SSL_SESSION_GET_COMPRESS_ID(3) | Library Functions Manual | SSL_SESSION_GET_COMPRESS_ID(3)

# NAME

`SSL_SESSION_get_compress_id` — get details about the compression associated with a session

# SYNOPSIS

library “libssl” libcrypto
`#include <openssl/ssl.h>`

unsigned int
`SSL_SESSION_get_compress_id`(const SSL_SESSION *s);

# DESCRIPTION

If compression has been negotiated for an ssl session, `SSL_SESSION_get_compress_id`() returns the id for the compression method, or 0 otherwise. The only built-in supported compression method is zlib, which has an id of 1.

# SEE ALSO

ssl(3), SSL_get_session(3), SSL_SESSION_get_id(3), SSL_SESSION_get_protocol_version(3), SSL_SESSION_new(3)

# HISTORY

`SSL_SESSION_get_compress_id`() first appeared in OpenSSL 1.0.1 and has been available since OpenBSD 5.3.

June 8, 2025 | Debian