Add field for peer's raw public key to TLS handshake param structure
When removing the (session-local) copy of the peer's CRT chain, we must
keep a handshake-local copy of the peer's public key, as (naturally) every
key exchange will make use of that public key at some point to verify that
the peer actually owns the corresponding private key (e.g., verify signatures
from ServerKeyExchange or CertificateVerify, or encrypt a PMS in a RSA-based
exchange, or extract static (EC)DH parameters).
This commit adds a PK context field `peer_pubkey` to the handshake parameter
structure `mbedtls_handshake_params_init()` and adapts the init and free
functions accordingly. It does not yet make actual use of the new field.
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index d46895c..7b9265c 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -401,6 +401,10 @@
#endif /* MBEDTLS_X509_CRT_PARSE_C */
size_t ecrs_n; /*!< place for saving a length */
#endif
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+ !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+ mbedtls_pk_context peer_pubkey; /*!< The public key from the peer. */
+#endif /* MBEDTLS_X509_CRT_PARSE_C && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
unsigned int out_msg_seq; /*!< Outgoing handshake sequence number */
unsigned int in_msg_seq; /*!< Incoming handshake sequence number */