36 lines
1.5 KiB
Markdown
36 lines
1.5 KiB
Markdown
SSL key export interface change
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-------------------------------
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This affects users of the SSL key export APIs:
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```
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mbedtls_ssl_conf_export_keys_cb()
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mbedtls_ssl_conf_export_keys_ext_cb()
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```
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Those APIs have been removed and replaced by the new API
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`mbedtls_ssl_set_export_keys_cb()`. This API differs from
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the previous key export API in the following ways:
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- It is no longer bound to an SSL configuration, but to an
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SSL context. This allows users to more easily identify the
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connection an exported key belongs to.
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- It no longer exports raw keys and IV.
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- A secret type parameter has been added to identify which key
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is being exported. For TLS 1.2, only the master secret is
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exported, but upcoming TLS 1.3 support will add other kinds of keys.
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- The callback now specifies a void return type, rather than
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returning an error code. It is the responsibility of the application
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to handle failures in the key export callback, for example by
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shutting down the TLS connection.
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For users which do not rely on raw keys and IV, adjusting to the new
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callback type should be straightforward - see the example programs
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programs/ssl/ssl_client2 and programs/ssl/ssl_server2 for callbacks
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for NSSKeylog, EAP-TLS and DTLS-SRTP.
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Users which require access to the raw keys used to secure application
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traffic may derive those by hand based on the master secret and the
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handshake transcript hashes which can be obtained from the raw data
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on the wire. Such users are also encouraged to reach out to the
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Mbed TLS team on the mailing list, to let the team know about their
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use case.
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