curl/docs/cmdline-opts/pinnedpubkey.md
Daniel Stenberg 08a3e8e19a
TLS: remove support for Secure Transport and BearSSL
These libraries do not support TLS 1.3 and have been marked for removal
for over a year. We want to help users select a TLS dependency that is
future-proof and reliable, and not supporting TLS 1.3 in 2025 does not
infer confidence. Users who build libcurl are likely to be served better
and get something more future-proof with a TLS library that supports
1.3.

Closes #16677
2025-06-11 07:54:19 +02:00

1.3 KiB

c SPDX-License-Identifier Long Arg Help Protocols Category Added Multi See-also Example
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl pinnedpubkey <hashes> Public key to verify peer against TLS tls 7.39.0 single
hostpubsha256
--pinnedpubkey keyfile $URL
--pinnedpubkey 'sha256//ce118b51897f4452dc' $URL

--pinnedpubkey

Use the specified public key file (or hashes) to verify the peer. This can be a path to a file which contains a single public key in PEM or DER format, or any number of base64 encoded sha256 hashes preceded by 'sha256//' and separated by ';'.

When negotiating a TLS or SSL connection, the server sends a certificate indicating its identity. A public key is extracted from this certificate and if it does not exactly match the public key provided to this option, curl aborts the connection before sending or receiving any data.

This option is independent of option --insecure. If you use both options together then the peer is still verified by public key.

PEM/DER support:

OpenSSL and GnuTLS (added in 7.39.0), wolfSSL (added in 7.43.0), mbedTLS (added in 7.47.0), Schannel (added in 7.58.1)

sha256 support:

OpenSSL, GnuTLS and wolfSSL (added in 7.44.0), mbedTLS (added in 7.47.0), Schannel (added in 7.58.1)

Other SSL backends not supported.