Uprev NSS to 3.23 on iOS

net/third_party/nss/ssl/tls13hkdf.c

+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * TLS 1.3 Protocol
+ *
+ * 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/. */
+
+#include "keyhi.h"
+#include "pk11func.h"
+#include "secitem.h"
+#include "sslt.h"
+#include "sslerr.h"
+
+// TODO(ekr@rtfm.com): Export this separately.
+unsigned char *tls13_EncodeUintX(PRUint32 value, unsigned int bytes, unsigned char *to);
+
+/* This table contains the mapping between TLS hash identifiers and the
+ * PKCS#11 identifiers */
+static const struct {
+    SSLHashType hash;
+    CK_MECHANISM_TYPE pkcs11Mech;
+    unsigned int hashSize;
+} kTlsHkdfInfo[] = {
+    { ssl_hash_none, 0, 0 },
+    { ssl_hash_md5, 0, 0 },
+    { ssl_hash_sha1, 0, 0 },
+    { ssl_hash_sha224, 0 },
+    { ssl_hash_sha256, CKM_NSS_HKDF_SHA256, 32 },
+    { ssl_hash_sha384, CKM_NSS_HKDF_SHA384, 48 },
+    { ssl_hash_sha512, CKM_NSS_HKDF_SHA512, 64 }
+};
+
+SECStatus
+tls13_HkdfExtract(PK11SymKey *ikm1, PK11SymKey *ikm2, SSLHashType baseHash,
+                  PK11SymKey **prkp)
+{
+    CK_NSS_HKDFParams params;
+    SECItem paramsi;
+    SECStatus rv;
+    SECItem *salt;
+    PK11SymKey *prk;
+
+    params.bExtract = CK_TRUE;
+    params.bExpand = CK_FALSE;
+    params.pInfo = NULL;
+    params.ulInfoLen = 0UL;
+
+    if (ikm1) {
+        /* TODO(ekr@rtfm.com): This violates the PKCS#11 key boundary
+         * but is imposed on us by the present HKDF interface. */
+        rv = PK11_ExtractKeyValue(ikm1);
+        if (rv != SECSuccess)
+            return rv;
+
+        salt = PK11_GetKeyData(ikm1);
+        if (!salt)
+            return SECFailure;
+
+        params.pSalt = salt->data;
+        params.ulSaltLen = salt->len;
+        PORT_Assert(salt->len > 0);
+    } else {
+        /* Per documentation for CKM_NSS_HKDF_*:
+         *
+         *  If the optional salt is given, it is used; otherwise, the salt is
+         *  set to a sequence of zeros equal in length to the HMAC output.
+         */
+        params.pSalt = NULL;
+        params.ulSaltLen = 0UL;
+    }
+    paramsi.data = (unsigned char *)&params;
+    paramsi.len = sizeof(params);
+
+    PORT_Assert(kTlsHkdfInfo[baseHash].pkcs11Mech);
+    PORT_Assert(kTlsHkdfInfo[baseHash].hashSize);
+    PORT_Assert(kTlsHkdfInfo[baseHash].hash == baseHash);
+    prk = PK11_Derive(ikm2, kTlsHkdfInfo[baseHash].pkcs11Mech,
+                      &paramsi, kTlsHkdfInfo[baseHash].pkcs11Mech,
+                      CKA_DERIVE, kTlsHkdfInfo[baseHash].hashSize);
+    if (!prk)
+        return SECFailure;
+
+    *prkp = prk;
+    return SECSuccess;
+}
+
+SECStatus
+tls13_HkdfExpandLabel(PK11SymKey *prk, SSLHashType baseHash,
+                      const PRUint8 *handshakeHash, unsigned int handshakeHashLen,
+                      const char *label, unsigned int labelLen,
+                      CK_MECHANISM_TYPE algorithm, unsigned int keySize,
+                      PK11SymKey **keyp)
+{
+    CK_NSS_HKDFParams params;
+    SECItem paramsi = { siBuffer, NULL, 0 };
+    PRUint8 info[100];
+    PRUint8 *ptr = info;
+    unsigned int infoLen;
+    PK11SymKey *derived;
+    const char *kLabelPrefix = "TLS 1.3, ";
+    const unsigned int kLabelPrefixLen = strlen(kLabelPrefix);
+
+    if (handshakeHash) {
+        PORT_Assert(handshakeHashLen == kTlsHkdfInfo[baseHash].hashSize);
+    } else {
+        PORT_Assert(!handshakeHashLen);
+    }
+
+    /*
+     *  [draft-ietf-tls-tls13-11] Section 7.1:
+     *
+     *  HKDF-Expand-Label(Secret, Label, HashValue, Length) =
+     *       HKDF-Expand(Secret, HkdfLabel, Length)
+     *
+     *  Where HkdfLabel is specified as:
+     *
+     *  struct HkdfLabel {
+     *    uint16 length;
+     *    opaque label<9..255>;
+     *    opaque hash_value<0..255>;
+     *  };
+     *
+     *  Where:
+     *  - HkdfLabel.length is Length
+     *  - HkdfLabel.hash_value is HashValue.
+     *  - HkdfLabel.label is "TLS 1.3, " + Label
+     *
+     */
+    infoLen = 2 + 1 + kLabelPrefixLen + labelLen + 1 + handshakeHashLen;
+    if (infoLen > sizeof(info)) {
+        PORT_Assert(0);
+        goto abort;
+    }
+
+    ptr = tls13_EncodeUintX(keySize, 2, ptr);
+    ptr = tls13_EncodeUintX(labelLen + kLabelPrefixLen, 1, ptr);
+    PORT_Memcpy(ptr, kLabelPrefix, kLabelPrefixLen);
+    ptr += kLabelPrefixLen;
+    PORT_Memcpy(ptr, label, labelLen);
+    ptr += labelLen;
+    ptr = tls13_EncodeUintX(handshakeHashLen, 1, ptr);
+    if (handshakeHash) {
+        PORT_Memcpy(ptr, handshakeHash, handshakeHashLen);
+        ptr += handshakeHashLen;
+    }
+    PORT_Assert((ptr - info) == infoLen);
+
+    params.bExtract = CK_FALSE;
+    params.bExpand = CK_TRUE;
+    params.pInfo = info;
+    params.ulInfoLen = infoLen;
+    paramsi.data = (unsigned char *)&params;
+    paramsi.len = sizeof(params);
+
+    derived = PK11_DeriveWithFlags(prk, kTlsHkdfInfo[baseHash].pkcs11Mech,
+                                   &paramsi, algorithm,
+                                   CKA_DERIVE, keySize,
+                                   CKF_SIGN | CKF_VERIFY);
+    if (!derived)
+        return SECFailure;
+
+    *keyp = derived;
+
+    return SECSuccess;
+
+abort:
+    PORT_SetError(SSL_ERROR_SYM_KEY_CONTEXT_FAILURE);
+    return SECFailure;
+}
+
+SECStatus
+tls13_HkdfExpandLabelRaw(PK11SymKey *prk, SSLHashType baseHash,
+                         const PRUint8 *handshakeHash, unsigned int handshakeHashLen,
+                         const char *label, unsigned int labelLen,
+                         unsigned char *output, unsigned int outputLen)
+{
+    PK11SymKey *derived = NULL;
+    SECItem *rawkey;
+    SECStatus rv;
+
+    rv = tls13_HkdfExpandLabel(prk, baseHash, handshakeHash, handshakeHashLen,
+                               label, labelLen,
+                               kTlsHkdfInfo[baseHash].pkcs11Mech, outputLen,
+                               &derived);
+    if (rv != SECSuccess || !derived) {
+        goto abort;
+    }
+
+    rv = PK11_ExtractKeyValue(derived);
+    if (rv != SECSuccess) {
+        goto abort;
+    }
+
+    rawkey = PK11_GetKeyData(derived);
+    if (!rawkey) {
+        goto abort;
+    }
+
+    PORT_Assert(rawkey->len == outputLen);
+    memcpy(output, rawkey->data, outputLen);
+    PK11_FreeSymKey(derived);
+
+    return SECSuccess;
+
+abort:
+    if (derived) {
+        PK11_FreeSymKey(derived);
+    }
+    PORT_SetError(SSL_ERROR_SYM_KEY_CONTEXT_FAILURE);
+    return SECFailure;
+}