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- /*
- * 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 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 (%ld)\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 (%ld)\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 are not supported\n");
- ret = -1;
- 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, s->listen ? SECPKG_CRED_INBOUND : 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 (%ld)\n", sspi_ret);
- ret = AVERROR_UNKNOWN;
- goto fail;
- }
- ret = tls_client_handshake(h);
- if (ret < 0)
- goto fail;
- return 0;
- fail:
- FreeCredentialsHandle(&c->cred_handle);
- return ret;
- }
- static int tls_close(URLContext *h)
- {
- TLSContext *c = h->priv_data;
- DeleteSecurityContext(&c->ctxt_handle);
- FreeCredentialsHandle(&c->cred_handle);
- av_freep(&c->enc_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 -1;
- }
- 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,
- };
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