tls13: add ecdh_read_public
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ecdh.c b/library/ecdh.c
index b72bd1f..0067e0b 100644
--- a/library/ecdh.c
+++ b/library/ecdh.c
@@ -806,6 +806,64 @@
#endif
}
+static int ecdh_tls1_3_read_public_internal( mbedtls_ecdh_context_mbed *ctx,
+ const unsigned char *buf,
+ size_t blen )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ const unsigned char *p = buf;
+ const unsigned char *end = buf + blen;
+ size_t data_len;
+
+ if( end - p < 3 )
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+
+ data_len = MBEDTLS_GET_UINT16_BE( p, 0 );
+ p += 2;
+
+ if( data_len < 1 || data_len != ( blen - 2 ) )
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+
+ /*
+ * Save buffer start for read_binary and update buf
+ */
+ if( ( ret = mbedtls_ecp_point_read_binary( &ctx->grp,
+ &ctx->Qp, p, data_len ) ) != 0)
+ {
+ return( ret );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Parse and import the client's TLS 1.3 public value
+ */
+int mbedtls_ecdh_tls1_3_read_public( mbedtls_ecdh_context *ctx,
+ const unsigned char *buf,
+ size_t blen )
+{
+ ECDH_VALIDATE_RET( ctx != NULL );
+ ECDH_VALIDATE_RET( buf != NULL );
+
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+ return( ecdh_tls1_3_read_public_internal( ctx, buf, blen ) );
+#else
+ switch( ctx->var )
+ {
+#if defined(MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED)
+ case MBEDTLS_ECDH_VARIANT_EVEREST:
+ return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
+#endif
+ case MBEDTLS_ECDH_VARIANT_MBEDTLS_2_0:
+ return( ecdh_tls1_3_read_public_internal( &ctx->ctx.mbed_ecdh,
+ buf, blen ) );
+ default:
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ }
+#endif
+}
+
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
#endif /* MBEDTLS_ECDH_C */