Move the TLSv1.3 code that interfaces with the legacy APIs/stack into a

separate file.

Discussed with beck@ and tb@

3 files changed, 330 insertions, 309 deletions

diff --git a/src/lib/libssl/Makefile b/src/lib/libssl/Makefile
index afbd6d148e..22209d574b 100644
--- a/src/lib/libssl/Makefile
+++ b/src/lib/libssl/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.62 2020/01/30 17:09:23 jsing Exp $
+# $OpenBSD: Makefile,v 1.63 2020/02/15 14:40:38 jsing Exp $
 
 .include <bsd.own.mk>
 .ifndef NOMAN
@@ -74,6 +74,7 @@ SRCS= \
         tls13_handshake_msg.c \
         tls13_key_schedule.c \
         tls13_key_share.c \
+        tls13_legacy.c \
         tls13_lib.c \
         tls13_record.c \
         tls13_record_layer.c \
diff --git a/src/lib/libssl/tls13_legacy.c b/src/lib/libssl/tls13_legacy.c
new file mode 100644
index 0000000000..642374af92
--- /dev/null
+++ b/src/lib/libssl/tls13_legacy.c
@@ -0,0 +1,327 @@
+/*      $OpenBSD: tls13_legacy.c,v 1.1 2020/02/15 14:40:38 jsing Exp $ */
+/*
+ * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <limits.h>
+
+#include "ssl_locl.h"
+#include "tls13_internal.h"
+
+SSL3_ENC_METHOD TLSv1_3_enc_data = {
+        .enc = NULL,
+        .enc_flags = SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_TLS1_3_CIPHERS,
+};
+
+static ssize_t
+tls13_legacy_wire_read(SSL *ssl, uint8_t *buf, size_t len)
+{
+        int n;
+
+        if (ssl->rbio == NULL) {
+                SSLerror(ssl, SSL_R_BIO_NOT_SET);
+                return TLS13_IO_FAILURE;
+        }
+
+        ssl->internal->rwstate = SSL_READING;
+
+        if ((n = BIO_read(ssl->rbio, buf, len)) <= 0) {
+                if (BIO_should_read(ssl->rbio))
+                        return TLS13_IO_WANT_POLLIN;
+                if (BIO_should_write(ssl->rbio))
+                        return TLS13_IO_WANT_POLLOUT;
+                if (n == 0)
+                        return TLS13_IO_EOF;
+
+                return TLS13_IO_FAILURE;
+        }
+
+        if (n == len)
+                ssl->internal->rwstate = SSL_NOTHING;
+
+        return n;
+}
+
+ssize_t
+tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg)
+{
+        struct tls13_ctx *ctx = arg;
+
+        return tls13_legacy_wire_read(ctx->ssl, buf, n);
+}
+
+static ssize_t
+tls13_legacy_wire_write(SSL *ssl, const uint8_t *buf, size_t len)
+{
+        int n;
+
+        if (ssl->wbio == NULL) {
+                SSLerror(ssl, SSL_R_BIO_NOT_SET);
+                return TLS13_IO_FAILURE;
+        }
+
+        ssl->internal->rwstate = SSL_WRITING;
+
+        if ((n = BIO_write(ssl->wbio, buf, len)) <= 0) {
+                if (BIO_should_read(ssl->wbio))
+                        return TLS13_IO_WANT_POLLIN;
+                if (BIO_should_write(ssl->wbio))
+                        return TLS13_IO_WANT_POLLOUT;
+
+                return TLS13_IO_FAILURE;
+        }
+
+        if (n == len)
+                ssl->internal->rwstate = SSL_NOTHING;
+
+        return n;
+}
+
+ssize_t
+tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg)
+{
+        struct tls13_ctx *ctx = arg;
+
+        return tls13_legacy_wire_write(ctx->ssl, buf, n);
+}
+
+static void
+tls13_legacy_error(SSL *ssl)
+{
+        struct tls13_ctx *ctx = ssl->internal->tls13;
+        int reason = SSL_R_UNKNOWN;
+
+        /* If we received a fatal alert we already put an error on the stack. */
+        if (S3I(ssl)->fatal_alert != 0)
+                return;
+
+        switch (ctx->error.code) {
+        case TLS13_ERR_VERIFY_FAILED:
+                reason = SSL_R_CERTIFICATE_VERIFY_FAILED;
+                break;
+        case TLS13_ERR_HRR_FAILED:
+                reason = SSL_R_NO_CIPHERS_AVAILABLE;
+                break;
+        case TLS13_ERR_TRAILING_DATA:
+                reason = SSL_R_EXTRA_DATA_IN_MESSAGE;
+                break;
+        case TLS13_ERR_NO_SHARED_CIPHER:
+                reason = SSL_R_NO_SHARED_CIPHER;
+                break;
+        }
+
+        /* Something (probably libcrypto) already pushed an error on the stack. */
+        if (reason == SSL_R_UNKNOWN && ERR_peek_error() != 0)
+                return;
+
+        ERR_put_error(ERR_LIB_SSL, (0xfff), reason, ctx->error.file,
+            ctx->error.line);
+}
+
+int
+tls13_legacy_return_code(SSL *ssl, ssize_t ret)
+{
+        if (ret > INT_MAX) {
+                SSLerror(ssl, ERR_R_INTERNAL_ERROR);
+                return -1;
+        }
+
+        /* A successful read, write or other operation. */
+        if (ret > 0)
+                return ret;
+
+        ssl->internal->rwstate = SSL_NOTHING;
+
+        switch (ret) {
+        case TLS13_IO_EOF:
+                return 0;
+
+        case TLS13_IO_FAILURE:
+                tls13_legacy_error(ssl);
+                return -1;
+
+        case TLS13_IO_ALERT:
+                tls13_legacy_error(ssl);
+                return -1;
+
+        case TLS13_IO_WANT_POLLIN:
+                BIO_set_retry_read(ssl->rbio);
+                ssl->internal->rwstate = SSL_READING;
+                return -1;
+
+        case TLS13_IO_WANT_POLLOUT:
+                BIO_set_retry_write(ssl->wbio);
+                ssl->internal->rwstate = SSL_WRITING;
+                return -1;
+
+        case TLS13_IO_WANT_RETRY:
+                SSLerror(ssl, ERR_R_INTERNAL_ERROR);
+                return -1;
+        }
+
+        SSLerror(ssl, ERR_R_INTERNAL_ERROR);
+        return -1;
+}
+
+int
+tls13_legacy_pending(const SSL *ssl)
+{
+        struct tls13_ctx *ctx = ssl->internal->tls13;
+        ssize_t ret;
+
+        if (ctx == NULL)
+                return 0;
+
+        ret = tls13_pending_application_data(ctx->rl);
+        if (ret < 0 || ret > INT_MAX)
+                return 0;
+
+        return ret;
+}
+
+int
+tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len, int peek)
+{
+        struct tls13_ctx *ctx = ssl->internal->tls13;
+        ssize_t ret;
+
+        if (ctx == NULL || !ctx->handshake_completed) {
+                if ((ret = ssl->internal->handshake_func(ssl)) <= 0)
+                        return ret;
+                return tls13_legacy_return_code(ssl, TLS13_IO_WANT_POLLIN);
+        }
+
+        if (type != SSL3_RT_APPLICATION_DATA) {
+                SSLerror(ssl, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+                return -1;
+        }
+        if (len < 0) {
+                SSLerror(ssl, SSL_R_BAD_LENGTH); 
+                return -1;
+        }
+
+        if (peek)
+                ret = tls13_peek_application_data(ctx->rl, buf, len);
+        else
+                ret = tls13_read_application_data(ctx->rl, buf, len);
+
+        return tls13_legacy_return_code(ssl, ret);
+}
+
+int
+tls13_legacy_write_bytes(SSL *ssl, int type, const void *vbuf, int len)
+{
+        struct tls13_ctx *ctx = ssl->internal->tls13;
+        const uint8_t *buf = vbuf;
+        size_t n, sent;
+        ssize_t ret;
+
+        if (ctx == NULL || !ctx->handshake_completed) {
+                if ((ret = ssl->internal->handshake_func(ssl)) <= 0)
+                        return ret;
+                return tls13_legacy_return_code(ssl, TLS13_IO_WANT_POLLOUT);
+        }
+
+        if (type != SSL3_RT_APPLICATION_DATA) {
+                SSLerror(ssl, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+                return -1;
+        }
+        if (len < 0) {
+                SSLerror(ssl, SSL_R_BAD_LENGTH); 
+                return -1;
+        }
+
+        /*
+         * The TLSv1.3 record layer write behaviour is the same as
+         * SSL_MODE_ENABLE_PARTIAL_WRITE.
+         */
+        if (ssl->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE) {
+                ret = tls13_write_application_data(ctx->rl, buf, len);
+                return tls13_legacy_return_code(ssl, ret);
+        }
+
+        /*
+         * In the non-SSL_MODE_ENABLE_PARTIAL_WRITE case we have to loop until
+         * we have written out all of the requested data.
+         */
+        sent = S3I(ssl)->wnum;
+        if (len < sent) {
+                SSLerror(ssl, SSL_R_BAD_LENGTH); 
+                return -1;
+        }
+        n = len - sent;
+        for (;;) {
+                if (n == 0) {
+                        S3I(ssl)->wnum = 0;
+                        return sent;
+                }
+                if ((ret = tls13_write_application_data(ctx->rl,
+                    &buf[sent], n)) <= 0) {
+                        S3I(ssl)->wnum = sent;
+                        return tls13_legacy_return_code(ssl, ret);
+                }
+                sent += ret;
+                n -= ret;
+        }
+}
+
+int
+tls13_legacy_shutdown(SSL *ssl)
+{
+        struct tls13_ctx *ctx = ssl->internal->tls13;
+        uint8_t buf[512]; /* XXX */
+        ssize_t ret;
+
+        /*
+         * We need to return 0 when we have sent a close-notify but have not
+         * yet received one. We return 1 only once we have sent and received
+         * close-notify alerts. All other cases return -1 and set internal
+         * state appropriately.
+         */
+        if (ctx == NULL || ssl->internal->quiet_shutdown) {
+                ssl->internal->shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN;
+                return 1;
+        }
+
+        /* Send close notify. */
+        if (!ctx->close_notify_sent) {
+                ctx->close_notify_sent = 1;
+                if ((ret = tls13_send_alert(ctx->rl, SSL_AD_CLOSE_NOTIFY)) < 0)
+                        return tls13_legacy_return_code(ssl, ret);
+        }
+
+        /* Ensure close notify has been sent. */
+        if ((ret = tls13_record_layer_send_pending(ctx->rl)) != TLS13_IO_SUCCESS)
+                return tls13_legacy_return_code(ssl, ret);
+
+        /* Receive close notify. */
+        if (!ctx->close_notify_recv) {
+                /*
+                 * If there is still application data pending then we have no
+                 * option but to discard it here. The application should have
+                 * continued to call SSL_read() instead of SSL_shutdown().
+                 */
+                /* XXX - tls13_drain_application_data()? */
+                if ((ret = tls13_read_application_data(ctx->rl, buf, sizeof(buf))) > 0)
+                        ret = TLS13_IO_WANT_POLLIN;
+                if (ret != TLS13_IO_EOF)
+                        return tls13_legacy_return_code(ssl, ret);
+        }
+
+        if (ctx->close_notify_recv)
+                return 1;
+
+        return 0;
+}
diff --git a/src/lib/libssl/tls13_lib.c b/src/lib/libssl/tls13_lib.c
index 92743ef4b3..bdf547c8d9 100644
--- a/src/lib/libssl/tls13_lib.c
+++ b/src/lib/libssl/tls13_lib.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: tls13_lib.c,v 1.33 2020/02/05 06:12:43 tb Exp $ */
+/*      $OpenBSD: tls13_lib.c,v 1.34 2020/02/15 14:40:38 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2019 Bob Beck <beck@openbsd.org>
@@ -16,7 +16,6 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include <limits.h>
 #include <stddef.h>
 
 #include <openssl/evp.h>
@@ -24,11 +23,6 @@
 #include "ssl_locl.h"
 #include "tls13_internal.h"
 
-SSL3_ENC_METHOD TLSv1_3_enc_data = {
-        .enc = NULL,
-        .enc_flags = SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_TLS1_3_CIPHERS,
-};
-
 /*
  * RFC 8446 section 4.1.3, magic values which must be set by the
  * server in server random if it is willing to downgrade but supports
@@ -317,307 +311,6 @@ tls13_ctx_free(struct tls13_ctx *ctx)
         freezero(ctx, sizeof(struct tls13_ctx));
 }
 
-static ssize_t
-tls13_legacy_wire_read(SSL *ssl, uint8_t *buf, size_t len)
-{
-        int n;
-
-        if (ssl->rbio == NULL) {
-                SSLerror(ssl, SSL_R_BIO_NOT_SET);
-                return TLS13_IO_FAILURE;
-        }
-
-        ssl->internal->rwstate = SSL_READING;
-
-        if ((n = BIO_read(ssl->rbio, buf, len)) <= 0) {
-                if (BIO_should_read(ssl->rbio))
-                        return TLS13_IO_WANT_POLLIN;
-                if (BIO_should_write(ssl->rbio))
-                        return TLS13_IO_WANT_POLLOUT;
-                if (n == 0)
-                        return TLS13_IO_EOF;
-
-                return TLS13_IO_FAILURE;
-        }
-
-        if (n == len)
-                ssl->internal->rwstate = SSL_NOTHING;
-
-        return n;
-}
-
-ssize_t
-tls13_legacy_wire_read_cb(void *buf, size_t n, void *arg)
-{
-        struct tls13_ctx *ctx = arg;
-
-        return tls13_legacy_wire_read(ctx->ssl, buf, n);
-}
-
-static ssize_t
-tls13_legacy_wire_write(SSL *ssl, const uint8_t *buf, size_t len)
-{
-        int n;
-
-        if (ssl->wbio == NULL) {
-                SSLerror(ssl, SSL_R_BIO_NOT_SET);
-                return TLS13_IO_FAILURE;
-        }
-
-        ssl->internal->rwstate = SSL_WRITING;
-
-        if ((n = BIO_write(ssl->wbio, buf, len)) <= 0) {
-                if (BIO_should_read(ssl->wbio))
-                        return TLS13_IO_WANT_POLLIN;
-                if (BIO_should_write(ssl->wbio))
-                        return TLS13_IO_WANT_POLLOUT;
-
-                return TLS13_IO_FAILURE;
-        }
-
-        if (n == len)
-                ssl->internal->rwstate = SSL_NOTHING;
-
-        return n;
-}
-
-ssize_t
-tls13_legacy_wire_write_cb(const void *buf, size_t n, void *arg)
-{
-        struct tls13_ctx *ctx = arg;
-
-        return tls13_legacy_wire_write(ctx->ssl, buf, n);
-}
-
-static void
-tls13_legacy_error(SSL *ssl)
-{
-        struct tls13_ctx *ctx = ssl->internal->tls13;
-        int reason = SSL_R_UNKNOWN;
-
-        /* If we received a fatal alert we already put an error on the stack. */
-        if (S3I(ssl)->fatal_alert != 0)
-                return;
-
-        switch (ctx->error.code) {
-        case TLS13_ERR_VERIFY_FAILED:
-                reason = SSL_R_CERTIFICATE_VERIFY_FAILED;
-                break;
-        case TLS13_ERR_HRR_FAILED:
-                reason = SSL_R_NO_CIPHERS_AVAILABLE;
-                break;
-        case TLS13_ERR_TRAILING_DATA:
-                reason = SSL_R_EXTRA_DATA_IN_MESSAGE;
-                break;
-        case TLS13_ERR_NO_SHARED_CIPHER:
-                reason = SSL_R_NO_SHARED_CIPHER;
-                break;
-        }
-
-        /* Something (probably libcrypto) already pushed an error on the stack. */
-        if (reason == SSL_R_UNKNOWN && ERR_peek_error() != 0)
-                return;
-
-        ERR_put_error(ERR_LIB_SSL, (0xfff), reason, ctx->error.file,
-            ctx->error.line);
-}
-
-int
-tls13_legacy_return_code(SSL *ssl, ssize_t ret)
-{
-        if (ret > INT_MAX) {
-                SSLerror(ssl, ERR_R_INTERNAL_ERROR);
-                return -1;
-        }
-
-        /* A successful read, write or other operation. */
-        if (ret > 0)
-                return ret;
-
-        ssl->internal->rwstate = SSL_NOTHING;
-
-        switch (ret) {
-        case TLS13_IO_EOF:
-                return 0;
-
-        case TLS13_IO_FAILURE:
-                tls13_legacy_error(ssl);
-                return -1;
-
-        case TLS13_IO_ALERT:
-                tls13_legacy_error(ssl);
-                return -1;
-
-        case TLS13_IO_WANT_POLLIN:
-                BIO_set_retry_read(ssl->rbio);
-                ssl->internal->rwstate = SSL_READING;
-                return -1;
-
-        case TLS13_IO_WANT_POLLOUT:
-                BIO_set_retry_write(ssl->wbio);
-                ssl->internal->rwstate = SSL_WRITING;
-                return -1;
-
-        case TLS13_IO_WANT_RETRY:
-                SSLerror(ssl, ERR_R_INTERNAL_ERROR);
-                return -1;
-        }
-
-        SSLerror(ssl, ERR_R_INTERNAL_ERROR);
-        return -1;
-}
-
-int
-tls13_legacy_pending(const SSL *ssl)
-{
-        struct tls13_ctx *ctx = ssl->internal->tls13;
-        ssize_t ret;
-
-        if (ctx == NULL)
-                return 0;
-
-        ret = tls13_pending_application_data(ctx->rl);
-        if (ret < 0 || ret > INT_MAX)
-                return 0;
-
-        return ret;
-}
-
-int
-tls13_legacy_read_bytes(SSL *ssl, int type, unsigned char *buf, int len, int peek)
-{
-        struct tls13_ctx *ctx = ssl->internal->tls13;
-        ssize_t ret;
-
-        if (ctx == NULL || !ctx->handshake_completed) {
-                if ((ret = ssl->internal->handshake_func(ssl)) <= 0)
-                        return ret;
-                return tls13_legacy_return_code(ssl, TLS13_IO_WANT_POLLIN);
-        }
-
-        if (type != SSL3_RT_APPLICATION_DATA) {
-                SSLerror(ssl, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-                return -1;
-        }
-        if (len < 0) {
-                SSLerror(ssl, SSL_R_BAD_LENGTH); 
-                return -1;
-        }
-
-        if (peek)
-                ret = tls13_peek_application_data(ctx->rl, buf, len);
-        else
-                ret = tls13_read_application_data(ctx->rl, buf, len);
-
-        return tls13_legacy_return_code(ssl, ret);
-}
-
-int
-tls13_legacy_write_bytes(SSL *ssl, int type, const void *vbuf, int len)
-{
-        struct tls13_ctx *ctx = ssl->internal->tls13;
-        const uint8_t *buf = vbuf;
-        size_t n, sent;
-        ssize_t ret;
-
-        if (ctx == NULL || !ctx->handshake_completed) {
-                if ((ret = ssl->internal->handshake_func(ssl)) <= 0)
-                        return ret;
-                return tls13_legacy_return_code(ssl, TLS13_IO_WANT_POLLOUT);
-        }
-
-        if (type != SSL3_RT_APPLICATION_DATA) {
-                SSLerror(ssl, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-                return -1;
-        }
-        if (len < 0) {
-                SSLerror(ssl, SSL_R_BAD_LENGTH); 
-                return -1;
-        }
-
-        /*
-         * The TLSv1.3 record layer write behaviour is the same as
-         * SSL_MODE_ENABLE_PARTIAL_WRITE.
-         */
-        if (ssl->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE) {
-                ret = tls13_write_application_data(ctx->rl, buf, len);
-                return tls13_legacy_return_code(ssl, ret);
-        }
-
-        /*
-         * In the non-SSL_MODE_ENABLE_PARTIAL_WRITE case we have to loop until
-         * we have written out all of the requested data.
-         */
-        sent = S3I(ssl)->wnum;
-        if (len < sent) {
-                SSLerror(ssl, SSL_R_BAD_LENGTH); 
-                return -1;
-        }
-        n = len - sent;
-        for (;;) {
-                if (n == 0) {
-                        S3I(ssl)->wnum = 0;
-                        return sent;
-                }
-                if ((ret = tls13_write_application_data(ctx->rl,
-                    &buf[sent], n)) <= 0) {
-                        S3I(ssl)->wnum = sent;
-                        return tls13_legacy_return_code(ssl, ret);
-                }
-                sent += ret;
-                n -= ret;
-        }
-}
-
-int
-tls13_legacy_shutdown(SSL *ssl)
-{
-        struct tls13_ctx *ctx = ssl->internal->tls13;
-        uint8_t buf[512]; /* XXX */
-        ssize_t ret;
-
-        /*
-         * We need to return 0 when we have sent a close-notify but have not
-         * yet received one. We return 1 only once we have sent and received
-         * close-notify alerts. All other cases return -1 and set internal
-         * state appropriately.
-         */
-        if (ctx == NULL || ssl->internal->quiet_shutdown) {
-                ssl->internal->shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN;
-                return 1;
-        }
-
-        /* Send close notify. */
-        if (!ctx->close_notify_sent) {
-                ctx->close_notify_sent = 1;
-                if ((ret = tls13_send_alert(ctx->rl, SSL_AD_CLOSE_NOTIFY)) < 0)
-                        return tls13_legacy_return_code(ssl, ret);
-        }
-
-        /* Ensure close notify has been sent. */
-        if ((ret = tls13_record_layer_send_pending(ctx->rl)) != TLS13_IO_SUCCESS)
-                return tls13_legacy_return_code(ssl, ret);
-
-        /* Receive close notify. */
-        if (!ctx->close_notify_recv) {
-                /*
-                 * If there is still application data pending then we have no
-                 * option but to discard it here. The application should have
-                 * continued to call SSL_read() instead of SSL_shutdown().
-                 */
-                /* XXX - tls13_drain_application_data()? */
-                if ((ret = tls13_read_application_data(ctx->rl, buf, sizeof(buf))) > 0)
-                        ret = TLS13_IO_WANT_POLLIN;
-                if (ret != TLS13_IO_EOF)
-                        return tls13_legacy_return_code(ssl, ret);
-        }
-
-        if (ctx->close_notify_recv)
-                return 1;
-
-        return 0;
-}
-
 /*
  * Certificate Verify padding - RFC 8446 section 4.4.3.
  */