crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm

Add Elliptic Curve Russian Digital Signature Algorithm (GOST R
34.10-2012, RFC 7091, ISO/IEC 14888-3) is one of the Russian (and since
2018 the CIS countries) cryptographic standard algorithms (called GOST
algorithms). Only signature verification is supported, with intent to be
used in the IMA.

Summary of the changes:

* crypto/Kconfig:
  - EC-RDSA is added into Public-key cryptography section.

* crypto/Makefile:
  - ecrdsa objects are added.

* crypto/asymmetric_keys/x509_cert_parser.c:
  - Recognize EC-RDSA and Streebog OIDs.

* include/linux/oid_registry.h:
  - EC-RDSA OIDs are added to the enum. Also, a two currently not
    implemented curve OIDs are added for possible extension later (to
    not change numbering and grouping).

* crypto/ecc.c:
  - Kenneth MacKay copyright date is updated to 2014, because
    vli_mmod_slow, ecc_point_add, ecc_point_mult_shamir are based on his
    code from micro-ecc.
  - Functions needed for ecrdsa are EXPORT_SYMBOL'ed.
  - New functions:
    vli_is_negative - helper to determine sign of vli;
    vli_from_be64 - unpack big-endian array into vli (used for
      a signature);
    vli_from_le64 - unpack little-endian array into vli (used for
      a public key);
    vli_uadd, vli_usub - add/sub u64 value to/from vli (used for
      increment/decrement);
    mul_64_64 - optimized to use __int128 where appropriate, this speeds
      up point multiplication (and as a consequence signature
      verification) by the factor of 1.5-2;
    vli_umult - multiply vli by a small value (speeds up point
      multiplication by another factor of 1.5-2, depending on vli sizes);
    vli_mmod_special - module reduction for some form of Pseudo-Mersenne
      primes (used for the curves A);
    vli_mmod_special2 - module reduction for another form of
      Pseudo-Mersenne primes (used for the curves B);
    vli_mmod_barrett - module reduction using pre-computed value (used
      for the curve C);
    vli_mmod_slow - more general module reduction which is much slower
     (used when the modulus is subgroup order);
    vli_mod_mult_slow - modular multiplication;
    ecc_point_add - add two points;
    ecc_point_mult_shamir - add two points multiplied by scalars in one
      combined multiplication (this gives speed up by another factor 2 in
      compare to two separate multiplications).
    ecc_is_pubkey_valid_partial - additional samity check is added.
  - Updated vli_mmod_fast with non-strict heuristic to call optimal
      module reduction function depending on the prime value;
  - All computations for the previously defined (two NIST) curves should
    not unaffected.

* crypto/ecc.h:
  - Newly exported functions are documented.

* crypto/ecrdsa_defs.h
  - Five curves are defined.

* crypto/ecrdsa.c:
  - Signature verification is implemented.

* crypto/ecrdsa_params.asn1, crypto/ecrdsa_pub_key.asn1:
  - Templates for BER decoder for EC-RDSA parameters and public key.

Cc: linux-integrity@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/Kconfig

@@ -259,6 +259,17 @@ config CRYPTO_ECDH
 	help
 	  Generic implementation of the ECDH algorithm
 
+config CRYPTO_ECRDSA
+	tristate "EC-RDSA (GOST 34.10) algorithm"
+	select CRYPTO_ECC
+	select CRYPTO_AKCIPHER
+	select CRYPTO_STREEBOG
+	help
+	  Elliptic Curve Russian Digital Signature Algorithm (GOST R 34.10-2012,
+	  RFC 7091, ISO/IEC 14888-3:2018) is one of the Russian cryptographic
+	  standard algorithms (called GOST algorithms). Only signature verification
+	  is implemented.
+
 comment "Authenticated Encryption with Associated Data"
 
 config CRYPTO_CCM

crypto/Makefile

@@ -153,6 +153,14 @@ ecdh_generic-y += ecdh.o
 ecdh_generic-y += ecdh_helper.o
 obj-$(CONFIG_CRYPTO_ECDH) += ecdh_generic.o
 
+$(obj)/ecrdsa_params.asn1.o: $(obj)/ecrdsa_params.asn1.c $(obj)/ecrdsa_params.asn1.h
+$(obj)/ecrdsa_pub_key.asn1.o: $(obj)/ecrdsa_pub_key.asn1.c $(obj)/ecrdsa_pub_key.asn1.h
+$(obj)/ecrdsa.o: $(obj)/ecrdsa_params.asn1.h $(obj)/ecrdsa_pub_key.asn1.h
+ecrdsa_generic-y += ecrdsa.o
+ecrdsa_generic-y += ecrdsa_params.asn1.o
+ecrdsa_generic-y += ecrdsa_pub_key.asn1.o
+obj-$(CONFIG_CRYPTO_ECRDSA) += ecrdsa_generic.o
+
 #
 # generic algorithms and the async_tx api
 #

crypto/asymmetric_keys/x509_cert_parser.c

@@ -230,13 +230,26 @@ int x509_note_pkey_algo(void *context, size_t hdrlen,
 	case OID_sha224WithRSAEncryption:
 		ctx->cert->sig->hash_algo = "sha224";
 		goto rsa_pkcs1;
+
+	case OID_gost2012Signature256:
+		ctx->cert->sig->hash_algo = "streebog256";
+		goto ecrdsa;
+
+	case OID_gost2012Signature512:
+		ctx->cert->sig->hash_algo = "streebog512";
+		goto ecrdsa;
 	}
 
 rsa_pkcs1:
 	ctx->cert->sig->pkey_algo = "rsa";
 	ctx->cert->sig->encoding = "pkcs1";
 	ctx->algo_oid = ctx->last_oid;
 	return 0;
+ecrdsa:
+	ctx->cert->sig->pkey_algo = "ecrdsa";
+	ctx->cert->sig->encoding = "raw";
+	ctx->algo_oid = ctx->last_oid;
+	return 0;
 }
 
 /*
@@ -256,7 +269,8 @@ int x509_note_signature(void *context, size_t hdrlen,
 		return -EINVAL;
 	}
 
-	if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0) {
+	if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
+	    strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0) {
 		/* Discard the BIT STRING metadata */
 		if (vlen < 1 || *(const u8 *)value != 0)
 			return -EBADMSG;
@@ -440,11 +454,15 @@ int x509_extract_key_data(void *context, size_t hdrlen,
 {
 	struct x509_parse_context *ctx = context;
 
-	if (ctx->last_oid != OID_rsaEncryption)
+	ctx->key_algo = ctx->last_oid;
+	if (ctx->last_oid == OID_rsaEncryption)
+		ctx->cert->pub->pkey_algo = "rsa";
+	else if (ctx->last_oid == OID_gost2012PKey256 ||
+		 ctx->last_oid == OID_gost2012PKey512)
+		ctx->cert->pub->pkey_algo = "ecrdsa";
+	else
 		return -ENOPKG;
 
-	ctx->cert->pub->pkey_algo = "rsa";
-
 	/* Discard the BIT STRING metadata */
 	if (vlen < 1 || *(const u8 *)value != 0)
 		return -EBADMSG;