Remove peer_pkeys from SSL_SESSION.

peer_pkeys comes from some world where peers can send multiple certificates
- in fact, one of each known type. Since we do not live in such a world,
get rid of peer_pkeys and simply use peer_cert instead (in both TLSv1.2
and TLSv1.3, both clients and servers can only send a single leaf
(aka end-entity) certificate).

ok inoguchi@ tb@

6 files changed, 58 insertions, 96 deletions

diff --git a/src/lib/libssl/ssl_clnt.c b/src/lib/libssl/ssl_clnt.c
index 8b5ccd480a..61c1d71c8e 100644
--- a/src/lib/libssl/ssl_clnt.c
+++ b/src/lib/libssl/ssl_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_clnt.c,v 1.136 2022/01/11 18:39:28 jsing Exp $ */
+/* $OpenBSD: ssl_clnt.c,v 1.137 2022/01/11 19:03:15 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1071,12 +1071,13 @@ ssl3_get_server_hello(SSL *s)
 int
 ssl3_get_server_certificate(SSL *s)
 {
-        int al, i, ret;
         CBS cbs, cert_list;
         X509 *x = NULL;
         const unsigned char *q;
         STACK_OF(X509) *sk = NULL;
-        EVP_PKEY *pkey = NULL;
+        EVP_PKEY *pkey;
+        int cert_type;
+        int al, ret;
 
         if ((ret = ssl3_get_message(s, SSL3_ST_CR_CERT_A,
             SSL3_ST_CR_CERT_B, -1, s->internal->max_cert_list)) <= 0)
@@ -1144,12 +1145,11 @@ ssl3_get_server_certificate(SSL *s)
                 x = NULL;
         }
 
-        i = ssl_verify_cert_chain(s, sk);
-        if ((s->verify_mode != SSL_VERIFY_NONE) && (i <= 0)) {
+        if (ssl_verify_cert_chain(s, sk) <= 0 &&
+            s->verify_mode != SSL_VERIFY_NONE) {
                 al = ssl_verify_alarm_type(s->verify_result);
                 SSLerror(s, SSL_R_CERTIFICATE_VERIFY_FAILED);
                 goto fatal_err;
-
         }
         ERR_clear_error(); /* but we keep s->verify_result */
 
@@ -1159,39 +1159,31 @@ ssl3_get_server_certificate(SSL *s)
          */
         x = sk_X509_value(sk, 0);
 
-        pkey = X509_get_pubkey(x);
-
-        if (pkey == NULL || EVP_PKEY_missing_parameters(pkey)) {
+        if ((pkey = X509_get0_pubkey(x)) == NULL ||
+            EVP_PKEY_missing_parameters(pkey)) {
                 x = NULL;
                 al = SSL3_AL_FATAL;
                 SSLerror(s, SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS);
                 goto fatal_err;
         }
-
-        i = ssl_cert_type(x, pkey);
-        if (i < 0) {
+        if ((cert_type = ssl_cert_type(x, pkey)) < 0) {
                 x = NULL;
                 al = SSL3_AL_FATAL;
                 SSLerror(s, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
                 goto fatal_err;
         }
-        s->session->peer_cert_type = i;
-
-        sk_X509_pop_free(s->session->cert_chain, X509_free);
-        s->session->cert_chain = sk;
-        sk = NULL;
-
-        X509_up_ref(x);
-        X509_free(s->session->peer_pkeys[i].x509);
-        s->session->peer_pkeys[i].x509 = x;
-        s->session->peer_key = &s->session->peer_pkeys[i];
 
         X509_up_ref(x);
         X509_free(s->session->peer_cert);
         s->session->peer_cert = x;
+        s->session->peer_cert_type = cert_type;
 
         s->session->verify_result = s->verify_result;
 
+        sk_X509_pop_free(s->session->cert_chain, X509_free);
+        s->session->cert_chain = sk;
+        sk = NULL;
+
         x = NULL;
         ret = 1;
 
@@ -1204,7 +1196,6 @@ ssl3_get_server_certificate(SSL *s)
                 ssl3_send_alert(s, SSL3_AL_FATAL, al);
         }
  err:
-        EVP_PKEY_free(pkey);
         X509_free(x);
         sk_X509_pop_free(sk, X509_free);
 
@@ -1377,12 +1368,12 @@ ssl3_get_server_key_exchange(SSL *s)
                 EVP_PKEY_CTX *pctx;
                 EVP_PKEY *pkey = NULL;
 
-                if ((alg_a & SSL_aRSA) != 0) {
-                        pkey = X509_get0_pubkey(
-                            s->session->peer_pkeys[SSL_PKEY_RSA].x509);
-                } else if ((alg_a & SSL_aECDSA) != 0) {
-                        pkey = X509_get0_pubkey(
-                            s->session->peer_pkeys[SSL_PKEY_ECC].x509);
+                if ((alg_a & SSL_aRSA) != 0 &&
+                    s->session->peer_cert_type == SSL_PKEY_RSA) {
+                        pkey = X509_get0_pubkey(s->session->peer_cert);
+                } else if ((alg_a & SSL_aECDSA) != 0 &&
+                    s->session->peer_cert_type == SSL_PKEY_ECC) {
+                        pkey = X509_get0_pubkey(s->session->peer_cert);
                 }
                 if (pkey == NULL) {
                         al = SSL_AD_ILLEGAL_PARAMETER;
@@ -1800,7 +1791,7 @@ ssl3_send_client_kex_rsa(SSL *s, CBB *cbb)
         unsigned char pms[SSL_MAX_MASTER_KEY_LENGTH];
         unsigned char *enc_pms = NULL;
         uint16_t max_legacy_version;
-        EVP_PKEY *pkey = NULL;
+        EVP_PKEY *pkey;
         RSA *rsa;
         int ret = 0;
         int enc_len;
@@ -1810,7 +1801,7 @@ ssl3_send_client_kex_rsa(SSL *s, CBB *cbb)
          * RSA-Encrypted Premaster Secret Message - RFC 5246 section 7.4.7.1.
          */
 
-        pkey = X509_get_pubkey(s->session->peer_pkeys[SSL_PKEY_RSA].x509);
+        pkey = X509_get0_pubkey(s->session->peer_cert);
         if (pkey == NULL || (rsa = EVP_PKEY_get0_RSA(pkey)) == NULL) {
                 SSLerror(s, ERR_R_INTERNAL_ERROR);
                 goto err;
@@ -1855,7 +1846,6 @@ ssl3_send_client_kex_rsa(SSL *s, CBB *cbb)
 
  err:
         explicit_bzero(pms, sizeof(pms));
-        EVP_PKEY_free(pkey);
         free(enc_pms);
 
         return ret;
@@ -1938,8 +1928,7 @@ ssl3_send_client_kex_gost(SSL *s, CBB *cbb)
         unsigned char premaster_secret[32], shared_ukm[32], tmp[256];
         EVP_PKEY_CTX *pkey_ctx = NULL;
         EVP_MD_CTX *ukm_hash = NULL;
-        EVP_PKEY *pub_key;
-        X509 *peer_cert;
+        EVP_PKEY *pkey;
         size_t msglen;
         unsigned int md_len;
         CBB gostblob;
@@ -1947,12 +1936,12 @@ ssl3_send_client_kex_gost(SSL *s, CBB *cbb)
         int ret = 0;
 
         /* Get server sertificate PKEY and create ctx from it */
-        peer_cert = s->session->peer_pkeys[SSL_PKEY_GOST01].x509;
-        if ((pub_key = X509_get0_pubkey(peer_cert)) == NULL) {
+        pkey = X509_get0_pubkey(s->session->peer_cert);
+        if (pkey == NULL || s->session->peer_cert_type != SSL_PKEY_GOST01) {
                 SSLerror(s, SSL_R_NO_GOST_CERTIFICATE_SENT_BY_PEER);
                 goto err;
         }
-        if ((pkey_ctx = EVP_PKEY_CTX_new(pub_key, NULL)) == NULL) {
+        if ((pkey_ctx = EVP_PKEY_CTX_new(pkey, NULL)) == NULL) {
                 SSLerror(s, ERR_R_MALLOC_FAILURE);
                 goto err;
         }
@@ -2449,9 +2438,8 @@ int
 ssl3_check_cert_and_algorithm(SSL *s)
 {
         long alg_k, alg_a;
-        EVP_PKEY *pkey = NULL;
         int nid = NID_undef;
-        int i, idx;
+        int i;
 
         alg_k = S3I(s)->hs.cipher->algorithm_mkey;
         alg_a = S3I(s)->hs.cipher->algorithm_auth;
@@ -2465,20 +2453,15 @@ ssl3_check_cert_and_algorithm(SSL *s)
 
         /* This is the passed certificate. */
 
-        idx = s->session->peer_cert_type;
-        if (idx == SSL_PKEY_ECC) {
-                if (!ssl_check_srvr_ecc_cert_and_alg(s,
-                    s->session->peer_pkeys[idx].x509)) {
-                        /* check failed */
+        if (s->session->peer_cert_type == SSL_PKEY_ECC) {
+                if (!ssl_check_srvr_ecc_cert_and_alg(s, s->session->peer_cert)) {
                         SSLerror(s, SSL_R_BAD_ECC_CERT);
                         goto fatal_err;
-                } else {
-                        return (1);
                 }
+                return (1);
         }
-        pkey = X509_get_pubkey(s->session->peer_pkeys[idx].x509);
-        i = X509_certificate_type(s->session->peer_pkeys[idx].x509, pkey);
-        EVP_PKEY_free(pkey);
+
+        i = X509_certificate_type(s->session->peer_cert, NULL);
 
         /* Check that we have a certificate if we require one. */
         if ((alg_a & SSL_aRSA) && !has_bits(i, EVP_PK_RSA|EVP_PKT_SIGN)) {
diff --git a/src/lib/libssl/ssl_locl.h b/src/lib/libssl/ssl_locl.h
index 36823d6462..546854b462 100644
--- a/src/lib/libssl/ssl_locl.h
+++ b/src/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.382 2022/01/11 18:39:28 jsing Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.383 2022/01/11 19:03:15 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -475,8 +475,9 @@ struct ssl_session_st {
         unsigned int sid_ctx_length;
         unsigned char sid_ctx[SSL_MAX_SID_CTX_LENGTH];
 
-        /* This is the cert for the other end. */
+        /* Peer provided leaf (end-entity) certificate. */
         X509 *peer_cert;
+        int peer_cert_type;
 
         /* when app_verify_callback accepts a session where the peer's certificate
          * is not ok, we must remember the error for session reuse: */
@@ -513,14 +514,6 @@ struct ssl_session_st {
 
         STACK_OF(X509) *cert_chain; /* as received from peer */
 
-        /* The 'peer_...' members are used only by clients. */
-        int peer_cert_type;
-
-        /* Obviously we don't have the private keys of these,
-         * so maybe we shouldn't even use the SSL_CERT_PKEY type here. */
-        SSL_CERT_PKEY *peer_key; /* points to an element of peer_pkeys (never NULL!) */
-        SSL_CERT_PKEY peer_pkeys[SSL_PKEY_NUM];
-
         size_t tlsext_ecpointformatlist_length;
         uint8_t *tlsext_ecpointformatlist; /* peer's list */
         size_t tlsext_supportedgroups_length;
diff --git a/src/lib/libssl/ssl_sess.c b/src/lib/libssl/ssl_sess.c
index a49076be74..44c2e846ba 100644
--- a/src/lib/libssl/ssl_sess.c
+++ b/src/lib/libssl/ssl_sess.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_sess.c,v 1.108 2022/01/11 18:39:28 jsing Exp $ */
+/* $OpenBSD: ssl_sess.c,v 1.109 2022/01/11 19:03:15 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -230,8 +230,6 @@ SSL_SESSION_new(void)
         ss->next = NULL;
         ss->tlsext_hostname = NULL;
 
-        ss->peer_key = &ss->peer_pkeys[SSL_PKEY_RSA];
-
         ss->tlsext_ecpointformatlist_length = 0;
         ss->tlsext_ecpointformatlist = NULL;
         ss->tlsext_supportedgroups_length = 0;
@@ -763,8 +761,6 @@ SSL_SESSION_free(SSL_SESSION *ss)
         explicit_bzero(ss->session_id, sizeof ss->session_id);
 
         sk_X509_pop_free(ss->cert_chain, X509_free);
-        for (i = 0; i < SSL_PKEY_NUM; i++)
-                X509_free(ss->peer_pkeys[i].x509);
 
         X509_free(ss->peer_cert);
 
diff --git a/src/lib/libssl/ssl_srvr.c b/src/lib/libssl/ssl_srvr.c
index 786362ea02..30545320b3 100644
--- a/src/lib/libssl/ssl_srvr.c
+++ b/src/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.139 2022/01/11 18:39:28 jsing Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.140 2022/01/11 19:03:15 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1905,7 +1905,7 @@ ssl3_get_cert_verify(SSL *s)
         CBS cbs, signature;
         const struct ssl_sigalg *sigalg = NULL;
         uint16_t sigalg_value = SIGALG_NONE;
-        EVP_PKEY *pkey = NULL;
+        EVP_PKEY *pkey;
         X509 *peer_cert = NULL;
         EVP_MD_CTX *mctx = NULL;
         int al, verify;
@@ -1928,11 +1928,9 @@ ssl3_get_cert_verify(SSL *s)
 
         CBS_init(&cbs, s->internal->init_msg, s->internal->init_num);
 
-        if (s->session->peer_cert != NULL) {
-                peer_cert = s->session->peer_cert;
-                pkey = X509_get_pubkey(peer_cert);
-                type = X509_certificate_type(peer_cert, pkey);
-        }
+        peer_cert = s->session->peer_cert;
+        pkey = X509_get0_pubkey(peer_cert);
+        type = X509_certificate_type(peer_cert, pkey);
 
         if (S3I(s)->hs.tls12.message_type != SSL3_MT_CERTIFICATE_VERIFY) {
                 S3I(s)->hs.tls12.reuse_message = 1;
@@ -2131,7 +2129,7 @@ ssl3_get_cert_verify(SSL *s)
         tls1_transcript_free(s);
  err:
         EVP_MD_CTX_free(mctx);
-        EVP_PKEY_free(pkey);
+
         return (ret);
 }
 
diff --git a/src/lib/libssl/tls13_client.c b/src/lib/libssl/tls13_client.c
index 3e168a0b54..4b52f6cf62 100644
--- a/src/lib/libssl/tls13_client.c
+++ b/src/lib/libssl/tls13_client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_client.c,v 1.92 2022/01/11 18:39:28 jsing Exp $ */
+/* $OpenBSD: tls13_client.c,v 1.93 2022/01/11 19:03:15 jsing Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -561,7 +561,7 @@ tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs)
         X509 *cert = NULL;
         EVP_PKEY *pkey;
         const uint8_t *p;
-        int cert_idx, alert_desc;
+        int alert_desc, cert_type;
         int ret = 0;
 
         if ((certs = sk_X509_new_null()) == NULL)
@@ -625,24 +625,20 @@ tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs)
                 goto err;
         if (EVP_PKEY_missing_parameters(pkey))
                 goto err;
-        if ((cert_idx = ssl_cert_type(cert, pkey)) < 0)
+        if ((cert_type = ssl_cert_type(cert, pkey)) < 0)
                 goto err;
 
-        sk_X509_pop_free(s->session->cert_chain, X509_free);
-        s->session->cert_chain = certs;
-        certs = NULL;
-
-        X509_up_ref(cert);
-        X509_free(s->session->peer_pkeys[cert_idx].x509);
-        s->session->peer_pkeys[cert_idx].x509 = cert;
-        s->session->peer_key = &s->session->peer_pkeys[cert_idx];
-
         X509_up_ref(cert);
         X509_free(s->session->peer_cert);
         s->session->peer_cert = cert;
+        s->session->peer_cert_type = cert_type;
 
         s->session->verify_result = s->verify_result;
 
+        sk_X509_pop_free(s->session->cert_chain, X509_free);
+        s->session->cert_chain = certs;
+        certs = NULL;
+
         if (ctx->ocsp_status_recv_cb != NULL &&
             !ctx->ocsp_status_recv_cb(ctx))
                 goto err;
diff --git a/src/lib/libssl/tls13_server.c b/src/lib/libssl/tls13_server.c
index 3330023430..10e49104d4 100644
--- a/src/lib/libssl/tls13_server.c
+++ b/src/lib/libssl/tls13_server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_server.c,v 1.94 2022/01/11 18:39:28 jsing Exp $ */
+/* $OpenBSD: tls13_server.c,v 1.95 2022/01/11 19:03:15 jsing Exp $ */
 /*
  * Copyright (c) 2019, 2020 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2020 Bob Beck <beck@openbsd.org>
@@ -857,7 +857,7 @@ tls13_client_certificate_recv(struct tls13_ctx *ctx, CBS *cbs)
         X509 *cert = NULL;
         EVP_PKEY *pkey;
         const uint8_t *p;
-        int cert_idx;
+        int cert_type;
         int ret = 0;
 
         if (!CBS_get_u8_length_prefixed(cbs, &cert_request_context))
@@ -918,24 +918,20 @@ tls13_client_certificate_recv(struct tls13_ctx *ctx, CBS *cbs)
                 goto err;
         if (EVP_PKEY_missing_parameters(pkey))
                 goto err;
-        if ((cert_idx = ssl_cert_type(cert, pkey)) < 0)
+        if ((cert_type = ssl_cert_type(cert, pkey)) < 0)
                 goto err;
 
-        sk_X509_pop_free(s->session->cert_chain, X509_free);
-        s->session->cert_chain = certs;
-        certs = NULL;
-
-        X509_up_ref(cert);
-        X509_free(s->session->peer_pkeys[cert_idx].x509);
-        s->session->peer_pkeys[cert_idx].x509 = cert;
-        s->session->peer_key = &s->session->peer_pkeys[cert_idx];
-
         X509_up_ref(cert);
         X509_free(s->session->peer_cert);
         s->session->peer_cert = cert;
+        s->session->peer_cert_type = cert_type;
 
         s->session->verify_result = s->verify_result;
 
+        sk_X509_pop_free(s->session->cert_chain, X509_free);
+        s->session->cert_chain = certs;
+        certs = NULL;
+
         ctx->handshake_stage.hs_type |= WITH_CCV;
         ret = 1;