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-rw-r--r--contrib/bearssl/src/x509/encode_ec_pk8der.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/contrib/bearssl/src/x509/encode_ec_pk8der.c b/contrib/bearssl/src/x509/encode_ec_pk8der.c
new file mode 100644
index 000000000000..53717ce3d9e9
--- /dev/null
+++ b/contrib/bearssl/src/x509/encode_ec_pk8der.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/* see bearssl_x509.h */
+size_t
+br_encode_ec_pkcs8_der(void *dest,
+ const br_ec_private_key *sk, const br_ec_public_key *pk)
+{
+ /*
+ * ASN.1 format:
+ *
+ * OneAsymmetricKey ::= SEQUENCE {
+ * version Version,
+ * privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
+ * privateKey PrivateKey,
+ * attributes [0] Attributes OPTIONAL,
+ * ...,
+ * [[2: publicKey [1] PublicKey OPTIONAL ]],
+ * ...
+ * }
+ *
+ * We don't include attributes or public key (the public key
+ * is included in the private key value instead). The
+ * 'version' field is an INTEGER that we will set to 0
+ * (meaning 'v1', compatible with previous versions of PKCS#8).
+ * The 'privateKeyAlgorithm' structure is an AlgorithmIdentifier
+ * whose OID should be id-ecPublicKey, with, as parameters, the
+ * curve OID. The 'privateKey' is an OCTET STRING, whose value
+ * is the "raw DER" encoding of the key pair.
+ */
+
+ /*
+ * OID id-ecPublicKey (1.2.840.10045.2.1), DER-encoded (with
+ * the tag).
+ */
+ static const unsigned char OID_ECPUBKEY[] = {
+ 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01
+ };
+
+ size_t len_version, len_privateKeyAlgorithm, len_privateKeyValue;
+ size_t len_privateKey, len_seq;
+ const unsigned char *oid;
+
+ oid = br_get_curve_OID(sk->curve);
+ if (oid == NULL) {
+ return 0;
+ }
+ len_version = 3;
+ len_privateKeyAlgorithm = 2 + sizeof OID_ECPUBKEY + 2 + oid[0];
+ len_privateKeyValue = br_encode_ec_raw_der_inner(NULL, sk, pk, 0);
+ len_privateKey = 1 + len_of_len(len_privateKeyValue)
+ + len_privateKeyValue;
+ len_seq = len_version + len_privateKeyAlgorithm + len_privateKey;
+
+ if (dest == NULL) {
+ return 1 + len_of_len(len_seq) + len_seq;
+ } else {
+ unsigned char *buf;
+ size_t lenlen;
+
+ buf = dest;
+ *buf ++ = 0x30; /* SEQUENCE tag */
+ lenlen = br_asn1_encode_length(buf, len_seq);
+ buf += lenlen;
+
+ /* version */
+ *buf ++ = 0x02;
+ *buf ++ = 0x01;
+ *buf ++ = 0x00;
+
+ /* privateKeyAlgorithm */
+ *buf ++ = 0x30;
+ *buf ++ = (sizeof OID_ECPUBKEY) + 2 + oid[0];
+ memcpy(buf, OID_ECPUBKEY, sizeof OID_ECPUBKEY);
+ buf += sizeof OID_ECPUBKEY;
+ *buf ++ = 0x06;
+ memcpy(buf, oid, 1 + oid[0]);
+ buf += 1 + oid[0];
+
+ /* privateKey */
+ *buf ++ = 0x04;
+ buf += br_asn1_encode_length(buf, len_privateKeyValue);
+ br_encode_ec_raw_der_inner(buf, sk, pk, 0);
+
+ return 1 + lenlen + len_seq;
+ }
+}