PACKET: simplify ServerKeyExchange parsing
[openssl.git] / ssl / s3_clnt.c
index a911bb154a46e711768f8fbe0cfee38bb27829d2..2df5afe14e726ebb2e128798645ec294fca8dbf8 100644 (file)
 
 static int ssl_set_version(SSL *s);
 static int ca_dn_cmp(const X509_NAME *const *a, const X509_NAME *const *b);
-static int ssl3_check_finished(SSL *s);
+static int ssl3_check_change(SSL *s);
 static int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
-                                    unsigned char *p,
-                                    int (*put_cb) (const SSL_CIPHER *,
-                                                 unsigned char *));
+                                    unsigned char *p);
 
 
 int ssl3_connect(SSL *s)
@@ -276,7 +274,6 @@ int ssl3_connect(SSL *s)
             s->state = SSL3_ST_CW_CLNT_HELLO_A;
             s->ctx->stats.sess_connect++;
             s->init_num = 0;
-            s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
             /*
              * Should have been reset by ssl3_get_finished, too.
              */
@@ -306,7 +303,7 @@ int ssl3_connect(SSL *s)
                 goto end;
 
             if (s->hit) {
-                s->state = SSL3_ST_CR_FINISHED_A;
+                s->state = SSL3_ST_CR_CHANGE_A;
                 if (s->tlsext_ticket_expected) {
                     /* receive renewed session ticket */
                     s->state = SSL3_ST_CR_SESSION_TICKET_A;
@@ -319,22 +316,20 @@ int ssl3_connect(SSL *s)
         case SSL3_ST_CR_CERT_A:
         case SSL3_ST_CR_CERT_B:
             /* Noop (ret = 0) for everything but EAP-FAST. */
-            ret = ssl3_check_finished(s);
+            ret = ssl3_check_change(s);
             if (ret < 0)
                 goto end;
             if (ret == 1) {
                 s->hit = 1;
-                s->state = SSL3_ST_CR_FINISHED_A;
+                s->state = SSL3_ST_CR_CHANGE_A;
                 s->init_num = 0;
                 break;
             }
 
             /* Check if it is anon DH/ECDH, SRP auth */
             /* or PSK */
-            if (!
-                (s->s3->tmp.
-                 new_cipher->algorithm_auth & (SSL_aNULL | SSL_aSRP))
-                    && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
+            if (!(s->s3->tmp.new_cipher->algorithm_auth &
+                    (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
                 ret = ssl3_get_server_certificate(s);
                 if (ret <= 0)
                     goto end;
@@ -518,15 +513,8 @@ int ssl3_connect(SSL *s)
                 goto end;
             s->state = SSL3_ST_CW_FLUSH;
 
-            /* clear flags */
-            s->s3->flags &= ~SSL3_FLAGS_POP_BUFFER;
             if (s->hit) {
                 s->s3->tmp.next_state = SSL_ST_OK;
-                if (s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED) {
-                    s->state = SSL_ST_OK;
-                    s->s3->flags |= SSL3_FLAGS_POP_BUFFER;
-                    s->s3->delay_buf_pop_ret = 0;
-                }
             } else {
                 /*
                  * Allow NewSessionTicket if ticket expected
@@ -534,7 +522,7 @@ int ssl3_connect(SSL *s)
                 if (s->tlsext_ticket_expected)
                     s->s3->tmp.next_state = SSL3_ST_CR_SESSION_TICKET_A;
                 else
-                    s->s3->tmp.next_state = SSL3_ST_CR_FINISHED_A;
+                    s->s3->tmp.next_state = SSL3_ST_CR_CHANGE_A;
             }
             s->init_num = 0;
             break;
@@ -544,7 +532,7 @@ int ssl3_connect(SSL *s)
             ret = ssl3_get_new_session_ticket(s);
             if (ret <= 0)
                 goto end;
-            s->state = SSL3_ST_CR_FINISHED_A;
+            s->state = SSL3_ST_CR_CHANGE_A;
             s->init_num = 0;
             break;
 
@@ -557,10 +545,19 @@ int ssl3_connect(SSL *s)
             s->init_num = 0;
             break;
 
+        case SSL3_ST_CR_CHANGE_A:
+        case SSL3_ST_CR_CHANGE_B:
+            ret = ssl3_get_change_cipher_spec(s, SSL3_ST_CR_CHANGE_A,
+                                              SSL3_ST_CR_CHANGE_B);
+            if (ret <= 0)
+                goto end;
+
+            s->state = SSL3_ST_CR_FINISHED_A;
+            s->init_num = 0;
+            break;
+
         case SSL3_ST_CR_FINISHED_A:
         case SSL3_ST_CR_FINISHED_B:
-            if (!s->s3->change_cipher_spec)
-                s->s3->flags |= SSL3_FLAGS_CCS_OK;
             ret = ssl3_get_finished(s, SSL3_ST_CR_FINISHED_A,
                                     SSL3_ST_CR_FINISHED_B);
             if (ret <= 0)
@@ -589,13 +586,8 @@ int ssl3_connect(SSL *s)
             BUF_MEM_free(s->init_buf);
             s->init_buf = NULL;
 
-            /*
-             * If we are not 'joining' the last two packets, remove the
-             * buffering now
-             */
-            if (!(s->s3->flags & SSL3_FLAGS_POP_BUFFER))
-                ssl_free_wbio_buffer(s);
-            /* else do it later in ssl3_write */
+            /* remove the buffering */
+            ssl_free_wbio_buffer(s);
 
             s->init_num = 0;
             s->renegotiate = 0;
@@ -868,7 +860,7 @@ int ssl3_client_hello(SSL *s)
         }
 
         /* Ciphers supported */
-        i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &(p[2]), 0);
+        i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &(p[2]));
         if (i == 0) {
             SSLerr(SSL_F_SSL3_CLIENT_HELLO, SSL_R_NO_CIPHERS_AVAILABLE);
             goto err;
@@ -936,9 +928,11 @@ int ssl3_get_server_hello(SSL *s)
 {
     STACK_OF(SSL_CIPHER) *sk;
     const SSL_CIPHER *c;
-    unsigned char *p, *d;
+    PACKET pkt, session_id;
+    size_t session_id_len;
+    unsigned char *cipherchars;
     int i, al = SSL_AD_INTERNAL_ERROR, ok;
-    unsigned int j;
+    unsigned int compression;
     long n;
 #ifndef OPENSSL_NO_COMP
     SSL_COMP *comp;
@@ -977,10 +971,20 @@ int ssl3_get_server_hello(SSL *s)
         goto f_err;
     }
 
-    d = p = (unsigned char *)s->init_msg;
+    if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
+        goto f_err;
+    }
 
     if (s->method->version == TLS_ANY_VERSION) {
-        int sversion = (p[0] << 8) | p[1];
+        unsigned int sversion;
+
+        if (!PACKET_get_net_2(&pkt, &sversion)) {
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+            goto f_err;
+        }
 
 #if TLS_MAX_VERSION != TLS1_2_VERSION
 #error Code needs updating for new TLS version
@@ -1018,8 +1022,16 @@ int ssl3_get_server_hello(SSL *s)
         }
     } else if (s->method->version == DTLS_ANY_VERSION) {
         /* Work out correct protocol version to use */
-        int hversion = (p[0] << 8) | p[1];
-        int options = s->options;
+        unsigned int hversion;
+        int options;
+
+        if (!PACKET_get_net_2(&pkt, &hversion)) {
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+            goto f_err;
+        }
+
+        options = s->options;
         if (hversion == DTLS1_2_VERSION && !(options & SSL_OP_NO_DTLSv1_2))
             s->method = DTLSv1_2_client_method();
         else if (tls1_suiteb(s)) {
@@ -1037,30 +1049,53 @@ int ssl3_get_server_hello(SSL *s)
             goto f_err;
         }
         s->session->ssl_version = s->version = s->method->version;
-    } else if ((p[0] != (s->version >> 8)) || (p[1] != (s->version & 0xff))) {
-        SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_WRONG_SSL_VERSION);
-        s->version = (s->version & 0xff00) | p[1];
-        al = SSL_AD_PROTOCOL_VERSION;
-        goto f_err;
+    } else {
+        unsigned char *vers;
+
+        if (!PACKET_get_bytes(&pkt, &vers, 2)) {
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+            goto f_err;
+        }
+        if ((vers[0] != (s->version >> 8))
+                || (vers[1] != (s->version & 0xff))) {
+            SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_WRONG_SSL_VERSION);
+            s->version = (s->version & 0xff00) | vers[1];
+            al = SSL_AD_PROTOCOL_VERSION;
+            goto f_err;
+        }
     }
-    p += 2;
 
     /* load the server hello data */
     /* load the server random */
-    memcpy(s->s3->server_random, p, SSL3_RANDOM_SIZE);
-    p += SSL3_RANDOM_SIZE;
+    if (!PACKET_copy_bytes(&pkt, s->s3->server_random, SSL3_RANDOM_SIZE)) {
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+        goto f_err;
+    }
 
     s->hit = 0;
 
-    /* get the session-id */
-    j = *(p++);
-
-    if ((j > sizeof s->session->session_id) || (j > SSL3_SESSION_ID_SIZE)) {
+    /* Get the session-id. */
+    if (!PACKET_get_length_prefixed_1(&pkt, &session_id)) {
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+        goto f_err;
+    }
+    session_id_len = PACKET_remaining(&session_id);
+    if (session_id_len > sizeof s->session->session_id
+        || session_id_len > SSL3_SESSION_ID_SIZE) {
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_SSL3_SESSION_ID_TOO_LONG);
         goto f_err;
     }
 
+    if (!PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
+        SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+        al = SSL_AD_DECODE_ERROR;
+        goto f_err;
+    }
+
     /*
      * Check if we can resume the session based on external pre-shared secret.
      * EAP-FAST (RFC 4851) supports two types of session resumption.
@@ -1082,7 +1117,7 @@ int ssl3_get_server_hello(SSL *s)
                                      NULL, &pref_cipher,
                                      s->tls_session_secret_cb_arg)) {
             s->session->cipher = pref_cipher ?
-                pref_cipher : ssl_get_cipher_by_char(s, p + j);
+                pref_cipher : ssl_get_cipher_by_char(s, cipherchars);
         } else {
             SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
             al = SSL_AD_INTERNAL_ERROR;
@@ -1090,8 +1125,9 @@ int ssl3_get_server_hello(SSL *s)
         }
     }
 
-    if (j != 0 && j == s->session->session_id_length
-        && memcmp(p, s->session->session_id, j) == 0) {
+    if (session_id_len != 0 && session_id_len == s->session->session_id_length
+        && memcmp(PACKET_data(&session_id), s->session->session_id,
+                  session_id_len) == 0) {
         if (s->sid_ctx_length != s->session->sid_ctx_length
             || memcmp(s->session->sid_ctx, s->sid_ctx, s->sid_ctx_length)) {
             /* actually a client application bug */
@@ -1114,11 +1150,14 @@ int ssl3_get_server_hello(SSL *s)
                 goto f_err;
             }
         }
-        s->session->session_id_length = j;
-        memcpy(s->session->session_id, p, j); /* j could be 0 */
+
+        s->session->session_id_length = session_id_len;
+        /* session_id_len could be 0 */
+        memcpy(s->session->session_id, PACKET_data(&session_id),
+               session_id_len);
     }
-    p += j;
-    c = ssl_get_cipher_by_char(s, p);
+
+    c = ssl_get_cipher_by_char(s, cipherchars);
     if (c == NULL) {
         /* unknown cipher */
         al = SSL_AD_ILLEGAL_PARAMETER;
@@ -1139,7 +1178,6 @@ int ssl3_get_server_hello(SSL *s)
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_WRONG_CIPHER_RETURNED);
         goto f_err;
     }
-    p += ssl_put_cipher_by_char(s, NULL, NULL);
 
     sk = ssl_get_ciphers_by_id(s);
     i = sk_SSL_CIPHER_find(sk, c);
@@ -1172,8 +1210,13 @@ int ssl3_get_server_hello(SSL *s)
         goto f_err;
     /* lets get the compression algorithm */
     /* COMPRESSION */
+    if (!PACKET_get_1(&pkt, &compression)) {
+        SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
+        al = SSL_AD_DECODE_ERROR;
+        goto f_err;
+    }
 #ifdef OPENSSL_NO_COMP
-    if (*(p++) != 0) {
+    if (compression != 0) {
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
                SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
@@ -1188,23 +1231,23 @@ int ssl3_get_server_hello(SSL *s)
         goto f_err;
     }
 #else
-    j = *(p++);
-    if (s->hit && j != s->session->compress_meth) {
+    if (s->hit && compression != s->session->compress_meth) {
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
                SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
         goto f_err;
     }
-    if (j == 0)
+    if (compression == 0)
         comp = NULL;
     else if (!ssl_allow_compression(s)) {
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_COMPRESSION_DISABLED);
         goto f_err;
-    } else
-        comp = ssl3_comp_find(s->ctx->comp_methods, j);
+    } else {
+        comp = ssl3_comp_find(s->ctx->comp_methods, compression);
+    }
 
-    if ((j != 0) && (comp == NULL)) {
+    if (compression != 0 && comp == NULL) {
         al = SSL_AD_ILLEGAL_PARAMETER;
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
                SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
@@ -1215,12 +1258,12 @@ int ssl3_get_server_hello(SSL *s)
 #endif
 
     /* TLS extensions */
-    if (!ssl_parse_serverhello_tlsext(s, &p, d, n)) {
+    if (!ssl_parse_serverhello_tlsext(s, &pkt)) {
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_PARSE_TLSEXT);
         goto err;
     }
 
-    if (p != (d + n)) {
+    if (PACKET_remaining(&pkt) != 0) {
         /* wrong packet length */
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_BAD_PACKET_LENGTH);
@@ -1238,12 +1281,12 @@ int ssl3_get_server_hello(SSL *s)
 int ssl3_get_server_certificate(SSL *s)
 {
     int al, i, ok, ret = -1, exp_idx;
-    unsigned long n, nc, llen, l;
+    unsigned long n, cert_list_len, cert_len;
     X509 *x = NULL;
-    const unsigned char *q, *p;
-    unsigned char *d;
+    unsigned char *certstart, *certbytes;
     STACK_OF(X509) *sk = NULL;
     EVP_PKEY *pkey = NULL;
+    PACKET pkt;
 
     n = s->method->ssl_get_message(s,
                                    SSL3_ST_CR_CERT_A,
@@ -1263,36 +1306,41 @@ int ssl3_get_server_certificate(SSL *s)
         SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE, SSL_R_BAD_MESSAGE_TYPE);
         goto f_err;
     }
-    p = d = (unsigned char *)s->init_msg;
+
+    if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE, ERR_R_INTERNAL_ERROR);
+        goto f_err;
+    }
 
     if ((sk = sk_X509_new_null()) == NULL) {
         SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE, ERR_R_MALLOC_FAILURE);
         goto err;
     }
 
-    n2l3(p, llen);
-    if (llen + 3 != n) {
+    if (!PACKET_get_net_3(&pkt, &cert_list_len)
+            || PACKET_remaining(&pkt) != cert_list_len) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE, SSL_R_LENGTH_MISMATCH);
         goto f_err;
     }
-    for (nc = 0; nc < llen;) {
-        n2l3(p, l);
-        if ((l + nc + 3) > llen) {
+    while (PACKET_remaining(&pkt)) {
+        if (!PACKET_get_net_3(&pkt, &cert_len)
+                || !PACKET_get_bytes(&pkt, &certbytes, cert_len)) {
             al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE,
                    SSL_R_CERT_LENGTH_MISMATCH);
             goto f_err;
         }
 
-        q = p;
-        x = d2i_X509(NULL, &q, l);
+        certstart = certbytes;
+        x = d2i_X509(NULL, (const unsigned char **)&certbytes, cert_len);
         if (x == NULL) {
             al = SSL_AD_BAD_CERTIFICATE;
             SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE, ERR_R_ASN1_LIB);
             goto f_err;
         }
-        if (q != (p + l)) {
+        if (certbytes != (certstart + cert_len)) {
             al = SSL_AD_DECODE_ERROR;
             SSLerr(SSL_F_SSL3_GET_SERVER_CERTIFICATE,
                    SSL_R_CERT_LENGTH_MISMATCH);
@@ -1303,8 +1351,6 @@ int ssl3_get_server_certificate(SSL *s)
             goto err;
         }
         x = NULL;
-        nc += l + 3;
-        p = q;
     }
 
     i = ssl_verify_cert_chain(s, sk);
@@ -1362,7 +1408,7 @@ int ssl3_get_server_certificate(SSL *s)
     s->session->peer_type = i;
 
     X509_free(s->session->peer);
-    CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
+    X509_up_ref(x);
     s->session->peer = x;
     s->session->verify_result = s->verify_result;
 
@@ -1387,9 +1433,8 @@ int ssl3_get_key_exchange(SSL *s)
     unsigned char *q, md_buf[EVP_MAX_MD_SIZE * 2];
 #endif
     EVP_MD_CTX md_ctx;
-    unsigned char *param, *p;
-    int al, j, ok;
-    long i, param_len, n, alg_k, alg_a;
+    int al, j, verify_ret, ok;
+    long n, alg_k, alg_a;
     EVP_PKEY *pkey = NULL;
     const EVP_MD *md = NULL;
 #ifndef OPENSSL_NO_RSA
@@ -1403,8 +1448,8 @@ int ssl3_get_key_exchange(SSL *s)
     BN_CTX *bn_ctx = NULL;
     EC_POINT *srvr_ecpoint = NULL;
     int curve_nid = 0;
-    int encoded_pt_len = 0;
 #endif
+    PACKET pkt, save_param_start, signature;
 
     EVP_MD_CTX_init(&md_ctx);
 
@@ -1426,27 +1471,22 @@ int ssl3_get_key_exchange(SSL *s)
          * Can't skip server key exchange if this is an ephemeral
          * ciphersuite.
          */
-        if (alg_k & (SSL_kDHE | SSL_kECDHE)) {
+        if (alg_k & (SSL_kDHE | SSL_kECDHE | SSL_kDHEPSK | SSL_kECDHEPSK)) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_UNEXPECTED_MESSAGE);
             al = SSL_AD_UNEXPECTED_MESSAGE;
             goto f_err;
         }
-#ifndef OPENSSL_NO_PSK
-        /*
-         * In plain PSK ciphersuite, ServerKeyExchange can be omitted if no
-         * identity hint is sent. Set session->sess_cert anyway to avoid
-         * problems later.
-         */
-        if (alg_k & SSL_kPSK) {
-            OPENSSL_free(s->ctx->psk_identity_hint);
-            s->ctx->psk_identity_hint = NULL;
-        }
-#endif
+
         s->s3->tmp.reuse_message = 1;
         return (1);
     }
 
-    param = p = (unsigned char *)s->init_msg;
+    if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+            al = SSL_AD_INTERNAL_ERROR;
+            goto f_err;
+    }
+    save_param_start = pkt;
 
 #ifndef OPENSSL_NO_RSA
     RSA_free(s->s3->peer_rsa_tmp);
@@ -1461,23 +1501,18 @@ int ssl3_get_key_exchange(SSL *s)
     s->s3->peer_ecdh_tmp = NULL;
 #endif
 
-    /* Total length of the parameters including the length prefix */
-    param_len = 0;
-
     alg_a = s->s3->tmp.new_cipher->algorithm_auth;
 
     al = SSL_AD_DECODE_ERROR;
 
 #ifndef OPENSSL_NO_PSK
-    if (alg_k & SSL_kPSK) {
-        char tmp_id_hint[PSK_MAX_IDENTITY_LEN + 1];
-
-        param_len = 2;
-        if (param_len > n) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
+    /* PSK ciphersuites are preceded by an identity hint */
+    if (alg_k & SSL_PSK) {
+        PACKET psk_identity_hint;
+        if (!PACKET_get_length_prefixed_2(&pkt, &psk_identity_hint)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
             goto f_err;
         }
-        n2s(p, i);
 
         /*
          * Store PSK identity hint for later use, hint is used in
@@ -1485,119 +1520,49 @@ int ssl3_get_key_exchange(SSL *s)
          * a PSK identity hint can be as long as the maximum length of a PSK
          * identity.
          */
-        if (i > PSK_MAX_IDENTITY_LEN) {
+        if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {
             al = SSL_AD_HANDSHAKE_FAILURE;
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_DATA_LENGTH_TOO_LONG);
             goto f_err;
         }
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE,
-                   SSL_R_BAD_PSK_IDENTITY_HINT_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
 
-        /*
-         * If received PSK identity hint contains NULL characters, the hint
-         * is truncated from the first NULL. p may not be ending with NULL,
-         * so create a NULL-terminated string.
-         */
-        memcpy(tmp_id_hint, p, i);
-        memset(tmp_id_hint + i, 0, PSK_MAX_IDENTITY_LEN + 1 - i);
-        OPENSSL_free(s->ctx->psk_identity_hint);
-        s->ctx->psk_identity_hint = BUF_strdup(tmp_id_hint);
-        if (s->ctx->psk_identity_hint == NULL) {
-            al = SSL_AD_HANDSHAKE_FAILURE;
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
+        if (!PACKET_strndup(&psk_identity_hint,
+                            &s->session->psk_identity_hint)) {
+            al = SSL_AD_INTERNAL_ERROR;
             goto f_err;
         }
+    }
 
-        p += i;
-        n -= param_len;
+    /* Nothing else to do for plain PSK or RSAPSK */
+    if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
     } else
 #endif                          /* !OPENSSL_NO_PSK */
 #ifndef OPENSSL_NO_SRP
     if (alg_k & SSL_kSRP) {
-        param_len = 2;
-        if (param_len > n) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        n2s(p, i);
-
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SRP_N_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((s->srp_ctx.N = BN_bin2bn(p, i, NULL)) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto err;
-        }
-        p += i;
-
-        if (2 > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        param_len += 2;
-
-        n2s(p, i);
-
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SRP_G_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((s->srp_ctx.g = BN_bin2bn(p, i, NULL)) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto err;
-        }
-        p += i;
-
-        if (1 > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        param_len += 1;
-
-        i = (unsigned int)(p[0]);
-        p++;
-
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SRP_S_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((s->srp_ctx.s = BN_bin2bn(p, i, NULL)) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto err;
-        }
-        p += i;
-
-        if (2 > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        param_len += 2;
-
-        n2s(p, i);
-
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SRP_B_LENGTH);
+        PACKET prime, generator, salt, server_pub;
+        if (!PACKET_get_length_prefixed_2(&pkt, &prime)
+            || !PACKET_get_length_prefixed_2(&pkt, &generator)
+            || !PACKET_get_length_prefixed_1(&pkt, &salt)
+            || !PACKET_get_length_prefixed_2(&pkt, &server_pub)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
             goto f_err;
         }
-        param_len += i;
 
-        if ((s->srp_ctx.B = BN_bin2bn(p, i, NULL)) == NULL) {
+        if ((s->srp_ctx.N =
+             BN_bin2bn(PACKET_data(&prime),
+                       PACKET_remaining(&prime), NULL)) == NULL
+            || (s->srp_ctx.g =
+                BN_bin2bn(PACKET_data(&generator),
+                          PACKET_remaining(&generator), NULL)) == NULL
+            || (s->srp_ctx.s =
+                BN_bin2bn(PACKET_data(&salt),
+                          PACKET_remaining(&salt), NULL)) == NULL
+            || (s->srp_ctx.B =
+                BN_bin2bn(PACKET_data(&server_pub),
+                          PACKET_remaining(&server_pub), NULL)) == NULL) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
             goto err;
         }
-        p += i;
-        n -= param_len;
 
         if (!srp_verify_server_param(s, &al)) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SRP_PARAMETERS);
@@ -1611,56 +1576,32 @@ int ssl3_get_key_exchange(SSL *s)
 #endif                          /* !OPENSSL_NO_SRP */
 #ifndef OPENSSL_NO_RSA
     if (alg_k & SSL_kRSA) {
+        PACKET mod, exp;
         /* Temporary RSA keys only allowed in export ciphersuites */
         if (!SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)) {
             al = SSL_AD_UNEXPECTED_MESSAGE;
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_UNEXPECTED_MESSAGE);
             goto f_err;
         }
-        if ((rsa = RSA_new()) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
-            goto err;
-        }
 
-        param_len = 2;
-        if (param_len > n) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
+        if (!PACKET_get_length_prefixed_2(&pkt, &mod)
+            || !PACKET_get_length_prefixed_2(&pkt, &exp)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
             goto f_err;
         }
-        n2s(p, i);
 
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_RSA_MODULUS_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((rsa->n = BN_bin2bn(p, i, rsa->n)) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
+        if ((rsa = RSA_new()) == NULL) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
             goto err;
         }
-        p += i;
-
-        if (2 > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        param_len += 2;
 
-        n2s(p, i);
-
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_RSA_E_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((rsa->e = BN_bin2bn(p, i, rsa->e)) == NULL) {
+        if ((rsa->n = BN_bin2bn(PACKET_data(&mod), PACKET_remaining(&mod),
+                                rsa->n)) == NULL
+            || (rsa->e = BN_bin2bn(PACKET_data(&exp), PACKET_remaining(&exp),
+                                   rsa->e)) == NULL) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
             goto err;
         }
-        p += i;
-        n -= param_len;
 
         /* this should be because we are using an export cipher */
         if (alg_a & SSL_aRSA)
@@ -1683,71 +1624,36 @@ int ssl3_get_key_exchange(SSL *s)
     if (0) ;
 #endif
 #ifndef OPENSSL_NO_DH
-    else if (alg_k & SSL_kDHE) {
-        if ((dh = DH_new()) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_DH_LIB);
-            goto err;
-        }
+    else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
+        PACKET prime, generator, pub_key;
 
-        param_len = 2;
-        if (param_len > n) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
+        if (!PACKET_get_length_prefixed_2(&pkt, &prime)
+            || !PACKET_get_length_prefixed_2(&pkt, &generator)
+            || !PACKET_get_length_prefixed_2(&pkt, &pub_key)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
             goto f_err;
         }
-        n2s(p, i);
 
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_DH_P_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((dh->p = BN_bin2bn(p, i, NULL)) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
+        if ((dh = DH_new()) == NULL) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_DH_LIB);
             goto err;
         }
-        p += i;
 
-        if (2 > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        param_len += 2;
-
-        n2s(p, i);
-
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_DH_G_LENGTH);
-            goto f_err;
-        }
-        param_len += i;
-
-        if ((dh->g = BN_bin2bn(p, i, NULL)) == NULL) {
+        if ((dh->p = BN_bin2bn(PACKET_data(&prime),
+                               PACKET_remaining(&prime), NULL)) == NULL
+            || (dh->g = BN_bin2bn(PACKET_data(&generator),
+                                  PACKET_remaining(&generator), NULL)) == NULL
+            || (dh->pub_key =
+                BN_bin2bn(PACKET_data(&pub_key),
+                          PACKET_remaining(&pub_key), NULL)) == NULL) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
             goto err;
         }
-        p += i;
-
-        if (2 > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
-            goto f_err;
-        }
-        param_len += 2;
-
-        n2s(p, i);
 
-        if (i > n - param_len) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_DH_PUB_KEY_LENGTH);
+        if (BN_is_zero(dh->p) || BN_is_zero(dh->g) || BN_is_zero(dh->pub_key)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_DH_VALUE);
             goto f_err;
         }
-        param_len += i;
-
-        if ((dh->pub_key = BN_bin2bn(p, i, NULL)) == NULL) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_BN_LIB);
-            goto err;
-        }
-        p += i;
-        n -= param_len;
 
         if (!ssl_security(s, SSL_SECOP_TMP_DH, DH_security_bits(dh), 0, dh)) {
             al = SSL_AD_HANDSHAKE_FAILURE;
@@ -1764,9 +1670,11 @@ int ssl3_get_key_exchange(SSL *s)
 #endif                          /* !OPENSSL_NO_DH */
 
 #ifndef OPENSSL_NO_EC
-    else if (alg_k & SSL_kECDHE) {
+    else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
         EC_GROUP *ngroup;
         const EC_GROUP *group;
+        PACKET encoded_pt;
+        unsigned char *ecparams;
 
         if ((ecdh = EC_KEY_new()) == NULL) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
@@ -1775,17 +1683,10 @@ int ssl3_get_key_exchange(SSL *s)
 
         /*
          * Extract elliptic curve parameters and the server's ephemeral ECDH
-         * public key. Keep accumulating lengths of various components in
-         * param_len and make sure it never exceeds n.
-         */
-
-        /*
-         * XXX: For now we only support named (not generic) curves and the
-         * ECParameters in this case is just three bytes. We also need one
-         * byte for the length of the encoded point
+         * public key. For now we only support named (not generic) curves and
+         * ECParameters in this case is just three bytes.
          */
-        param_len = 4;
-        if (param_len > n) {
+        if (!PACKET_get_bytes(&pkt, &ecparams, 3)) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
             goto f_err;
         }
@@ -1793,12 +1694,12 @@ int ssl3_get_key_exchange(SSL *s)
          * Check curve is one of our preferences, if not server has sent an
          * invalid curve. ECParameters is 3 bytes.
          */
-        if (!tls1_check_curve(s, p, 3)) {
+        if (!tls1_check_curve(s, ecparams, 3)) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_WRONG_CURVE);
             goto f_err;
         }
 
-        if ((curve_nid = tls1_ec_curve_id2nid(*(p + 2))) == 0) {
+        if ((curve_nid = tls1_ec_curve_id2nid(*(ecparams + 2))) == 0) {
             al = SSL_AD_INTERNAL_ERROR;
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE,
                    SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
@@ -1826,8 +1727,6 @@ int ssl3_get_key_exchange(SSL *s)
             goto f_err;
         }
 
-        p += 3;
-
         /* Next, get the encoded ECPoint */
         if (((srvr_ecpoint = EC_POINT_new(group)) == NULL) ||
             ((bn_ctx = BN_CTX_new()) == NULL)) {
@@ -1835,19 +1734,16 @@ int ssl3_get_key_exchange(SSL *s)
             goto err;
         }
 
-        encoded_pt_len = *p;    /* length of encoded point */
-        p += 1;
+        if (!PACKET_get_length_prefixed_1(&pkt, &encoded_pt)) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
+            goto f_err;
+        }
 
-        if ((encoded_pt_len > n - param_len) ||
-            (EC_POINT_oct2point(group, srvr_ecpoint,
-                                p, encoded_pt_len, bn_ctx) == 0)) {
+        if (EC_POINT_oct2point(group, srvr_ecpoint, PACKET_data(&encoded_pt),
+                               PACKET_remaining(&encoded_pt), bn_ctx) == 0) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_ECPOINT);
             goto f_err;
         }
-        param_len += encoded_pt_len;
-
-        n -= param_len;
-        p += encoded_pt_len;
 
         /*
          * The ECC/TLS specification does not mention the use of DSA to sign
@@ -1878,17 +1774,29 @@ int ssl3_get_key_exchange(SSL *s)
     }
 #endif                          /* !OPENSSL_NO_EC */
 
-    /* p points to the next byte, there are 'n' bytes left */
-
     /* if it was signed, check the signature */
     if (pkey != NULL) {
+        PACKET params;
+        /*
+         * |pkt| now points to the beginning of the signature, so the difference
+         * equals the length of the parameters.
+         */
+        if (!PACKET_get_sub_packet(&save_param_start, &params,
+                                   PACKET_remaining(&save_param_start) -
+                                   PACKET_remaining(&pkt))) {
+            al = SSL_AD_INTERNAL_ERROR;
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+            goto f_err;
+        }
+
         if (SSL_USE_SIGALGS(s)) {
+            unsigned char *sigalgs;
             int rv;
-            if (2 > n) {
+            if (!PACKET_get_bytes(&pkt, &sigalgs, 2)) {
                 SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
                 goto f_err;
             }
-            rv = tls12_check_peer_sigalg(&md, s, p, pkey);
+            rv = tls12_check_peer_sigalg(&md, s, sigalgs, pkey);
             if (rv == -1)
                 goto err;
             else if (rv == 0) {
@@ -1897,23 +1805,25 @@ int ssl3_get_key_exchange(SSL *s)
 #ifdef SSL_DEBUG
             fprintf(stderr, "USING TLSv1.2 HASH %s\n", EVP_MD_name(md));
 #endif
-            p += 2;
-            n -= 2;
-        } else
+        } else {
             md = EVP_sha1();
+        }
 
-        if (2 > n) {
-            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_TOO_SHORT);
+        if (!PACKET_get_length_prefixed_2(&pkt, &signature)
+            || PACKET_remaining(&pkt) != 0) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
             goto f_err;
         }
-        n2s(p, i);
-        n -= 2;
         j = EVP_PKEY_size(pkey);
+        if (j < 0) {
+            SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+            goto f_err;
+        }
 
         /*
-         * Check signature length. If n is 0 then signature is empty
+         * Check signature length
          */
-        if ((i != n) || (n > j) || (n <= 0)) {
+        if (PACKET_remaining(&signature) > (size_t)j) {
             /* wrong packet length */
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_WRONG_SIGNATURE_LENGTH);
             goto f_err;
@@ -1933,18 +1843,21 @@ int ssl3_get_key_exchange(SSL *s)
                                  SSL3_RANDOM_SIZE);
                 EVP_DigestUpdate(&md_ctx, &(s->s3->server_random[0]),
                                  SSL3_RANDOM_SIZE);
-                EVP_DigestUpdate(&md_ctx, param, param_len);
+                EVP_DigestUpdate(&md_ctx, PACKET_data(&params),
+                                 PACKET_remaining(&params));
                 EVP_DigestFinal_ex(&md_ctx, q, &size);
                 q += size;
                 j += size;
             }
-            i = RSA_verify(NID_md5_sha1, md_buf, j, p, n, pkey->pkey.rsa);
-            if (i < 0) {
+            verify_ret =
+                RSA_verify(NID_md5_sha1, md_buf, j, PACKET_data(&signature),
+                           PACKET_remaining(&signature), pkey->pkey.rsa);
+            if (verify_ret < 0) {
                 al = SSL_AD_DECRYPT_ERROR;
                 SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_RSA_DECRYPT);
                 goto f_err;
             }
-            if (i == 0) {
+            if (verify_ret == 0) {
                 /* bad signature */
                 al = SSL_AD_DECRYPT_ERROR;
                 SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SIGNATURE);
@@ -1958,8 +1871,10 @@ int ssl3_get_key_exchange(SSL *s)
                              SSL3_RANDOM_SIZE);
             EVP_VerifyUpdate(&md_ctx, &(s->s3->server_random[0]),
                              SSL3_RANDOM_SIZE);
-            EVP_VerifyUpdate(&md_ctx, param, param_len);
-            if (EVP_VerifyFinal(&md_ctx, p, (int)n, pkey) <= 0) {
+            EVP_VerifyUpdate(&md_ctx, PACKET_data(&params),
+                             PACKET_remaining(&params));
+            if (EVP_VerifyFinal(&md_ctx, PACKET_data(&signature),
+                                PACKET_remaining(&signature), pkey) <= 0) {
                 /* bad signature */
                 al = SSL_AD_DECRYPT_ERROR;
                 SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_BAD_SIGNATURE);
@@ -1967,8 +1882,8 @@ int ssl3_get_key_exchange(SSL *s)
             }
         }
     } else {
-        /* aNULL, aSRP or kPSK do not need public keys */
-        if (!(alg_a & (SSL_aNULL | SSL_aSRP)) && !(alg_k & SSL_kPSK)) {
+        /* aNULL, aSRP or PSK do not need public keys */
+        if (!(alg_a & (SSL_aNULL | SSL_aSRP)) && !(alg_k & SSL_PSK)) {
             /* Might be wrong key type, check it */
             if (ssl3_check_cert_and_algorithm(s))
                 /* Otherwise this shouldn't happen */
@@ -1976,7 +1891,7 @@ int ssl3_get_key_exchange(SSL *s)
             goto err;
         }
         /* still data left over */
-        if (n != 0) {
+        if (PACKET_remaining(&pkt) != 0) {
             SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_EXTRA_DATA_IN_MESSAGE);
             goto f_err;
         }
@@ -2007,12 +1922,13 @@ int ssl3_get_key_exchange(SSL *s)
 int ssl3_get_certificate_request(SSL *s)
 {
     int ok, ret = 0;
-    unsigned long n, nc, l;
-    unsigned int llen, ctype_num, i;
+    unsigned long n;
+    unsigned int list_len, ctype_num, i, name_len;
     X509_NAME *xn = NULL;
-    const unsigned char *p, *q;
-    unsigned char *d;
+    unsigned char *data;
+    unsigned char *namestart, *namebytes;
     STACK_OF(X509_NAME) *ca_sk = NULL;
+    PACKET pkt;
 
     n = s->method->ssl_get_message(s,
                                    SSL3_ST_CR_CERT_REQ_A,
@@ -2051,7 +1967,11 @@ int ssl3_get_certificate_request(SSL *s)
         }
     }
 
-    p = d = (unsigned char *)s->init_msg;
+    if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
+        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+        SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
 
     if ((ca_sk = sk_X509_NAME_new(ca_dn_cmp)) == NULL) {
         SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, ERR_R_MALLOC_FAILURE);
@@ -2059,7 +1979,12 @@ int ssl3_get_certificate_request(SSL *s)
     }
 
     /* get the certificate types */
-    ctype_num = *(p++);
+    if (!PACKET_get_1(&pkt, &ctype_num)
+            || !PACKET_get_bytes(&pkt, &data, ctype_num)) {
+        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
+        SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, SSL_R_LENGTH_MISMATCH);
+        goto err;
+    }
     OPENSSL_free(s->cert->ctypes);
     s->cert->ctypes = NULL;
     if (ctype_num > SSL3_CT_NUMBER) {
@@ -2069,31 +1994,27 @@ int ssl3_get_certificate_request(SSL *s)
             SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, ERR_R_MALLOC_FAILURE);
             goto err;
         }
-        memcpy(s->cert->ctypes, p, ctype_num);
+        memcpy(s->cert->ctypes, data, ctype_num);
         s->cert->ctype_num = (size_t)ctype_num;
         ctype_num = SSL3_CT_NUMBER;
     }
     for (i = 0; i < ctype_num; i++)
-        s->s3->tmp.ctype[i] = p[i];
-    p += p[-1];
+        s->s3->tmp.ctype[i] = data[i];
+
     if (SSL_USE_SIGALGS(s)) {
-        n2s(p, llen);
-        /*
-         * Check we have enough room for signature algorithms and following
-         * length value.
-         */
-        if ((unsigned long)(p - d + llen + 2) > n) {
+        if (!PACKET_get_net_2(&pkt, &list_len)
+                || !PACKET_get_bytes(&pkt, &data, list_len)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
-            SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST,
-                   SSL_R_DATA_LENGTH_TOO_LONG);
+            SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, SSL_R_LENGTH_MISMATCH);
             goto err;
         }
+
         /* Clear certificate digests and validity flags */
         for (i = 0; i < SSL_PKEY_NUM; i++) {
             s->s3->tmp.md[i] = NULL;
             s->s3->tmp.valid_flags[i] = 0;
         }
-        if ((llen & 1) || !tls1_save_sigalgs(s, p, llen)) {
+        if ((list_len & 1) || !tls1_save_sigalgs(s, data, list_len)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
             SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST,
                    SSL_R_SIGNATURE_ALGORITHMS_ERROR);
@@ -2104,35 +2025,34 @@ int ssl3_get_certificate_request(SSL *s)
             SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, ERR_R_MALLOC_FAILURE);
             goto err;
         }
-        p += llen;
     }
 
     /* get the CA RDNs */
-    n2s(p, llen);
-
-    if ((unsigned long)(p - d + llen) != n) {
+    if (!PACKET_get_net_2(&pkt, &list_len)
+            || PACKET_remaining(&pkt) != list_len) {
         ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
         SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, SSL_R_LENGTH_MISMATCH);
         goto err;
     }
 
-    for (nc = 0; nc < llen;) {
-        n2s(p, l);
-        if ((l + nc + 2) > llen) {
+    while (PACKET_remaining(&pkt)) {
+        if (!PACKET_get_net_2(&pkt, &name_len)
+                || !PACKET_get_bytes(&pkt, &namebytes, name_len)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
-            SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, SSL_R_CA_DN_TOO_LONG);
+            SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, SSL_R_LENGTH_MISMATCH);
             goto err;
         }
 
-        q = p;
+        namestart = namebytes;
 
-        if ((xn = d2i_X509_NAME(NULL, &q, l)) == NULL) {
+        if ((xn = d2i_X509_NAME(NULL, (const unsigned char **)&namebytes,
+                                name_len)) == NULL) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
             SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, ERR_R_ASN1_LIB);
             goto err;
         }
 
-        if (q != (p + l)) {
+        if (namebytes != (namestart + name_len)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
             SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST,
                    SSL_R_CA_DN_LENGTH_MISMATCH);
@@ -2142,9 +2062,6 @@ int ssl3_get_certificate_request(SSL *s)
             SSLerr(SSL_F_SSL3_GET_CERTIFICATE_REQUEST, ERR_R_MALLOC_FAILURE);
             goto err;
         }
-
-        p += l;
-        nc += l + 2;
     }
 
     /* we should setup a certificate to return.... */
@@ -2170,10 +2087,11 @@ static int ca_dn_cmp(const X509_NAME *const *a, const X509_NAME *const *b)
 
 int ssl3_get_new_session_ticket(SSL *s)
 {
-    int ok, al, ret = 0, ticklen;
+    int ok, al, ret = 0;
+    unsigned int ticklen;
+    unsigned long ticket_lifetime_hint;
     long n;
-    const unsigned char *p;
-    unsigned char *d;
+    PACKET pkt;
 
     n = s->method->ssl_get_message(s,
                                    SSL3_ST_CR_SESSION_TICKET_A,
@@ -2183,14 +2101,23 @@ int ssl3_get_new_session_ticket(SSL *s)
     if (!ok)
         return ((int)n);
 
-    if (n < 6) {
-        /* need at least ticket_lifetime_hint + ticket length */
+    if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_SSL3_GET_NEW_SESSION_TICKET, ERR_R_INTERNAL_ERROR);
+        goto f_err;
+    }
+
+    if (!PACKET_get_net_4(&pkt, &ticket_lifetime_hint)
+            || !PACKET_get_net_2(&pkt, &ticklen)
+            || PACKET_remaining(&pkt) != ticklen) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_SSL3_GET_NEW_SESSION_TICKET, SSL_R_LENGTH_MISMATCH);
         goto f_err;
     }
 
-    p = d = (unsigned char *)s->init_msg;
+    /* Server is allowed to change its mind and send an empty ticket. */
+    if (ticklen == 0)
+        return 1;
 
     if (s->session->session_id_length > 0) {
         int i = s->session_ctx->session_cache_mode;
@@ -2223,22 +2150,21 @@ int ssl3_get_new_session_ticket(SSL *s)
         s->session = new_sess;
     }
 
-    n2l(p, s->session->tlsext_tick_lifetime_hint);
-    n2s(p, ticklen);
-    /* ticket_lifetime_hint + ticket_length + ticket */
-    if (ticklen + 6 != n) {
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_SSL3_GET_NEW_SESSION_TICKET, SSL_R_LENGTH_MISMATCH);
-        goto f_err;
-    }
     OPENSSL_free(s->session->tlsext_tick);
     s->session->tlsext_ticklen = 0;
+
     s->session->tlsext_tick = OPENSSL_malloc(ticklen);
     if (!s->session->tlsext_tick) {
         SSLerr(SSL_F_SSL3_GET_NEW_SESSION_TICKET, ERR_R_MALLOC_FAILURE);
         goto err;
     }
-    memcpy(s->session->tlsext_tick, p, ticklen);
+    if (!PACKET_copy_bytes(&pkt, s->session->tlsext_tick, ticklen)) {
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_SSL3_GET_NEW_SESSION_TICKET, SSL_R_LENGTH_MISMATCH);
+        goto f_err;
+    }
+
+    s->session->tlsext_tick_lifetime_hint = ticket_lifetime_hint;
     s->session->tlsext_ticklen = ticklen;
     /*
      * There are two ways to detect a resumed ticket session. One is to set
@@ -2251,7 +2177,7 @@ int ssl3_get_new_session_ticket(SSL *s)
      * elsewhere in OpenSSL. The session ID is set to the SHA256 (or SHA1 is
      * SHA256 is disabled) hash of the ticket.
      */
-    EVP_Digest(p, ticklen,
+    EVP_Digest(s->session->tlsext_tick, ticklen,
                s->session->session_id, &s->session->session_id_length,
                EVP_sha256(), NULL);
     ret = 1;
@@ -2267,7 +2193,8 @@ int ssl3_get_cert_status(SSL *s)
 {
     int ok, al;
     unsigned long resplen, n;
-    const unsigned char *p;
+    unsigned int type;
+    PACKET pkt;
 
     n = s->method->ssl_get_message(s,
                                    SSL3_ST_CR_CERT_STATUS_A,
@@ -2276,31 +2203,36 @@ int ssl3_get_cert_status(SSL *s)
 
     if (!ok)
         return ((int)n);
-    if (n < 4) {
-        /* need at least status type + length */
-        al = SSL_AD_DECODE_ERROR;
-        SSLerr(SSL_F_SSL3_GET_CERT_STATUS, SSL_R_LENGTH_MISMATCH);
+
+    if (!PACKET_buf_init(&pkt, s->init_msg, n)) {
+        al = SSL_AD_INTERNAL_ERROR;
+        SSLerr(SSL_F_SSL3_GET_CERT_STATUS, ERR_R_INTERNAL_ERROR);
         goto f_err;
     }
-    p = (unsigned char *)s->init_msg;
-    if (*p++ != TLSEXT_STATUSTYPE_ocsp) {
+    if (!PACKET_get_1(&pkt, &type)
+            || type != TLSEXT_STATUSTYPE_ocsp) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_SSL3_GET_CERT_STATUS, SSL_R_UNSUPPORTED_STATUS_TYPE);
         goto f_err;
     }
-    n2l3(p, resplen);
-    if (resplen + 4 != n) {
+    if (!PACKET_get_net_3(&pkt, &resplen)
+            || PACKET_remaining(&pkt) != resplen) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_SSL3_GET_CERT_STATUS, SSL_R_LENGTH_MISMATCH);
         goto f_err;
     }
     OPENSSL_free(s->tlsext_ocsp_resp);
-    s->tlsext_ocsp_resp = BUF_memdup(p, resplen);
+    s->tlsext_ocsp_resp = OPENSSL_malloc(resplen);
     if (!s->tlsext_ocsp_resp) {
         al = SSL_AD_INTERNAL_ERROR;
         SSLerr(SSL_F_SSL3_GET_CERT_STATUS, ERR_R_MALLOC_FAILURE);
         goto f_err;
     }
+    if (!PACKET_copy_bytes(&pkt, s->tlsext_ocsp_resp, resplen)) {
+        al = SSL_AD_DECODE_ERROR;
+        SSLerr(SSL_F_SSL3_GET_CERT_STATUS, SSL_R_LENGTH_MISMATCH);
+        goto f_err;
+    }
     s->tlsext_ocsp_resplen = resplen;
     if (s->ctx->tlsext_status_cb) {
         int ret;
@@ -2351,6 +2283,9 @@ int ssl3_send_client_key_exchange(SSL *s)
 {
     unsigned char *p;
     int n;
+#ifndef OPENSSL_NO_PSK
+    size_t pskhdrlen = 0;
+#endif
     unsigned long alg_k;
 #ifndef OPENSSL_NO_RSA
     unsigned char *q;
@@ -2366,17 +2301,93 @@ int ssl3_send_client_key_exchange(SSL *s)
 #endif
     unsigned char *pms = NULL;
     size_t pmslen = 0;
+    alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 
     if (s->state == SSL3_ST_CW_KEY_EXCH_A) {
         p = ssl_handshake_start(s);
 
-        alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
+
+#ifndef OPENSSL_NO_PSK
+        if (alg_k & SSL_PSK) {
+            int psk_err = 1;
+            /*
+             * The callback needs PSK_MAX_IDENTITY_LEN + 1 bytes to return a
+             * \0-terminated identity. The last byte is for us for simulating
+             * strnlen.
+             */
+            char identity[PSK_MAX_IDENTITY_LEN + 1];
+            size_t identitylen;
+            unsigned char psk[PSK_MAX_PSK_LEN];
+            size_t psklen;
+
+            if (s->psk_client_callback == NULL) {
+                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
+                       SSL_R_PSK_NO_CLIENT_CB);
+                goto err;
+            }
+
+            memset(identity, 0, sizeof(identity));
+
+            psklen = s->psk_client_callback(s, s->session->psk_identity_hint,
+                                            identity, sizeof(identity) - 1,
+                                            psk, sizeof(psk));
+
+            if (psklen > PSK_MAX_PSK_LEN) {
+                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
+                       ERR_R_INTERNAL_ERROR);
+                goto psk_err;
+            } else if (psklen == 0) {
+                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
+                       SSL_R_PSK_IDENTITY_NOT_FOUND);
+                goto psk_err;
+            }
+
+            OPENSSL_free(s->s3->tmp.psk);
+            s->s3->tmp.psk = BUF_memdup(psk, psklen);
+            OPENSSL_cleanse(psk, psklen);
+
+            if (s->s3->tmp.psk == NULL) {
+                OPENSSL_cleanse(identity, sizeof(identity));
+                goto memerr;
+            }
+
+            s->s3->tmp.psklen = psklen;
+
+            identitylen = strlen(identity);
+            if (identitylen > PSK_MAX_IDENTITY_LEN) {
+                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
+                       ERR_R_INTERNAL_ERROR);
+                goto psk_err;
+            }
+            OPENSSL_free(s->session->psk_identity);
+            s->session->psk_identity = BUF_strdup(identity);
+            if (s->session->psk_identity == NULL) {
+                OPENSSL_cleanse(identity, sizeof(identity));
+                goto memerr;
+            }
+
+            s2n(identitylen, p);
+            memcpy(p, identity, identitylen);
+            pskhdrlen = 2 + identitylen;
+            p += identitylen;
+            psk_err = 0;
+ psk_err:
+            OPENSSL_cleanse(identity, sizeof(identity));
+            if (psk_err != 0) {
+                ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
+                goto err;
+            }
+        }
+        if (alg_k & SSL_kPSK) {
+            n = 0;
+        } else
+#endif
 
         /* Fool emacs indentation */
         if (0) {
         }
 #ifndef OPENSSL_NO_RSA
-        else if (alg_k & SSL_kRSA) {
+        else if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
             RSA *rsa;
             pmslen = SSL_MAX_MASTER_KEY_LENGTH;
             pms = OPENSSL_malloc(pmslen);
@@ -2436,7 +2447,7 @@ int ssl3_send_client_key_exchange(SSL *s)
         }
 #endif
 #ifndef OPENSSL_NO_DH
-        else if (alg_k & (SSL_kDHE | SSL_kDHr | SSL_kDHd)) {
+        else if (alg_k & (SSL_kDHE | SSL_kDHr | SSL_kDHd | SSL_kDHEPSK)) {
             DH *dh_srvr, *dh_clnt;
             if (s->s3->peer_dh_tmp != NULL)
                 dh_srvr = s->s3->peer_dh_tmp;
@@ -2515,7 +2526,7 @@ int ssl3_send_client_key_exchange(SSL *s)
 #endif
 
 #ifndef OPENSSL_NO_EC
-        else if (alg_k & (SSL_kECDHE | SSL_kECDHr | SSL_kECDHe)) {
+        else if (alg_k & (SSL_kECDHE | SSL_kECDHr | SSL_kECDHe | SSL_kECDHEPSK)) {
             const EC_GROUP *srvr_group = NULL;
             EC_KEY *tkey;
             int ecdh_clnt_cert = 0;
@@ -2802,92 +2813,6 @@ int ssl3_send_client_key_exchange(SSL *s)
                 goto err;
             }
         }
-#endif
-#ifndef OPENSSL_NO_PSK
-        else if (alg_k & SSL_kPSK) {
-            /*
-             * The callback needs PSK_MAX_IDENTITY_LEN + 1 bytes to return a
-             * \0-terminated identity. The last byte is for us for simulating
-             * strnlen.
-             */
-            char identity[PSK_MAX_IDENTITY_LEN + 2];
-            size_t identity_len;
-            unsigned char *t = NULL;
-            unsigned int psk_len = 0;
-            int psk_err = 1;
-
-            n = 0;
-            if (s->psk_client_callback == NULL) {
-                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
-                       SSL_R_PSK_NO_CLIENT_CB);
-                goto err;
-            }
-
-            memset(identity, 0, sizeof(identity));
-            /* Allocate maximum size buffer */
-            pmslen = PSK_MAX_PSK_LEN * 2 + 4;
-            pms = OPENSSL_malloc(pmslen);
-            if (!pms)
-                goto memerr;
-
-            psk_len = s->psk_client_callback(s, s->ctx->psk_identity_hint,
-                                             identity, sizeof(identity) - 1,
-                                             pms, pmslen);
-            if (psk_len > PSK_MAX_PSK_LEN) {
-                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
-                       ERR_R_INTERNAL_ERROR);
-                goto psk_err;
-            } else if (psk_len == 0) {
-                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
-                       SSL_R_PSK_IDENTITY_NOT_FOUND);
-                goto psk_err;
-            }
-            /* Change pmslen to real length */
-            pmslen = 2 + psk_len + 2 + psk_len;
-            identity[PSK_MAX_IDENTITY_LEN + 1] = '\0';
-            identity_len = strlen(identity);
-            if (identity_len > PSK_MAX_IDENTITY_LEN) {
-                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
-                       ERR_R_INTERNAL_ERROR);
-                goto psk_err;
-            }
-            /* create PSK pre_master_secret */
-            t = pms;
-            memmove(pms + psk_len + 4, pms, psk_len);
-            s2n(psk_len, t);
-            memset(t, 0, psk_len);
-            t += psk_len;
-            s2n(psk_len, t);
-
-            OPENSSL_free(s->session->psk_identity_hint);
-            s->session->psk_identity_hint =
-                BUF_strdup(s->ctx->psk_identity_hint);
-            if (s->ctx->psk_identity_hint != NULL
-                && s->session->psk_identity_hint == NULL) {
-                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
-                       ERR_R_MALLOC_FAILURE);
-                goto psk_err;
-            }
-
-            OPENSSL_free(s->session->psk_identity);
-            s->session->psk_identity = BUF_strdup(identity);
-            if (s->session->psk_identity == NULL) {
-                SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
-                       ERR_R_MALLOC_FAILURE);
-                goto psk_err;
-            }
-
-            s2n(identity_len, p);
-            memcpy(p, identity, identity_len);
-            n = 2 + identity_len;
-            psk_err = 0;
- psk_err:
-            OPENSSL_cleanse(identity, sizeof(identity));
-            if (psk_err != 0) {
-                ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
-                goto err;
-            }
-        }
 #endif
         else {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
@@ -2895,6 +2820,10 @@ int ssl3_send_client_key_exchange(SSL *s)
             goto err;
         }
 
+#ifndef OPENSSL_NO_PSK
+        n += pskhdrlen;
+#endif
+
         if (!ssl_set_handshake_header(s, SSL3_MT_CLIENT_KEY_EXCHANGE, n)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
             SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
@@ -2908,16 +2837,13 @@ int ssl3_send_client_key_exchange(SSL *s)
     n = ssl_do_write(s);
 #ifndef OPENSSL_NO_SRP
     /* Check for SRP */
-    if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
+    if (alg_k & SSL_kSRP) {
         /*
          * If everything written generate master key: no need to save PMS as
-         * SRP_generate_client_master_secret generates it internally.
+         * srp_generate_client_master_secret generates it internally.
          */
         if (n > 0) {
-            if ((s->session->master_key_length =
-                 SRP_generate_client_master_secret(s,
-                                                   s->session->master_key)) <
-                0) {
+            if (!srp_generate_client_master_secret(s)) {
                 SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,
                        ERR_R_INTERNAL_ERROR);
                 goto err;
@@ -2935,19 +2861,12 @@ int ssl3_send_client_key_exchange(SSL *s)
             pms = s->s3->tmp.pms;
             pmslen = s->s3->tmp.pmslen;
         }
-        if (pms == NULL) {
+        if (pms == NULL && !(alg_k & SSL_kPSK)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
             SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);
             goto err;
         }
-        s->session->master_key_length =
-            s->method->ssl3_enc->generate_master_secret(s,
-                                                        s->
-                                                        session->master_key,
-                                                        pms, pmslen);
-        OPENSSL_clear_free(pms, pmslen);
-        s->s3->tmp.pms = NULL;
-        if (s->session->master_key_length < 0) {
+        if (!ssl_generate_master_secret(s, pms, pmslen, 1)) {
             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
             SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
             goto err;
@@ -2965,6 +2884,10 @@ int ssl3_send_client_key_exchange(SSL *s)
     OPENSSL_free(encodedPoint);
     EC_KEY_free(clnt_ecdh);
     EVP_PKEY_free(srvr_pub_pkey);
+#endif
+#ifndef OPENSSL_NO_PSK
+    OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);
+    s->s3->tmp.psk = NULL;
 #endif
     s->state = SSL_ST_ERR;
     return (-1);
@@ -3067,8 +2990,7 @@ int ssl3_send_client_verify(SSL *s)
             n = j + 2;
         } else
 #endif
-        if (pkey->type == NID_id_GostR3410_94
-                || pkey->type == NID_id_GostR3410_2001) {
+        if (pkey->type == NID_id_GostR3410_2001) {
             unsigned char signbuf[64];
             int i;
             size_t sigsize = 64;
@@ -3303,7 +3225,7 @@ int ssl3_check_cert_and_algorithm(SSL *s)
     }
 #endif
 #ifndef OPENSSL_NO_RSA
-    if (alg_k & SSL_kRSA) {
+    if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
         if (!SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) &&
             !has_bits(i, EVP_PK_RSA | EVP_PKT_ENC)) {
             SSLerr(SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
@@ -3400,11 +3322,11 @@ int ssl3_check_cert_and_algorithm(SSL *s)
  * the session ID. EAP-FAST (RFC 4851), however, relies on the next server
  * message after the ServerHello to determine if the server is resuming.
  * Therefore, we allow EAP-FAST to peek ahead.
- * ssl3_check_finished returns 1 if we are resuming from an external
- * pre-shared secret, we have a "ticket" and the next server handshake message
- * is Finished; and 0 otherwise. It returns -1 upon an error.
+ * ssl3_check_change returns 1 if we are resuming from an external
+ * pre-shared secret, we have a "ticket" and the next server message
+ * is CCS; and 0 otherwise. It returns -1 upon an error.
  */
-static int ssl3_check_finished(SSL *s)
+static int ssl3_check_change(SSL *s)
 {
     int ok = 0;
 
@@ -3412,8 +3334,6 @@ static int ssl3_check_finished(SSL *s)
         !s->session->tlsext_tick)
         return 0;
 
-    /* Need to permit this temporarily, in case the next message is Finished. */
-    s->s3->flags |= SSL3_FLAGS_CCS_OK;
     /*
      * This function is called when we might get a Certificate message instead,
      * so permit appropriate message length.
@@ -3424,23 +3344,15 @@ static int ssl3_check_finished(SSL *s)
                                SSL3_ST_CR_CERT_A,
                                SSL3_ST_CR_CERT_B,
                                -1, s->max_cert_list, &ok);
-    s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
 
     if (!ok)
         return -1;
 
     s->s3->tmp.reuse_message = 1;
 
-    if (s->s3->tmp.message_type == SSL3_MT_FINISHED)
+    if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC)
         return 1;
 
-    /* If we're not done, then the CCS arrived early and we should bail. */
-    if (s->s3->change_cipher_spec) {
-        SSLerr(SSL_F_SSL3_CHECK_FINISHED, SSL_R_CCS_RECEIVED_EARLY);
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
-        return -1;
-    }
-
     return 0;
 }
 
@@ -3487,9 +3399,7 @@ int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
 }
 
 int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
-                             unsigned char *p,
-                             int (*put_cb) (const SSL_CIPHER *,
-                                            unsigned char *))
+                             unsigned char *p)
 {
     int i, j = 0;
     SSL_CIPHER *c;
@@ -3501,8 +3411,6 @@ int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
     if (sk == NULL)
         return (0);
     q = p;
-    if (put_cb == NULL)
-        put_cb = s->method->put_cipher_by_char;
 
     for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
         c = sk_SSL_CIPHER_value(sk, i);
@@ -3517,7 +3425,7 @@ int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
                 empty_reneg_info_scsv = 0;
         }
 #endif
-        j = put_cb(c, p);
+        j = s->method->put_cipher_by_char(c, p);
         p += j;
     }
     /*
@@ -3529,7 +3437,7 @@ int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
             static SSL_CIPHER scsv = {
                 0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
             };
-            j = put_cb(&scsv, p);
+            j = s->method->put_cipher_by_char(&scsv, p);
             p += j;
 #ifdef OPENSSL_RI_DEBUG
             fprintf(stderr,
@@ -3540,7 +3448,7 @@ int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
             static SSL_CIPHER scsv = {
                 0, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
             };
-            j = put_cb(&scsv, p);
+            j = s->method->put_cipher_by_char(&scsv, p);
             p += j;
         }
     }