pkcs15-pubkey.c - return EC_POINT as OCTET STRING by default

 On branch X25519-improvements-2
 Changes to be committed:
	modified:   libopensc/pkcs15-pubkey.c

src/libopensc/pkcs15-pubkey.c

@@ -541,16 +541,16 @@ static struct sc_asn1_entry c_asn1_gostr3410_pub_coefficients[C_ASN1_GOSTR3410_P
 /* accept either */
 #define C_ASN1_EC_POINTQ_SIZE 3
 static struct sc_asn1_entry c_asn1_ec_pointQ[C_ASN1_EC_POINTQ_SIZE] = {
-		{ "ecpointQ",    SC_ASN1_BIT_STRING_NI, SC_ASN1_TAG_BIT_STRING,   SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
 		{ "ecpointQ-OS", SC_ASN1_OCTET_STRING,  SC_ASN1_TAG_OCTET_STRING, SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
+		{ "ecpointQ-BS", SC_ASN1_BIT_STRING_NI, SC_ASN1_TAG_BIT_STRING,   SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
 		{ NULL, 0, 0, 0, NULL, NULL }
 };
 
 /*  See RFC8410 */
 #define C_ASN1_EDDSA_PUBKEY_SIZE 3
 static struct sc_asn1_entry c_asn1_eddsa_pubkey[C_ASN1_EDDSA_PUBKEY_SIZE] = {
-		{ "ecpointQ", SC_ASN1_BIT_STRING_NI,    SC_ASN1_TAG_BIT_STRING,	  SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
 		{ "ecpointQ-OS", SC_ASN1_OCTET_STRING,  SC_ASN1_TAG_OCTET_STRING, SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
+		{ "ecpointQ-BS", SC_ASN1_BIT_STRING_NI, SC_ASN1_TAG_BIT_STRING,	  SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
 		{ NULL, 0, 0, 0, NULL, NULL }
 };
 // clang-format on
@@ -665,6 +665,10 @@ sc_pkcs15_decode_pubkey_ec(sc_context_t *ctx,
 		LOG_FUNC_RETURN(ctx, SC_ERROR_INVALID_ASN1_OBJECT);
 	}
 
+	/* if from bit string */
+	if (asn1_ec_pointQ[1].flags & SC_ASN1_PRESENT)
+		ecpoint_len = (ecpoint_len + 7) / 8;
+
 	if (*ecpoint_data != 0x04) {
 		free(ecpoint_data);
 		LOG_TEST_RET(ctx, SC_ERROR_NOT_SUPPORTED, "Supported only uncompressed EC pointQ value");
@@ -690,7 +694,7 @@ sc_pkcs15_encode_pubkey_ec(sc_context_t *ctx, struct sc_pkcs15_pubkey_ec *key,
 	 * But some PKCS11 modules define a CKA_VALUE for a public key 
 	 * and PKCS11 says ECPOINT is encoded as "DER-encoding of ANSI X9.62 ECPoint value Q"  
 	 * But ANSI X9.62 (early draft at least) says encode as BIT STRING
-	 * IETF encodes in SubjectPublicKeyInfo (SPKI) in BIT STRING
+	 * IETF encodes it in SubjectPublicKeyInfo (SPKI) in BIT STRING
 	 * PKCS11 V3 does add CKA_PUBLIC_KEY_INFO as SPKI
 	 * For now return as OCTET STRING.
 	 */
@@ -699,11 +703,11 @@ sc_pkcs15_encode_pubkey_ec(sc_context_t *ctx, struct sc_pkcs15_pubkey_ec *key,
 	LOG_FUNC_CALLED(ctx);
 	sc_copy_asn1_entry(c_asn1_ec_pointQ, asn1_ec_pointQ);
 
-	if (gdb_test == 1) {
-		key_len = key->ecpointQ.len * 8; /* encode in bit string */
+	if (gdb_test == 0) {
+		key_len = key->ecpointQ.len;
 		sc_format_asn1_entry(asn1_ec_pointQ + 0, key->ecpointQ.value, &key_len, 1);
 	} else {
-		key_len = key->ecpointQ.len;
+		key_len = key->ecpointQ.len * 8; /* encode in bit string */
 		sc_format_asn1_entry(asn1_ec_pointQ + 1, key->ecpointQ.value, &key_len, 1);
 	}
 
@@ -736,6 +740,9 @@ sc_pkcs15_decode_pubkey_eddsa(sc_context_t *ctx,
 		LOG_FUNC_RETURN(ctx, SC_ERROR_INVALID_ASN1_OBJECT);
 	}
 
+	if ( asn1_ec_pointQ[1].flags & SC_ASN1_PRESENT)
+		ecpoint_len = (ecpoint_len  + 7) /8;
+
 	key->ecpointQ.len = ecpoint_len;
 	key->ecpointQ.value = ecpoint_data;
 	key->params.field_length = ecpoint_len * 8;