\xF1\x53\xC8\x97\xA1\x89\x1B"
+ "\xD9\x8B\xAB\x43\x57\xC9\xEC\xBE"
+ "\xE1\xE3\xBF\x42\xE0\x0B\x8E\x38"
+ "\x0A\xEA\xE5\x7C\x2D\x10\x75\x64"
+ "\x94\x18\x85\x94\x2A\xF5\xA7\xF4"
+ "\x60\x17\x23\xC4\x19\x5D\x17\x6C"
+ "\xED\x3E"
+ "\x01\x7C\xAE\x20\xB6\x64\x1D\x2E"
+ "\xEB\x69\x57\x86\xD8\xC9\x46\x14"
+ "\x62\x39\xD0\x99\xE1\x8E\x1D\x5A"
+ "\x51\x4C\x73\x9D\x7C\xB4\xA1\x0A"
+ "\xD8\xA7\x88\x01\x5A\xC4\x05\xD7"
+ "\x79\x9D\xC7\x5E\x7B\x7D\x5B\x6C"
+ "\xF2\x26\x1A\x6A\x7F\x15\x07\x43"
+ "\x8B\xF0\x1B\xEB\x6C\xA3\x92\x6F"
+ "\x95\x82",
+ .expected_ss =
+ "\x01\x14\x4C\x7D\x79\xAE\x69\x56"
+ "\xBC\x8E\xDB\x8E\x7C\x78\x7C\x45"
+ "\x21\xCB\x08\x6F\xA6\x44\x07\xF9"
+ "\x78\x94\xE5\xE6\xB2\xD7\x9B\x04"
+ "\xD1\x42\x7E\x73\xCA\x4B\xAA\x24"
+ "\x0A\x34\x78\x68\x59\x81\x0C\x06"
+ "\xB3\xC7\x15\xA3\xA8\xCC\x31\x51"
+ "\xF2\xBE\xE4\x17\x99\x6D\x19\xF3"
+ "\xDD\xEA",
+ .secret_size = 72,
+ .b_public_size = 132,
+ .expected_a_public_size = 132,
+ .expected_ss_size = 66
+ }
+};
+
/*
* MD4 test vectors from RFC1320
*/
diff --git a/include/crypto/internal/ecc.h b/include/crypto/internal/ecc.h
index 328a82bd35c8..a04b313f2871 100644
--- a/include/crypto/internal/ecc.h
+++ b/include/crypto/internal/ecc.h
@@ -33,6 +33,7 @@
#define ECC_CURVE_NIST_P192_DIGITS 3
#define ECC_CURVE_NIST_P256_DIGITS 4
#define ECC_CURVE_NIST_P384_DIGITS 6
+#define ECC_CURVE_NIST_P521_DIGITS 9
#define ECC_MAX_DIGITS (576 / 64) /* due to NIST P521 */

#define ECC_DIGITS_TO_BYTES_SHIFT 3
--
2.43.0