curl/docs/cmdline-opts/pinnedpubkey.md

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c: Copyright (C) Daniel Stenberg, daniel@haxx.se, et al. SPDX-License-Identifier: curl Long: pinnedpubkey Arg: Help: Public key to verify peer against Protocols: TLS Category: tls Added: 7.39.0 Multi: single See-also:

• hostpubsha256 Example:
• --pinnedpubkey keyfile $URL
• --pinnedpubkey 'sha256//ce118b5189' $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), Secure Transport macOS 10.7+/iOS 10+ (added in 7.54.1), Schannel (added in 7.58.1)

sha256 support:

OpenSSL, GnuTLS and wolfSSL (added in 7.44.0), mbedTLS (added in 7.47.0), Secure Transport macOS 10.7+/iOS 10+ (added in 7.54.1), Schannel (added in 7.58.1)

Other SSL backends not supported.