SChannel/WinSSL: Implement public key pinning (e178fbd4) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP curl

docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3

+5 −1

Original line number	Diff line number	Diff line
		@@ -5,7 +5,7 @@
		.\" * \| (__\| \|_\| \| _ <\| \|___
		.\" * \___\|\___/\|_\| \_\_____\|
		.\" *
		.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
		.\" * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
		.\" *
		.\" * This software is licensed as described in the file COPYING, which
		.\" * you should have received as part of this distribution. The terms
		@@ -105,6 +105,8 @@ PEM/DER support:

		7.54.1: SecureTransport/DarwinSSL on macOS 10.7+/iOS 10+

		7.58.1: SChannel/WinSSL

		sha256 support:

		7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL/CyaSSL
		@@ -115,6 +117,8 @@ sha256 support:

		7.54.1: SecureTransport/DarwinSSL on macOS 10.7+/iOS 10+

		7.58.1: SChannel/WinSSL Windows XP SP3+

		Other SSL backends not supported.
		.SH RETURN VALUE
		Returns CURLE_OK if TLS enabled, CURLE_UNKNOWN_OPTION if not, or

lib/vtls/schannel.c

+140 −3

Original line number	Diff line number	Diff line
		@@ -7,7 +7,7 @@
		*
		* Copyright (C) 2012 - 2016, Marc Hoersken, <info@marc-hoersken.de>
		* Copyright (C) 2012, Mark Salisbury, <mark.salisbury@hp.com>
		* Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
		* Copyright (C) 2012 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
		*
		* This software is licensed as described in the file COPYING, which
		* you should have received as part of this distribution. The terms
		@@ -129,6 +129,10 @@
		* #define failf(x, y, ...) printf(y, __VA_ARGS__)
		*/

		#ifndef CALG_SHA_256
		# define CALG_SHA_256 0x0000800c
		#endif

		/* Structs to store Schannel handles */
		struct curl_schannel_cred {
		CredHandle cred_handle;
		@@ -165,6 +169,9 @@ struct ssl_backend_data {
		static Curl_recv schannel_recv;
		static Curl_send schannel_send;

		static CURLcode pkp_pin_peer_pubkey(struct connectdata *conn, int sockindex,
		const char *pinnedpubkey);

		#ifdef _WIN32_WCE
		static CURLcode verify_certificate(struct connectdata *conn, int sockindex);
		#endif
		@@ -542,6 +549,7 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
		bool doread;
		char * const hostname = SSL_IS_PROXY() ? conn->http_proxy.host.name :
		conn->host.name;
		const char *pubkey_ptr;

		doread = (connssl->connecting_state != ssl_connect_2_writing) ? TRUE : FALSE;

		@@ -761,6 +769,17 @@ schannel_connect_step2(struct connectdata *conn, int sockindex)
		infof(data, "schannel: SSL/TLS handshake complete\n");
		}

		pubkey_ptr = SSL_IS_PROXY() ?
		data->set.str[STRING_SSL_PINNEDPUBLICKEY_PROXY] :
		data->set.str[STRING_SSL_PINNEDPUBLICKEY_ORIG];
		if(pubkey_ptr) {
		result = pkp_pin_peer_pubkey(conn, sockindex, pubkey_ptr);
		if(result) {
		failf(data, "SSL: public key does not match pinned public key!");
		return result;
		}
		}

		#ifdef _WIN32_WCE
		/* Windows CE doesn't do any server certificate validation.
		We have to do it manually. */
		@@ -1669,6 +1688,68 @@ static CURLcode Curl_schannel_random(struct Curl_easy *data UNUSED_PARAM,
		return CURLE_OK;
		}

		static CURLcode pkp_pin_peer_pubkey(struct connectdata *conn, int sockindex,
		const char *pinnedpubkey)
		{
		SECURITY_STATUS status;
		struct Curl_easy *data = conn->data;
		struct ssl_connect_data *connssl = &conn->ssl[sockindex];
		CERT_CONTEXT *pCertContextServer = NULL;
		const char *x509_der;
		int x509_der_len;
		curl_X509certificate x509_parsed;
		curl_asn1Element *pubkey;

		/* Result is returned to caller */
		CURLcode result = CURLE_SSL_PINNEDPUBKEYNOTMATCH;

		/* if a path wasn't specified, don't pin */
		if(!pinnedpubkey)
		return CURLE_OK;

		do {
		status = s_pSecFn->QueryContextAttributes(&BACKEND->ctxt->ctxt_handle,
		SECPKG_ATTR_REMOTE_CERT_CONTEXT,
		&pCertContextServer);

		if((status != SEC_E_OK) \|\| (pCertContextServer == NULL)) {
		failf(data, "schannel: Failed to read remote certificate context: %s",
		Curl_sspi_strerror(conn, status));
		break; /* failed */
		}


		if(!(((pCertContextServer->dwCertEncodingType & X509_ASN_ENCODING) != 0) &&
		(pCertContextServer->cbCertEncoded > 0)))
		break;

		x509_der = pCertContextServer->pbCertEncoded;
		x509_der_len = pCertContextServer->cbCertEncoded;
		memset(&x509_parsed, 0, sizeof x509_parsed);
		if(Curl_parseX509(&x509_parsed, x509_der, x509_der + x509_der_len))
		break;

		pubkey = &x509_parsed.subjectPublicKeyInfo;
		if(!pubkey->header \|\| pubkey->end <= pubkey->header) {
		failf(data, "SSL: failed retrieving public key from server certificate");
		break;
		}

		result = Curl_pin_peer_pubkey(data,
		pinnedpubkey,
		(const unsigned char *)pubkey->header,
		(size_t)(pubkey->end - pubkey->header));
		if(result) {
		failf(data, "SSL: public key does not match pinned public key!");
		}
		} while(0);

		if(pCertContextServer)
		CertFreeCertificateContext(pCertContextServer);

		return result;
		}

		#ifdef _WIN32_WCE
		static CURLcode verify_certificate(struct connectdata *conn, int sockindex)
		{
		@@ -1809,6 +1890,62 @@ static CURLcode verify_certificate(struct connectdata *conn, int sockindex)
		}
		#endif /* _WIN32_WCE */

		static void Curl_schannel_checksum(const unsigned char *input,
		size_t inputlen,
		unsigned char *checksum,
		size_t checksumlen,
		const unsigned char *pszProvider,
		const unsigned int algId)
		{
		HCRYPTPROV hProv = 0;
		HCRYPTHASH hHash = 0;
		size_t cbHashSize = 0, dwCount = sizeof(size_t);

		/* since this can fail in multiple ways, zero memory first so we never
		* return old data
		*/
		memset(checksum, 0, checksumlen);

		if(!CryptAcquireContext(&hProv, NULL, NULL, pszProvider,
		CRYPT_VERIFYCONTEXT))
		return; /* failed */

		do {
		if(!CryptCreateHash(hProv, algId, 0, 0, &hHash))
		break; /* failed */

		if(!CryptHashData(hHash, (const BYTE*) input, inputlen, 0))
		break; /* failed */

		/* get hash size */
		if(!CryptGetHashParam(hHash, HP_HASHSIZE, (BYTE *)&cbHashSize,
		&dwCount, 0))
		break; /* failed */

		/* check hash size */
		if(checksumlen < cbHashSize)
		break; /* failed */

		if(CryptGetHashParam(hHash, HP_HASHVAL, checksum, &checksumlen, 0))
		break; /* failed */
		} while(0);

		if(hHash)
		CryptDestroyHash(hHash);

		if(hProv)
		CryptReleaseContext(hProv, 0);
		}

		void Curl_schannel_sha256sum(unsigned char *input,
		size_t inputlen,
		unsigned char *sha256sum,
		size_t sha256len)
		{
		Curl_schannel_checksum(input, inputlen, sha256sum, sha256len,
		PROV_RSA_AES, CALG_SHA_256);
		}

		static void Curl_schannel_get_internals(struct ssl_connect_data connssl,
		CURLINFO info UNUSED_PARAM)
		{
		@@ -1821,7 +1958,7 @@ const struct Curl_ssl Curl_ssl_schannel = {

		0, /* have_ca_path */
		1, /* have_certinfo */
		0, /* have_pinnedpubkey */
		1, /* have_pinnedpubkey */
		0, /* have_ssl_ctx */
		0, /* support_https_proxy */

		@@ -1846,7 +1983,7 @@ const struct Curl_ssl Curl_ssl_schannel = {
		Curl_none_engines_list, /* engines_list */
		Curl_none_false_start, /* false_start */
		Curl_none_md5sum, /* md5sum */
		NULL /* sha256sum */
		Curl_schannel_sha256sum /* sha256sum */
		};

		#endif /* USE_SCHANNEL */

tests/runtests.pl

+1 −0

Original line number	Diff line number	Diff line
		@@ -2772,6 +2772,7 @@ sub checksystem {
		}
		if ($libcurl =~ /winssl/i) {
		$has_winssl=1;
		$has_sslpinning=1;
		$ssllib="WinSSL";
		}
		elsif ($libcurl =~ /openssl/i) {