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From:   Ignat Korchagin <ignat@cloudflare.com>
To:     David Howells <dhowells@redhat.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>, keyrings@vger.kernel.org,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     kernel-team@cloudflare.com, lei he <helei.sig11@bytedance.com>,
        Ignat Korchagin <ignat@cloudflare.com>
Subject: [PATCH v2 3/4] crypto: pkcs8 parser support ECDSA private keys
Date:   Fri, 14 Oct 2022 11:07:36 +0100
Message-Id: <20221014100737.94742-4-ignat@cloudflare.com>
In-Reply-To: <20221014100737.94742-1-ignat@cloudflare.com>
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From: lei he <helei.sig11@bytedance.com>

Make pkcs8_private_key_parser can identify ECDSA private keys.

Signed-off-by: lei he <helei.sig11@bytedance.com>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
---
 crypto/asymmetric_keys/pkcs8.asn1     |  2 +-
 crypto/asymmetric_keys/pkcs8_parser.c | 45 +++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/crypto/asymmetric_keys/pkcs8.asn1 b/crypto/asymmetric_keys/pkcs8.asn1
index 702c41a3c713..1791ddf4168a 100644
--- a/crypto/asymmetric_keys/pkcs8.asn1
+++ b/crypto/asymmetric_keys/pkcs8.asn1
@@ -20,5 +20,5 @@ Attribute ::= ANY
 
 AlgorithmIdentifier ::= SEQUENCE {
 	algorithm   OBJECT IDENTIFIER ({ pkcs8_note_OID }),
-	parameters  ANY OPTIONAL
+	parameters  ANY OPTIONAL ({ pkcs8_note_algo_parameter })
 }
diff --git a/crypto/asymmetric_keys/pkcs8_parser.c b/crypto/asymmetric_keys/pkcs8_parser.c
index 105dcce27f71..e507c635ead5 100644
--- a/crypto/asymmetric_keys/pkcs8_parser.c
+++ b/crypto/asymmetric_keys/pkcs8_parser.c
@@ -24,6 +24,8 @@ struct pkcs8_parse_context {
 	enum OID	algo_oid;		/* Algorithm OID */
 	u32		key_size;
 	const void	*key;
+	const void	*algo_param;
+	u32		algo_param_len;
 };
 
 /*
@@ -47,6 +49,17 @@ int pkcs8_note_OID(void *context, size_t hdrlen,
 	return 0;
 }
 
+int pkcs8_note_algo_parameter(void *context, size_t hdrlen,
+			      unsigned char tag,
+			      const void *value, size_t vlen)
+{
+	struct pkcs8_parse_context *ctx = context;
+
+	ctx->algo_param = value;
+	ctx->algo_param_len = vlen;
+	return 0;
+}
+
 /*
  * Note the version number of the ASN.1 blob.
  */
@@ -69,11 +82,37 @@ int pkcs8_note_algo(void *context, size_t hdrlen,
 		    const void *value, size_t vlen)
 {
 	struct pkcs8_parse_context *ctx = context;
-
-	if (ctx->last_oid != OID_rsaEncryption)
+	enum OID curve_id;
+
+	switch (ctx->last_oid) {
+	case OID_id_ecPublicKey:
+		if (!ctx->algo_param || ctx->algo_param_len == 0)
+			return -EBADMSG;
+		curve_id = look_up_OID(ctx->algo_param, ctx->algo_param_len);
+
+		switch (curve_id) {
+		case OID_id_prime192v1:
+			ctx->pub->pkey_algo = "ecdsa-nist-p192";
+			break;
+		case OID_id_prime256v1:
+			ctx->pub->pkey_algo = "ecdsa-nist-p256";
+			break;
+		case OID_id_ansip384r1:
+			ctx->pub->pkey_algo = "ecdsa-nist-p384";
+			break;
+		default:
+			return -ENOPKG;
+		}
+		break;
+
+	case OID_rsaEncryption:
+		ctx->pub->pkey_algo = "rsa";
+		break;
+
+	default:
 		return -ENOPKG;
+	}
 
-	ctx->pub->pkey_algo = "rsa";
 	return 0;
 }
 
-- 
2.30.2