- NAME
- SYNOPSIS
- DESCRIPTION
- NOTES
- RETURN VALUES
- SEE ALSO
- HISTORY

# NAME

SSL_CTX_use_serverinfo, SSL_CTX_use_serverinfo_file - use serverinfo extension

# SYNOPSIS

     #include <openssl/ssl.h>

     int SSL_CTX_use_serverinfo(SSL_CTX *ctx, const unsigned char *serverinfo,
                                size_t serverinfo_length);

     int SSL_CTX_use_serverinfo_file(SSL_CTX *ctx, const char *file);

# DESCRIPTION

These functions load ``serverinfo'' TLS ServerHello Extensions into the SSL_CTX. A ``serverinfo'' extension is returned in response to an empty ClientHello Extension.

`SSL_CTX_use_serverinfo()` loads one or more serverinfo extensions from a byte array into ctx. The extensions must be concatenated into a sequence of bytes. Each extension must consist of a 2-byte Extension Type, a 2-byte length, and then length bytes of extension_data.

`SSL_CTX_use_serverinfo_file()` loads one or more serverinfo extensions from file into ctx. The extensions must be in PEM format. Each extension must consist of a 2-byte Extension Type, a 2-byte length, and then length bytes of extension_data. Each PEM extension name must begin with the phrase ``BEGIN SERVERINFO FOR ''.

If more than one certificate (RSA/DSA) is installed using SSL_CTX_use_certificate(), the serverinfo extension will be loaded into the last certificate installed. If e.g. the last item was a RSA certificate, the loaded serverinfo extension data will be loaded for that certificate. To use the serverinfo extension for multiple certificates, `SSL_CTX_use_serverinfo()` needs to be called multiple times, once after each time a certificate is loaded.

# NOTES

# RETURN VALUES

On success, the functions return 1. On failure, the functions return 0. Check out the error stack to find out the reason.

# SEE ALSO

# HISTORY