Rewrite the TLS status request extension to use the new TLS extension framework.

ok jsing@

3 files changed, 179 insertions, 177 deletions

diff --git a/src/lib/libssl/ssl_tlsext.c b/src/lib/libssl/ssl_tlsext.c
index 9db2d1ab41..646c59e5d6 100644
--- a/src/lib/libssl/ssl_tlsext.c
+++ b/src/lib/libssl/ssl_tlsext.c
@@ -1,7 +1,8 @@
-/* $OpenBSD: ssl_tlsext.c,v 1.8 2017/08/12 21:47:59 jsing Exp $ */
+/* $OpenBSD: ssl_tlsext.c,v 1.9 2017/08/12 23:38:12 beck Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
+ * Copyright (c) 2017 Bob Beck <beck@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
@@ -15,6 +16,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include <openssl/ocsp.h>
 
 #include "ssl_locl.h"
 
@@ -551,6 +553,160 @@ tlsext_sni_serverhello_parse(SSL *s, CBS *cbs, int *alert)
 }
 
 /*
+ *Certificate Status Request - RFC 6066 section 8.
+ */
+
+int
+tlsext_ocsp_clienthello_needs(SSL *s)
+{
+        return (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
+            s->version != DTLS1_VERSION);
+}
+
+int
+tlsext_ocsp_clienthello_build(SSL *s, CBB *cbb)
+{
+        CBB ocsp_respid_list, respid, exts;
+        unsigned char *ext_data;
+        size_t ext_len;
+        int i;
+
+        if (!CBB_add_u8(cbb, TLSEXT_STATUSTYPE_ocsp))
+                return 0;
+        if (!CBB_add_u16_length_prefixed(cbb, &ocsp_respid_list))
+                return 0;
+        if (!CBB_add_u16_length_prefixed(cbb, &exts))
+                return 0;
+        for (i = 0; i < sk_OCSP_RESPID_num(s->internal->tlsext_ocsp_ids); i++) {
+                unsigned char *respid_data;
+                OCSP_RESPID *id;
+                size_t id_len;
+
+                if ((id = sk_OCSP_RESPID_value(s->internal->tlsext_ocsp_ids,
+                    i)) ==  NULL)
+                        return 0;
+                if ((id_len = i2d_OCSP_RESPID(id, NULL)) == -1)
+                        return 0;
+                if (!CBB_add_u16_length_prefixed(&ocsp_respid_list, &respid))
+                        return 0;
+                if (!CBB_add_space(&respid, &respid_data, id_len))
+                        return 0;
+                if ((i2d_OCSP_RESPID(id, &respid_data)) != id_len)
+                        return 0;
+        }
+        if ((ext_len = i2d_X509_EXTENSIONS(s->internal->tlsext_ocsp_exts,
+            NULL)) == -1)
+                return 0;
+        if (!CBB_add_space(&exts, &ext_data, ext_len))
+                return 0;
+        if ((i2d_X509_EXTENSIONS(s->internal->tlsext_ocsp_exts, &ext_data) !=
+            ext_len))
+                return 0;
+        if (!CBB_flush(cbb))
+                return 0;
+        return 1;
+}
+
+int
+tlsext_ocsp_clienthello_parse(SSL *s, CBS *cbs, int *alert)
+{
+        int failure = SSL_AD_DECODE_ERROR;
+        unsigned char *respid_data = NULL;
+        unsigned char *ext_data = NULL;
+        size_t ext_len, respid_len;
+        uint8_t status_type;
+        CBS respids, exts;
+        int ret = 0;
+
+        if (!CBS_get_u8(cbs, &status_type))
+                goto err;
+        if (status_type != TLSEXT_STATUSTYPE_ocsp) {
+                /* ignore unknown status types */
+                s->tlsext_status_type = -1;
+                return 1;
+        }
+        s->tlsext_status_type = status_type;
+        if (!CBS_get_u16_length_prefixed(cbs, &respids))
+                goto err;
+
+        /* XXX */
+        sk_OCSP_RESPID_pop_free(s->internal->tlsext_ocsp_ids, OCSP_RESPID_free);
+        s->internal->tlsext_ocsp_ids = NULL;
+        if (CBS_len(cbs) > 0) {
+                s->internal->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
+                if (s->internal->tlsext_ocsp_ids == NULL) {
+                        failure = SSL_AD_INTERNAL_ERROR;
+                        goto err;
+                }
+        }
+
+        while (CBS_len(&respids) > 0) {
+                OCSP_RESPID *id = NULL;
+
+                if (!CBS_stow(cbs, &respid_data, &respid_len))
+                        goto err;
+                if ((id = d2i_OCSP_RESPID(NULL,
+                    (const unsigned char **)&respid_data, respid_len)) == NULL)
+                        goto err;
+                if (!sk_OCSP_RESPID_push(s->internal->tlsext_ocsp_ids, id)) {
+                        failure = SSL_AD_INTERNAL_ERROR;
+                        OCSP_RESPID_free(id);
+                        goto err;
+                }
+                free(respid_data);
+                respid_data = NULL;
+        }
+
+        /* Read in request_extensions */
+        if (!CBS_get_u16_length_prefixed(cbs, &exts))
+                goto err;
+        if (!CBS_stow(&exts, &ext_data, &ext_len))
+                goto err;
+        if (ext_len > 0) {
+                sk_X509_EXTENSION_pop_free(s->internal->tlsext_ocsp_exts,
+                    X509_EXTENSION_free);
+                if ((s->internal->tlsext_ocsp_exts = d2i_X509_EXTENSIONS(NULL,
+                    (const unsigned char **)&ext_data, ext_len)) == NULL)
+                        goto err;
+        }
+        /* should be nothing left */
+        if (CBS_len(cbs) > 0)
+                goto err;
+
+        ret = 1;
+ err:
+        free(respid_data);
+        free(ext_data);
+        if (ret == 0)
+                *alert = failure;
+        return ret;
+}
+
+int
+tlsext_ocsp_serverhello_needs(SSL *s)
+{
+        return s->internal->tlsext_status_expected;
+}
+
+int
+tlsext_ocsp_serverhello_build(SSL *s, CBB *cbb)
+{
+        return 1;
+}
+
+int
+tlsext_ocsp_serverhello_parse(SSL *s, CBS *cbs, int *alert)
+{
+        if (s->tlsext_status_type == -1) {
+                *alert = TLS1_AD_UNSUPPORTED_EXTENSION;
+                return 0;
+        }
+        /* Set flag to expect CertificateStatus message */
+        s->internal->tlsext_status_expected = 1;
+        return 1;
+}
+
+/*
  * SessionTicket extension - RFC 5077 section 3.2
  */
 int
@@ -705,6 +861,15 @@ static struct tls_extension tls_extensions[] = {
                 .serverhello_parse = tlsext_ri_serverhello_parse,
         },
         {
+                .type = TLSEXT_TYPE_status_request,
+                .clienthello_needs = tlsext_ocsp_clienthello_needs,
+                .clienthello_build = tlsext_ocsp_clienthello_build,
+                .clienthello_parse = tlsext_ocsp_clienthello_parse,
+                .serverhello_needs = tlsext_ocsp_serverhello_needs,
+                .serverhello_build = tlsext_ocsp_serverhello_build,
+                .serverhello_parse = tlsext_ocsp_serverhello_parse,
+        },
+        {
                 .type = TLSEXT_TYPE_ec_point_formats,
                 .clienthello_needs = tlsext_ecpf_clienthello_needs,
                 .clienthello_build = tlsext_ecpf_clienthello_build,
@@ -758,7 +923,7 @@ tlsext_clienthello_build(SSL *s, CBB *cbb)
 
                 if (!tlsext->clienthello_needs(s))
                         continue;
-                
+
                 if (!CBB_add_u16(cbb, tlsext->type))
                         return 0;
                 if (!CBB_add_u16_length_prefixed(cbb, &extension_data))
@@ -811,7 +976,7 @@ tlsext_serverhello_build(SSL *s, CBB *cbb)
 
                 if (!tlsext->serverhello_needs(s))
                         continue;
-                
+
                 if (!CBB_add_u16(cbb, tlsext->type))
                         return 0;
                 if (!CBB_add_u16_length_prefixed(cbb, &extension_data))
diff --git a/src/lib/libssl/ssl_tlsext.h b/src/lib/libssl/ssl_tlsext.h
index 4f8ae0cf35..bba8bdbea9 100644
--- a/src/lib/libssl/ssl_tlsext.h
+++ b/src/lib/libssl/ssl_tlsext.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.h,v 1.7 2017/08/12 21:47:59 jsing Exp $ */
+/* $OpenBSD: ssl_tlsext.h,v 1.8 2017/08/12 23:38:12 beck Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -51,6 +51,13 @@ int tlsext_ecpf_serverhello_needs(SSL *s);
 int tlsext_ecpf_serverhello_build(SSL *s, CBB *cbb);
 int tlsext_ecpf_serverhello_parse(SSL *s, CBS *cbs, int *alert);
 
+int tlsext_ocsp_clienthello_needs(SSL *s);
+int tlsext_ocsp_clienthello_build(SSL *s, CBB *cbb);
+int tlsext_ocsp_clienthello_parse(SSL *s, CBS *cbs, int *alert);
+int tlsext_ocsp_serverhello_needs(SSL *s);
+int tlsext_ocsp_serverhello_build(SSL *s, CBB *cbb);
+int tlsext_ocsp_serverhello_parse(SSL *s, CBS *cbs, int *alert);
+
 int tlsext_sessionticket_clienthello_needs(SSL *s);
 int tlsext_sessionticket_clienthello_build(SSL *s, CBB *cbb);
 int tlsext_sessionticket_clienthello_parse(SSL *s, CBS *cbs, int *alert);
diff --git a/src/lib/libssl/t1_lib.c b/src/lib/libssl/t1_lib.c
index e27a7d1a59..405f08ed33 100644
--- a/src/lib/libssl/t1_lib.c
+++ b/src/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.130 2017/08/12 21:47:59 jsing Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.131 2017/08/12 23:38:12 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -687,51 +687,6 @@ ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
                 return NULL;
         ret += len;
 
-        if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
-            s->version != DTLS1_VERSION) {
-                int i;
-                long extlen, idlen, itmp;
-                OCSP_RESPID *id;
-
-                idlen = 0;
-                for (i = 0; i < sk_OCSP_RESPID_num(s->internal->tlsext_ocsp_ids); i++) {
-                        id = sk_OCSP_RESPID_value(s->internal->tlsext_ocsp_ids, i);
-                        itmp = i2d_OCSP_RESPID(id, NULL);
-                        if (itmp <= 0)
-                                return NULL;
-                        idlen += itmp + 2;
-                }
-
-                if (s->internal->tlsext_ocsp_exts) {
-                        extlen = i2d_X509_EXTENSIONS(s->internal->tlsext_ocsp_exts, NULL);
-                        if (extlen < 0)
-                                return NULL;
-                } else
-                        extlen = 0;
-
-                if ((size_t)(limit - ret) < 7 + extlen + idlen)
-                        return NULL;
-                s2n(TLSEXT_TYPE_status_request, ret);
-                if (extlen + idlen > 0xFFF0)
-                        return NULL;
-                s2n(extlen + idlen + 5, ret);
-                *(ret++) = TLSEXT_STATUSTYPE_ocsp;
-                s2n(idlen, ret);
-                for (i = 0; i < sk_OCSP_RESPID_num(s->internal->tlsext_ocsp_ids); i++) {
-                        /* save position of id len */
-                        unsigned char *q = ret;
-                        id = sk_OCSP_RESPID_value(s->internal->tlsext_ocsp_ids, i);
-                        /* skip over id len */
-                        ret += 2;
-                        itmp = i2d_OCSP_RESPID(id, &ret);
-                        /* write id len */
-                        s2n(itmp, q);
-                }
-                s2n(extlen, ret);
-                if (extlen > 0)
-                        i2d_X509_EXTENSIONS(s->internal->tlsext_ocsp_exts, &ret);
-        }
-
         if (s->internal->alpn_client_proto_list != NULL &&
             S3I(s)->tmp.finish_md_len == 0) {
                 if ((size_t)(limit - ret) <
@@ -837,14 +792,6 @@ ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
          * extension.
          */
 
-        if (s->internal->tlsext_status_expected) {
-                if ((size_t)(limit - ret) < 4)
-                        return NULL;
-
-                s2n(TLSEXT_TYPE_status_request, ret);
-                s2n(0, ret);
-        }
-
 #ifndef OPENSSL_NO_SRTP
         if (SSL_IS_DTLS(s) && s->internal->srtp_profile) {
                 int el;
@@ -1011,111 +958,7 @@ ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
                 if (!tlsext_clienthello_parse_one(s, &cbs, type, al))
                         return 0;
 
-                if (type == TLSEXT_TYPE_status_request &&
-                    s->version != DTLS1_VERSION) {
-
-                        if (size < 5) {
-                                *al = SSL_AD_DECODE_ERROR;
-                                return 0;
-                        }
-
-                        s->tlsext_status_type = *data++;
-                        size--;
-                        if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
-                                const unsigned char *sdata;
-                                int dsize;
-                                /* Read in responder_id_list */
-                                n2s(data, dsize);
-                                size -= 2;
-                                if (dsize > size) {
-                                        *al = SSL_AD_DECODE_ERROR;
-                                        return 0;
-                                }
-
-                                /*
-                                 * We remove any OCSP_RESPIDs from a
-                                 * previous handshake to prevent
-                                 * unbounded memory growth.
-                                 */
-                                sk_OCSP_RESPID_pop_free(s->internal->tlsext_ocsp_ids,
-                                    OCSP_RESPID_free);
-                                s->internal->tlsext_ocsp_ids = NULL;
-                                if (dsize > 0) {
-                                        s->internal->tlsext_ocsp_ids =
-                                            sk_OCSP_RESPID_new_null();
-                                        if (s->internal->tlsext_ocsp_ids == NULL) {
-                                                *al = SSL_AD_INTERNAL_ERROR;
-                                                return 0;
-                                        }
-                                }
-
-                                while (dsize > 0) {
-                                        OCSP_RESPID *id;
-                                        int idsize;
-                                        if (dsize < 4) {
-                                                *al = SSL_AD_DECODE_ERROR;
-                                                return 0;
-                                        }
-                                        n2s(data, idsize);
-                                        dsize -= 2 + idsize;
-                                        size -= 2 + idsize;
-                                        if (dsize < 0) {
-                                                *al = SSL_AD_DECODE_ERROR;
-                                                return 0;
-                                        }
-                                        sdata = data;
-                                        data += idsize;
-                                        id = d2i_OCSP_RESPID(NULL,
-                                            &sdata, idsize);
-                                        if (!id) {
-                                                *al = SSL_AD_DECODE_ERROR;
-                                                return 0;
-                                        }
-                                        if (data != sdata) {
-                                                OCSP_RESPID_free(id);
-                                                *al = SSL_AD_DECODE_ERROR;
-                                                return 0;
-                                        }
-                                        if (!sk_OCSP_RESPID_push(
-                                            s->internal->tlsext_ocsp_ids, id)) {
-                                                OCSP_RESPID_free(id);
-                                                *al = SSL_AD_INTERNAL_ERROR;
-                                                return 0;
-                                        }
-                                }
-
-                                /* Read in request_extensions */
-                                if (size < 2) {
-                                        *al = SSL_AD_DECODE_ERROR;
-                                        return 0;
-                                }
-                                n2s(data, dsize);
-                                size -= 2;
-                                if (dsize != size) {
-                                        *al = SSL_AD_DECODE_ERROR;
-                                        return 0;
-                                }
-                                sdata = data;
-                                if (dsize > 0) {
-                                        sk_X509_EXTENSION_pop_free(s->internal->tlsext_ocsp_exts,
-                                            X509_EXTENSION_free);
-
-                                        s->internal->tlsext_ocsp_exts =
-                                            d2i_X509_EXTENSIONS(NULL,
-                                            &sdata, dsize);
-                                        if (!s->internal->tlsext_ocsp_exts ||
-                                                    (data + dsize != sdata)) {
-                                                *al = SSL_AD_DECODE_ERROR;
-                                                return 0;
-                                        }
-                                }
-                        } else {
-                                /* We don't know what to do with any other type
-                                * so ignore it.
-                                */
-                                s->tlsext_status_type = -1;
-                        }
-                } else if (type ==
+                if (type ==
                     TLSEXT_TYPE_application_layer_protocol_negotiation &&
                     s->ctx->internal->alpn_select_cb != NULL &&
                     S3I(s)->tmp.finish_md_len == 0) {
@@ -1123,7 +966,6 @@ ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
                             size, al) != 1)
                                 return (0);
                 }
-
                 /* session ticket processed earlier */
 #ifndef OPENSSL_NO_SRTP
                 else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
@@ -1197,19 +1039,7 @@ ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, size_t n, int *al)
                 if (!tlsext_serverhello_parse_one(s, &cbs, type, al))
                         return 0;
 
-                if (type == TLSEXT_TYPE_status_request &&
-                    s->version != DTLS1_VERSION) {
-                        /* MUST be empty and only sent if we've requested
-                         * a status request message.
-                         */
-                        if ((s->tlsext_status_type == -1) || (size > 0)) {
-                                *al = TLS1_AD_UNSUPPORTED_EXTENSION;
-                                return 0;
-                        }
-                        /* Set flag to expect CertificateStatus message */
-                        s->internal->tlsext_status_expected = 1;
-                } else if (type ==
-                    TLSEXT_TYPE_application_layer_protocol_negotiation) {
+                if (type == TLSEXT_TYPE_application_layer_protocol_negotiation) {
                         unsigned int len;
 
                         /* We must have requested it. */