ref: ca70040abf8d8ab2cb03575f65131ad8ef8f12a1
dir: /third_party/boringssl/src/tool/transport_common.cc/
/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
// Suppress MSVC's STL warnings. It flags |std::copy| calls with a raw output
// pointer, on grounds that MSVC cannot check them. Unfortunately, there is no
// way to suppress the warning just on one line. The warning is flagged inside
// the STL itself, so suppressing at the |std::copy| call does not work.
#if !defined(_SCL_SECURE_NO_WARNINGS)
#define _SCL_SECURE_NO_WARNINGS
#endif
#include <openssl/base.h>
#include <string>
#include <vector>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#if !defined(OPENSSL_WINDOWS)
#include <arpa/inet.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <unistd.h>
#else
#include <algorithm>
#include <condition_variable>
#include <deque>
#include <memory>
#include <mutex>
#include <thread>
#include <utility>
#include <io.h>
OPENSSL_MSVC_PRAGMA(warning(push, 3))
#include <winsock2.h>
#include <ws2tcpip.h>
OPENSSL_MSVC_PRAGMA(warning(pop))
OPENSSL_MSVC_PRAGMA(comment(lib, "Ws2_32.lib"))
#endif
#include <openssl/err.h>
#include <openssl/ssl.h>
#include <openssl/x509.h>
#include "../crypto/internal.h"
#include "internal.h"
#include "transport_common.h"
#if defined(OPENSSL_WINDOWS)
using socket_result_t = int;
#else
using socket_result_t = ssize_t;
static int closesocket(int sock) {
return close(sock);
}
#endif
bool InitSocketLibrary() {
#if defined(OPENSSL_WINDOWS)
WSADATA wsaData;
int err = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (err != 0) {
fprintf(stderr, "WSAStartup failed with error %d\n", err);
return false;
}
#endif
return true;
}
static void SplitHostPort(std::string *out_hostname, std::string *out_port,
const std::string &hostname_and_port) {
size_t colon_offset = hostname_and_port.find_last_of(':');
const size_t bracket_offset = hostname_and_port.find_last_of(']');
std::string hostname, port;
// An IPv6 literal may have colons internally, guarded by square brackets.
if (bracket_offset != std::string::npos &&
colon_offset != std::string::npos && bracket_offset > colon_offset) {
colon_offset = std::string::npos;
}
if (colon_offset == std::string::npos) {
*out_hostname = hostname_and_port;
*out_port = "443";
} else {
*out_hostname = hostname_and_port.substr(0, colon_offset);
*out_port = hostname_and_port.substr(colon_offset + 1);
}
}
static std::string GetLastSocketErrorString() {
#if defined(OPENSSL_WINDOWS)
int error = WSAGetLastError();
char *buffer;
DWORD len = FormatMessageA(
FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER, 0, error, 0,
reinterpret_cast<char *>(&buffer), 0, nullptr);
if (len == 0) {
char buf[256];
snprintf(buf, sizeof(buf), "unknown error (0x%x)", error);
return buf;
}
std::string ret(buffer, len);
LocalFree(buffer);
return ret;
#else
return strerror(errno);
#endif
}
static void PrintSocketError(const char *function) {
// On Windows, |perror| and |errno| are part of the C runtime, while sockets
// are separate, so we must print errors manually.
std::string error = GetLastSocketErrorString();
fprintf(stderr, "%s: %s\n", function, error.c_str());
}
// Connect sets |*out_sock| to be a socket connected to the destination given
// in |hostname_and_port|, which should be of the form "www.example.com:123".
// It returns true on success and false otherwise.
bool Connect(int *out_sock, const std::string &hostname_and_port) {
std::string hostname, port;
SplitHostPort(&hostname, &port, hostname_and_port);
// Handle IPv6 literals.
if (hostname.size() >= 2 && hostname[0] == '[' &&
hostname[hostname.size() - 1] == ']') {
hostname = hostname.substr(1, hostname.size() - 2);
}
struct addrinfo hint, *result;
OPENSSL_memset(&hint, 0, sizeof(hint));
hint.ai_family = AF_UNSPEC;
hint.ai_socktype = SOCK_STREAM;
int ret = getaddrinfo(hostname.c_str(), port.c_str(), &hint, &result);
if (ret != 0) {
#if defined(OPENSSL_WINDOWS)
const char *error = gai_strerrorA(ret);
#else
const char *error = gai_strerror(ret);
#endif
fprintf(stderr, "getaddrinfo returned: %s\n", error);
return false;
}
bool ok = false;
char buf[256];
*out_sock =
socket(result->ai_family, result->ai_socktype, result->ai_protocol);
if (*out_sock < 0) {
PrintSocketError("socket");
goto out;
}
switch (result->ai_family) {
case AF_INET: {
struct sockaddr_in *sin =
reinterpret_cast<struct sockaddr_in *>(result->ai_addr);
fprintf(stderr, "Connecting to %s:%d\n",
inet_ntop(result->ai_family, &sin->sin_addr, buf, sizeof(buf)),
ntohs(sin->sin_port));
break;
}
case AF_INET6: {
struct sockaddr_in6 *sin6 =
reinterpret_cast<struct sockaddr_in6 *>(result->ai_addr);
fprintf(stderr, "Connecting to [%s]:%d\n",
inet_ntop(result->ai_family, &sin6->sin6_addr, buf, sizeof(buf)),
ntohs(sin6->sin6_port));
break;
}
}
if (connect(*out_sock, result->ai_addr, result->ai_addrlen) != 0) {
PrintSocketError("connect");
goto out;
}
ok = true;
out:
freeaddrinfo(result);
return ok;
}
Listener::~Listener() {
if (server_sock_ >= 0) {
closesocket(server_sock_);
}
}
bool Listener::Init(const std::string &port) {
if (server_sock_ >= 0) {
return false;
}
struct sockaddr_in6 addr;
OPENSSL_memset(&addr, 0, sizeof(addr));
addr.sin6_family = AF_INET6;
// Windows' IN6ADDR_ANY_INIT does not have enough curly braces for clang-cl
// (https://crbug.com/772108), while other platforms like NaCl are missing
// in6addr_any, so use a mix of both.
#if defined(OPENSSL_WINDOWS)
addr.sin6_addr = in6addr_any;
#else
addr.sin6_addr = IN6ADDR_ANY_INIT;
#endif
addr.sin6_port = htons(atoi(port.c_str()));
#if defined(OPENSSL_WINDOWS)
const BOOL enable = TRUE;
#else
const int enable = 1;
#endif
server_sock_ = socket(addr.sin6_family, SOCK_STREAM, 0);
if (server_sock_ < 0) {
PrintSocketError("socket");
return false;
}
if (setsockopt(server_sock_, SOL_SOCKET, SO_REUSEADDR, (const char *)&enable,
sizeof(enable)) < 0) {
PrintSocketError("setsockopt");
return false;
}
if (bind(server_sock_, (struct sockaddr *)&addr, sizeof(addr)) != 0) {
PrintSocketError("connect");
return false;
}
listen(server_sock_, SOMAXCONN);
return true;
}
bool Listener::Accept(int *out_sock) {
struct sockaddr_in6 addr;
socklen_t addr_len = sizeof(addr);
*out_sock = accept(server_sock_, (struct sockaddr *)&addr, &addr_len);
return *out_sock >= 0;
}
bool VersionFromString(uint16_t *out_version, const std::string &version) {
if (version == "tls1" || version == "tls1.0") {
*out_version = TLS1_VERSION;
return true;
} else if (version == "tls1.1") {
*out_version = TLS1_1_VERSION;
return true;
} else if (version == "tls1.2") {
*out_version = TLS1_2_VERSION;
return true;
} else if (version == "tls1.3") {
*out_version = TLS1_3_VERSION;
return true;
}
return false;
}
void PrintConnectionInfo(BIO *bio, const SSL *ssl) {
const SSL_CIPHER *cipher = SSL_get_current_cipher(ssl);
BIO_printf(bio, " Version: %s\n", SSL_get_version(ssl));
BIO_printf(bio, " Resumed session: %s\n",
SSL_session_reused(ssl) ? "yes" : "no");
BIO_printf(bio, " Cipher: %s\n", SSL_CIPHER_standard_name(cipher));
uint16_t curve = SSL_get_curve_id(ssl);
if (curve != 0) {
BIO_printf(bio, " ECDHE curve: %s\n", SSL_get_curve_name(curve));
}
uint16_t sigalg = SSL_get_peer_signature_algorithm(ssl);
if (sigalg != 0) {
BIO_printf(bio, " Signature algorithm: %s\n",
SSL_get_signature_algorithm_name(
sigalg, SSL_version(ssl) != TLS1_2_VERSION));
}
BIO_printf(bio, " Secure renegotiation: %s\n",
SSL_get_secure_renegotiation_support(ssl) ? "yes" : "no");
BIO_printf(bio, " Extended master secret: %s\n",
SSL_get_extms_support(ssl) ? "yes" : "no");
const uint8_t *next_proto;
unsigned next_proto_len;
SSL_get0_next_proto_negotiated(ssl, &next_proto, &next_proto_len);
BIO_printf(bio, " Next protocol negotiated: %.*s\n", next_proto_len,
next_proto);
const uint8_t *alpn;
unsigned alpn_len;
SSL_get0_alpn_selected(ssl, &alpn, &alpn_len);
BIO_printf(bio, " ALPN protocol: %.*s\n", alpn_len, alpn);
const char *host_name = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
if (host_name != nullptr && SSL_is_server(ssl)) {
BIO_printf(bio, " Client sent SNI: %s\n", host_name);
}
if (!SSL_is_server(ssl)) {
const uint8_t *ocsp_staple;
size_t ocsp_staple_len;
SSL_get0_ocsp_response(ssl, &ocsp_staple, &ocsp_staple_len);
BIO_printf(bio, " OCSP staple: %s\n", ocsp_staple_len > 0 ? "yes" : "no");
const uint8_t *sct_list;
size_t sct_list_len;
SSL_get0_signed_cert_timestamp_list(ssl, &sct_list, &sct_list_len);
BIO_printf(bio, " SCT list: %s\n", sct_list_len > 0 ? "yes" : "no");
}
BIO_printf(
bio, " Early data: %s\n",
(SSL_early_data_accepted(ssl) || SSL_in_early_data(ssl)) ? "yes" : "no");
BIO_printf(bio, " Encrypted ClientHello: %s\n",
SSL_ech_accepted(ssl) ? "yes" : "no");
// Print the server cert subject and issuer names.
bssl::UniquePtr<X509> peer(SSL_get_peer_certificate(ssl));
if (peer != nullptr) {
BIO_printf(bio, " Cert subject: ");
X509_NAME_print_ex(bio, X509_get_subject_name(peer.get()), 0,
XN_FLAG_ONELINE);
BIO_printf(bio, "\n Cert issuer: ");
X509_NAME_print_ex(bio, X509_get_issuer_name(peer.get()), 0,
XN_FLAG_ONELINE);
BIO_printf(bio, "\n");
}
}
bool SocketSetNonBlocking(int sock, bool is_non_blocking) {
bool ok;
#if defined(OPENSSL_WINDOWS)
u_long arg = is_non_blocking;
ok = 0 == ioctlsocket(sock, FIONBIO, &arg);
#else
int flags = fcntl(sock, F_GETFL, 0);
if (flags < 0) {
return false;
}
if (is_non_blocking) {
flags |= O_NONBLOCK;
} else {
flags &= ~O_NONBLOCK;
}
ok = 0 == fcntl(sock, F_SETFL, flags);
#endif
if (!ok) {
PrintSocketError("Failed to set socket non-blocking");
}
return ok;
}
enum class StdinWait {
kStdinRead,
kSocketWrite,
};
#if !defined(OPENSSL_WINDOWS)
// SocketWaiter abstracts waiting for either the socket or stdin to be readable
// between Windows and POSIX.
class SocketWaiter {
public:
explicit SocketWaiter(int sock) : sock_(sock) {}
SocketWaiter(const SocketWaiter &) = delete;
SocketWaiter &operator=(const SocketWaiter &) = delete;
// Init initializes the SocketWaiter. It returns whether it succeeded.
bool Init() { return true; }
// Wait waits for at least on of the socket or stdin or be ready. On success,
// it sets |*socket_ready| and |*stdin_ready| to whether the respective
// objects are readable and returns true. On error, it returns false. stdin's
// readiness may either be the socket being writable or stdin being readable,
// depending on |stdin_wait|.
bool Wait(StdinWait stdin_wait, bool *socket_ready, bool *stdin_ready) {
*socket_ready = true;
*stdin_ready = false;
fd_set read_fds, write_fds;
FD_ZERO(&read_fds);
FD_ZERO(&write_fds);
if (stdin_wait == StdinWait::kSocketWrite) {
FD_SET(sock_, &write_fds);
} else if (stdin_open_) {
FD_SET(STDIN_FILENO, &read_fds);
}
FD_SET(sock_, &read_fds);
if (select(sock_ + 1, &read_fds, &write_fds, NULL, NULL) <= 0) {
perror("select");
return false;
}
if (FD_ISSET(STDIN_FILENO, &read_fds) || FD_ISSET(sock_, &write_fds)) {
*stdin_ready = true;
}
if (FD_ISSET(sock_, &read_fds)) {
*socket_ready = true;
}
return true;
}
// ReadStdin reads at most |max_out| bytes from stdin. On success, it writes
// them to |out| and sets |*out_len| to the number of bytes written. On error,
// it returns false. This method may only be called after |Wait| returned
// stdin was ready.
bool ReadStdin(void *out, size_t *out_len, size_t max_out) {
ssize_t n;
do {
n = read(STDIN_FILENO, out, max_out);
} while (n == -1 && errno == EINTR);
if (n <= 0) {
stdin_open_ = false;
}
if (n < 0) {
perror("read from stdin");
return false;
}
*out_len = static_cast<size_t>(n);
return true;
}
private:
bool stdin_open_ = true;
int sock_;
};
#else // OPENSSL_WINDOWs
class ScopedWSAEVENT {
public:
ScopedWSAEVENT() = default;
ScopedWSAEVENT(WSAEVENT event) { reset(event); }
ScopedWSAEVENT(const ScopedWSAEVENT &) = delete;
ScopedWSAEVENT(ScopedWSAEVENT &&other) { *this = std::move(other); }
~ScopedWSAEVENT() { reset(); }
ScopedWSAEVENT &operator=(const ScopedWSAEVENT &) = delete;
ScopedWSAEVENT &operator=(ScopedWSAEVENT &&other) {
reset(other.release());
return *this;
}
explicit operator bool() const { return event_ != WSA_INVALID_EVENT; }
WSAEVENT get() const { return event_; }
WSAEVENT release() {
WSAEVENT ret = event_;
event_ = WSA_INVALID_EVENT;
return ret;
}
void reset(WSAEVENT event = WSA_INVALID_EVENT) {
if (event_ != WSA_INVALID_EVENT) {
WSACloseEvent(event_);
}
event_ = event;
}
private:
WSAEVENT event_ = WSA_INVALID_EVENT;
};
// SocketWaiter, on Windows, is more complicated. While |WaitForMultipleObjects|
// works for both sockets and stdin, the latter is often a line-buffered
// console. The |HANDLE| is considered readable if there are any console events
// available, but reading blocks until a full line is available.
//
// So that |Wait| reflects final stdin read, we spawn a stdin reader thread that
// writes to an in-memory buffer and signals a |WSAEVENT| to coordinate with the
// socket.
class SocketWaiter {
public:
explicit SocketWaiter(int sock) : sock_(sock) {}
SocketWaiter(const SocketWaiter &) = delete;
SocketWaiter &operator=(const SocketWaiter &) = delete;
bool Init() {
stdin_ = std::make_shared<StdinState>();
stdin_->event.reset(WSACreateEvent());
if (!stdin_->event) {
PrintSocketError("Error in WSACreateEvent");
return false;
}
// Spawn a thread to block on stdin.
std::shared_ptr<StdinState> state = stdin_;
std::thread thread([state]() {
for (;;) {
uint8_t buf[512];
int ret = _read(0 /* stdin */, buf, sizeof(buf));
if (ret <= 0) {
if (ret < 0) {
perror("read from stdin");
}
// Report the error or EOF to the caller.
std::lock_guard<std::mutex> lock(state->lock);
state->error = ret < 0;
state->open = false;
WSASetEvent(state->event.get());
return;
}
size_t len = static_cast<size_t>(ret);
size_t written = 0;
while (written < len) {
std::unique_lock<std::mutex> lock(state->lock);
// Wait for there to be room in the buffer.
state->cond.wait(lock, [&] { return !state->buffer_full(); });
// Copy what we can and signal to the caller.
size_t todo = std::min(len - written, state->buffer_remaining());
state->buffer.insert(state->buffer.end(), buf + written,
buf + written + todo);
written += todo;
WSASetEvent(state->event.get());
}
}
});
thread.detach();
return true;
}
bool Wait(StdinWait stdin_wait, bool *socket_ready, bool *stdin_ready) {
*socket_ready = true;
*stdin_ready = false;
ScopedWSAEVENT sock_read_event(WSACreateEvent());
if (!sock_read_event ||
WSAEventSelect(sock_, sock_read_event.get(), FD_READ | FD_CLOSE) != 0) {
PrintSocketError("Error waiting for socket read");
return false;
}
DWORD count = 1;
WSAEVENT events[3] = {sock_read_event.get(), WSA_INVALID_EVENT};
ScopedWSAEVENT sock_write_event;
if (stdin_wait == StdinWait::kSocketWrite) {
sock_write_event.reset(WSACreateEvent());
if (!sock_write_event || WSAEventSelect(sock_, sock_write_event.get(),
FD_WRITE | FD_CLOSE) != 0) {
PrintSocketError("Error waiting for socket write");
return false;
}
events[1] = sock_write_event.get();
count++;
} else if (listen_stdin_) {
events[1] = stdin_->event.get();
count++;
}
switch (WSAWaitForMultipleEvents(count, events, FALSE /* wait all */,
WSA_INFINITE, FALSE /* alertable */)) {
case WSA_WAIT_EVENT_0 + 0:
*socket_ready = true;
return true;
case WSA_WAIT_EVENT_0 + 1:
*stdin_ready = true;
return true;
case WSA_WAIT_TIMEOUT:
return true;
default:
PrintSocketError("Error waiting for events");
return false;
}
}
bool ReadStdin(void *out, size_t *out_len, size_t max_out) {
std::lock_guard<std::mutex> locked(stdin_->lock);
if (stdin_->buffer.empty()) {
// |ReadStdin| may only be called when |Wait| signals it is ready, so
// stdin must have reached EOF or error.
assert(!stdin_->open);
listen_stdin_ = false;
if (stdin_->error) {
return false;
}
*out_len = 0;
return true;
}
bool was_full = stdin_->buffer_full();
// Copy as many bytes as well fit.
*out_len = std::min(max_out, stdin_->buffer.size());
auto begin = stdin_->buffer.begin();
auto end = stdin_->buffer.begin() + *out_len;
std::copy(begin, end, static_cast<uint8_t *>(out));
stdin_->buffer.erase(begin, end);
// Notify the stdin thread if there is more space.
if (was_full && !stdin_->buffer_full()) {
stdin_->cond.notify_one();
}
// If stdin is now waiting for input, clear the event.
if (stdin_->buffer.empty() && stdin_->open) {
WSAResetEvent(stdin_->event.get());
}
return true;
}
private:
struct StdinState {
static constexpr size_t kMaxBuffer = 1024;
StdinState() = default;
StdinState(const StdinState &) = delete;
StdinState &operator=(const StdinState &) = delete;
size_t buffer_remaining() const { return kMaxBuffer - buffer.size(); }
bool buffer_full() const { return buffer_remaining() == 0; }
ScopedWSAEVENT event;
// lock protects the following fields.
std::mutex lock;
// cond notifies the stdin thread that |buffer| is no longer full.
std::condition_variable cond;
std::deque<uint8_t> buffer;
bool open = true;
bool error = false;
};
int sock_;
std::shared_ptr<StdinState> stdin_;
// listen_stdin_ is set to false when we have consumed an EOF or error from
// |stdin_|. This is separate from |stdin_->open| because the signal may not
// have been consumed yet.
bool listen_stdin_ = true;
};
#endif // OPENSSL_WINDOWS
void PrintSSLError(FILE *file, const char *msg, int ssl_err, int ret) {
switch (ssl_err) {
case SSL_ERROR_SSL:
fprintf(file, "%s: %s\n", msg, ERR_reason_error_string(ERR_peek_error()));
break;
case SSL_ERROR_SYSCALL:
if (ret == 0) {
fprintf(file, "%s: peer closed connection\n", msg);
} else {
std::string error = GetLastSocketErrorString();
fprintf(file, "%s: %s\n", msg, error.c_str());
}
break;
case SSL_ERROR_ZERO_RETURN:
fprintf(file, "%s: received close_notify\n", msg);
break;
default:
fprintf(file, "%s: unexpected error: %s\n", msg,
SSL_error_description(ssl_err));
}
ERR_print_errors_fp(file);
}
bool TransferData(SSL *ssl, int sock) {
if (!SocketSetNonBlocking(sock, true)) {
return false;
}
SocketWaiter waiter(sock);
if (!waiter.Init()) {
return false;
}
uint8_t pending_write[512];
size_t pending_write_len = 0;
for (;;) {
bool socket_ready = false;
bool stdin_ready = false;
if (!waiter.Wait(pending_write_len == 0 ? StdinWait::kStdinRead
: StdinWait::kSocketWrite,
&socket_ready, &stdin_ready)) {
return false;
}
if (stdin_ready) {
if (pending_write_len == 0) {
if (!waiter.ReadStdin(pending_write, &pending_write_len,
sizeof(pending_write))) {
return false;
}
if (pending_write_len == 0) {
#if !defined(OPENSSL_WINDOWS)
shutdown(sock, SHUT_WR);
#else
shutdown(sock, SD_SEND);
#endif
continue;
}
}
int ssl_ret =
SSL_write(ssl, pending_write, static_cast<int>(pending_write_len));
if (ssl_ret <= 0) {
int ssl_err = SSL_get_error(ssl, ssl_ret);
if (ssl_err == SSL_ERROR_WANT_WRITE) {
continue;
}
PrintSSLError(stderr, "Error while writing", ssl_err, ssl_ret);
return false;
}
if (ssl_ret != static_cast<int>(pending_write_len)) {
fprintf(stderr, "Short write from SSL_write.\n");
return false;
}
pending_write_len = 0;
}
if (socket_ready) {
for (;;) {
uint8_t buffer[512];
int ssl_ret = SSL_read(ssl, buffer, sizeof(buffer));
if (ssl_ret < 0) {
int ssl_err = SSL_get_error(ssl, ssl_ret);
if (ssl_err == SSL_ERROR_WANT_READ) {
break;
}
PrintSSLError(stderr, "Error while reading", ssl_err, ssl_ret);
return false;
} else if (ssl_ret == 0) {
return true;
}
size_t n;
if (!WriteToFD(1, &n, buffer, ssl_ret)) {
fprintf(stderr, "Error writing to stdout.\n");
return false;
}
if (n != static_cast<size_t>(ssl_ret)) {
fprintf(stderr, "Short write to stderr.\n");
return false;
}
}
}
}
}
// SocketLineReader wraps a small buffer around a socket for line-orientated
// protocols.
class SocketLineReader {
public:
explicit SocketLineReader(int sock) : sock_(sock) {}
// Next reads a '\n'- or '\r\n'-terminated line from the socket and, on
// success, sets |*out_line| to it and returns true. Otherwise it returns
// false.
bool Next(std::string *out_line) {
for (;;) {
for (size_t i = 0; i < buf_len_; i++) {
if (buf_[i] != '\n') {
continue;
}
size_t length = i;
if (i > 0 && buf_[i - 1] == '\r') {
length--;
}
out_line->assign(buf_, length);
buf_len_ -= i + 1;
OPENSSL_memmove(buf_, &buf_[i + 1], buf_len_);
return true;
}
if (buf_len_ == sizeof(buf_)) {
fprintf(stderr, "Received line too long!\n");
return false;
}
socket_result_t n;
do {
n = recv(sock_, &buf_[buf_len_], sizeof(buf_) - buf_len_, 0);
} while (n == -1 && errno == EINTR);
if (n < 0) {
fprintf(stderr, "Read error from socket\n");
return false;
}
buf_len_ += n;
}
}
// ReadSMTPReply reads one or more lines that make up an SMTP reply. On
// success, it sets |*out_code| to the reply's code (e.g. 250) and
// |*out_content| to the body of the reply (e.g. "OK") and returns true.
// Otherwise it returns false.
//
// See https://tools.ietf.org/html/rfc821#page-48
bool ReadSMTPReply(unsigned *out_code, std::string *out_content) {
out_content->clear();
// kMaxLines is the maximum number of lines that we'll accept in an SMTP
// reply.
static const unsigned kMaxLines = 512;
for (unsigned i = 0; i < kMaxLines; i++) {
std::string line;
if (!Next(&line)) {
return false;
}
if (line.size() < 4) {
fprintf(stderr, "Short line from SMTP server: %s\n", line.c_str());
return false;
}
const std::string code_str = line.substr(0, 3);
char *endptr;
const unsigned long code = strtoul(code_str.c_str(), &endptr, 10);
if (*endptr || code > UINT_MAX) {
fprintf(stderr, "Failed to parse code from line: %s\n", line.c_str());
return false;
}
if (i == 0) {
*out_code = code;
} else if (code != *out_code) {
fprintf(stderr,
"Reply code varied within a single reply: was %u, now %u\n",
*out_code, static_cast<unsigned>(code));
return false;
}
if (line[3] == ' ') {
// End of reply.
*out_content += line.substr(4, std::string::npos);
return true;
} else if (line[3] == '-') {
// Another line of reply will follow this one.
*out_content += line.substr(4, std::string::npos);
out_content->push_back('\n');
} else {
fprintf(stderr, "Bad character after code in SMTP reply: %s\n",
line.c_str());
return false;
}
}
fprintf(stderr, "Rejected SMTP reply of more then %u lines\n", kMaxLines);
return false;
}
private:
const int sock_;
char buf_[512];
size_t buf_len_ = 0;
};
// SendAll writes |data_len| bytes from |data| to |sock|. It returns true on
// success and false otherwise.
static bool SendAll(int sock, const char *data, size_t data_len) {
size_t done = 0;
while (done < data_len) {
socket_result_t n;
do {
n = send(sock, &data[done], data_len - done, 0);
} while (n == -1 && errno == EINTR);
if (n < 0) {
fprintf(stderr, "Error while writing to socket\n");
return false;
}
done += n;
}
return true;
}
bool DoSMTPStartTLS(int sock) {
SocketLineReader line_reader(sock);
unsigned code_220 = 0;
std::string reply_220;
if (!line_reader.ReadSMTPReply(&code_220, &reply_220)) {
return false;
}
if (code_220 != 220) {
fprintf(stderr, "Expected 220 line from SMTP server but got code %u\n",
code_220);
return false;
}
static const char kHelloLine[] = "EHLO BoringSSL\r\n";
if (!SendAll(sock, kHelloLine, sizeof(kHelloLine) - 1)) {
return false;
}
unsigned code_250 = 0;
std::string reply_250;
if (!line_reader.ReadSMTPReply(&code_250, &reply_250)) {
return false;
}
if (code_250 != 250) {
fprintf(stderr, "Expected 250 line after EHLO but got code %u\n", code_250);
return false;
}
// https://tools.ietf.org/html/rfc1869#section-4.3
if (("\n" + reply_250 + "\n").find("\nSTARTTLS\n") == std::string::npos) {
fprintf(stderr, "Server does not support STARTTLS\n");
return false;
}
static const char kSTARTTLSLine[] = "STARTTLS\r\n";
if (!SendAll(sock, kSTARTTLSLine, sizeof(kSTARTTLSLine) - 1)) {
return false;
}
if (!line_reader.ReadSMTPReply(&code_220, &reply_220)) {
return false;
}
if (code_220 != 220) {
fprintf(
stderr,
"Expected 220 line from SMTP server after STARTTLS, but got code %u\n",
code_220);
return false;
}
return true;
}
bool DoHTTPTunnel(int sock, const std::string &hostname_and_port) {
std::string hostname, port;
SplitHostPort(&hostname, &port, hostname_and_port);
fprintf(stderr, "Establishing HTTP tunnel to %s:%s.\n", hostname.c_str(),
port.c_str());
char buf[1024];
snprintf(buf, sizeof(buf), "CONNECT %s:%s HTTP/1.0\r\n\r\n", hostname.c_str(),
port.c_str());
if (!SendAll(sock, buf, strlen(buf))) {
return false;
}
SocketLineReader line_reader(sock);
// Read until an empty line, signaling the end of the HTTP response.
std::string line;
for (;;) {
if (!line_reader.Next(&line)) {
return false;
}
if (line.empty()) {
return true;
}
fprintf(stderr, "%s\n", line.c_str());
}
}