Mercurial > hg > nginx
view src/core/ngx_crc.h @ 7938:dc955d274130
Mail: connections with wrong ALPN protocols are now rejected.
This is a recommended behavior by RFC 7301 and is useful
for mitigation of protocol confusion attacks [1].
For POP3 and IMAP protocols IANA-assigned ALPN IDs are used [2].
For the SMTP protocol "smtp" is used.
[1] https://alpaca-attack.com/
[2] https://www.iana.org/assignments/tls-extensiontype-values/
author | Vladimir Homutov <vl@nginx.com> |
---|---|
date | Wed, 20 Oct 2021 09:45:34 +0300 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_CRC_H_INCLUDED_ #define _NGX_CRC_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> /* 32-bit crc16 */ static ngx_inline uint32_t ngx_crc(u_char *data, size_t len) { uint32_t sum; for (sum = 0; len; len--) { /* * gcc 2.95.2 x86 and icc 7.1.006 compile * that operator into the single "rol" opcode, * msvc 6.0sp2 compiles it into four opcodes. */ sum = sum >> 1 | sum << 31; sum += *data++; } return sum; } #endif /* _NGX_CRC_H_INCLUDED_ */