| Relaxed semantics for PSK configuration |
| ----------------------------------------------------------------- |
| |
| This affects users which call the PSK configuration APIs |
| `mbedtlsl_ssl_conf_psk()` and `mbedtls_ssl_conf_psk_opaque()` |
| multiple times on the same SSL configuration. |
| |
| In Mbed TLS 2.x, users would observe later calls overwriting |
| the effect of earlier calls, with the prevailing PSK being |
| the one that has been configured last. In Mbed TLS 3.0, |
| calling `mbedtls_ssl_conf_[opaque_]psk()` multiple times |
| will return an error, leaving the first PSK intact. |
| |
| To achieve equivalent functionality when migrating to Mbed TLS 3.0, |
| users calling `mbedtls_ssl_conf_[opaque_]psk()` multiple times should |
| remove all but the last call, so that only one call to _either_ |
| `mbedtls_ssl_conf_psk()` _or_ `mbedtls_ssl_conf_psk_opaque()` |
| remains. |