RSA with OpenSSL

1 files changed, 422 insertions, 0 deletions

diff --git a/src/libstrongswan/plugins/openssl/openssl_rsa_private_key.c b/src/libstrongswan/plugins/openssl/openssl_rsa_private_key.c
new file mode 100644
index 000000000..efc3ba6bc
--- /dev/null
+++ b/src/libstrongswan/plugins/openssl/openssl_rsa_private_key.c
@@ -0,0 +1,422 @@
+/*
+ * Copyright (C) 2008 Tobias Brunner
+ * 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.
+ *
+ * $Id$
+ */
+
+#include "openssl_rsa_private_key.h"
+#include "openssl_rsa_public_key.h"
+
+#include <debug.h>
+
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+
+/**
+ *  Public exponent to use for key generation.
+ */
+#define PUBLIC_EXPONENT 0x10001
+
+typedef struct private_openssl_rsa_private_key_t private_openssl_rsa_private_key_t;
+
+/**
+ * Private data of a openssl_rsa_private_key_t object.
+ */
+struct private_openssl_rsa_private_key_t {
+	/**
+	 * Public interface for this signer.
+	 */
+	openssl_rsa_private_key_t public;
+	
+	/**
+	 * RSA object from OpenSSL
+	 */
+	RSA *rsa;
+
+	/**
+	 * Keyid formed as a SHA-1 hash of a privateKey object
+	 */
+	identification_t* keyid;
+
+	/**
+	 * Keyid formed as a SHA-1 hash of a privateKeyInfo object
+	 */
+	identification_t* keyid_info;
+	
+	/**
+	 * reference count
+	 */
+	refcount_t ref;	
+};
+
+/**
+ * shared functions, implemented in openssl_rsa_public_key.c
+ */
+bool openssl_rsa_public_key_build_id(RSA *rsa, identification_t **keyid,
+								 identification_t **keyid_info);
+
+
+openssl_rsa_public_key_t *openssl_rsa_public_key_create_from_n_e(BIGNUM *n, BIGNUM *e);
+
+
+/**
+ * Build an EMPSA PKCS1 signature described in PKCS#1
+ */
+static bool build_emsa_pkcs1_signature(private_openssl_rsa_private_key_t *this,
+									   int type, chunk_t data, chunk_t *signature)
+{
+	bool success = FALSE;
+	const EVP_MD *hasher = EVP_get_digestbynid(type);
+	if (!hasher)
+	{
+		return FALSE;
+	}
+	
+	EVP_MD_CTX *ctx = EVP_MD_CTX_create();
+	EVP_PKEY *key = EVP_PKEY_new();
+	if (!ctx || !key)
+	{
+		goto error;
+	}
+	
+	if (!EVP_PKEY_set1_RSA(key, this->rsa))
+	{
+		goto error;
+	}
+	
+	if (!EVP_SignInit_ex(ctx, hasher, NULL))
+	{
+		goto error;
+	}
+	
+	if (!EVP_SignUpdate(ctx, data.ptr, data.len))
+	{
+		goto error;
+	}
+	
+	*signature = chunk_alloc(RSA_size(this->rsa));
+	
+	if (!EVP_SignFinal(ctx, signature->ptr, &signature->len, key))
+	{
+		goto error;
+	}
+	
+	success = TRUE;
+	
+error:
+	if (key)
+	{
+		EVP_PKEY_free(key);
+	}
+	if (ctx)
+	{
+		EVP_MD_CTX_destroy(ctx);
+	}
+	return success;
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static key_type_t get_type(private_openssl_rsa_private_key_t *this)
+{
+	return KEY_RSA;
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static bool sign(private_openssl_rsa_private_key_t *this, signature_scheme_t scheme, 
+				 chunk_t data, chunk_t *signature)
+{
+	switch (scheme)
+	{
+		case SIGN_DEFAULT:
+			/* default is EMSA-PKCS1 using SHA1 */
+		case SIGN_RSA_EMSA_PKCS1_SHA1:
+			return build_emsa_pkcs1_signature(this, NID_sha1, data, signature);
+		case SIGN_RSA_EMSA_PKCS1_SHA256:
+			return build_emsa_pkcs1_signature(this, NID_sha256, data, signature);
+		case SIGN_RSA_EMSA_PKCS1_SHA384:
+			return build_emsa_pkcs1_signature(this, NID_sha384, data, signature);
+		case SIGN_RSA_EMSA_PKCS1_SHA512:
+			return build_emsa_pkcs1_signature(this, NID_sha512, data, signature);
+		case SIGN_RSA_EMSA_PKCS1_MD5:
+			return build_emsa_pkcs1_signature(this, NID_md5, data, signature);
+		default:
+			DBG1("signature scheme %N not supported in RSA",
+				 signature_scheme_names, scheme);
+			return FALSE;
+	}
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static bool decrypt(private_openssl_rsa_private_key_t *this,
+					chunk_t crypto, chunk_t *plain)
+{
+	DBG1("RSA private key decryption not implemented");
+	return FALSE;
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static size_t get_keysize(private_openssl_rsa_private_key_t *this)
+{
+	return RSA_size(this->rsa);
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static identification_t* get_id(private_openssl_rsa_private_key_t *this,
+								id_type_t type)
+{
+	switch (type)
+	{
+		case ID_PUBKEY_INFO_SHA1:
+			return this->keyid_info;
+		case ID_PUBKEY_SHA1:
+			return this->keyid;
+		default:
+			return NULL;
+	}
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static openssl_rsa_public_key_t* get_public_key(private_openssl_rsa_private_key_t *this)
+{
+	return openssl_rsa_public_key_create_from_n_e(this->rsa->n, this->rsa->e);
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static bool belongs_to(private_openssl_rsa_private_key_t *this, public_key_t *public)
+{
+	identification_t *keyid;
+
+	if (public->get_type(public) != KEY_RSA)
+	{
+		return FALSE;
+	}
+	keyid = public->get_id(public, ID_PUBKEY_SHA1);
+	if (keyid && keyid->equals(keyid, this->keyid))
+	{
+		return TRUE;
+	}
+	keyid = public->get_id(public, ID_PUBKEY_INFO_SHA1);
+	if (keyid && keyid->equals(keyid, this->keyid_info))
+	{
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * Implementation of private_key_t.get_encoding.
+ */
+static chunk_t get_encoding(private_openssl_rsa_private_key_t *this)
+{
+	chunk_t enc = chunk_alloc(i2d_RSAPrivateKey(this->rsa, NULL));
+	u_char *p = enc.ptr;
+	i2d_RSAPrivateKey(this->rsa, &p);
+	return enc;
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static private_openssl_rsa_private_key_t* get_ref(private_openssl_rsa_private_key_t *this)
+{
+	ref_get(&this->ref);
+	return this;
+
+}
+
+/**
+ * Implementation of openssl_rsa_private_key.destroy.
+ */
+static void destroy(private_openssl_rsa_private_key_t *this)
+{
+	if (ref_put(&this->ref))
+	{
+		if (this->rsa)
+		{
+			RSA_free(this->rsa);
+		}
+		DESTROY_IF(this->keyid);
+		DESTROY_IF(this->keyid_info);
+		free(this);
+	}
+}
+
+/**
+ * Internal generic constructor
+ */
+static private_openssl_rsa_private_key_t *openssl_rsa_private_key_create_empty(void)
+{
+	private_openssl_rsa_private_key_t *this = malloc_thing(private_openssl_rsa_private_key_t);
+	
+	this->public.interface.get_type = (key_type_t (*)(private_key_t *this))get_type;
+	this->public.interface.sign = (bool (*)(private_key_t *this, signature_scheme_t scheme, chunk_t data, chunk_t *signature))sign;
+	this->public.interface.decrypt = (bool (*)(private_key_t *this, chunk_t crypto, chunk_t *plain))decrypt;
+	this->public.interface.get_keysize = (size_t (*) (private_key_t *this))get_keysize;
+	this->public.interface.get_id = (identification_t* (*) (private_key_t *this,id_type_t))get_id;
+	this->public.interface.get_public_key = (public_key_t* (*)(private_key_t *this))get_public_key;
+	this->public.interface.belongs_to = (bool (*) (private_key_t *this, public_key_t *public))belongs_to;
+	this->public.interface.get_encoding = (chunk_t(*)(private_key_t*))get_encoding;
+	this->public.interface.get_ref = (private_key_t* (*)(private_key_t *this))get_ref;
+	this->public.interface.destroy = (void (*)(private_key_t *this))destroy;
+	
+	this->keyid = NULL;
+	this->keyid_info = NULL;
+	this->ref = 1;
+	
+	return this;
+}
+
+/**
+ * Generate an RSA key of specified key size
+ */
+static openssl_rsa_private_key_t *generate(size_t key_size)
+{
+	private_openssl_rsa_private_key_t *this = openssl_rsa_private_key_create_empty();
+	
+	this->rsa = RSA_generate_key(key_size, PUBLIC_EXPONENT, NULL, NULL);
+	
+	if (!openssl_rsa_public_key_build_id(this->rsa, &this->keyid, &this->keyid_info))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	return &this->public;
+}
+
+/**
+ * load private key from an ASN1 encoded blob
+ */
+static openssl_rsa_private_key_t *load(chunk_t blob)
+{
+	u_char *p = blob.ptr;
+	private_openssl_rsa_private_key_t *this = openssl_rsa_private_key_create_empty();
+	
+	this->rsa = d2i_RSAPrivateKey(NULL, (const u_char**)&p, blob.len);
+	
+	chunk_clear(&blob);
+
+	if (!this->rsa)
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	if (!openssl_rsa_public_key_build_id(this->rsa, &this->keyid, &this->keyid_info))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	if (!RSA_check_key(this->rsa))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	return &this->public;
+}
+
+typedef struct private_builder_t private_builder_t;
+/**
+ * Builder implementation for key loading/generation
+ */
+struct private_builder_t {
+	/** implements the builder interface */
+	builder_t public;
+	/** loaded/generated private key */
+	openssl_rsa_private_key_t *key;
+};
+
+/**
+ * Implementation of builder_t.build
+ */
+static openssl_rsa_private_key_t *build(private_builder_t *this)
+{
+	openssl_rsa_private_key_t *key = this->key;
+	
+	free(this);
+	return key;
+}
+
+/**
+ * Implementation of builder_t.add
+ */
+static void add(private_builder_t *this, builder_part_t part, ...)
+{
+	va_list args;
+	
+	if (this->key)
+	{
+		DBG1("ignoring surplus build part %N", builder_part_names, part);
+		return;
+	}
+	
+	switch (part)
+	{
+		case BUILD_BLOB_ASN1_DER:
+		{
+			va_start(args, part);
+			this->key = load(va_arg(args, chunk_t));
+			va_end(args);
+			break;
+		}		
+		case BUILD_KEY_SIZE:
+		{
+			va_start(args, part);
+			this->key = generate(va_arg(args, u_int));
+			va_end(args);
+			break;
+		}
+		default:
+			DBG1("ignoring unsupported build part %N", builder_part_names, part);
+			break;
+	}
+}
+
+/**
+ * Builder construction function
+ */
+builder_t *openssl_rsa_private_key_builder(key_type_t type)
+{
+	private_builder_t *this;
+	
+	if (type != KEY_RSA)
+	{
+		return NULL;
+	}
+	
+	this = malloc_thing(private_builder_t);
+	
+	this->key = NULL;
+	this->public.add = (void(*)(builder_t *this, builder_part_t part, ...))add;
+	this->public.build = (void*(*)(builder_t *this))build;
+	
+	return &this->public;
+}
+