[FFmpeg-devel] [PATCH] avformat: implement SChannel SSP TLS protocol
Hendrik Leppkes
h.leppkes at gmail.com
Wed Oct 28 16:51:54 CET 2015
On Wed, Oct 21, 2015 at 1:52 PM, Hendrik Leppkes <h.leppkes at gmail.com> wrote:
> This implementation does not support TLS listen sockets and loading
> CA/Certs from files.
>
> The Windows API does not support loading PEM certs, and would either
> require a manual loader or instead be limited to loading Windows PFX
> certificates
>
> TLS listen sockets would have to be implemented quite separately, as many
> of the APIs are different for server-mode (as opposed to client mode).
> ---
>
> Because of the limitations in comparison to OpenSSL or GnuTLS,
> we might make this implementation not active by default, if someone feels
> like thats a better course of action.
>
>
> configure | 20 +-
> libavformat/Makefile | 1 +
> libavformat/allformats.c | 1 +
> libavformat/tls.h | 2 +-
> libavformat/tls_schannel.c | 601 +++++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 621 insertions(+), 4 deletions(-)
> create mode 100644 libavformat/tls_schannel.c
>
> diff --git a/configure b/configure
> index 5e7ded1..6b9b99c 100755
> --- a/configure
> +++ b/configure
> @@ -280,6 +280,8 @@ External library support:
> --enable-opengl enable OpenGL rendering [no]
> --enable-openssl enable openssl, needed for https support
> if gnutls is not used [no]
> + --disable-schannel disable SChannel SSP, needed for TLS support on
> + Windows if openssl and gnutls are not used [autodetect]
> --disable-sdl disable sdl [autodetect]
> --disable-securetransport disable Secure Transport, needed for TLS support
> on OSX if openssl and gnutls are not used [autodetect]
> @@ -1465,6 +1467,7 @@ EXTERNAL_LIBRARY_LIST="
> opencl
> opengl
> openssl
> + schannel
> sdl
> securetransport
> x11grab
> @@ -2754,13 +2757,15 @@ sctp_protocol_deps="struct_sctp_event_subscribe"
> sctp_protocol_select="network"
> srtp_protocol_select="rtp_protocol"
> tcp_protocol_select="network"
> -tls_gnutls_protocol_deps="gnutls !tls_securetransport_protocol"
> +tls_gnutls_protocol_deps="gnutls !tls_schannel_protocol !tls_securetransport_protocol"
> tls_gnutls_protocol_select="tcp_protocol"
> -tls_openssl_protocol_deps="openssl !tls_securetransport_protocol !tls_gnutls_protocol"
> +tls_openssl_protocol_deps="openssl !tls_schannel_protocol !tls_securetransport_protocol !tls_gnutls_protocol"
> tls_openssl_protocol_select="tcp_protocol"
> +tls_schannel_protocol_deps="schannel"
> +tls_schannel_protocol_select="tcp_protocol"
> tls_securetransport_protocol_deps="securetransport"
> tls_securetransport_protocol_select="tcp_protocol"
> -tls_protocol_deps_any="tls_securetransport_protocol tls_gnutls_protocol tls_openssl_protocol"
> +tls_protocol_deps_any="tls_schannel_protocol tls_securetransport_protocol tls_gnutls_protocol tls_openssl_protocol"
> udp_protocol_select="network"
> udplite_protocol_select="network"
> unix_protocol_deps="sys_un_h"
> @@ -5501,6 +5506,15 @@ disabled securetransport || { check_func SecIdentityCreate "-Wl,-framework,CoreF
> check_lib2 "Security/SecureTransport.h Security/Security.h" "SSLCreateContext SecItemImport" "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
> enable securetransport; }
>
> +if ! disabled schannel; then
> +check_cc <<EOF && enable schannel && add_extralibs -lSecur32
> +#define SECURITY_WIN32
> +#include <windows.h>
> +#include <Security.h>
> +int main(void) { InitializeSecurityContext(NULL, NULL, NULL, 0, 0, 0, NULL, 0, NULL, NULL, NULL, NULL); return 0; }
> +EOF
> +fi
> +
> makeinfo --version > /dev/null 2>&1 && enable makeinfo || disable makeinfo
> enabled makeinfo \
> && [ 0$(makeinfo --version | grep "texinfo" | sed 's/.*texinfo[^0-9]*\([0-9]*\)\..*/\1/') -ge 5 ] \
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index ded2d54..b2d6057 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -535,6 +535,7 @@ OBJS-$(CONFIG_SUBFILE_PROTOCOL) += subfile.o
> OBJS-$(CONFIG_TCP_PROTOCOL) += tcp.o
> OBJS-$(CONFIG_TLS_GNUTLS_PROTOCOL) += tls_gnutls.o tls.o
> OBJS-$(CONFIG_TLS_OPENSSL_PROTOCOL) += tls_openssl.o tls.o
> +OBJS-$(CONFIG_TLS_SCHANNEL_PROTOCOL) += tls_schannel.o tls.o
> OBJS-$(CONFIG_TLS_SECURETRANSPORT_PROTOCOL) += tls_securetransport.o tls.o
> OBJS-$(CONFIG_UDP_PROTOCOL) += udp.o
> OBJS-$(CONFIG_UDPLITE_PROTOCOL) += udp.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 40fea8e..dad2644 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -387,6 +387,7 @@ void av_register_all(void)
> REGISTER_PROTOCOL(SRTP, srtp);
> REGISTER_PROTOCOL(SUBFILE, subfile);
> REGISTER_PROTOCOL(TCP, tcp);
> + REGISTER_PROTOCOL(TLS_SCHANNEL, tls_schannel);
> REGISTER_PROTOCOL(TLS_SECURETRANSPORT, tls_securetransport);
> REGISTER_PROTOCOL(TLS_GNUTLS, tls_gnutls);
> REGISTER_PROTOCOL(TLS_OPENSSL, tls_openssl);
> diff --git a/libavformat/tls.h b/libavformat/tls.h
> index 2a36f34..0326ef7 100644
> --- a/libavformat/tls.h
> +++ b/libavformat/tls.h
> @@ -26,7 +26,7 @@
> #include "url.h"
> #include "libavutil/opt.h"
>
> -#define CONFIG_TLS_PROTOCOL (CONFIG_TLS_GNUTLS_PROTOCOL | CONFIG_TLS_OPENSSL_PROTOCOL | CONFIG_TLS_SECURETRANSPORT_PROTOCOL)
> +#define CONFIG_TLS_PROTOCOL (CONFIG_TLS_GNUTLS_PROTOCOL | CONFIG_TLS_OPENSSL_PROTOCOL | CONFIG_TLS_SECURETRANSPORT_PROTOCOL | CONFIG_TLS_SCHANNEL_PROTOCOL)
>
> typedef struct TLSShared {
> char *ca_file;
> diff --git a/libavformat/tls_schannel.c b/libavformat/tls_schannel.c
> new file mode 100644
> index 0000000..d8a35bc
> --- /dev/null
> +++ b/libavformat/tls_schannel.c
> @@ -0,0 +1,601 @@
> +/*
> + * Copyright (c) 2015 Hendrik Leppkes
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg 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
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +/** Based on the CURL SChannel module */
> +
> +#include "avformat.h"
> +#include "internal.h"
> +#include "network.h"
> +#include "os_support.h"
> +#include "url.h"
> +#include "tls.h"
> +
> +#define SECURITY_WIN32
> +#include <security.h>
> +#include <schnlsp.h>
> +
> +#define SCHANNEL_INITIAL_BUFFER_SIZE 4096
> +#define SCHANNEL_FREE_BUFFER_SIZE 1024
> +
> +#ifndef SECBUFFER_ALERT
> +#define SECBUFFER_ALERT 17
> +#endif
> +
> +typedef struct TLSContext {
> + const AVClass *class;
> + TLSShared tls_shared;
> +
> + CredHandle cred_handle;
> + TimeStamp cred_timestamp;
> +
> + CtxtHandle ctxt_handle;
> + TimeStamp ctxt_timestamp;
> +
> + ULONG request_flags;
> + ULONG context_flags;
> +
> + uint8_t *enc_buf;
> + int enc_buf_size;
> + int enc_buf_offset;
> +
> + uint8_t *dec_buf;
> + int dec_buf_size;
> + int dec_buf_offset;
> +
> + SecPkgContext_StreamSizes Sizes;
> +
> + int connected;
> + int connection_closed;
> + int sspi_close_notify;
> +} TLSContext;
> +
> +static void InitSecBuffer(SecBuffer *buffer, unsigned long BufType,
> + void *BufDataPtr, unsigned long BufByteSize)
> +{
> + buffer->cbBuffer = BufByteSize;
> + buffer->BufferType = BufType;
> + buffer->pvBuffer = BufDataPtr;
> +}
> +
> +static void InitSecBufferDesc(SecBufferDesc *desc, SecBuffer *BufArr,
> + unsigned long NumArrElem)
> +{
> + desc->ulVersion = SECBUFFER_VERSION;
> + desc->pBuffers = BufArr;
> + desc->cBuffers = NumArrElem;
> +}
> +
> +static int tls_client_handshake_loop(URLContext *h, int initial)
> +{
> + TLSContext *c = h->priv_data;
> + TLSShared *s = &c->tls_shared;
> + SECURITY_STATUS sspi_ret = SEC_I_CONTINUE_NEEDED;
> + SecBuffer outbuf[3];
> + SecBufferDesc outbuf_desc;
> + SecBuffer inbuf[2];
> + SecBufferDesc inbuf_desc;
> + int i, ret = 0, read_data = initial;
> +
> + if (c->enc_buf == NULL) {
> + c->enc_buf_offset = 0;
> + c->enc_buf_size = SCHANNEL_INITIAL_BUFFER_SIZE;
> + ret = av_reallocp(&c->enc_buf, c->enc_buf_size);
> + if (ret < 0)
> + goto fail;
> + }
> +
> + if (c->dec_buf == NULL) {
> + c->dec_buf_offset = 0;
> + c->dec_buf_size = SCHANNEL_INITIAL_BUFFER_SIZE;
> + ret = av_reallocp(&c->dec_buf, c->dec_buf_size);
> + if (ret < 0)
> + goto fail;
> + }
> +
> + while (1)
> + {
> + if (c->enc_buf_size - c->enc_buf_offset < SCHANNEL_FREE_BUFFER_SIZE) {
> + c->enc_buf_size = c->enc_buf_offset + SCHANNEL_FREE_BUFFER_SIZE;
> + ret = av_reallocp(&c->enc_buf, c->enc_buf_size);
> + if (ret < 0)
> + goto fail;
> + }
> +
> + if (read_data) {
> + ret = ffurl_read(c->tls_shared.tcp, c->enc_buf + c->enc_buf_offset,
> + c->enc_buf_size - c->enc_buf_offset);
> + if (ret < 0) {
> + av_log(h, AV_LOG_ERROR, "Failed to read handshake response\n");
> + goto fail;
> + }
> + c->enc_buf_offset += ret;
> + }
> +
> + /* input buffers */
> + InitSecBuffer(&inbuf[0], SECBUFFER_TOKEN, av_malloc(c->enc_buf_offset), c->enc_buf_offset);
> + InitSecBuffer(&inbuf[1], SECBUFFER_EMPTY, NULL, 0);
> + InitSecBufferDesc(&inbuf_desc, inbuf, 2);
> +
> + if (inbuf[0].pvBuffer == NULL) {
> + av_log(h, AV_LOG_ERROR, "Failed to allocate input buffer\n");
> + ret = AVERROR(ENOMEM);
> + goto fail;
> + }
> +
> + memcpy(inbuf[0].pvBuffer, c->enc_buf, c->enc_buf_offset);
> +
> + /* output buffers */
> + InitSecBuffer(&outbuf[0], SECBUFFER_TOKEN, NULL, 0);
> + InitSecBuffer(&outbuf[1], SECBUFFER_ALERT, NULL, 0);
> + InitSecBuffer(&outbuf[2], SECBUFFER_EMPTY, NULL, 0);
> + InitSecBufferDesc(&outbuf_desc, outbuf, 3);
> +
> + sspi_ret = InitializeSecurityContext(&c->cred_handle, &c->ctxt_handle, s->host, c->request_flags,
> + 0, 0, &inbuf_desc, 0, NULL, &outbuf_desc, &c->context_flags,
> + &c->ctxt_timestamp);
> + av_freep(&inbuf[0].pvBuffer);
> +
> + if (sspi_ret == SEC_E_INCOMPLETE_MESSAGE) {
> + av_log(h, AV_LOG_DEBUG, "Received incomplete handshake, need more data\n");
> + read_data = 1;
> + continue;
> + }
> +
> + /* remote requests a client certificate - attempt to continue without one anyway */
> + if (sspi_ret == SEC_I_INCOMPLETE_CREDENTIALS &&
> + !(c->request_flags & ISC_REQ_USE_SUPPLIED_CREDS)) {
> + av_log(h, AV_LOG_VERBOSE, "Client certificate has been requested, ignoring\n");
> + c->request_flags |= ISC_REQ_USE_SUPPLIED_CREDS;
> + read_data = 0;
> + continue;
> + }
> +
> + /* continue handshake */
> + if (sspi_ret == SEC_I_CONTINUE_NEEDED || sspi_ret == SEC_E_OK) {
> + for(i = 0; i < 3; i++) {
> + if (outbuf[i].BufferType == SECBUFFER_TOKEN && outbuf[i].cbBuffer > 0) {
> + ret = ffurl_write(c->tls_shared.tcp, outbuf[i].pvBuffer, outbuf[i].cbBuffer);
> + if (ret < 0 || ret != outbuf[i].cbBuffer) {
> + av_log(h, AV_LOG_VERBOSE, "Failed to send handshake data\n");
> + ret = AVERROR(EIO);
> + goto fail;
> + }
> + }
> +
> + if (outbuf[i].pvBuffer != NULL) {
> + FreeContextBuffer(outbuf[i].pvBuffer);
> + outbuf[i].pvBuffer = NULL;
> + }
> + }
> + } else {
> + if (sspi_ret == SEC_E_WRONG_PRINCIPAL)
> + av_log(h, AV_LOG_ERROR, "SNI or certificate check failed\n");
> + else
> + av_log(h, AV_LOG_ERROR, "Creating security context failed (0x%lx)\n", sspi_ret);
> + ret = AVERROR_UNKNOWN;
> + goto fail;
> + }
> +
> + if (inbuf[1].BufferType == SECBUFFER_EXTRA && inbuf[1].cbBuffer > 0) {
> + if (c->enc_buf_offset > inbuf[1].cbBuffer) {
> + memmove(c->enc_buf, (c->enc_buf + c->enc_buf_offset) - inbuf[1].cbBuffer,
> + inbuf[1].cbBuffer);
> + c->enc_buf_offset = inbuf[1].cbBuffer;
> + if (sspi_ret == SEC_I_CONTINUE_NEEDED) {
> + read_data = 0;
> + continue;
> + }
> + }
> + } else {
> + c->enc_buf_offset = 0;
> + }
> +
> + if (sspi_ret == SEC_I_CONTINUE_NEEDED) {
> + read_data = 1;
> + continue;
> + }
> +
> + break;
> + }
> +
> + return 0;
> +
> +fail:
> + /* free any remaining output data */
> + for(i = 0; i < 3; i++) {
> + if (outbuf[i].pvBuffer != NULL) {
> + FreeContextBuffer(outbuf[i].pvBuffer);
> + outbuf[i].pvBuffer = NULL;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int tls_client_handshake(URLContext *h)
> +{
> + TLSContext *c = h->priv_data;
> + TLSShared *s = &c->tls_shared;
> + SecBuffer outbuf;
> + SecBufferDesc outbuf_desc;
> + SECURITY_STATUS sspi_ret;
> + int ret;
> +
> + InitSecBuffer(&outbuf, SECBUFFER_EMPTY, NULL, 0);
> + InitSecBufferDesc(&outbuf_desc, &outbuf, 1);
> +
> + c->request_flags = ISC_REQ_SEQUENCE_DETECT | ISC_REQ_REPLAY_DETECT |
> + ISC_REQ_CONFIDENTIALITY | ISC_REQ_ALLOCATE_MEMORY |
> + ISC_REQ_STREAM;
> +
> + sspi_ret = InitializeSecurityContext(&c->cred_handle, NULL, s->host, c->request_flags, 0, 0,
> + NULL, 0, &c->ctxt_handle, &outbuf_desc, &c->context_flags,
> + &c->ctxt_timestamp);
> + if(sspi_ret != SEC_I_CONTINUE_NEEDED) {
> + av_log(h, AV_LOG_ERROR, "Unable to create initial security context (0x%lx)\n", sspi_ret);
> + ret = AVERROR_UNKNOWN;
> + goto fail;
> + }
> +
> + ret = ffurl_write(s->tcp, outbuf.pvBuffer, outbuf.cbBuffer);
> + FreeContextBuffer(outbuf.pvBuffer);
> + if (ret < 0 || ret != outbuf.cbBuffer) {
> + av_log(h, AV_LOG_ERROR, "Failed to send initial handshake data\n");
> + ret = AVERROR(EIO);
> + goto fail;
> + }
> +
> + return tls_client_handshake_loop(h, 1);
> +
> +fail:
> + DeleteSecurityContext(&c->ctxt_handle);
> + return ret;
> +}
> +
> +static int tls_open(URLContext *h, const char *uri, int flags, AVDictionary **options)
> +{
> + TLSContext *c = h->priv_data;
> + TLSShared *s = &c->tls_shared;
> + SECURITY_STATUS sspi_ret;
> + SCHANNEL_CRED schannel_cred;
> + int ret;
> +
> + if ((ret = ff_tls_open_underlying(s, h, uri, options)) < 0)
> + goto fail;
> +
> + if (s->listen) {
> + av_log(h, AV_LOG_ERROR, "TLS Listen Sockets with SChannel is not implemented.\n");
> + ret = AVERROR(EINVAL);
> + goto fail;
> + }
> +
> + /* SChannel Options */
> + memset(&schannel_cred, 0, sizeof(schannel_cred));
> + schannel_cred.dwVersion = SCHANNEL_CRED_VERSION;
> +
> + if (s->verify)
> + schannel_cred.dwFlags = SCH_CRED_AUTO_CRED_VALIDATION |
> + SCH_CRED_REVOCATION_CHECK_CHAIN;
> + else
> + schannel_cred.dwFlags = SCH_CRED_MANUAL_CRED_VALIDATION |
> + SCH_CRED_IGNORE_NO_REVOCATION_CHECK |
> + SCH_CRED_IGNORE_REVOCATION_OFFLINE;
> +
> + /* Get credential handle */
> + sspi_ret = AcquireCredentialsHandle(NULL, (TCHAR *)UNISP_NAME, SECPKG_CRED_OUTBOUND,
> + NULL, &schannel_cred, NULL, NULL, &c->cred_handle,
> + &c->cred_timestamp);
> + if (sspi_ret != SEC_E_OK) {
> + av_log(h, AV_LOG_ERROR, "Unable to acquire security credentials (0x%lx)\n", sspi_ret);
> + ret = AVERROR_UNKNOWN;
> + goto fail;
> + }
> +
> + ret = tls_client_handshake(h);
> + if (ret < 0)
> + goto fail;
> +
> + c->connected = 1;
> +
> + return 0;
> +
> +fail:
> + FreeCredentialsHandle(&c->cred_handle);
> + return ret;
> +}
> +
> +static int tls_shutdown_client(URLContext *h)
> +{
> + TLSContext *c = h->priv_data;
> + TLSShared *s = &c->tls_shared;
> + int ret;
> +
> + if (c->connected) {
> + SecBufferDesc BuffDesc;
> + SecBuffer Buffer;
> + SECURITY_STATUS sspi_ret;
> + SecBuffer outbuf;
> + SecBufferDesc outbuf_desc;
> +
> + DWORD dwshut = SCHANNEL_SHUTDOWN;
> + InitSecBuffer(&Buffer, SECBUFFER_TOKEN, &dwshut, sizeof(dwshut));
> + InitSecBufferDesc(&BuffDesc, &Buffer, 1);
> +
> + sspi_ret = ApplyControlToken(&c->ctxt_handle, &BuffDesc);
> + if (sspi_ret != SEC_E_OK)
> + av_log(h, AV_LOG_ERROR, "ApplyControlToken failed\n");
> +
> + InitSecBuffer(&outbuf, SECBUFFER_EMPTY, NULL, 0);
> + InitSecBufferDesc(&outbuf_desc, &outbuf, 1);
> +
> + sspi_ret = InitializeSecurityContext(&c->cred_handle, &c->ctxt_handle, s->host,
> + c->request_flags, 0, 0, NULL, 0, &c->ctxt_handle,
> + &outbuf_desc, &c->context_flags, &c->ctxt_timestamp);
> + if (sspi_ret == SEC_E_OK || sspi_ret == SEC_I_CONTEXT_EXPIRED) {
> + ret = ffurl_write(s->tcp, outbuf.pvBuffer, outbuf.cbBuffer);
> + FreeContextBuffer(outbuf.pvBuffer);
> + if (ret < 0 || ret != outbuf.cbBuffer)
> + av_log(h, AV_LOG_ERROR, "Failed to send close message\n");
> + }
> +
> + c->connected = 0;
> + }
> + return 0;
> +}
> +
> +static int tls_close(URLContext *h)
> +{
> + TLSContext *c = h->priv_data;
> +
> + tls_shutdown_client(h);
> +
> + DeleteSecurityContext(&c->ctxt_handle);
> + FreeCredentialsHandle(&c->cred_handle);
> +
> + av_freep(&c->enc_buf);
> + av_freep(&c->dec_buf);
> +
> + if (c->tls_shared.tcp)
> + ffurl_close(c->tls_shared.tcp);
> + return 0;
> +}
> +
> +static int tls_read(URLContext *h, uint8_t *buf, int len)
> +{
> + TLSContext *c = h->priv_data;
> + TLSShared *s = &c->tls_shared;
> + SECURITY_STATUS sspi_ret = SEC_E_OK;
> + SecBuffer inbuf[4];
> + SecBufferDesc inbuf_desc;
> + int size, ret;
> + int min_enc_buf_size = len + SCHANNEL_FREE_BUFFER_SIZE;
> +
> + if (len && len <= c->dec_buf_offset)
> + goto cleanup;
> +
> + if (c->sspi_close_notify)
> + goto cleanup;
> +
> + if (!c->connection_closed) {
> + size = c->enc_buf_size - c->enc_buf_offset;
> + if (size < SCHANNEL_FREE_BUFFER_SIZE || c->enc_buf_size < min_enc_buf_size) {
> + c->enc_buf_size = c->enc_buf_offset + SCHANNEL_FREE_BUFFER_SIZE;
> + if (c->enc_buf_size < min_enc_buf_size)
> + c->enc_buf_size = min_enc_buf_size;
> + ret = av_reallocp(&c->enc_buf, c->enc_buf_size);
> + if (ret < 0)
> + goto fail;
> + }
> +
> + ret = ffurl_read(s->tcp, c->enc_buf + c->enc_buf_offset,
> + c->enc_buf_size - c->enc_buf_offset);
> + if (ret < 0) {
> + av_log(h, AV_LOG_ERROR, "Unable to read from socket\n");
> + goto fail;
> + } else if (ret == 0)
> + c->connection_closed = 1;
> +
> + c->enc_buf_offset += ret;
> + }
> +
> + while (c->enc_buf_offset > 0 && sspi_ret == SEC_E_OK &&
> + (!len || c->dec_buf_offset < len || c->connection_closed)) {
> + /* input buffer */
> + InitSecBuffer(&inbuf[0], SECBUFFER_DATA, c->enc_buf, c->enc_buf_offset);
> +
> + /* additional buffers for possible output */
> + InitSecBuffer(&inbuf[1], SECBUFFER_EMPTY, NULL, 0);
> + InitSecBuffer(&inbuf[2], SECBUFFER_EMPTY, NULL, 0);
> + InitSecBuffer(&inbuf[3], SECBUFFER_EMPTY, NULL, 0);
> + InitSecBufferDesc(&inbuf_desc, inbuf, 4);
> +
> + sspi_ret = DecryptMessage(&c->ctxt_handle, &inbuf_desc, 0, NULL);
> + if (sspi_ret == SEC_E_OK || sspi_ret == SEC_I_RENEGOTIATE ||
> + sspi_ret == SEC_I_CONTEXT_EXPIRED) {
> + /* handle decrypted data */
> + if (inbuf[1].BufferType == SECBUFFER_DATA) {
> + /* grow buffer if needed */
> + size = inbuf[1].cbBuffer > SCHANNEL_FREE_BUFFER_SIZE ?
> + inbuf[1].cbBuffer : SCHANNEL_FREE_BUFFER_SIZE;
> + if (c->dec_buf_size - c->dec_buf_offset < size || c->dec_buf_size < len) {
> + c->dec_buf_size = c->dec_buf_offset + size;
> + if (c->dec_buf_size < len)
> + c->dec_buf_size = len;
> + ret = av_reallocp(&c->dec_buf, c->dec_buf_size);
> + if (ret < 0)
> + goto fail;
> + }
> +
> + /* copy decrypted data to buffer */
> + size = inbuf[1].cbBuffer;
> + if (size) {
> + memcpy(c->dec_buf + c->dec_buf_offset, inbuf[1].pvBuffer, size);
> + c->dec_buf_offset += size;
> + }
> + }
> + if (inbuf[3].BufferType == SECBUFFER_EXTRA && inbuf[3].cbBuffer > 0) {
> + if (c->enc_buf_offset > inbuf[3].cbBuffer) {
> + memmove(c->enc_buf, (c->enc_buf + c->enc_buf_offset) - inbuf[3].cbBuffer,
> + inbuf[3].cbBuffer);
> + c->enc_buf_offset = inbuf[3].cbBuffer;
> + }
> + } else
> + c->enc_buf_offset = 0;
> +
> + if (sspi_ret == SEC_I_RENEGOTIATE) {
> + if (c->enc_buf_offset) {
> + av_log(h, AV_LOG_ERROR, "Cannot renegotiate, encrypted data buffer not empty\n");
> + ret = AVERROR_UNKNOWN;
> + goto cleanup;
> + }
> +
> + av_log(h, AV_LOG_VERBOSE, "Re-negotiating security context\n");
> + ret = tls_client_handshake_loop(h, 0);
> + if (ret < 0) {
> + goto cleanup;
> + }
> + sspi_ret = SEC_E_OK;
> + continue;
> + } else if (sspi_ret == SEC_I_CONTEXT_EXPIRED) {
> + c->sspi_close_notify = 1;
> + if (!c->connection_closed) {
> + c->connection_closed = 1;
> + av_log(h, AV_LOG_VERBOSE, "Server closed the connection\n");
> + }
> + ret = 0;
> + goto cleanup;
> + }
> + } else if (sspi_ret == SEC_E_INCOMPLETE_MESSAGE) {
> + ret = AVERROR(EAGAIN);
> + goto cleanup;
> + } else {
> + av_log(h, AV_LOG_ERROR, "Unable to decrypt message\n");
> + ret = AVERROR(EIO);
> + goto cleanup;
> + }
> + }
> +
> + ret = 0;
> +
> +cleanup:
> + size = len < c->dec_buf_offset ? len : c->dec_buf_offset;
> + if (size) {
> + memcpy(buf, c->dec_buf, size);
> + memmove(c->dec_buf, c->dec_buf + size, c->dec_buf_offset - size);
> + c->dec_buf_offset -= size;
> +
> + return size;
> + }
> +
> + if (ret == 0 && !c->connection_closed)
> + ret = AVERROR(EAGAIN);
> +
> + return ret < 0 ? ret : 0;
> +
> +fail:
> + return ret;
> +}
> +
> +static int tls_write(URLContext *h, const uint8_t *buf, int len)
> +{
> + TLSContext *c = h->priv_data;
> + TLSShared *s = &c->tls_shared;
> + SECURITY_STATUS sspi_ret;
> + int ret, data_size;
> + uint8_t *data = NULL;
> + SecBuffer outbuf[4];
> + SecBufferDesc outbuf_desc;
> +
> + if (c->Sizes.cbMaximumMessage == 0) {
> + sspi_ret = QueryContextAttributes(&c->ctxt_handle, SECPKG_ATTR_STREAM_SIZES, &c->Sizes);
> + if (sspi_ret != SEC_E_OK)
> + return AVERROR_UNKNOWN;
> + }
> +
> + if (len > c->Sizes.cbMaximumMessage) {
> + av_log(h, AV_LOG_ERROR, "Message exceeds max message size\n");
> + return AVERROR(EIO);
> + }
> +
> + data_size = c->Sizes.cbHeader + len + c->Sizes.cbTrailer;
> + data = av_malloc(data_size);
> + if (data == NULL)
> + return AVERROR(ENOMEM);
> +
> + InitSecBuffer(&outbuf[0], SECBUFFER_STREAM_HEADER,
> + data, c->Sizes.cbHeader);
> + InitSecBuffer(&outbuf[1], SECBUFFER_DATA,
> + data + c->Sizes.cbHeader, len);
> + InitSecBuffer(&outbuf[2], SECBUFFER_STREAM_TRAILER,
> + data + c->Sizes.cbHeader + len,
> + c->Sizes.cbTrailer);
> + InitSecBuffer(&outbuf[3], SECBUFFER_EMPTY, NULL, 0);
> + InitSecBufferDesc(&outbuf_desc, outbuf, 4);
> +
> + memcpy(outbuf[1].pvBuffer, buf, len);
> +
> + sspi_ret = EncryptMessage(&c->ctxt_handle, 0, &outbuf_desc, 0);
> + if (sspi_ret == SEC_E_OK) {
> + len = outbuf[0].cbBuffer + outbuf[1].cbBuffer + outbuf[2].cbBuffer;
> + ret = ffurl_write(s->tcp, data, len);
> + if (ret < 0 || ret != len) {
> + ret = AVERROR(EIO);
> + av_log(h, AV_LOG_ERROR, "Writing encrypted data to socket failed\n");
> + goto fail;
> + }
> + } else {
> + av_log(h, AV_LOG_ERROR, "Encrypting data failed\n");
> + if (sspi_ret == SEC_E_INSUFFICIENT_MEMORY)
> + ret = AVERROR(ENOMEM);
> + else
> + ret = AVERROR(EIO);
> + goto fail;
> + }
> +
> + av_freep(&data);
> + return outbuf[1].cbBuffer;
> +
> +fail:
> + av_freep(&data);
> + return ret;
> +}
> +
> +static const AVOption options[] = {
> + TLS_COMMON_OPTIONS(TLSContext, tls_shared),
> + { NULL }
> +};
> +
> +static const AVClass tls_class = {
> + .class_name = "tls",
> + .item_name = av_default_item_name,
> + .option = options,
> + .version = LIBAVUTIL_VERSION_INT,
> +};
> +
> +URLProtocol ff_tls_schannel_protocol = {
> + .name = "tls",
> + .url_open2 = tls_open,
> + .url_read = tls_read,
> + .url_write = tls_write,
> + .url_close = tls_close,
> + .priv_data_size = sizeof(TLSContext),
> + .flags = URL_PROTOCOL_FLAG_NETWORK,
> + .priv_data_class = &tls_class,
> +};
> --
> 2.6.2.windows.1
>
Anyone feel like reviewing ugly Windows code? :)
Or at least care to comment if the limitations in this implementation
(no ca/cert options, no listen mode) warrant it being disabled by
default instead?
-Hendrik
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