Try to be more consistent about the alerts we send

We are quite inconsistent about which alerts get sent. Specifically, these
alerts should be used (normally) in the following circumstances:

SSL_AD_DECODE_ERROR = The peer sent a syntactically incorrect message
SSL_AD_ILLEGAL_PARAMETER = The peer sent a message which was syntactically
correct, but a parameter given is invalid for the context
SSL_AD_HANDSHAKE_FAILURE = The peer's messages were syntactically and
semantically correct, but the parameters provided were unacceptable to us
(e.g. because we do not support the requested parameters)
SSL_AD_INTERNAL_ERROR = We messed up (e.g. malloc failure)

The standards themselves aren't always consistent but I think the above
represents the best interpretation.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3480)
diff --git a/ssl/record/ssl3_record.c b/ssl/record/ssl3_record.c
index bafc976..85d726f 100644
--- a/ssl/record/ssl3_record.c
+++ b/ssl/record/ssl3_record.c
@@ -209,7 +209,7 @@
             sslv2pkt = pkt;
             if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
                     || !PACKET_get_1(&sslv2pkt, &type)) {
-                al = SSL_AD_INTERNAL_ERROR;
+                al = SSL_AD_DECODE_ERROR;
                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
                 goto f_err;
             }
@@ -241,7 +241,7 @@
                 }
 
                 if (thisrr->length < MIN_SSL2_RECORD_LEN) {
-                    al = SSL_AD_HANDSHAKE_FAILURE;
+                    al = SSL_AD_DECODE_ERROR;
                     SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
                     goto f_err;
                 }
@@ -255,7 +255,7 @@
                 if (!PACKET_get_1(&pkt, &type)
                         || !PACKET_get_net_2(&pkt, &version)
                         || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
-                    al = SSL_AD_INTERNAL_ERROR;
+                    al = SSL_AD_DECODE_ERROR;
                     SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
                     goto f_err;
                 }
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index a12800d..b81b9ea 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -4753,7 +4753,7 @@
                                               TLS_CIPHER_LEN))
                     || (leadbyte != 0
                         && !PACKET_forward(&sslv2ciphers, TLS_CIPHER_LEN))) {
-                *al = SSL_AD_INTERNAL_ERROR;
+                *al = SSL_AD_DECODE_ERROR;
                 OPENSSL_free(s->s3->tmp.ciphers_raw);
                 s->s3->tmp.ciphers_raw = NULL;
                 s->s3->tmp.ciphers_rawlen = 0;
@@ -4840,8 +4840,8 @@
         }
     }
     if (PACKET_remaining(cipher_suites) > 0) {
-        *al = SSL_AD_INTERNAL_ERROR;
-        SSLerr(SSL_F_BYTES_TO_CIPHER_LIST, ERR_R_INTERNAL_ERROR);
+        *al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_BYTES_TO_CIPHER_LIST, SSL_R_BAD_LENGTH);
         goto err;
     }
 
diff --git a/ssl/ssl_rsa.c b/ssl/ssl_rsa.c
index 6f1c380..1ee8056 100644
--- a/ssl/ssl_rsa.c
+++ b/ssl/ssl_rsa.c
@@ -775,7 +775,7 @@
         int retval = serverinfo_find_extension(serverinfo, serverinfo_length,
                                                ext_type, out, outlen);
         if (retval == -1) {
-            *al = SSL_AD_DECODE_ERROR;
+            *al = SSL_AD_INTERNAL_ERROR;
             return -1;          /* Error */
         }
         if (retval == 0)
diff --git a/ssl/ssl_sess.c b/ssl/ssl_sess.c
index 7a3d858..5bef168 100644
--- a/ssl/ssl_sess.c
+++ b/ssl/ssl_sess.c
@@ -603,7 +603,7 @@
         /* If old session includes extms, but new does not: abort handshake */
         if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS)) {
             SSLerr(SSL_F_SSL_GET_PREV_SESSION, SSL_R_INCONSISTENT_EXTMS);
-            ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+            ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
             fatal = 1;
             goto err;
         }
diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c
index 68d8cea..d77d493 100644
--- a/ssl/statem/extensions.c
+++ b/ssl/statem/extensions.c
@@ -1116,7 +1116,7 @@
             && (!s->hit
                 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
         /* Nothing left we can do - just fail */
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_MISSING_EXTENSION;
         SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
         return 0;
     }
diff --git a/ssl/statem/extensions_clnt.c b/ssl/statem/extensions_clnt.c
index bbe94d0..c5f8d3d 100644
--- a/ssl/statem/extensions_clnt.c
+++ b/ssl/statem/extensions_clnt.c
@@ -930,7 +930,7 @@
     if (!PACKET_get_1_len(pkt, &ilen)) {
         SSLerr(SSL_F_TLS_PARSE_STOC_RENEGOTIATE,
                SSL_R_RENEGOTIATION_ENCODING_ERR);
-        *al = SSL_AD_ILLEGAL_PARAMETER;
+        *al = SSL_AD_DECODE_ERROR;
         return 0;
     }
 
@@ -938,7 +938,7 @@
     if (PACKET_remaining(pkt) != ilen) {
         SSLerr(SSL_F_TLS_PARSE_STOC_RENEGOTIATE,
                SSL_R_RENEGOTIATION_ENCODING_ERR);
-        *al = SSL_AD_ILLEGAL_PARAMETER;
+        *al = SSL_AD_DECODE_ERROR;
         return 0;
     }
 
@@ -946,7 +946,7 @@
     if (ilen != expected_len) {
         SSLerr(SSL_F_TLS_PARSE_STOC_RENEGOTIATE,
                SSL_R_RENEGOTIATION_MISMATCH);
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         return 0;
     }
 
@@ -955,7 +955,7 @@
                   s->s3->previous_client_finished_len) != 0) {
         SSLerr(SSL_F_TLS_PARSE_STOC_RENEGOTIATE,
                SSL_R_RENEGOTIATION_MISMATCH);
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         return 0;
     }
 
@@ -975,8 +975,13 @@
 int tls_parse_stoc_server_name(SSL *s, PACKET *pkt, unsigned int context,
                                X509 *x, size_t chainidx, int *al)
 {
-    if (s->ext.hostname == NULL || PACKET_remaining(pkt) > 0) {
-        *al = SSL_AD_UNRECOGNIZED_NAME;
+    if (s->ext.hostname == NULL) {
+        *al = SSL_AD_INTERNAL_ERROR;
+        return 0;
+    }
+
+    if (PACKET_remaining(pkt) > 0) {
+        *al = SSL_AD_DECODE_ERROR;
         return 0;
     }
 
@@ -1042,10 +1047,14 @@
         return 0;
     }
 
-    if (!tls_use_ticket(s) || PACKET_remaining(pkt) > 0) {
+    if (!tls_use_ticket(s)) {
         *al = SSL_AD_UNSUPPORTED_EXTENSION;
         return 0;
     }
+    if (PACKET_remaining(pkt) > 0) {
+        *al = SSL_AD_DECODE_ERROR;
+        return 0;
+    }
 
     s->ext.ticket_expected = 1;
 
@@ -1060,11 +1069,14 @@
      * MUST only be sent if we've requested a status
      * request message. In TLS <= 1.2 it must also be empty.
      */
-    if (s->ext.status_type != TLSEXT_STATUSTYPE_ocsp
-            || (!SSL_IS_TLS13(s) && PACKET_remaining(pkt) > 0)) {
+    if (s->ext.status_type != TLSEXT_STATUSTYPE_ocsp) {
         *al = SSL_AD_UNSUPPORTED_EXTENSION;
         return 0;
     }
+    if (!SSL_IS_TLS13(s) && PACKET_remaining(pkt) > 0) {
+        *al = SSL_AD_DECODE_ERROR;
+        return 0;
+    }
 
     if (SSL_IS_TLS13(s)) {
         /* We only know how to handle this if it's for the first Certificate in
@@ -1407,7 +1419,7 @@
     }
     if (!EVP_PKEY_set1_tls_encodedpoint(skey, PACKET_data(&encoded_pt),
                                         PACKET_remaining(&encoded_pt))) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PARSE_STOC_KEY_SHARE, SSL_R_BAD_ECPOINT);
         EVP_PKEY_free(skey);
         return 0;
diff --git a/ssl/statem/extensions_srvr.c b/ssl/statem/extensions_srvr.c
index 9cde695..95bacdf 100644
--- a/ssl/statem/extensions_srvr.c
+++ b/ssl/statem/extensions_srvr.c
@@ -25,7 +25,7 @@
         || !PACKET_get_bytes(pkt, &data, ilen)) {
         SSLerr(SSL_F_TLS_PARSE_CTOS_RENEGOTIATE,
                SSL_R_RENEGOTIATION_ENCODING_ERR);
-        *al = SSL_AD_ILLEGAL_PARAMETER;
+        *al = SSL_AD_DECODE_ERROR;
         return 0;
     }
 
@@ -154,7 +154,7 @@
      * upon resumption. Instead, we MUST ignore the login.
      */
     if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
-        *al = TLS1_AD_INTERNAL_ERROR;
+        *al = SSL_AD_INTERNAL_ERROR;
         return 0;
     }
 
@@ -178,7 +178,7 @@
         if (!PACKET_memdup(&ec_point_format_list,
                            &s->session->ext.ecpointformats,
                            &s->session->ext.ecpointformats_len)) {
-            *al = TLS1_AD_INTERNAL_ERROR;
+            *al = SSL_AD_INTERNAL_ERROR;
             return 0;
         }
     }
@@ -194,7 +194,7 @@
             !s->ext.session_ticket_cb(s, PACKET_data(pkt),
                                   PACKET_remaining(pkt),
                                   s->ext.session_ticket_cb_arg)) {
-        *al = TLS1_AD_INTERNAL_ERROR;
+        *al = SSL_AD_INTERNAL_ERROR;
         return 0;
     }
 
@@ -213,7 +213,7 @@
     }
 
     if (!s->hit && !tls1_save_sigalgs(s, &supported_sig_algs)) {
-        *al = TLS1_AD_DECODE_ERROR;
+        *al = SSL_AD_DECODE_ERROR;
         return 0;
     }
 
@@ -368,7 +368,7 @@
     s->s3->alpn_proposed_len = 0;
     if (!PACKET_memdup(&save_protocol_list,
                        &s->s3->alpn_proposed, &s->s3->alpn_proposed_len)) {
-        *al = TLS1_AD_INTERNAL_ERROR;
+        *al = SSL_AD_INTERNAL_ERROR;
         return 0;
     }
 
@@ -614,7 +614,7 @@
         if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
                 PACKET_data(&encoded_pt),
                 PACKET_remaining(&encoded_pt))) {
-            *al = SSL_AD_DECODE_ERROR;
+            *al = SSL_AD_ILLEGAL_PARAMETER;
             SSLerr(SSL_F_TLS_PARSE_CTOS_KEY_SHARE, SSL_R_BAD_ECPOINT);
             return 0;
         }
@@ -646,7 +646,7 @@
     if (!PACKET_memdup(&supported_groups_list,
                        &s->session->ext.supportedgroups,
                        &s->session->ext.supportedgroups_len)) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_INTERNAL_ERROR;
         return 0;
     }
 
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index e6a0b35..d4382e8 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -1183,7 +1183,6 @@
 
     /* TLS extensions */
     if (!tls_construct_extensions(s, pkt, SSL_EXT_CLIENT_HELLO, NULL, 0, &al)) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
         return 0;
     }
@@ -1928,7 +1927,6 @@
     }
 
     if (!srp_verify_server_param(s, al)) {
-        *al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_SKE_SRP, SSL_R_BAD_SRP_PARAMETERS);
         return 0;
     }
@@ -1987,7 +1985,7 @@
 
     /* test non-zero pubkey */
     if (BN_is_zero(bnpub_key)) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_BAD_DH_VALUE);
         goto err;
     }
@@ -2000,7 +1998,7 @@
     p = g = NULL;
 
     if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_DHE, SSL_R_BAD_DH_VALUE);
         goto err;
     }
@@ -2075,7 +2073,7 @@
      * invalid curve. ECParameters is 3 bytes.
      */
     if (!tls1_check_curve(s, ecparams, 3)) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_WRONG_CURVE);
         return 0;
     }
@@ -2124,7 +2122,7 @@
     if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
                                         PACKET_data(&encoded_pt),
                                         PACKET_remaining(&encoded_pt))) {
-        *al = SSL_AD_DECODE_ERROR;
+        *al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_TLS_PROCESS_SKE_ECDHE, SSL_R_BAD_ECPOINT);
         return 0;
     }
@@ -2201,7 +2199,7 @@
         if (!PACKET_get_sub_packet(&save_param_start, &params,
                                    PACKET_remaining(&save_param_start) -
                                    PACKET_remaining(pkt))) {
-            al = SSL_AD_INTERNAL_ERROR;
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
             goto err;
         }
@@ -2750,7 +2748,7 @@
     identitylen = strlen(identity);
     if (identitylen > PSK_MAX_IDENTITY_LEN) {
         SSLerr(SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_INTERNAL_ERROR;
         goto err;
     }
 
@@ -3137,7 +3135,7 @@
         if (!tls_construct_cke_srp(s, pkt, &al))
             goto err;
     } else if (!(alg_k & SSL_kPSK)) {
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
         SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
         goto err;
     }
diff --git a/ssl/statem/statem_dtls.c b/ssl/statem/statem_dtls.c
index b2ba357..5cab355 100644
--- a/ssl/statem/statem_dtls.c
+++ b/ssl/statem/statem_dtls.c
@@ -770,7 +770,7 @@
      * Fragments must not span records.
      */
     if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
-        al = SSL3_AD_ILLEGAL_PARAMETER;
+        al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
         goto f_err;
     }
@@ -845,8 +845,8 @@
      * to fail
      */
     if (readbytes != frag_len) {
-        al = SSL3_AD_ILLEGAL_PARAMETER;
-        SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL3_AD_ILLEGAL_PARAMETER);
+        al = SSL_AD_ILLEGAL_PARAMETER;
+        SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
         goto f_err;
     }
 
diff --git a/ssl/statem/statem_lib.c b/ssl/statem/statem_lib.c
index 4a399ca..e6f6293 100644
--- a/ssl/statem/statem_lib.c
+++ b/ssl/statem/statem_lib.c
@@ -333,10 +333,8 @@
 
     peer = s->session->peer;
     pkey = X509_get0_pubkey(peer);
-    if (pkey == NULL) {
-        al = SSL_AD_INTERNAL_ERROR;
+    if (pkey == NULL)
         goto f_err;
-    }
 
     type = X509_certificate_type(peer, pkey);
 
@@ -670,14 +668,14 @@
              && remain != DTLS1_CCS_HEADER_LENGTH + 1)
             || (s->version != DTLS1_BAD_VER
                 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
-            al = SSL_AD_ILLEGAL_PARAMETER;
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
                    SSL_R_BAD_CHANGE_CIPHER_SPEC);
             goto f_err;
         }
     } else {
         if (remain != 0) {
-            al = SSL_AD_ILLEGAL_PARAMETER;
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
                    SSL_R_BAD_CHANGE_CIPHER_SPEC);
             goto f_err;
diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c
index 5c22ba7..02c6e56 100644
--- a/ssl/statem/statem_srvr.c
+++ b/ssl/statem/statem_srvr.c
@@ -1260,7 +1260,7 @@
         unsigned int mt;
 
         if (!SSL_IS_FIRST_HANDSHAKE(s) || s->hello_retry_request) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
+            al = SSL_AD_UNEXPECTED_MESSAGE;
             SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_UNEXPECTED_MESSAGE);
             goto f_err;
         }
@@ -1318,7 +1318,7 @@
         }
 
         if (session_id_len > SSL_MAX_SSL_SESSION_ID_LENGTH) {
-            al = SSL_AD_DECODE_ERROR;
+            al = SSL_AD_ILLEGAL_PARAMETER;
             SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_LENGTH_MISMATCH);
             goto f_err;
         }
@@ -1376,8 +1376,8 @@
             if (!PACKET_copy_all(&cookie, clienthello->dtls_cookie,
                                  DTLS1_COOKIE_LENGTH,
                                  &clienthello->dtls_cookie_len)) {
-                al = SSL_AD_DECODE_ERROR;
-                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_LENGTH_MISMATCH);
+                al = SSL_AD_INTERNAL_ERROR;
+                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
                 goto f_err;
             }
             /*
@@ -1419,8 +1419,8 @@
     if (!PACKET_copy_all(&compression, clienthello->compressions,
                          MAX_COMPRESSIONS_SIZE,
                          &clienthello->compressions_len)) {
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_LENGTH_MISMATCH);
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
         goto f_err;
     }
 
@@ -2221,7 +2221,7 @@
             pkdhp = pkdh;
         }
         if (pkdhp == NULL) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
+            al = SSL_AD_INTERNAL_ERROR;
             SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                    SSL_R_MISSING_TMP_DH_KEY);
             goto f_err;
@@ -2314,7 +2314,7 @@
     } else
 #endif
     {
-        al = SSL_AD_HANDSHAKE_FAILURE;
+        al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_KEY_EXCHANGE,
                SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
         goto f_err;
@@ -2631,7 +2631,7 @@
 
     rsa = EVP_PKEY_get0_RSA(s->cert->pkeys[SSL_PKEY_RSA].privatekey);
     if (rsa == NULL) {
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_CKE_RSA, SSL_R_MISSING_RSA_CERTIFICATE);
         return 0;
     }
@@ -2794,20 +2794,20 @@
     int ret = 0;
 
     if (!PACKET_get_net_2(pkt, &i) || PACKET_remaining(pkt) != i) {
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_CKE_DHE,
                SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG);
         goto err;
     }
     skey = s->s3->tmp.pkey;
     if (skey == NULL) {
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_CKE_DHE, SSL_R_MISSING_TMP_DH_KEY);
         goto err;
     }
 
     if (PACKET_remaining(pkt) == 0L) {
-        *al = SSL_AD_HANDSHAKE_FAILURE;
+        *al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_CKE_DHE, SSL_R_MISSING_TMP_DH_KEY);
         goto err;
     }
@@ -2886,7 +2886,7 @@
             goto err;
         }
         if (EVP_PKEY_set1_tls_encodedpoint(ckey, data, i) == 0) {
-            *al = SSL_AD_HANDSHAKE_FAILURE;
+            *al = SSL_AD_ILLEGAL_PARAMETER;
             SSLerr(SSL_F_TLS_PROCESS_CKE_ECDHE, ERR_R_EC_LIB);
             goto err;
         }
@@ -2926,6 +2926,7 @@
         return 0;
     }
     if ((s->srp_ctx.A = BN_bin2bn(data, i, NULL)) == NULL) {
+        *al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_CKE_SRP, ERR_R_BN_LIB);
         return 0;
     }
@@ -3070,7 +3071,7 @@
     if (alg_k & SSL_kPSK) {
         /* Identity extracted earlier: should be nothing left */
         if (PACKET_remaining(pkt) != 0) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
+            al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_TLS_PROCESS_CLIENT_KEY_EXCHANGE,
                    SSL_R_LENGTH_MISMATCH);
             goto err;
@@ -3097,7 +3098,7 @@
         if (!tls_process_cke_gost(s, pkt, &al))
             goto err;
     } else {
-        al = SSL_AD_HANDSHAKE_FAILURE;
+        al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_CLIENT_KEY_EXCHANGE,
                SSL_R_UNKNOWN_CIPHER_TYPE);
         goto err;
@@ -3584,6 +3585,7 @@
 {
     PACKET next_proto, padding;
     size_t next_proto_len;
+    int al = SSL_AD_INTERNAL_ERROR;
 
     /*-
      * The payload looks like:
@@ -3595,6 +3597,7 @@
     if (!PACKET_get_length_prefixed_1(pkt, &next_proto)
         || !PACKET_get_length_prefixed_1(pkt, &padding)
         || PACKET_remaining(pkt) > 0) {
+        al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_NEXT_PROTO, SSL_R_LENGTH_MISMATCH);
         goto err;
     }
@@ -3608,6 +3611,7 @@
 
     return MSG_PROCESS_CONTINUE_READING;
  err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
     ossl_statem_set_error(s);
     return MSG_PROCESS_ERROR;
 }
@@ -3621,7 +3625,6 @@
                                   NULL, 0, &al)) {
         ssl3_send_alert(s, SSL3_AL_FATAL, al);
         SSLerr(SSL_F_TLS_CONSTRUCT_ENCRYPTED_EXTENSIONS, ERR_R_INTERNAL_ERROR);
-        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         return 0;
     }
 
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 0e1a97e..232bb41 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1117,9 +1117,9 @@
     }
     if (s->cert->shared_sigalgs != NULL)
         return 1;
-    /* Fatal error is no shared signature algorithms */
+    /* Fatal error if no shared signature algorithms */
     SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS, SSL_R_NO_SHARED_SIGNATURE_ALGORITHMS);
-    al = SSL_AD_ILLEGAL_PARAMETER;
+    al = SSL_AD_HANDSHAKE_FAILURE;
  err:
     ssl3_send_alert(s, SSL3_AL_FATAL, al);
     return 0;
@@ -2408,7 +2408,7 @@
                     if (al == NULL)
                         return 1;
                     SSLerr(SSL_F_TLS_CHOOSE_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
-                    *al = SSL_AD_HANDSHAKE_FAILURE;
+                    *al = SSL_AD_ILLEGAL_PARAMETER;
                     return 0;
                 }
             }