tls_openssl.c

IEEE 802.11a/b/g 服务器端AP

/*
 * WPA Supplicant / SSL/TLS interface functions for openssl
 * Copyright (c) 2004-2007, Jouni Malinen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#ifndef CONFIG_SMARTCARD
#ifndef OPENSSL_NO_ENGINE
#define OPENSSL_NO_ENGINE
#endif
#endif

#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/pkcs12.h>
#include <openssl/x509v3.h>
#ifndef OPENSSL_NO_ENGINE
#include <openssl/engine.h>
#endif /* OPENSSL_NO_ENGINE */

#include "common.h"
#include "tls.h"

#if OPENSSL_VERSION_NUMBER >= 0x0090800fL
#define OPENSSL_d2i_TYPE const unsigned char **
#else
#define OPENSSL_d2i_TYPE unsigned char **
#endif

static int tls_openssl_ref_count = 0;

struct tls_connection {
	SSL *ssl;
	BIO *ssl_in, *ssl_out;
#ifndef OPENSSL_NO_ENGINE
	ENGINE *engine;        /* functional reference to the engine */
	EVP_PKEY *private_key; /* the private key if using engine */
#endif /* OPENSSL_NO_ENGINE */
	char *subject_match, *altsubject_match;
	int read_alerts, write_alerts, failed;

	tls_session_ticket_cb session_ticket_cb;
	void *session_ticket_cb_ctx;

	/* SessionTicket received from OpenSSL hello_extension_cb (server) */
	u8 *session_ticket;
	size_t session_ticket_len;
};


#ifdef CONFIG_NO_STDOUT_DEBUG

static void _tls_show_errors(void)
{
	unsigned long err;

	while ((err = ERR_get_error())) {
		/* Just ignore the errors, since stdout is disabled */
	}
}
#define tls_show_errors(l, f, t) _tls_show_errors()

#else /* CONFIG_NO_STDOUT_DEBUG */

static void tls_show_errors(int level, const char *func, const char *txt)
{
	unsigned long err;

	wpa_printf(level, "OpenSSL: %s - %s %s",
		   func, txt, ERR_error_string(ERR_get_error(), NULL));

	while ((err = ERR_get_error())) {
		wpa_printf(MSG_INFO, "OpenSSL: pending error: %s",
			   ERR_error_string(err, NULL));
	}
}

#endif /* CONFIG_NO_STDOUT_DEBUG */


#ifdef CONFIG_NATIVE_WINDOWS

/* Windows CryptoAPI and access to certificate stores */
#include <wincrypt.h>

#ifdef __MINGW32_VERSION
/*
 * MinGW does not yet include all the needed definitions for CryptoAPI, so
 * define here whatever extra is needed.
 */
#define CALG_SSL3_SHAMD5 (ALG_CLASS_HASH | ALG_TYPE_ANY | ALG_SID_SSL3SHAMD5)
#define CERT_SYSTEM_STORE_CURRENT_USER (1 << 16)
#define CERT_STORE_READONLY_FLAG 0x00008000
#define CERT_STORE_OPEN_EXISTING_FLAG 0x00004000
#define CRYPT_ACQUIRE_COMPARE_KEY_FLAG 0x00000004

static BOOL WINAPI
(*CryptAcquireCertificatePrivateKey)(PCCERT_CONTEXT pCert, DWORD dwFlags,
				     void *pvReserved, HCRYPTPROV *phCryptProv,
				     DWORD *pdwKeySpec, BOOL *pfCallerFreeProv)
= NULL; /* to be loaded from crypt32.dll */

static PCCERT_CONTEXT WINAPI
(*CertEnumCertificatesInStore)(HCERTSTORE hCertStore,
			       PCCERT_CONTEXT pPrevCertContext)
= NULL; /* to be loaded from crypt32.dll */

static int mingw_load_crypto_func(void)
{
	HINSTANCE dll;

	/* MinGW does not yet have full CryptoAPI support, so load the needed
	 * function here. */

	if (CryptAcquireCertificatePrivateKey)
		return 0;

	dll = LoadLibrary("crypt32");
	if (dll == NULL) {
		wpa_printf(MSG_DEBUG, "CryptoAPI: Could not load crypt32 "
			   "library");
		return -1;
	}

	CryptAcquireCertificatePrivateKey = GetProcAddress(
		dll, "CryptAcquireCertificatePrivateKey");
	if (CryptAcquireCertificatePrivateKey == NULL) {
		wpa_printf(MSG_DEBUG, "CryptoAPI: Could not get "
			   "CryptAcquireCertificatePrivateKey() address from "
			   "crypt32 library");
		return -1;
	}

	CertEnumCertificatesInStore = (void *) GetProcAddress(
		dll, "CertEnumCertificatesInStore");
	if (CertEnumCertificatesInStore == NULL) {
		wpa_printf(MSG_DEBUG, "CryptoAPI: Could not get "
			   "CertEnumCertificatesInStore() address from "
			   "crypt32 library");
		return -1;
	}

	return 0;
}

#else /* __MINGW32_VERSION */

static int mingw_load_crypto_func(void)
{
	return 0;
}

#endif /* __MINGW32_VERSION */


struct cryptoapi_rsa_data {
	const CERT_CONTEXT *cert;
	HCRYPTPROV crypt_prov;
	DWORD key_spec;
	BOOL free_crypt_prov;
};


static void cryptoapi_error(const char *msg)
{
	wpa_printf(MSG_INFO, "CryptoAPI: %s; err=%u",
		   msg, (unsigned int) GetLastError());
}


static int cryptoapi_rsa_pub_enc(int flen, const unsigned char *from,
				 unsigned char *to, RSA *rsa, int padding)
{
	wpa_printf(MSG_DEBUG, "%s - not implemented", __func__);
	return 0;
}


static int cryptoapi_rsa_pub_dec(int flen, const unsigned char *from,
				 unsigned char *to, RSA *rsa, int padding)
{
	wpa_printf(MSG_DEBUG, "%s - not implemented", __func__);
	return 0;
}


static int cryptoapi_rsa_priv_enc(int flen, const unsigned char *from,
				  unsigned char *to, RSA *rsa, int padding)
{
	struct cryptoapi_rsa_data *priv =
		(struct cryptoapi_rsa_data *) rsa->meth->app_data;
	HCRYPTHASH hash;
	DWORD hash_size, len, i;
	unsigned char *buf = NULL;
	int ret = 0;

	if (priv == NULL) {
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
		       ERR_R_PASSED_NULL_PARAMETER);
		return 0;
	}

	if (padding != RSA_PKCS1_PADDING) {
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
		       RSA_R_UNKNOWN_PADDING_TYPE);
		return 0;
	}

	if (flen != 16 /* MD5 */ + 20 /* SHA-1 */) {
		wpa_printf(MSG_INFO, "%s - only MD5-SHA1 hash supported",
			   __func__);
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
		       RSA_R_INVALID_MESSAGE_LENGTH);
		return 0;
	}

	if (!CryptCreateHash(priv->crypt_prov, CALG_SSL3_SHAMD5, 0, 0, &hash))
	{
		cryptoapi_error("CryptCreateHash failed");
		return 0;
	}

	len = sizeof(hash_size);
	if (!CryptGetHashParam(hash, HP_HASHSIZE, (BYTE *) &hash_size, &len,
			       0)) {
		cryptoapi_error("CryptGetHashParam failed");
		goto err;
	}

	if ((int) hash_size != flen) {
		wpa_printf(MSG_INFO, "CryptoAPI: Invalid hash size (%u != %d)",
			   (unsigned) hash_size, flen);
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
		       RSA_R_INVALID_MESSAGE_LENGTH);
		goto err;
	}
	if (!CryptSetHashParam(hash, HP_HASHVAL, (BYTE * ) from, 0)) {
		cryptoapi_error("CryptSetHashParam failed");
		goto err;
	}

	len = RSA_size(rsa);
	buf = os_malloc(len);
	if (buf == NULL) {
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
		goto err;
	}

	if (!CryptSignHash(hash, priv->key_spec, NULL, 0, buf, &len)) {
		cryptoapi_error("CryptSignHash failed");
		goto err;
	}

	for (i = 0; i < len; i++)
		to[i] = buf[len - i - 1];
	ret = len;

err:
	os_free(buf);
	CryptDestroyHash(hash);

	return ret;
}


static int cryptoapi_rsa_priv_dec(int flen, const unsigned char *from,
				  unsigned char *to, RSA *rsa, int padding)
{
	wpa_printf(MSG_DEBUG, "%s - not implemented", __func__);
	return 0;
}


static void cryptoapi_free_data(struct cryptoapi_rsa_data *priv)
{
	if (priv == NULL)
		return;
	if (priv->crypt_prov && priv->free_crypt_prov)
		CryptReleaseContext(priv->crypt_prov, 0);
	if (priv->cert)
		CertFreeCertificateContext(priv->cert);
	os_free(priv);
}


static int cryptoapi_finish(RSA *rsa)
{
	cryptoapi_free_data((struct cryptoapi_rsa_data *) rsa->meth->app_data);
	os_free((void *) rsa->meth);
	rsa->meth = NULL;
	return 1;
}


static const CERT_CONTEXT * cryptoapi_find_cert(const char *name, DWORD store)
{
	HCERTSTORE cs;
	const CERT_CONTEXT *ret = NULL;

	cs = CertOpenStore((LPCSTR) CERT_STORE_PROV_SYSTEM, 0, 0,
			   store | CERT_STORE_OPEN_EXISTING_FLAG |
			   CERT_STORE_READONLY_FLAG, L"MY");
	if (cs == NULL) {
		cryptoapi_error("Failed to open 'My system store'");
		return NULL;
	}

	if (strncmp(name, "cert://", 7) == 0) {
		unsigned short wbuf[255];
		MultiByteToWideChar(CP_ACP, 0, name + 7, -1, wbuf, 255);
		ret = CertFindCertificateInStore(cs, X509_ASN_ENCODING |
						 PKCS_7_ASN_ENCODING,
						 0, CERT_FIND_SUBJECT_STR,
						 wbuf, NULL);
	} else if (strncmp(name, "hash://", 7) == 0) {
		CRYPT_HASH_BLOB blob;
		int len;
		const char *hash = name + 7;
		unsigned char *buf;

		len = os_strlen(hash) / 2;
		buf = os_malloc(len);
		if (buf && hexstr2bin(hash, buf, len) == 0) {
			blob.cbData = len;
			blob.pbData = buf;
			ret = CertFindCertificateInStore(cs,
							 X509_ASN_ENCODING |
							 PKCS_7_ASN_ENCODING,
							 0, CERT_FIND_HASH,
							 &blob, NULL);
		}
		os_free(buf);
	}

	CertCloseStore(cs, 0);

	return ret;
}


static int tls_cryptoapi_cert(SSL *ssl, const char *name)
{
	X509 *cert = NULL;
	RSA *rsa = NULL, *pub_rsa;
	struct cryptoapi_rsa_data *priv;
	RSA_METHOD *rsa_meth;

	if (name == NULL ||
	    (strncmp(name, "cert://", 7) != 0 &&
	     strncmp(name, "hash://", 7) != 0))
		return -1;

	priv = os_zalloc(sizeof(*priv));
	rsa_meth = os_zalloc(sizeof(*rsa_meth));
	if (priv == NULL || rsa_meth == NULL) {
		wpa_printf(MSG_WARNING, "CryptoAPI: Failed to allocate memory "
			   "for CryptoAPI RSA method");
		os_free(priv);
		os_free(rsa_meth);
		return -1;
	}

	priv->cert = cryptoapi_find_cert(name, CERT_SYSTEM_STORE_CURRENT_USER);
	if (priv->cert == NULL) {
		priv->cert = cryptoapi_find_cert(
			name, CERT_SYSTEM_STORE_LOCAL_MACHINE);
	}
	if (priv->cert == NULL) {
		wpa_printf(MSG_INFO, "CryptoAPI: Could not find certificate "
			   "'%s'", name);
		goto err;
	}

	cert = d2i_X509(NULL, (OPENSSL_d2i_TYPE) &priv->cert->pbCertEncoded,
			priv->cert->cbCertEncoded);
	if (cert == NULL) {
		wpa_printf(MSG_INFO, "CryptoAPI: Could not process X509 DER "
			   "encoding");
		goto err;
	}

	if (mingw_load_crypto_func())
		goto err;

	if (!CryptAcquireCertificatePrivateKey(priv->cert,
					       CRYPT_ACQUIRE_COMPARE_KEY_FLAG,
					       NULL, &priv->crypt_prov,
					       &priv->key_spec,
					       &priv->free_crypt_prov)) {
		cryptoapi_error("Failed to acquire a private key for the "
				"certificate");
		goto err;
	}

	rsa_meth->name = "Microsoft CryptoAPI RSA Method";
	rsa_meth->rsa_pub_enc = cryptoapi_rsa_pub_enc;
	rsa_meth->rsa_pub_dec = cryptoapi_rsa_pub_dec;
	rsa_meth->rsa_priv_enc = cryptoapi_rsa_priv_enc;
	rsa_meth->rsa_priv_dec = cryptoapi_rsa_priv_dec;
	rsa_meth->finish = cryptoapi_finish;
	rsa_meth->flags = RSA_METHOD_FLAG_NO_CHECK;
	rsa_meth->app_data = (char *) priv;

	rsa = RSA_new();
	if (rsa == NULL) {
		SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE,
		       ERR_R_MALLOC_FAILURE);
		goto err;
	}

	if (!SSL_use_certificate(ssl, cert)) {
		RSA_free(rsa);
		rsa = NULL;
		goto err;
	}
	pub_rsa = cert->cert_info->key->pkey->pkey.rsa;
	X509_free(cert);
	cert = NULL;

	rsa->n = BN_dup(pub_rsa->n);
	rsa->e = BN_dup(pub_rsa->e);
	if (!RSA_set_method(rsa, rsa_meth))
		goto err;

	if (!SSL_use_RSAPrivateKey(ssl, rsa))
		goto err;
	RSA_free(rsa);

	return 0;

err:
	if (cert)
		X509_free(cert);
	if (rsa)
		RSA_free(rsa);
	else {
		os_free(rsa_meth);
		cryptoapi_free_data(priv);
	}
	return -1;
}


static int tls_cryptoapi_ca_cert(SSL_CTX *ssl_ctx, SSL *ssl, const char *name)
{
	HCERTSTORE cs;
	PCCERT_CONTEXT ctx = NULL;
	X509 *cert;
	char buf[128];
	const char *store;
#ifdef UNICODE
	WCHAR *wstore;
#endif /* UNICODE */

	if (mingw_load_crypto_func())
		return -1;

	if (name == NULL || strncmp(name, "cert_store://", 13) != 0)
		return -1;

	store = name + 13;
#ifdef UNICODE
	wstore = os_malloc((os_strlen(store) + 1) * sizeof(WCHAR));
	if (wstore == NULL)
		return -1;
	wsprintf(wstore, L"%S", store);
	cs = CertOpenSystemStore(0, wstore);
	os_free(wstore);
#else /* UNICODE */
	cs = CertOpenSystemStore(0, store);
#endif /* UNICODE */
	if (cs == NULL) {
		wpa_printf(MSG_DEBUG, "%s: failed to open system cert store "
			   "'%s': error=%d", __func__, store,
			   (int) GetLastError());
		return -1;
	}

	while ((ctx = CertEnumCertificatesInStore(cs, ctx))) {
		cert = d2i_X509(NULL, (OPENSSL_d2i_TYPE) &ctx->pbCertEncoded,
				ctx->cbCertEncoded);
		if (cert == NULL) {
			wpa_printf(MSG_INFO, "CryptoAPI: Could not process "
				   "X509 DER encoding for CA cert");
			continue;
		}

		X509_NAME_oneline(X509_get_subject_name(cert), buf,
				  sizeof(buf));
		wpa_printf(MSG_DEBUG, "OpenSSL: Loaded CA certificate for "
			   "system certificate store: subject='%s'", buf);

		if (!X509_STORE_add_cert(ssl_ctx->cert_store, cert)) {
			tls_show_errors(MSG_WARNING, __func__,
					"Failed to add ca_cert to OpenSSL "
					"certificate store");
		}

		X509_free(cert);
	}

	if (!CertCloseStore(cs, 0)) {
		wpa_printf(MSG_DEBUG, "%s: failed to close system cert store "
			   "'%s': error=%d", __func__, name + 13,
			   (int) GetLastError());
	}

	return 0;
}


#else /* CONFIG_NATIVE_WINDOWS */

static int tls_cryptoapi_cert(SSL *ssl, const char *name)
{
	return -1;
}

#endif /* CONFIG_NATIVE_WINDOWS */


static void ssl_info_cb(const SSL *ssl, int where, int ret)
{