openssl: Add support for Ed25519/Ed448

2018-11-30 15:35:01 +01:00
parent d222699c78
commit cbf07ab5b0
7 changed files with 800 additions and 13 deletions
@@ -0,0 +1,356 @@
+/*
+ * Copyright (C) 2018 Tobias Brunner
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include <openssl/evp.h>
+
+#if OPENSSL_VERSION_NUMBER >= 0x1010100fL && !defined(OPENSSL_NO_EC)
+
+#include "openssl_ed_private_key.h"
+
+#include <utils/debug.h>
+
+typedef struct private_private_key_t private_private_key_t;
+
+/**
+ * Private data
+ */
+struct private_private_key_t {
+
+	/**
+	 * Public interface
+	 */
+	private_key_t public;
+
+	/**
+	 * Key object
+	 */
+	EVP_PKEY *key;
+
+	/**
+	 * Key type
+	 */
+	key_type_t type;
+
+	/**
+	 * TRUE if the key is from an OpenSSL ENGINE and might not be readable
+	 */
+	bool engine;
+
+	/**
+	 * reference count
+	 */
+	refcount_t ref;
+};
+
+/**
+ * We can't include asn1.h, declare function prototype directly
+ */
+int asn1_unwrap(chunk_t*, chunk_t*);
+
+/* from ed public key */
+int openssl_ed_key_type(key_type_t type);
+int openssl_ed_keysize(key_type_t type);
+bool openssl_ed_fingerprint(EVP_PKEY *key, cred_encoding_type_t type, chunk_t *fp);
+
+METHOD(private_key_t, sign, bool,
+	private_private_key_t *this, signature_scheme_t scheme,
+	void *params, chunk_t data, chunk_t *signature)
+{
+	EVP_MD_CTX *ctx;
+	bool success = FALSE;
+
+	if ((this->type == KEY_ED25519 && scheme != SIGN_ED25519) ||
+		(this->type == KEY_ED448 && scheme != SIGN_ED448))
+	{
+		DBG1(DBG_LIB, "signature scheme %N not supported by %N key",
+			 signature_scheme_names, scheme, key_type_names, this->type);
+		return FALSE;
+	}
+
+	ctx = EVP_MD_CTX_new();
+	if (!ctx ||
+		EVP_DigestSignInit(ctx, NULL, NULL, NULL, this->key) <= 0)
+	{
+		goto error;
+	}
+
+	if (EVP_DigestSign(ctx, NULL, &signature->len, data.ptr, data.len) <= 0)
+	{
+		goto error;
+	}
+
+	*signature = chunk_alloc(signature->len);
+
+	if (EVP_DigestSign(ctx, signature->ptr, &signature->len,
+					   data.ptr, data.len) <= 0)
+	{
+		goto error;
+	}
+
+	success = TRUE;
+
+error:
+	EVP_MD_CTX_free(ctx);
+	return success;
+}
+
+METHOD(private_key_t, decrypt, bool,
+	private_private_key_t *this, encryption_scheme_t scheme,
+	chunk_t crypto, chunk_t *plain)
+{
+	DBG1(DBG_LIB, "EdDSA private key decryption not implemented");
+	return FALSE;
+}
+
+METHOD(private_key_t, get_keysize, int,
+	private_private_key_t *this)
+{
+	return openssl_ed_keysize(this->type);
+}
+
+METHOD(private_key_t, get_type, key_type_t,
+	private_private_key_t *this)
+{
+	return this->type;
+}
+
+METHOD(private_key_t, get_public_key, public_key_t*,
+	private_private_key_t *this)
+{
+	public_key_t *public;
+	chunk_t key;
+
+	if (!EVP_PKEY_get_raw_public_key(this->key, NULL, &key.len))
+	{
+		return FALSE;
+	}
+	key = chunk_alloca(key.len);
+	if (!EVP_PKEY_get_raw_public_key(this->key, key.ptr, &key.len))
+	{
+		return FALSE;
+	}
+	public = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, this->type,
+								BUILD_EDDSA_PUB, key, BUILD_END);
+	return public;
+}
+
+METHOD(private_key_t, get_fingerprint, bool,
+	private_private_key_t *this, cred_encoding_type_t type,
+	chunk_t *fingerprint)
+{
+	return openssl_ed_fingerprint(this->key, type, fingerprint);
+}
+
+METHOD(private_key_t, get_encoding, bool,
+	private_private_key_t *this, cred_encoding_type_t type, chunk_t *encoding)
+{
+	u_char *p;
+
+	if (this->engine)
+	{
+		return FALSE;
+	}
+
+	switch (type)
+	{
+		case PRIVKEY_ASN1_DER:
+		case PRIVKEY_PEM:
+		{
+			bool success = TRUE;
+
+			*encoding = chunk_alloc(i2d_PrivateKey(this->key, NULL));
+			p = encoding->ptr;
+			i2d_PrivateKey(this->key, &p);
+
+			if (type == PRIVKEY_PEM)
+			{
+				chunk_t asn1_encoding = *encoding;
+
+				success = lib->encoding->encode(lib->encoding, PRIVKEY_PEM,
+								NULL, encoding, CRED_PART_EDDSA_PRIV_ASN1_DER,
+								asn1_encoding, CRED_PART_END);
+				chunk_clear(&asn1_encoding);
+			}
+			return success;
+		}
+		default:
+			return FALSE;
+	}
+}
+
+METHOD(private_key_t, get_ref, private_key_t*,
+	private_private_key_t *this)
+{
+	ref_get(&this->ref);
+	return &this->public;
+}
+
+METHOD(private_key_t, destroy, void,
+	private_private_key_t *this)
+{
+	if (ref_put(&this->ref))
+	{
+		lib->encoding->clear_cache(lib->encoding, this->key);
+		EVP_PKEY_free(this->key);
+		free(this);
+	}
+}
+
+/**
+ * Internal generic constructor
+ */
+static private_private_key_t *create_internal(key_type_t type, EVP_PKEY *key)
+{
+	private_private_key_t *this;
+
+	INIT(this,
+		.public = {
+			.get_type = _get_type,
+			.sign = _sign,
+			.decrypt = _decrypt,
+			.get_keysize = _get_keysize,
+			.get_public_key = _get_public_key,
+			.equals = private_key_equals,
+			.belongs_to = private_key_belongs_to,
+			.get_fingerprint = _get_fingerprint,
+			.has_fingerprint = private_key_has_fingerprint,
+			.get_encoding = _get_encoding,
+			.get_ref = _get_ref,
+			.destroy = _destroy,
+		},
+		.type = type,
+		.key = key,
+		.ref = 1,
+	);
+
+	return this;
+}
+
+/*
+ * Described in header
+ */
+private_key_t *openssl_ed_private_key_create(EVP_PKEY *key, bool engine)
+{
+	private_private_key_t *this;
+	key_type_t type;
+
+	switch (EVP_PKEY_base_id(key))
+	{
+		case EVP_PKEY_X25519:
+			type = KEY_ED25519;
+			break;
+		case EVP_PKEY_X448:
+			type = KEY_ED448;
+			break;
+		default:
+			EVP_PKEY_free(key);
+			return NULL;
+	}
+
+	this = create_internal(type, key);
+	this->engine = engine;
+	return &this->public;
+}
+
+/*
+ * Described in header
+ */
+private_key_t *openssl_ed_private_key_gen(key_type_t type, va_list args)
+{
+	private_private_key_t *this;
+	EVP_PKEY_CTX *ctx;
+	EVP_PKEY *key = NULL;
+
+	while (TRUE)
+	{
+		switch (va_arg(args, builder_part_t))
+		{
+			case BUILD_KEY_SIZE:
+				/* just ignore the key size */
+				va_arg(args, u_int);
+				continue;
+			case BUILD_END:
+				break;
+			default:
+				return NULL;
+		}
+		break;
+	}
+
+	ctx = EVP_PKEY_CTX_new_id(openssl_ed_key_type(type), NULL);
+	if (!ctx ||
+		EVP_PKEY_keygen_init(ctx) <= 0 ||
+		EVP_PKEY_keygen(ctx, &key) <= 0)
+	{
+		DBG1(DBG_LIB, "generating %N key failed", key_type_names, type);
+		EVP_PKEY_CTX_free(ctx);
+		return NULL;
+	}
+	EVP_PKEY_CTX_free(ctx);
+
+	this = create_internal(type, key);
+	return &this->public;
+}
+
+/*
+ * Described in header
+ */
+private_key_t *openssl_ed_private_key_load(key_type_t type, va_list args)
+{
+	private_private_key_t *this;
+	chunk_t blob = chunk_empty, priv = chunk_empty;
+	EVP_PKEY *key = NULL;
+
+	while (TRUE)
+	{
+		switch (va_arg(args, builder_part_t))
+		{
+			case BUILD_BLOB_ASN1_DER:
+				blob = va_arg(args, chunk_t);
+				continue;
+			case BUILD_EDDSA_PRIV_ASN1_DER:
+				priv = va_arg(args, chunk_t);
+				continue;
+			case BUILD_END:
+				break;
+			default:
+				return NULL;
+		}
+		break;
+	}
+
+	if (priv.len)
+	{
+		/* unwrap octet string */
+		if (asn1_unwrap(&priv, &priv) == 0x04 && priv.len)
+		{
+			key = EVP_PKEY_new_raw_private_key(openssl_ed_key_type(type), NULL,
+											   priv.ptr, priv.len);
+		}
+	}
+	else if (blob.len)
+	{
+		key = d2i_PrivateKey(openssl_ed_key_type(type), NULL,
+							 (const u_char**)&blob.ptr, blob.len);
+	}
+	if (!key)
+	{
+		return NULL;
+	}
+	this = create_internal(type, key);
+	return &this->public;
+}
+
+#endif /* OPENSSL_NO_ECDSA */