/* * 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 <windows.h> #include <security.h> #include <schnlsp.h> #define SCHANNEL_INITIAL_BUFFER_SIZE 4096 #define SCHANNEL_FREE_BUFFER_SIZE 1024 /* mingw does not define this symbol */ #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 init_sec_buffer(SecBuffer *buffer, unsigned long type, void *data, unsigned long size) { buffer->cbBuffer = size; buffer->BufferType = type; buffer->pvBuffer = data; } static void init_sec_buffer_desc(SecBufferDesc *desc, SecBuffer *buffers, unsigned long buffer_count) { desc->ulVersion = SECBUFFER_VERSION; desc->pBuffers = buffers; desc->cBuffers = buffer_count; } 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; init_sec_buffer(&Buffer, SECBUFFER_TOKEN, &dwshut, sizeof(dwshut)); init_sec_buffer_desc(&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"); init_sec_buffer(&outbuf, SECBUFFER_EMPTY, NULL, 0); init_sec_buffer_desc(&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); c->enc_buf_size = c->enc_buf_offset = 0; av_freep(&c->dec_buf); c->dec_buf_size = c->dec_buf_offset = 0; if (c->tls_shared.tcp) ffurl_close(c->tls_shared.tcp); return 0; } static int tls_client_handshake_loop(URLContext *h, int initial) { TLSContext *c = h->priv_data; TLSShared *s = &c->tls_shared; SECURITY_STATUS sspi_ret; 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; ret = av_reallocp(&c->enc_buf, SCHANNEL_INITIAL_BUFFER_SIZE); if (ret < 0) goto fail; c->enc_buf_size = SCHANNEL_INITIAL_BUFFER_SIZE; } if (c->dec_buf == NULL) { c->dec_buf_offset = 0; ret = av_reallocp(&c->dec_buf, SCHANNEL_INITIAL_BUFFER_SIZE); if (ret < 0) goto fail; c->dec_buf_size = SCHANNEL_INITIAL_BUFFER_SIZE; } 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) { c->enc_buf_size = c->enc_buf_offset = 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 */ init_sec_buffer(&inbuf[0], SECBUFFER_TOKEN, av_malloc(c->enc_buf_offset), c->enc_buf_offset); init_sec_buffer(&inbuf[1], SECBUFFER_EMPTY, NULL, 0); init_sec_buffer_desc(&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 */ init_sec_buffer(&outbuf[0], SECBUFFER_TOKEN, NULL, 0); init_sec_buffer(&outbuf[1], SECBUFFER_ALERT, NULL, 0); init_sec_buffer(&outbuf[2], SECBUFFER_EMPTY, NULL, 0); init_sec_buffer_desc(&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; init_sec_buffer(&outbuf, SECBUFFER_EMPTY, NULL, 0); init_sec_buffer_desc(&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 = { 0 }; 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 */ 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: tls_close(h); return ret; } 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 <= 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) { c->enc_buf_size = c->enc_buf_offset = 0; return ret; } } 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"); return ret; } else if (ret == 0) c->connection_closed = 1; c->enc_buf_offset += ret; } while (c->enc_buf_offset > 0 && sspi_ret == SEC_E_OK && c->dec_buf_offset < len) { /* input buffer */ init_sec_buffer(&inbuf[0], SECBUFFER_DATA, c->enc_buf, c->enc_buf_offset); /* additional buffers for possible output */ init_sec_buffer(&inbuf[1], SECBUFFER_EMPTY, NULL, 0); init_sec_buffer(&inbuf[2], SECBUFFER_EMPTY, NULL, 0); init_sec_buffer(&inbuf[3], SECBUFFER_EMPTY, NULL, 0); init_sec_buffer_desc(&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) { c->dec_buf_size = c->dec_buf_offset = 0; return ret; } } /* 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 = FFMIN(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; } 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 = 0, 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; } /* limit how much data we can consume */ len = FFMIN(len, c->sizes.cbMaximumMessage); data_size = c->sizes.cbHeader + len + c->sizes.cbTrailer; data = av_malloc(data_size); if (data == NULL) return AVERROR(ENOMEM); init_sec_buffer(&outbuf[0], SECBUFFER_STREAM_HEADER, data, c->sizes.cbHeader); init_sec_buffer(&outbuf[1], SECBUFFER_DATA, data + c->sizes.cbHeader, len); init_sec_buffer(&outbuf[2], SECBUFFER_STREAM_TRAILER, data + c->sizes.cbHeader + len, c->sizes.cbTrailer); init_sec_buffer(&outbuf[3], SECBUFFER_EMPTY, NULL, 0); init_sec_buffer_desc(&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 done; } } 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 done; } done: av_freep(&data); return ret < 0 ? ret : outbuf[1].cbBuffer; } static int tls_get_file_handle(URLContext *h) { TLSContext *c = h->priv_data; return ffurl_get_file_handle(c->tls_shared.tcp); } 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, }; const URLProtocol ff_tls_schannel_protocol = { .name = "tls", .url_open2 = tls_open, .url_read = tls_read, .url_write = tls_write, .url_close = tls_close, .url_get_file_handle = tls_get_file_handle, .priv_data_size = sizeof(TLSContext), .flags = URL_PROTOCOL_FLAG_NETWORK, .priv_data_class = &tls_class, };