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tls13subcerts.c (25729B)


      1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
      2 /*
      3 * This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "nss.h"
      8 #include "pk11func.h"
      9 #include "secder.h"
     10 #include "sechash.h"
     11 #include "ssl.h"
     12 #include "sslproto.h"
     13 #include "sslimpl.h"
     14 #include "ssl3exthandle.h"
     15 #include "tls13exthandle.h"
     16 #include "tls13hkdf.h"
     17 #include "tls13subcerts.h"
     18 
     19 /* Parses the delegated credential (DC) from the raw extension |b| of length
     20 * |length|. Memory for the DC is allocated and set to |*dcp|.
     21 *
     22 * It's the caller's responsibility to invoke |tls13_DestroyDelegatedCredential|
     23 * when this data is no longer needed.
     24 */
     25 SECStatus
     26 tls13_ReadDelegatedCredential(PRUint8 *b, PRUint32 length,
     27                              sslDelegatedCredential **dcp)
     28 {
     29    sslDelegatedCredential *dc = NULL;
     30    SECStatus rv;
     31    PRUint64 n;
     32    sslReadBuffer tmp;
     33    sslReader rdr = SSL_READER(b, length);
     34 
     35    PORT_Assert(!*dcp);
     36 
     37    dc = PORT_ZNew(sslDelegatedCredential);
     38    if (!dc) {
     39        PORT_SetError(SEC_ERROR_NO_MEMORY);
     40        goto loser;
     41    }
     42 
     43    /* Read the valid_time field of DelegatedCredential.cred. */
     44    rv = sslRead_ReadNumber(&rdr, 4, &n);
     45    if (rv != SECSuccess) {
     46        goto loser;
     47    }
     48    dc->validTime = n;
     49 
     50    /* Read the expected_cert_verify_algorithm field of
     51     * DelegatedCredential.cred. */
     52    rv = sslRead_ReadNumber(&rdr, 2, &n);
     53    if (rv != SECSuccess) {
     54        goto loser;
     55    }
     56    dc->expectedCertVerifyAlg = n;
     57 
     58    /* Read the ASN1_subjectPublicKeyInfo field of DelegatedCredential.cred. */
     59    rv = sslRead_ReadVariable(&rdr, 3, &tmp);
     60    if (rv != SECSuccess) {
     61        goto loser;
     62    }
     63    rv = SECITEM_MakeItem(NULL, &dc->derSpki, tmp.buf, tmp.len);
     64    if (rv != SECSuccess) {
     65        goto loser;
     66    }
     67 
     68    /* Parse the DER-encoded SubjectPublicKeyInfo. */
     69    dc->spki = SECKEY_DecodeDERSubjectPublicKeyInfo(&dc->derSpki);
     70    if (!dc->spki) {
     71        goto loser;
     72    }
     73 
     74    /* Read the algorithm field of the DelegatedCredential. */
     75    rv = sslRead_ReadNumber(&rdr, 2, &n);
     76    if (rv != SECSuccess) {
     77        goto loser;
     78    }
     79    dc->alg = n;
     80 
     81    /* Read the signature field of the DelegatedCredential. */
     82    rv = sslRead_ReadVariable(&rdr, 2, &tmp);
     83    if (rv != SECSuccess) {
     84        goto loser;
     85    }
     86    rv = SECITEM_MakeItem(NULL, &dc->signature, tmp.buf, tmp.len);
     87    if (rv != SECSuccess) {
     88        goto loser;
     89    }
     90 
     91    /* There should be nothing left to read. */
     92    if (SSL_READER_REMAINING(&rdr) > 0) {
     93        goto loser;
     94    }
     95 
     96    *dcp = dc;
     97    return SECSuccess;
     98 
     99 loser:
    100    tls13_DestroyDelegatedCredential(dc);
    101    *dcp = NULL;
    102    return SECFailure;
    103 }
    104 
    105 /* Frees |dc| from the heap. */
    106 void
    107 tls13_DestroyDelegatedCredential(sslDelegatedCredential *dc)
    108 {
    109    if (!dc) {
    110        return;
    111    }
    112 
    113    SECKEY_DestroySubjectPublicKeyInfo(dc->spki);
    114    SECITEM_FreeItem(&dc->derSpki, PR_FALSE);
    115    SECITEM_FreeItem(&dc->signature, PR_FALSE);
    116    PORT_ZFree(dc, sizeof(sslDelegatedCredential));
    117 }
    118 
    119 /* Sets |*certVerifyAlg| to the expected_cert_verify_algorithm field from the
    120 * serialized DC |in|. Returns SECSuccess upon success; SECFailure indicates a
    121 * decoding failure or the input wasn't long enough.
    122 */
    123 static SECStatus
    124 tls13_GetExpectedCertVerifyAlg(SECItem in, SSLSignatureScheme *certVerifyAlg)
    125 {
    126    SECStatus rv;
    127    PRUint64 n;
    128    sslReader rdr = SSL_READER(in.data, in.len);
    129 
    130    if (in.len < 6) { /* Buffer too short to contain the first two params. */
    131        return SECFailure;
    132    }
    133 
    134    rv = sslRead_ReadNumber(&rdr, 4, &n);
    135    if (rv != SECSuccess) {
    136        return SECFailure;
    137    }
    138 
    139    rv = sslRead_ReadNumber(&rdr, 2, &n);
    140    if (rv != SECSuccess) {
    141        return SECFailure;
    142    }
    143    *certVerifyAlg = n;
    144 
    145    return SECSuccess;
    146 }
    147 
    148 /* Returns PR_TRUE if the host is verifying the handshake with a DC. */
    149 PRBool
    150 tls13_IsVerifyingWithDelegatedCredential(const sslSocket *ss)
    151 {
    152    /* We currently do not support client-delegated credentials. */
    153    if (ss->sec.isServer ||
    154        !ss->opt.enableDelegatedCredentials ||
    155        !ss->xtnData.peerDelegCred) {
    156        return PR_FALSE;
    157    }
    158 
    159    return PR_TRUE;
    160 }
    161 
    162 /* Returns PR_TRUE if the host is signing the handshake with a DC. */
    163 PRBool
    164 tls13_IsSigningWithDelegatedCredential(const sslSocket *ss)
    165 {
    166    if (!ss->sec.isServer ||
    167        !ss->xtnData.sendingDelegCredToPeer ||
    168        !ss->xtnData.peerRequestedDelegCred) {
    169        return PR_FALSE;
    170    }
    171 
    172    return PR_TRUE;
    173 }
    174 
    175 /* Commits to authenticating with a DC if all of the following conditions hold:
    176 *  - the negotiated protocol is TLS 1.3 or newer;
    177 *  - the selected certificate has a DC configured;
    178 *  - the peer has indicated support for this extension;
    179 *  - the peer has indicated support for the DC signature scheme; and
    180 *  - the host supports the DC signature scheme.
    181 *
    182 * It's the caller's responsibility to ensure that the version has been
    183 * negotiated and the certificate has been selected.
    184 */
    185 SECStatus
    186 tls13_MaybeSetDelegatedCredential(sslSocket *ss)
    187 {
    188    SECStatus rv;
    189    PRBool doesRsaPss;
    190    SECKEYPrivateKey *priv;
    191    SSLSignatureScheme scheme;
    192 
    193    /* Assert that the host is the server (we do not currently support
    194     * client-delegated credentials), the certificate has been
    195     * chosen, TLS 1.3 or higher has been negotiated, and that the set of
    196     * signature schemes supported by the client is known.
    197     */
    198    PORT_Assert(ss->sec.isServer);
    199    PORT_Assert(ss->sec.serverCert);
    200    PORT_Assert(ss->version >= SSL_LIBRARY_VERSION_TLS_1_3);
    201    PORT_Assert(ss->xtnData.peerRequestedDelegCred == !!ss->xtnData.delegCredSigSchemes);
    202 
    203    /* Check that the peer has indicated support and that a DC has been
    204     * configured for the selected certificate.
    205     */
    206    if (!ss->xtnData.peerRequestedDelegCred ||
    207        !ss->xtnData.delegCredSigSchemes ||
    208        !ss->sec.serverCert->delegCred.len ||
    209        !ss->sec.serverCert->delegCredKeyPair) {
    210        return SECSuccess;
    211    }
    212 
    213    /* Check that the host and peer both support the signing algorithm used with
    214     * the DC.
    215     */
    216    rv = tls13_GetExpectedCertVerifyAlg(ss->sec.serverCert->delegCred,
    217                                        &scheme);
    218    if (rv != SECSuccess) {
    219        return SECFailure;
    220    }
    221 
    222    priv = ss->sec.serverCert->delegCredKeyPair->privKey;
    223    rv = ssl_PrivateKeySupportsRsaPss(priv, NULL, NULL, &doesRsaPss);
    224    if (rv != SECSuccess) {
    225        return SECFailure;
    226    }
    227 
    228    if (!ssl_SignatureSchemeEnabled(ss, scheme) ||
    229        !ssl_CanUseSignatureScheme(scheme,
    230                                   ss->xtnData.delegCredSigSchemes,
    231                                   ss->xtnData.numDelegCredSigSchemes,
    232                                   PR_FALSE /* requireSha1 */,
    233                                   doesRsaPss)) {
    234        return SECSuccess;
    235    }
    236 
    237    /* Commit to sending a DC and set the handshake signature scheme to the
    238     * indicated algorithm.
    239     */
    240    ss->xtnData.sendingDelegCredToPeer = PR_TRUE;
    241    ss->ssl3.hs.signatureScheme = scheme;
    242    return SECSuccess;
    243 }
    244 
    245 /* Serializes the DC up to the signature. */
    246 static SECStatus
    247 tls13_AppendCredentialParams(sslBuffer *buf, sslDelegatedCredential *dc)
    248 {
    249    SECStatus rv;
    250    rv = sslBuffer_AppendNumber(buf, dc->validTime, 4);
    251    if (rv != SECSuccess) {
    252        return SECFailure; /* Error set by caller. */
    253    }
    254 
    255    rv = sslBuffer_AppendNumber(buf, dc->expectedCertVerifyAlg, 2);
    256    if (rv != SECSuccess) {
    257        return SECFailure;
    258    }
    259 
    260    rv = sslBuffer_AppendVariable(buf, dc->derSpki.data, dc->derSpki.len, 3);
    261    if (rv != SECSuccess) {
    262        return SECFailure;
    263    }
    264 
    265    rv = sslBuffer_AppendNumber(buf, dc->alg, 2);
    266    if (rv != SECSuccess) {
    267        return SECFailure;
    268    }
    269 
    270    return SECSuccess;
    271 }
    272 
    273 /* Serializes the DC signature. */
    274 static SECStatus
    275 tls13_AppendCredentialSignature(sslBuffer *buf, sslDelegatedCredential *dc)
    276 {
    277    SECStatus rv;
    278    rv = sslBuffer_AppendVariable(buf, dc->signature.data,
    279                                  dc->signature.len, 2);
    280    if (rv != SECSuccess) {
    281        return SECFailure;
    282    }
    283 
    284    return SECSuccess;
    285 }
    286 
    287 /* Hashes the message used to sign/verify the DC. */
    288 static SECStatus
    289 tls13_HashCredentialAndSignOrVerifyMessage(SECKEYPrivateKey *privKey,
    290                                           SECKEYPublicKey *pubKey,
    291                                           SSLSignatureScheme scheme,
    292                                           sslSignOrVerify direction,
    293                                           const CERTCertificate *cert,
    294                                           const sslBuffer *dcBuf,
    295                                           SECItem *signature, void *pwArg)
    296 {
    297    SECStatus rv;
    298    tlsSignOrVerifyContext ctx;
    299 
    300    /* Set up sign and hash context. */
    301    ctx = tls_CreateSignOrVerifyContext(privKey, pubKey, scheme, direction,
    302                                        signature, pwArg);
    303    if (!ctx.u.ptr) {
    304        PORT_SetError(SEC_ERROR_NO_MEMORY);
    305        goto loser;
    306    }
    307 
    308    static const PRUint8 kCtxStrPadding[64] = {
    309        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    310        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    311        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    312        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    313        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    314        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    315        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    316        0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20
    317    };
    318 
    319    static const PRUint8 kCtxStr[] = "TLS, server delegated credentials";
    320 
    321    /* Hash the message signed by the peer. */
    322    rv = tls_SignOrVerifyUpdate(ctx, kCtxStrPadding, sizeof kCtxStrPadding);
    323    if (rv != SECSuccess)
    324        goto loser;
    325    rv = tls_SignOrVerifyUpdate(ctx, kCtxStr,
    326                                strlen((const char *)kCtxStr + 1 /* 0-byte */));
    327    if (rv != SECSuccess)
    328        goto loser;
    329    rv = tls_SignOrVerifyUpdate(ctx, cert->derCert.data, cert->derCert.len);
    330    if (rv != SECSuccess)
    331        goto loser;
    332    rv = tls_SignOrVerifyUpdate(ctx, dcBuf->buf, dcBuf->len);
    333    if (rv != SECSuccess)
    334        goto loser;
    335    rv = tls_SignOrVerifyEnd(ctx, signature);
    336    if (rv != SECSuccess)
    337        goto loser;
    338 
    339    return SECSuccess;
    340 
    341 loser:
    342    tls_DestroySignOrVerifyContext(ctx);
    343    return SECFailure;
    344 }
    345 
    346 /* Verifies the DC signature. */
    347 static SECStatus
    348 tls13_VerifyCredentialSignature(sslSocket *ss, sslDelegatedCredential *dc)
    349 {
    350    SECStatus rv = SECSuccess;
    351    sslBuffer dcBuf = SSL_BUFFER_EMPTY;
    352    CERTCertificate *cert = ss->sec.peerCert;
    353    SECKEYPublicKey *pubKey = NULL;
    354    void *pwArg = ss->pkcs11PinArg;
    355 
    356    /* Serialize the DC parameters. */
    357    rv = tls13_AppendCredentialParams(&dcBuf, dc);
    358    if (rv != SECSuccess) {
    359        goto loser; /* Error set by caller. */
    360    }
    361 
    362    pubKey = SECKEY_ExtractPublicKey(&cert->subjectPublicKeyInfo);
    363    if (pubKey == NULL) {
    364        FATAL_ERROR(ss, SSL_ERROR_EXTRACT_PUBLIC_KEY_FAILURE, internal_error);
    365        goto loser;
    366    }
    367 
    368    /* Verify the signature of the delegatormessage. */
    369    rv = tls13_HashCredentialAndSignOrVerifyMessage(NULL, pubKey, dc->alg,
    370                                                    sig_verify, cert, &dcBuf,
    371                                                    &dc->signature, pwArg);
    372    if (rv != SECSuccess) {
    373        FATAL_ERROR(ss, SSL_ERROR_DC_BAD_SIGNATURE, illegal_parameter);
    374        goto loser;
    375    }
    376 
    377    SECOidTag spkiAlg = SECOID_GetAlgorithmTag(&(dc->spki->algorithm));
    378    if (spkiAlg == SEC_OID_PKCS1_RSA_ENCRYPTION) {
    379        FATAL_ERROR(ss, SSL_ERROR_INCORRECT_SIGNATURE_ALGORITHM, illegal_parameter);
    380        goto loser;
    381    }
    382 
    383    SECKEY_DestroyPublicKey(pubKey);
    384    sslBuffer_Clear(&dcBuf);
    385    return SECSuccess;
    386 
    387 loser:
    388    SECKEY_DestroyPublicKey(pubKey);
    389    sslBuffer_Clear(&dcBuf);
    390    return SECFailure;
    391 }
    392 
    393 /* Checks that the peer's end-entity certificate has the correct key usage. */
    394 static SECStatus
    395 tls13_CheckCertDelegationUsage(sslSocket *ss)
    396 {
    397    int i;
    398    PRBool found;
    399    CERTCertExtension *ext;
    400    SECItem delegUsageOid = { siBuffer, NULL, 0 };
    401    const CERTCertificate *cert = ss->sec.peerCert;
    402 
    403    /* 1.3.6.1.4.1.44363.44, as defined in draft-ietf-tls-subcerts. */
    404    static unsigned char kDelegationUsageOid[] = {
    405        0x2b,
    406        0x06,
    407        0x01,
    408        0x04,
    409        0x01,
    410        0x82,
    411        0xda,
    412        0x4b,
    413        0x2c
    414    };
    415 
    416    delegUsageOid.data = kDelegationUsageOid;
    417    delegUsageOid.len = sizeof kDelegationUsageOid;
    418 
    419    /* The certificate must have the delegationUsage extension that authorizes
    420     * it to negotiate delegated credentials.
    421     */
    422    found = PR_FALSE;
    423    for (i = 0; cert->extensions[i] != NULL; i++) {
    424        ext = cert->extensions[i];
    425        if (SECITEM_CompareItem(&ext->id, &delegUsageOid) == SECEqual) {
    426            found = PR_TRUE;
    427            break;
    428        }
    429    }
    430 
    431    /* The certificate must also have the digitalSignature keyUsage set. */
    432    if (!found ||
    433        !cert->keyUsagePresent ||
    434        !(cert->keyUsage & KU_DIGITAL_SIGNATURE)) {
    435        FATAL_ERROR(ss, SSL_ERROR_DC_INVALID_KEY_USAGE, illegal_parameter);
    436        return SECFailure;
    437    }
    438 
    439    return SECSuccess;
    440 }
    441 
    442 static SECStatus
    443 tls13_CheckCredentialExpiration(sslSocket *ss, sslDelegatedCredential *dc)
    444 {
    445    SECStatus rv;
    446    CERTCertificate *cert = ss->sec.peerCert;
    447    /* 7 days in microseconds */
    448    static const PRTime kMaxDcValidity = ((PRTime)7 * 24 * 60 * 60 * PR_USEC_PER_SEC);
    449    PRTime start, now, end; /* microseconds */
    450 
    451    rv = DER_DecodeTimeChoice(&start, &cert->validity.notBefore);
    452    if (rv != SECSuccess) {
    453        FATAL_ERROR(ss, PORT_GetError(), internal_error);
    454        return SECFailure;
    455    }
    456 
    457    end = start + ((PRTime)dc->validTime * PR_USEC_PER_SEC);
    458    now = ssl_Time(ss);
    459    if (now > end || end < 0) {
    460        FATAL_ERROR(ss, SSL_ERROR_DC_EXPIRED, illegal_parameter);
    461        return SECFailure;
    462    }
    463 
    464    /* Not more than 7 days remaining in the validity period. */
    465    if (end - now > kMaxDcValidity) {
    466        FATAL_ERROR(ss, SSL_ERROR_DC_INAPPROPRIATE_VALIDITY_PERIOD, illegal_parameter);
    467        return SECFailure;
    468    }
    469 
    470    return SECSuccess;
    471 }
    472 
    473 /* Returns SECSucces if |dc| is a DC for the current handshake; otherwise it
    474 * returns SECFailure. A valid DC meets three requirements: (1) the signature
    475 * was produced by the peer's end-entity certificate, (2) the end-entity
    476 * certificate must have the correct key usage, and (3) the DC must not be
    477 * expired and its remaining TTL must be <= the maximum validity period (fixed
    478 * as 7 days).
    479 *
    480 * This function calls FATAL_ERROR() when an error occurs.
    481 */
    482 SECStatus
    483 tls13_VerifyDelegatedCredential(sslSocket *ss,
    484                                sslDelegatedCredential *dc)
    485 {
    486    SECStatus rv;
    487    PRTime start;
    488    PRExplodedTime end;
    489    CERTCertificate *cert = ss->sec.peerCert;
    490    char endStr[256];
    491 
    492    rv = DER_DecodeTimeChoice(&start, &cert->validity.notBefore);
    493    if (rv != SECSuccess) {
    494        FATAL_ERROR(ss, PORT_GetError(), internal_error);
    495        return SECFailure;
    496    }
    497 
    498    PR_ExplodeTime(start + (dc->validTime * PR_USEC_PER_SEC),
    499                   PR_GMTParameters, &end);
    500    if (PR_FormatTime(endStr, sizeof(endStr), "%a %b %d %H:%M:%S %Y", &end)) {
    501        SSL_TRC(20, ("%d: TLS13[%d]: Received delegated credential (expires %s)",
    502                     SSL_GETPID(), ss->fd, endStr));
    503    } else {
    504        SSL_TRC(20, ("%d: TLS13[%d]: Received delegated credential",
    505                     SSL_GETPID(), ss->fd));
    506    }
    507 
    508    rv = SECSuccess;
    509    rv |= tls13_VerifyCredentialSignature(ss, dc);
    510    rv |= tls13_CheckCertDelegationUsage(ss);
    511    rv |= tls13_CheckCredentialExpiration(ss, dc);
    512    return rv;
    513 }
    514 
    515 static CERTSubjectPublicKeyInfo *
    516 tls13_MakePssSpki(const SECKEYPublicKey *pub, SECOidTag hashOid)
    517 {
    518    SECStatus rv;
    519    PLArenaPool *arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
    520    if (!arena) {
    521        goto loser; /* Code already set. */
    522    }
    523    CERTSubjectPublicKeyInfo *spki = PORT_ArenaZNew(arena, CERTSubjectPublicKeyInfo);
    524    if (!spki) {
    525        goto loser; /* Code already set. */
    526    }
    527    spki->arena = arena;
    528 
    529    SECKEYRSAPSSParams params = { 0 };
    530    params.hashAlg = PORT_ArenaZNew(arena, SECAlgorithmID);
    531    rv = SECOID_SetAlgorithmID(arena, params.hashAlg, hashOid, NULL);
    532    if (rv != SECSuccess) {
    533        goto loser; /* Code already set. */
    534    }
    535 
    536    /* Set the mask hash algorithm too, which is an argument to
    537     * a SEC_OID_PKCS1_MGF1 value. */
    538    SECAlgorithmID maskHashAlg;
    539    memset(&maskHashAlg, 0, sizeof(maskHashAlg));
    540    rv = SECOID_SetAlgorithmID(arena, &maskHashAlg, hashOid, NULL);
    541    if (rv != SECSuccess) {
    542        goto loser; /* Code already set. */
    543    }
    544    SECItem *maskHashAlgItem =
    545        SEC_ASN1EncodeItem(arena, NULL, &maskHashAlg,
    546                           SEC_ASN1_GET(SECOID_AlgorithmIDTemplate));
    547    if (!maskHashAlgItem) {
    548        /* Probably OOM, but not certain. */
    549        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
    550        goto loser;
    551    }
    552 
    553    params.maskAlg = PORT_ArenaZNew(arena, SECAlgorithmID);
    554    rv = SECOID_SetAlgorithmID(arena, params.maskAlg, SEC_OID_PKCS1_MGF1,
    555                               maskHashAlgItem);
    556    if (rv != SECSuccess) {
    557        goto loser; /* Code already set. */
    558    }
    559 
    560    /* Always include saltLength: all hashes are larger than 20. */
    561    unsigned int saltLength = HASH_ResultLenByOidTag(hashOid);
    562    PORT_Assert(saltLength > 20);
    563    if (!SEC_ASN1EncodeInteger(arena, &params.saltLength, saltLength)) {
    564        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
    565        goto loser;
    566    }
    567    /* Omit the trailerField always. */
    568 
    569    SECItem *algorithmItem =
    570        SEC_ASN1EncodeItem(arena, NULL, &params,
    571                           SEC_ASN1_GET(SECKEY_RSAPSSParamsTemplate));
    572    if (!algorithmItem) {
    573        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
    574        goto loser; /* Code already set. */
    575    }
    576    rv = SECOID_SetAlgorithmID(arena, &spki->algorithm,
    577                               SEC_OID_PKCS1_RSA_PSS_SIGNATURE, algorithmItem);
    578    if (rv != SECSuccess) {
    579        goto loser; /* Code already set. */
    580    }
    581 
    582    SECItem *pubItem = SEC_ASN1EncodeItem(arena, &spki->subjectPublicKey, pub,
    583                                          SEC_ASN1_GET(SECKEY_RSAPublicKeyTemplate));
    584    if (!pubItem) {
    585        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
    586        goto loser;
    587    }
    588    spki->subjectPublicKey.len *= 8; /* Key length is in bits. */
    589    return spki;
    590 
    591 loser:
    592    PORT_FreeArena(arena, PR_FALSE);
    593    return NULL;
    594 }
    595 
    596 static CERTSubjectPublicKeyInfo *
    597 tls13_MakeDcSpki(const SECKEYPublicKey *dcPub, SSLSignatureScheme dcCertVerifyAlg)
    598 {
    599    switch (SECKEY_GetPublicKeyType(dcPub)) {
    600        case rsaKey: {
    601            SECOidTag hashOid;
    602            switch (dcCertVerifyAlg) {
    603                /* Note: RSAE schemes are NOT permitted within DC SPKIs. However,
    604                 * support for their issuance remains so as to enable negative
    605                 * testing of client behavior. */
    606                case ssl_sig_rsa_pss_rsae_sha256:
    607                case ssl_sig_rsa_pss_rsae_sha384:
    608                case ssl_sig_rsa_pss_rsae_sha512:
    609                    return SECKEY_CreateSubjectPublicKeyInfo(dcPub);
    610                case ssl_sig_rsa_pss_pss_sha256:
    611                    hashOid = SEC_OID_SHA256;
    612                    break;
    613                case ssl_sig_rsa_pss_pss_sha384:
    614                    hashOid = SEC_OID_SHA384;
    615                    break;
    616                case ssl_sig_rsa_pss_pss_sha512:
    617                    hashOid = SEC_OID_SHA512;
    618                    break;
    619 
    620                default:
    621                    PORT_SetError(SSL_ERROR_INCORRECT_SIGNATURE_ALGORITHM);
    622                    return NULL;
    623            }
    624            return tls13_MakePssSpki(dcPub, hashOid);
    625        }
    626 
    627        case ecKey: {
    628            const sslNamedGroupDef *group = ssl_ECPubKey2NamedGroup(dcPub);
    629            if (!group) {
    630                PORT_SetError(SSL_ERROR_INCORRECT_SIGNATURE_ALGORITHM);
    631                return NULL;
    632            }
    633            SSLSignatureScheme keyScheme;
    634            switch (group->name) {
    635                case ssl_grp_ec_secp256r1:
    636                    keyScheme = ssl_sig_ecdsa_secp256r1_sha256;
    637                    break;
    638                case ssl_grp_ec_secp384r1:
    639                    keyScheme = ssl_sig_ecdsa_secp384r1_sha384;
    640                    break;
    641                case ssl_grp_ec_secp521r1:
    642                    keyScheme = ssl_sig_ecdsa_secp521r1_sha512;
    643                    break;
    644                default:
    645                    PORT_SetError(SEC_ERROR_INVALID_KEY);
    646                    return NULL;
    647            }
    648            if (keyScheme != dcCertVerifyAlg) {
    649                PORT_SetError(SSL_ERROR_INCORRECT_SIGNATURE_ALGORITHM);
    650                return NULL;
    651            }
    652            return SECKEY_CreateSubjectPublicKeyInfo(dcPub);
    653        }
    654 
    655        default:
    656            break;
    657    }
    658 
    659    PORT_SetError(SEC_ERROR_INVALID_KEY);
    660    return NULL;
    661 }
    662 
    663 /* Returns a serialized DC with the given parameters.
    664 *
    665 * Note that this function is meant primarily for testing. In particular, it
    666 * DOES NOT verify any of the following:
    667 *  - |certPriv| is the private key corresponding to |cert|;
    668 *  - that |checkCertKeyUsage(cert) == SECSuccess|;
    669 *  - |dcValidFor| is less than 7 days (the maximum permitted by the spec); or
    670 *  - validTime doesn't overflow a PRUint32.
    671 *
    672 * These conditions are things we want to test for, which is why we allow them
    673 * here. A real API for creating DCs would want to explicitly check ALL of these
    674 * conditions are met.
    675 */
    676 SECStatus
    677 SSLExp_DelegateCredential(const CERTCertificate *cert,
    678                          const SECKEYPrivateKey *certPriv,
    679                          const SECKEYPublicKey *dcPub,
    680                          SSLSignatureScheme dcCertVerifyAlg,
    681                          PRUint32 dcValidFor,
    682                          PRTime now,
    683                          SECItem *out)
    684 {
    685    SECStatus rv;
    686    CERTSubjectPublicKeyInfo *spki = NULL;
    687    SECKEYPrivateKey *tmpPriv = NULL;
    688    void *pwArg = certPriv->wincx;
    689    sslDelegatedCredential *dc = NULL;
    690    sslBuffer dcBuf = SSL_BUFFER_EMPTY;
    691 
    692    if (!cert || !certPriv || !dcPub || !out) {
    693        PORT_SetError(SEC_ERROR_INVALID_ARGS);
    694        return SECFailure;
    695    }
    696 
    697    dc = PORT_ZNew(sslDelegatedCredential);
    698    if (!dc) {
    699        PORT_SetError(SEC_ERROR_NO_MEMORY);
    700        goto loser;
    701    }
    702 
    703    /* Serialize the DC parameters. */
    704    PRTime start;
    705    rv = DER_DecodeTimeChoice(&start, &cert->validity.notBefore);
    706    if (rv != SECSuccess) {
    707        goto loser;
    708    }
    709    dc->validTime = ((now - start) / PR_USEC_PER_SEC) + dcValidFor;
    710 
    711    /* Building the SPKI also validates |dcCertVerifyAlg|. */
    712    spki = tls13_MakeDcSpki(dcPub, dcCertVerifyAlg);
    713    if (!spki) {
    714        goto loser;
    715    }
    716    dc->expectedCertVerifyAlg = dcCertVerifyAlg;
    717 
    718    SECItem *spkiDer =
    719        SEC_ASN1EncodeItem(NULL /*arena*/, &dc->derSpki, spki,
    720                           SEC_ASN1_GET(CERT_SubjectPublicKeyInfoTemplate));
    721    if (!spkiDer) {
    722        goto loser;
    723    }
    724 
    725    rv = ssl_SignatureSchemeFromSpki(&cert->subjectPublicKeyInfo,
    726                                     PR_TRUE /* isTls13 */, &dc->alg);
    727    if (rv != SECSuccess) {
    728        goto loser;
    729    }
    730 
    731    if (dc->alg == ssl_sig_none) {
    732        SECOidTag spkiOid = SECOID_GetAlgorithmTag(&cert->subjectPublicKeyInfo.algorithm);
    733        /* If the Cert SPKI contained an AlgorithmIdentifier of "rsaEncryption", set a
    734         * default rsa_pss_rsae_sha256 scheme. NOTE: RSAE SPKIs are not permitted within
    735         * "real" Delegated Credentials. However, since this function is primarily used for
    736         * testing, we retain this support in order to verify that these DCs are rejected
    737         * by tls13_VerifyDelegatedCredential. */
    738        if (spkiOid == SEC_OID_PKCS1_RSA_ENCRYPTION) {
    739            SSLSignatureScheme scheme = ssl_sig_rsa_pss_rsae_sha256;
    740            if (ssl_SignatureSchemeValid(scheme, spkiOid, PR_TRUE /* isTls13 */)) {
    741                dc->alg = scheme;
    742            }
    743        }
    744    }
    745    PORT_Assert(dc->alg != ssl_sig_none);
    746 
    747    rv = tls13_AppendCredentialParams(&dcBuf, dc);
    748    if (rv != SECSuccess) {
    749        goto loser;
    750    }
    751 
    752    /* Sign the hash with the delegation key.
    753     *
    754     * The PK11 API discards const qualifiers, so we have to make a copy of
    755     * |certPriv| and pass the copy to
    756     * |tls13_HashCredentialAndSignOrVerifyMessage|.
    757     */
    758    tmpPriv = SECKEY_CopyPrivateKey(certPriv);
    759    rv = tls13_HashCredentialAndSignOrVerifyMessage(tmpPriv, NULL, dc->alg,
    760                                                    sig_sign, cert, &dcBuf,
    761                                                    &dc->signature, pwArg);
    762    if (rv != SECSuccess) {
    763        goto loser;
    764    }
    765 
    766    /* Serialize the DC signature. */
    767    rv = tls13_AppendCredentialSignature(&dcBuf, dc);
    768    if (rv != SECSuccess) {
    769        goto loser;
    770    }
    771 
    772    /* Copy the serialized DC to |out|. */
    773    rv = SECITEM_MakeItem(NULL, out, dcBuf.buf, dcBuf.len);
    774    if (rv != SECSuccess) {
    775        goto loser;
    776    }
    777 
    778    PRINT_BUF(20, (NULL, "delegated credential", dcBuf.buf, dcBuf.len));
    779 
    780    SECKEY_DestroySubjectPublicKeyInfo(spki);
    781    SECKEY_DestroyPrivateKey(tmpPriv);
    782    tls13_DestroyDelegatedCredential(dc);
    783    sslBuffer_Clear(&dcBuf);
    784    return SECSuccess;
    785 
    786 loser:
    787    SECKEY_DestroySubjectPublicKeyInfo(spki);
    788    SECKEY_DestroyPrivateKey(tmpPriv);
    789    tls13_DestroyDelegatedCredential(dc);
    790    sslBuffer_Clear(&dcBuf);
    791    return SECFailure;
    792 }