Update NSS to 3.41

1 files changed, 844 insertions, 0 deletions

diff --git a/security/nss/lib/ssl/tls13esni.c b/security/nss/lib/ssl/tls13esni.c
new file mode 100644
index 000000000..e2328769b
--- /dev/null
+++ b/security/nss/lib/ssl/tls13esni.c
@@ -0,0 +1,844 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#define TLS13_ESNI_VERSION 0xff01
+
+/*
+ *  struct {
+ *      uint16 version;
+ *      uint8 checksum[4];
+ *      KeyShareEntry keys<4..2^16-1>;
+ *      CipherSuite cipher_suites<2..2^16-2>;
+ *      uint16 padded_length;
+ *      uint64 not_before;
+ *      uint64 not_after;
+ *      Extension extensions<0..2^16-1>;
+ *  } ESNIKeys;
+ */
+#include "nss.h"
+#include "pk11func.h"
+#include "ssl.h"
+#include "sslproto.h"
+#include "sslimpl.h"
+#include "ssl3exthandle.h"
+#include "tls13esni.h"
+#include "tls13exthandle.h"
+#include "tls13hkdf.h"
+
+const char kHkdfPurposeEsniKey[] = "esni key";
+const char kHkdfPurposeEsniIv[] = "esni iv";
+
+void
+tls13_DestroyESNIKeys(sslEsniKeys *keys)
+{
+    if (!keys) {
+        return;
+    }
+    SECITEM_FreeItem(&keys->data, PR_FALSE);
+    PORT_Free((void *)keys->dummySni);
+    tls13_DestroyKeyShares(&keys->keyShares);
+    ssl_FreeEphemeralKeyPair(keys->privKey);
+    SECITEM_FreeItem(&keys->suites, PR_FALSE);
+    PORT_ZFree(keys, sizeof(sslEsniKeys));
+}
+
+sslEsniKeys *
+tls13_CopyESNIKeys(sslEsniKeys *okeys)
+{
+    sslEsniKeys *nkeys;
+    SECStatus rv;
+
+    PORT_Assert(okeys);
+
+    nkeys = PORT_ZNew(sslEsniKeys);
+    if (!nkeys) {
+        return NULL;
+    }
+    PR_INIT_CLIST(&nkeys->keyShares);
+    rv = SECITEM_CopyItem(NULL, &nkeys->data, &okeys->data);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    if (okeys->dummySni) {
+        nkeys->dummySni = PORT_Strdup(okeys->dummySni);
+        if (!nkeys->dummySni) {
+            goto loser;
+        }
+    }
+    for (PRCList *cur_p = PR_LIST_HEAD(&okeys->keyShares);
+         cur_p != &okeys->keyShares;
+         cur_p = PR_NEXT_LINK(cur_p)) {
+        TLS13KeyShareEntry *copy = tls13_CopyKeyShareEntry(
+            (TLS13KeyShareEntry *)cur_p);
+        if (!copy) {
+            goto loser;
+        }
+        PR_APPEND_LINK(&copy->link, &nkeys->keyShares);
+    }
+    if (okeys->privKey) {
+        nkeys->privKey = ssl_CopyEphemeralKeyPair(okeys->privKey);
+        if (!nkeys->privKey) {
+            goto loser;
+        }
+    }
+    rv = SECITEM_CopyItem(NULL, &nkeys->suites, &okeys->suites);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    nkeys->paddedLength = okeys->paddedLength;
+    nkeys->notBefore = okeys->notBefore;
+    nkeys->notAfter = okeys->notAfter;
+    return nkeys;
+
+loser:
+    tls13_DestroyESNIKeys(nkeys);
+    return NULL;
+}
+
+/* Checksum is a 4-byte array. */
+static SECStatus
+tls13_ComputeESNIKeysChecksum(const PRUint8 *buf, unsigned int len,
+                              PRUint8 *checksum)
+{
+    SECItem copy;
+    SECStatus rv;
+    PRUint8 sha256[32];
+
+    rv = SECITEM_MakeItem(NULL, &copy, buf, len);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+
+    /* Stomp the checksum. */
+    PORT_Memset(copy.data + 2, 0, 4);
+
+    rv = PK11_HashBuf(ssl3_HashTypeToOID(ssl_hash_sha256),
+                      sha256,
+                      copy.data, copy.len);
+    SECITEM_FreeItem(&copy, PR_FALSE);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+    PORT_Memcpy(checksum, sha256, 4);
+    return SECSuccess;
+}
+
+static SECStatus
+tls13_DecodeESNIKeys(SECItem *data, sslEsniKeys **keysp)
+{
+    SECStatus rv;
+    sslReadBuffer tmp;
+    PRUint64 tmpn;
+    sslEsniKeys *keys;
+    PRUint8 checksum[4];
+    sslReader rdr = SSL_READER(data->data, data->len);
+
+    rv = sslRead_ReadNumber(&rdr, 2, &tmpn);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+    if (tmpn != TLS13_ESNI_VERSION) {
+        PORT_SetError(SSL_ERROR_UNSUPPORTED_VERSION);
+        return SECFailure;
+    }
+    keys = PORT_ZNew(sslEsniKeys);
+    if (!keys) {
+        return SECFailure;
+    }
+    PR_INIT_CLIST(&keys->keyShares);
+
+    /* Make a copy. */
+    rv = SECITEM_CopyItem(NULL, &keys->data, data);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    rv = tls13_ComputeESNIKeysChecksum(data->data, data->len, checksum);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Read and check checksum. */
+    rv = sslRead_Read(&rdr, 4, &tmp);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    if (0 != NSS_SecureMemcmp(tmp.buf, checksum, 4)) {
+        goto loser;
+    }
+
+    /* Parse the key shares. */
+    rv = sslRead_ReadVariable(&rdr, 2, &tmp);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    sslReader rdr2 = SSL_READER(tmp.buf, tmp.len);
+    while (SSL_READER_REMAINING(&rdr2)) {
+        TLS13KeyShareEntry *ks = NULL;
+
+        rv = tls13_DecodeKeyShareEntry(&rdr2, &ks);
+        if (rv != SECSuccess) {
+            goto loser;
+        }
+
+        if (ks) {
+            PR_APPEND_LINK(&ks->link, &keys->keyShares);
+        }
+    }
+
+    /* Parse cipher suites. */
+    rv = sslRead_ReadVariable(&rdr, 2, &tmp);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    /* This can't be odd. */
+    if (tmp.len & 1) {
+        goto loser;
+    }
+    rv = SECITEM_MakeItem(NULL, &keys->suites, (PRUint8 *)tmp.buf, tmp.len);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Padded Length */
+    rv = sslRead_ReadNumber(&rdr, 2, &tmpn);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    keys->paddedLength = (PRUint16)tmpn;
+
+    /* Not Before */
+    rv = sslRead_ReadNumber(&rdr, 8, &keys->notBefore);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Not After */
+    rv = sslRead_ReadNumber(&rdr, 8, &keys->notAfter);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Extensions, which we ignore. */
+    rv = sslRead_ReadVariable(&rdr, 2, &tmp);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Check that this is empty. */
+    if (SSL_READER_REMAINING(&rdr) > 0) {
+        goto loser;
+    }
+
+    *keysp = keys;
+    return SECSuccess;
+
+loser:
+    tls13_DestroyESNIKeys(keys);
+    PORT_SetError(SSL_ERROR_RX_MALFORMED_ESNI_KEYS);
+
+    return SECFailure;
+}
+
+/* Encode an ESNI keys structure. We only allow one key
+ * share. */
+SECStatus
+SSLExp_EncodeESNIKeys(PRUint16 *cipherSuites, unsigned int cipherSuiteCount,
+                      SSLNamedGroup group, SECKEYPublicKey *pubKey,
+                      PRUint16 pad, PRUint64 notBefore, PRUint64 notAfter,
+                      PRUint8 *out, unsigned int *outlen, unsigned int maxlen)
+{
+    unsigned int savedOffset;
+    SECStatus rv;
+    sslBuffer b = SSL_BUFFER_EMPTY;
+
+    rv = sslBuffer_AppendNumber(&b, TLS13_ESNI_VERSION, 2);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    rv = sslBuffer_Skip(&b, 4, &savedOffset);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Length of vector. */
+    rv = sslBuffer_AppendNumber(
+        &b, tls13_SizeOfKeyShareEntry(pubKey), 2);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Our one key share. */
+    rv = tls13_EncodeKeyShareEntry(&b, group, pubKey);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Cipher suites. */
+    rv = sslBuffer_AppendNumber(&b, cipherSuiteCount * 2, 2);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    for (unsigned int i = 0; i < cipherSuiteCount; i++) {
+        rv = sslBuffer_AppendNumber(&b, cipherSuites[i], 2);
+        if (rv != SECSuccess) {
+            goto loser;
+        }
+    }
+
+    /* Padding Length. Fixed for now. */
+    rv = sslBuffer_AppendNumber(&b, pad, 2);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Start time. */
+    rv = sslBuffer_AppendNumber(&b, notBefore, 8);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* End time. */
+    rv = sslBuffer_AppendNumber(&b, notAfter, 8);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* No extensions. */
+    rv = sslBuffer_AppendNumber(&b, 0, 2);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    rv = tls13_ComputeESNIKeysChecksum(SSL_BUFFER_BASE(&b),
+                                       SSL_BUFFER_LEN(&b),
+                                       SSL_BUFFER_BASE(&b) + 2);
+    if (rv != SECSuccess) {
+        PORT_Assert(PR_FALSE);
+        goto loser;
+    }
+
+    if (SSL_BUFFER_LEN(&b) > maxlen) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        goto loser;
+    }
+    PORT_Memcpy(out, SSL_BUFFER_BASE(&b), SSL_BUFFER_LEN(&b));
+    *outlen = SSL_BUFFER_LEN(&b);
+
+    sslBuffer_Clear(&b);
+    return SECSuccess;
+loser:
+    sslBuffer_Clear(&b);
+    return SECFailure;
+}
+
+SECStatus
+SSLExp_SetESNIKeyPair(PRFileDesc *fd,
+                      SECKEYPrivateKey *privKey,
+                      const PRUint8 *record, unsigned int recordLen)
+{
+    sslSocket *ss;
+    SECStatus rv;
+    sslEsniKeys *keys = NULL;
+    SECKEYPublicKey *pubKey = NULL;
+    SECItem data = { siBuffer, CONST_CAST(PRUint8, record), recordLen };
+    PLArenaPool *arena = NULL;
+
+    ss = ssl_FindSocket(fd);
+    if (!ss) {
+        SSL_DBG(("%d: SSL[%d]: bad socket in %s",
+                 SSL_GETPID(), fd, __FUNCTION__));
+        return SECFailure;
+    }
+
+    rv = tls13_DecodeESNIKeys(&data, &keys);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+
+    /* Check the cipher suites. */
+    (void)ssl3_config_match_init(ss);
+    /* Make sure the cipher suite is OK. */
+    SSLVersionRange vrange = { SSL_LIBRARY_VERSION_TLS_1_3,
+                               SSL_LIBRARY_VERSION_TLS_1_3 };
+
+    sslReader csrdr = SSL_READER(keys->suites.data,
+                                 keys->suites.len);
+    while (SSL_READER_REMAINING(&csrdr)) {
+        PRUint64 asuite;
+
+        rv = sslRead_ReadNumber(&csrdr, 2, &asuite);
+        if (rv != SECSuccess) {
+            goto loser;
+        }
+        const ssl3CipherSuiteCfg *suiteCfg =
+            ssl_LookupCipherSuiteCfg(asuite, ss->cipherSuites);
+        if (!ssl3_config_match(suiteCfg, ss->ssl3.policy, &vrange, ss)) {
+            /* Illegal suite. */
+            PORT_SetError(SEC_ERROR_INVALID_ARGS);
+            goto loser;
+        }
+    }
+
+    if (PR_CLIST_IS_EMPTY(&keys->keyShares)) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        goto loser;
+    }
+    if (PR_PREV_LINK(&keys->keyShares) != PR_NEXT_LINK(&keys->keyShares)) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        goto loser;
+    }
+    TLS13KeyShareEntry *entry = (TLS13KeyShareEntry *)PR_LIST_HEAD(
+        &keys->keyShares);
+    if (entry->group->keaType != ssl_kea_ecdh) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        goto loser;
+    }
+    arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
+    if (!arena) {
+        goto loser;
+    }
+    pubKey = PORT_ArenaZNew(arena, SECKEYPublicKey);
+    if (!pubKey) {
+        goto loser;
+    }
+    pubKey->arena = arena;
+    arena = NULL; /* From here, this will be destroyed with the pubkey. */
+    /* Dummy PKCS11 values because this key isn't on a slot. */
+    pubKey->pkcs11Slot = NULL;
+    pubKey->pkcs11ID = CK_INVALID_HANDLE;
+    rv = ssl_ImportECDHKeyShare(pubKey,
+                                entry->key_exchange.data,
+                                entry->key_exchange.len,
+                                entry->group);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    privKey = SECKEY_CopyPrivateKey(privKey);
+    if (!privKey) {
+        goto loser;
+    }
+    keys->privKey = ssl_NewEphemeralKeyPair(entry->group, privKey, pubKey);
+    if (!keys->privKey) {
+        goto loser;
+    }
+    pubKey = NULL;
+    ss->esniKeys = keys;
+    return SECSuccess;
+
+loser:
+    PORT_FreeArena(arena, PR_FALSE);
+    SECKEY_DestroyPublicKey(pubKey);
+    tls13_DestroyESNIKeys(keys);
+    return SECFailure;
+}
+
+SECStatus
+SSLExp_EnableESNI(PRFileDesc *fd,
+                  const PRUint8 *esniKeys,
+                  unsigned int esniKeysLen,
+                  const char *dummySNI)
+{
+    sslSocket *ss;
+    sslEsniKeys *keys = NULL;
+    SECItem data = { siBuffer, CONST_CAST(PRUint8, esniKeys), esniKeysLen };
+    SECStatus rv;
+
+    ss = ssl_FindSocket(fd);
+    if (!ss) {
+        SSL_DBG(("%d: SSL[%d]: bad socket in %s",
+                 SSL_GETPID(), fd, __FUNCTION__));
+        return SECFailure;
+    }
+
+    rv = tls13_DecodeESNIKeys(&data, &keys);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+
+    if (dummySNI) {
+        keys->dummySni = PORT_Strdup(dummySNI);
+        if (!keys->dummySni) {
+            tls13_DestroyESNIKeys(keys);
+            return SECFailure;
+        }
+    }
+
+    /* Delete in case it was set before. */
+    tls13_DestroyESNIKeys(ss->esniKeys);
+    ss->esniKeys = keys;
+
+    return SECSuccess;
+}
+
+/*
+ * struct {
+ *     opaque record_digest<0..2^16-1>;
+ *     KeyShareEntry esni_key_share;
+ *     Random client_hello_random;
+ * } ESNIContents;
+ */
+SECStatus
+tls13_ComputeESNIKeys(const sslSocket *ss,
+                      TLS13KeyShareEntry *entry,
+                      sslKeyPair *keyPair,
+                      const ssl3CipherSuiteDef *suite,
+                      const PRUint8 *esniKeysHash,
+                      const PRUint8 *keyShareBuf,
+                      unsigned int keyShareBufLen,
+                      const PRUint8 *clientRandom,
+                      ssl3KeyMaterial *keyMat)
+{
+    PK11SymKey *Z = NULL;
+    PK11SymKey *Zx = NULL;
+    SECStatus ret = SECFailure;
+    PRUint8 esniContentsBuf[256]; /* Just big enough. */
+    sslBuffer esniContents = SSL_BUFFER(esniContentsBuf);
+    PRUint8 hash[64];
+    const ssl3BulkCipherDef *cipherDef = ssl_GetBulkCipherDef(suite);
+    size_t keySize = cipherDef->key_size;
+    size_t ivSize = cipherDef->iv_size +
+                    cipherDef->explicit_nonce_size; /* This isn't always going to
+                                                     * work, but it does for
+                                                     * AES-GCM */
+    unsigned int hashSize = tls13_GetHashSizeForHash(suite->prf_hash);
+    SECStatus rv;
+
+    rv = tls13_HandleKeyShare(CONST_CAST(sslSocket, ss), entry, keyPair,
+                              suite->prf_hash, &Z);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    rv = tls13_HkdfExtract(NULL, Z, suite->prf_hash, &Zx);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Encode ESNIContents. */
+    rv = sslBuffer_AppendVariable(&esniContents,
+                                  esniKeysHash, hashSize, 2);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    rv = sslBuffer_Append(&esniContents, keyShareBuf, keyShareBufLen);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    rv = sslBuffer_Append(&esniContents, clientRandom, SSL3_RANDOM_LENGTH);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    PORT_Assert(hashSize <= sizeof(hash));
+    rv = PK11_HashBuf(ssl3_HashTypeToOID(suite->prf_hash),
+                      hash,
+                      SSL_BUFFER_BASE(&esniContents),
+                      SSL_BUFFER_LEN(&esniContents));
+    ;
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    rv = tls13_HkdfExpandLabel(Zx, suite->prf_hash,
+                               hash, hashSize,
+                               kHkdfPurposeEsniKey, strlen(kHkdfPurposeEsniKey),
+                               ssl3_Alg2Mech(cipherDef->calg),
+                               keySize,
+                               &keyMat->key);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    rv = tls13_HkdfExpandLabelRaw(Zx, suite->prf_hash,
+                                  hash, hashSize,
+                                  kHkdfPurposeEsniIv, strlen(kHkdfPurposeEsniIv),
+                                  keyMat->iv, ivSize);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    ret = SECSuccess;
+
+loser:
+    PK11_FreeSymKey(Z);
+    PK11_FreeSymKey(Zx);
+    return ret;
+}
+
+/* Set up ESNI. This generates a private key as a side effect. */
+SECStatus
+tls13_ClientSetupESNI(sslSocket *ss)
+{
+    ssl3CipherSuite suite;
+    sslEphemeralKeyPair *keyPair;
+    size_t i;
+    PRCList *cur;
+    SECStatus rv;
+    TLS13KeyShareEntry *share;
+    const sslNamedGroupDef *group = NULL;
+    PRTime now = PR_Now() / PR_USEC_PER_SEC;
+
+    if (!ss->esniKeys) {
+        return SECSuccess;
+    }
+
+    if ((ss->esniKeys->notBefore > now) || (ss->esniKeys->notAfter < now)) {
+        return SECSuccess;
+    }
+
+    /* If we're not sending SNI, don't send ESNI. */
+    if (!ssl_ShouldSendSNIExtension(ss, ss->url)) {
+        return SECSuccess;
+    }
+
+    /* Pick the group. */
+    for (i = 0; i < SSL_NAMED_GROUP_COUNT; ++i) {
+        for (cur = PR_NEXT_LINK(&ss->esniKeys->keyShares);
+             cur != &ss->esniKeys->keyShares;
+             cur = PR_NEXT_LINK(cur)) {
+            if (!ss->namedGroupPreferences[i]) {
+                continue;
+            }
+            share = (TLS13KeyShareEntry *)cur;
+            if (share->group->name == ss->namedGroupPreferences[i]->name) {
+                group = ss->namedGroupPreferences[i];
+                break;
+            }
+        }
+    }
+
+    if (!group) {
+        /* No compatible group. */
+        return SECSuccess;
+    }
+
+    rv = ssl3_NegotiateCipherSuiteInner(ss, &ss->esniKeys->suites,
+                                        SSL_LIBRARY_VERSION_TLS_1_3, &suite);
+    if (rv != SECSuccess) {
+        return SECSuccess;
+    }
+
+    rv = tls13_CreateKeyShare(ss, group, &keyPair);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+
+    ss->xtnData.esniPrivateKey = keyPair;
+    ss->xtnData.esniSuite = suite;
+    ss->xtnData.peerEsniShare = share;
+
+    return SECSuccess;
+}
+
+/*
+ * struct {
+ *     CipherSuite suite;
+ *     KeyShareEntry key_share;
+ *     opaque record_digest<0..2^16-1>;
+ *     opaque encrypted_sni<0..2^16-1>;
+ * } ClientEncryptedSNI;
+ *
+ * struct {
+ *     ServerNameList sni;
+ *     opaque zeros[ESNIKeys.padded_length - length(sni)];
+ * } PaddedServerNameList;
+ *
+ * struct {
+ *     uint8 nonce[16];
+ *     PaddedServerNameList realSNI;
+ * } ClientESNIInner;
+ */
+SECStatus
+tls13_FormatEsniAADInput(sslBuffer *aadInput,
+                         PRUint8 *keyShare, unsigned int keyShareLen)
+{
+    SECStatus rv;
+
+    /* 8 bytes of 0 for the sequence number. */
+    rv = sslBuffer_AppendNumber(aadInput, 0, 8);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+
+    /* Key share. */
+    PORT_Assert(keyShareLen > 0);
+    rv = sslBuffer_Append(aadInput, keyShare, keyShareLen);
+    if (rv != SECSuccess) {
+        return SECFailure;
+    }
+
+    return SECSuccess;
+}
+
+static SECStatus
+tls13_ServerGetEsniAEAD(const sslSocket *ss, PRUint64 suite,
+                        const ssl3CipherSuiteDef **suiteDefp,
+                        SSLAEADCipher *aeadp)
+{
+    SECStatus rv;
+    const ssl3CipherSuiteDef *suiteDef;
+    SSLAEADCipher aead;
+
+    /* Check against the suite list for ESNI */
+    PRBool csMatch = PR_FALSE;
+    sslReader csrdr = SSL_READER(ss->esniKeys->suites.data,
+                                 ss->esniKeys->suites.len);
+    while (SSL_READER_REMAINING(&csrdr)) {
+        PRUint64 asuite;
+
+        rv = sslRead_ReadNumber(&csrdr, 2, &asuite);
+        if (rv != SECSuccess) {
+            return SECFailure;
+        }
+        if (asuite == suite) {
+            csMatch = PR_TRUE;
+            break;
+        }
+    }
+    if (!csMatch) {
+        return SECFailure;
+    }
+
+    suiteDef = ssl_LookupCipherSuiteDef(suite);
+    PORT_Assert(suiteDef);
+    if (!suiteDef) {
+        return SECFailure;
+    }
+    aead = tls13_GetAead(ssl_GetBulkCipherDef(suiteDef));
+    if (!aead) {
+        return SECFailure;
+    }
+
+    *suiteDefp = suiteDef;
+    *aeadp = aead;
+    return SECSuccess;
+}
+
+SECStatus
+tls13_ServerDecryptEsniXtn(const sslSocket *ss, PRUint8 *in, unsigned int inLen,
+                           PRUint8 *out, int *outLen, int maxLen)
+{
+    sslReader rdr = SSL_READER(in, inLen);
+    PRUint64 suite;
+    const ssl3CipherSuiteDef *suiteDef;
+    SSLAEADCipher aead = NULL;
+    TLSExtension *keyShareExtension;
+    TLS13KeyShareEntry *entry = NULL;
+    ssl3KeyMaterial keyMat = { NULL };
+
+    sslBuffer aadInput = SSL_BUFFER_EMPTY;
+    const PRUint8 *keyShareBuf;
+    sslReadBuffer buf;
+    unsigned int keyShareBufLen;
+    PRUint8 hash[64];
+    SECStatus rv;
+
+    /* Read the cipher suite. */
+    rv = sslRead_ReadNumber(&rdr, 2, &suite);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Find the AEAD */
+    rv = tls13_ServerGetEsniAEAD(ss, suite, &suiteDef, &aead);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Note where the KeyShare starts. */
+    keyShareBuf = SSL_READER_CURRENT(&rdr);
+    rv = tls13_DecodeKeyShareEntry(&rdr, &entry);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+    keyShareBufLen = SSL_READER_CURRENT(&rdr) - keyShareBuf;
+    if (!entry || entry->group->name != ss->esniKeys->privKey->group->name) {
+        goto loser;
+    }
+
+    /* The hash of the ESNIKeys structure. */
+    rv = sslRead_ReadVariable(&rdr, 2, &buf);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Check that the hash matches. */
+    unsigned int hashLen = tls13_GetHashSizeForHash(suiteDef->prf_hash);
+    PORT_Assert(hashLen <= sizeof(hash));
+    rv = PK11_HashBuf(ssl3_HashTypeToOID(suiteDef->prf_hash),
+                      hash,
+                      ss->esniKeys->data.data, ss->esniKeys->data.len);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    if (buf.len != hashLen) {
+        /* This is malformed. */
+        goto loser;
+    }
+    if (0 != NSS_SecureMemcmp(hash, buf.buf, hashLen)) {
+        goto loser;
+    }
+
+    rv = tls13_ComputeESNIKeys(ss, entry,
+                               ss->esniKeys->privKey->keys,
+                               suiteDef,
+                               hash, keyShareBuf, keyShareBufLen,
+                               ((sslSocket *)ss)->ssl3.hs.client_random,
+                               &keyMat);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Read the ciphertext. */
+    rv = sslRead_ReadVariable(&rdr, 2, &buf);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    /* Check that this is empty. */
+    if (SSL_READER_REMAINING(&rdr) > 0) {
+        goto loser;
+    }
+
+    /* Find the key share extension. */
+    keyShareExtension = ssl3_FindExtension(CONST_CAST(sslSocket, ss),
+                                           ssl_tls13_key_share_xtn);
+    if (!keyShareExtension) {
+        goto loser;
+    }
+    rv = tls13_FormatEsniAADInput(&aadInput,
+                                  keyShareExtension->data.data,
+                                  keyShareExtension->data.len);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    rv = aead(&keyMat, PR_TRUE /* Decrypt */,
+              out, outLen, maxLen,
+              buf.buf, buf.len,
+              SSL_BUFFER_BASE(&aadInput),
+              SSL_BUFFER_LEN(&aadInput));
+    sslBuffer_Clear(&aadInput);
+    if (rv != SECSuccess) {
+        goto loser;
+    }
+
+    ssl_DestroyKeyMaterial(&keyMat);
+    tls13_DestroyKeyShareEntry(entry);
+    return SECSuccess;
+
+loser:
+    FATAL_ERROR(CONST_CAST(sslSocket, ss), SSL_ERROR_RX_MALFORMED_ESNI_EXTENSION, illegal_parameter);
+    ssl_DestroyKeyMaterial(&keyMat); /* Safe because zeroed. */
+    if (entry) {
+        tls13_DestroyKeyShareEntry(entry);
+    }
+    return SECFailure;
+}