@@ 1,354 0,0 @@
-Fixes CVE-2021-43527.
-Copied from <https://hg.mozilla.org/projects/nss/rev/dea71cbef9e03636f37c6cb120f8deccce6e17dd>,
-but with the file names adjusted to allow easy use within GNU Guix.
-
-# HG changeset patch
-# User Dennis Jackson <djackson@mozilla.com>
-# Date 1637577642 0
-# Node ID dea71cbef9e03636f37c6cb120f8deccce6e17dd
-# Parent da3d22d708c9cc0a32cff339658aeb627575e371
-Bug 1737470 - Ensure DER encoded signatures are within size limits. r=jschanck,mt,bbeurdouche,rrelyea
-
-Differential Revision: https://phabricator.services.mozilla.com/D129514
-
---- a/security/nss/lib/cryptohi/secvfy.c
-+++ b/security/nss/lib/cryptohi/secvfy.c
-@@ -159,58 +159,89 @@ verifyPKCS1DigestInfo(const VFYContext *
- SECItem pkcs1DigestInfo;
- pkcs1DigestInfo.data = cx->pkcs1RSADigestInfo;
- pkcs1DigestInfo.len = cx->pkcs1RSADigestInfoLen;
- return _SGN_VerifyPKCS1DigestInfo(
- cx->hashAlg, digest, &pkcs1DigestInfo,
- PR_FALSE /*XXX: unsafeAllowMissingParameters*/);
- }
-
-+static unsigned int
-+checkedSignatureLen(const SECKEYPublicKey *pubk)
-+{
-+ unsigned int sigLen = SECKEY_SignatureLen(pubk);
-+ if (sigLen == 0) {
-+ /* Error set by SECKEY_SignatureLen */
-+ return sigLen;
-+ }
-+ unsigned int maxSigLen;
-+ switch (pubk->keyType) {
-+ case rsaKey:
-+ case rsaPssKey:
-+ maxSigLen = (RSA_MAX_MODULUS_BITS + 7) / 8;
-+ break;
-+ case dsaKey:
-+ maxSigLen = DSA_MAX_SIGNATURE_LEN;
-+ break;
-+ case ecKey:
-+ maxSigLen = 2 * MAX_ECKEY_LEN;
-+ break;
-+ default:
-+ PORT_SetError(SEC_ERROR_UNSUPPORTED_KEYALG);
-+ return 0;
-+ }
-+ if (sigLen > maxSigLen) {
-+ PORT_SetError(SEC_ERROR_INVALID_KEY);
-+ return 0;
-+ }
-+ return sigLen;
-+}
-+
- /*
- * decode the ECDSA or DSA signature from it's DER wrapping.
- * The unwrapped/raw signature is placed in the buffer pointed
- * to by dsig and has enough room for len bytes.
- */
- static SECStatus
- decodeECorDSASignature(SECOidTag algid, const SECItem *sig, unsigned char *dsig,
- unsigned int len)
- {
- SECItem *dsasig = NULL; /* also used for ECDSA */
-- SECStatus rv = SECSuccess;
-
-- if ((algid != SEC_OID_ANSIX9_DSA_SIGNATURE) &&
-- (algid != SEC_OID_ANSIX962_EC_PUBLIC_KEY)) {
-- if (sig->len != len) {
-- PORT_SetError(SEC_ERROR_BAD_DER);
-- return SECFailure;
-+ /* Safety: Ensure algId is as expected and that signature size is within maxmimums */
-+ if (algid == SEC_OID_ANSIX9_DSA_SIGNATURE) {
-+ if (len > DSA_MAX_SIGNATURE_LEN) {
-+ goto loser;
- }
--
-- PORT_Memcpy(dsig, sig->data, sig->len);
-- return SECSuccess;
-+ } else if (algid == SEC_OID_ANSIX962_EC_PUBLIC_KEY) {
-+ if (len > MAX_ECKEY_LEN * 2) {
-+ goto loser;
-+ }
-+ } else {
-+ goto loser;
- }
-
-- if (algid == SEC_OID_ANSIX962_EC_PUBLIC_KEY) {
-- if (len > MAX_ECKEY_LEN * 2) {
-- PORT_SetError(SEC_ERROR_BAD_DER);
-- return SECFailure;
-- }
-+ /* Decode and pad to length */
-+ dsasig = DSAU_DecodeDerSigToLen((SECItem *)sig, len);
-+ if (dsasig == NULL) {
-+ goto loser;
- }
-- dsasig = DSAU_DecodeDerSigToLen((SECItem *)sig, len);
--
-- if ((dsasig == NULL) || (dsasig->len != len)) {
-- rv = SECFailure;
-- } else {
-- PORT_Memcpy(dsig, dsasig->data, dsasig->len);
-+ if (dsasig->len != len) {
-+ SECITEM_FreeItem(dsasig, PR_TRUE);
-+ goto loser;
- }
-
-- if (dsasig != NULL)
-- SECITEM_FreeItem(dsasig, PR_TRUE);
-- if (rv == SECFailure)
-- PORT_SetError(SEC_ERROR_BAD_DER);
-- return rv;
-+ PORT_Memcpy(dsig, dsasig->data, len);
-+ SECITEM_FreeItem(dsasig, PR_TRUE);
-+
-+ return SECSuccess;
-+
-+loser:
-+ PORT_SetError(SEC_ERROR_BAD_DER);
-+ return SECFailure;
- }
-
- const SEC_ASN1Template hashParameterTemplate[] =
- {
- { SEC_ASN1_SEQUENCE, 0, NULL, sizeof(SECItem) },
- { SEC_ASN1_OBJECT_ID, 0 },
- { SEC_ASN1_SKIP_REST },
- { 0 }
-@@ -276,17 +307,17 @@ sec_GetEncAlgFromSigAlg(SECOidTag sigAlg
- *
- * Returns: SECSuccess if the algorithm was acceptable, SECFailure if the
- * algorithm was not found or was not a signing algorithm.
- */
- SECStatus
- sec_DecodeSigAlg(const SECKEYPublicKey *key, SECOidTag sigAlg,
- const SECItem *param, SECOidTag *encalgp, SECOidTag *hashalg)
- {
-- int len;
-+ unsigned int len;
- PLArenaPool *arena;
- SECStatus rv;
- SECItem oid;
- SECOidTag encalg;
-
- PR_ASSERT(hashalg != NULL);
- PR_ASSERT(encalgp != NULL);
-
-@@ -461,58 +492,62 @@ vfy_CreateContext(const SECKEYPublicKey
- cx->wincx = wincx;
- cx->hasSignature = (sig != NULL);
- cx->encAlg = encAlg;
- cx->hashAlg = hashAlg;
- cx->key = SECKEY_CopyPublicKey(key);
- cx->pkcs1RSADigestInfo = NULL;
- rv = SECSuccess;
- if (sig) {
-- switch (type) {
-- case rsaKey:
-- rv = recoverPKCS1DigestInfo(hashAlg, &cx->hashAlg,
-- &cx->pkcs1RSADigestInfo,
-- &cx->pkcs1RSADigestInfoLen,
-- cx->key,
-- sig, wincx);
-- break;
-- case rsaPssKey:
-- sigLen = SECKEY_SignatureLen(key);
-- if (sigLen == 0) {
-- /* error set by SECKEY_SignatureLen */
-- rv = SECFailure;
-+ rv = SECFailure;
-+ if (type == rsaKey) {
-+ rv = recoverPKCS1DigestInfo(hashAlg, &cx->hashAlg,
-+ &cx->pkcs1RSADigestInfo,
-+ &cx->pkcs1RSADigestInfoLen,
-+ cx->key,
-+ sig, wincx);
-+ } else {
-+ sigLen = checkedSignatureLen(key);
-+ /* Check signature length is within limits */
-+ if (sigLen == 0) {
-+ /* error set by checkedSignatureLen */
-+ rv = SECFailure;
-+ goto loser;
-+ }
-+ if (sigLen > sizeof(cx->u)) {
-+ PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
-+ rv = SECFailure;
-+ goto loser;
-+ }
-+ switch (type) {
-+ case rsaPssKey:
-+ if (sig->len != sigLen) {
-+ PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
-+ rv = SECFailure;
-+ goto loser;
-+ }
-+ PORT_Memcpy(cx->u.buffer, sig->data, sigLen);
-+ rv = SECSuccess;
- break;
-- }
-- if (sig->len != sigLen) {
-- PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
-+ case ecKey:
-+ case dsaKey:
-+ /* decodeECorDSASignature will check sigLen == sig->len after padding */
-+ rv = decodeECorDSASignature(encAlg, sig, cx->u.buffer, sigLen);
-+ break;
-+ default:
-+ /* Unreachable */
- rv = SECFailure;
-- break;
-- }
-- PORT_Memcpy(cx->u.buffer, sig->data, sigLen);
-- break;
-- case dsaKey:
-- case ecKey:
-- sigLen = SECKEY_SignatureLen(key);
-- if (sigLen == 0) {
-- /* error set by SECKEY_SignatureLen */
-- rv = SECFailure;
-- break;
-- }
-- rv = decodeECorDSASignature(encAlg, sig, cx->u.buffer, sigLen);
-- break;
-- default:
-- rv = SECFailure;
-- PORT_SetError(SEC_ERROR_UNSUPPORTED_KEYALG);
-- break;
-+ goto loser;
-+ }
-+ }
-+ if (rv != SECSuccess) {
-+ goto loser;
- }
- }
-
-- if (rv)
-- goto loser;
--
- /* check hash alg again, RSA may have changed it.*/
- if (HASH_GetHashTypeByOidTag(cx->hashAlg) == HASH_AlgNULL) {
- /* error set by HASH_GetHashTypeByOidTag */
- goto loser;
- }
- /* check the policy on the hash algorithm. Do this after
- * the rsa decode because some uses of this function get hash implicitly
- * from the RSA signature itself. */
-@@ -645,21 +680,26 @@ VFY_EndWithSignature(VFYContext *cx, SEC
- if (cx->hashcx == NULL) {
- PORT_SetError(SEC_ERROR_INVALID_ARGS);
- return SECFailure;
- }
- (*cx->hashobj->end)(cx->hashcx, final, &part, sizeof(final));
- switch (cx->key->keyType) {
- case ecKey:
- case dsaKey:
-- dsasig.data = cx->u.buffer;
-- dsasig.len = SECKEY_SignatureLen(cx->key);
-+ dsasig.len = checkedSignatureLen(cx->key);
- if (dsasig.len == 0) {
- return SECFailure;
- }
-+ if (dsasig.len > sizeof(cx->u)) {
-+ PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
-+ return SECFailure;
-+ }
-+ dsasig.data = cx->u.buffer;
-+
- if (sig) {
- rv = decodeECorDSASignature(cx->encAlg, sig, dsasig.data,
- dsasig.len);
- if (rv != SECSuccess) {
- PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
- return SECFailure;
- }
- }
-@@ -681,18 +721,23 @@ VFY_EndWithSignature(VFYContext *cx, SEC
- cx->params,
- &mech);
- PORT_DestroyCheapArena(&tmpArena);
- if (rv != SECSuccess) {
- return SECFailure;
- }
-
- rsasig.data = cx->u.buffer;
-- rsasig.len = SECKEY_SignatureLen(cx->key);
-+ rsasig.len = checkedSignatureLen(cx->key);
- if (rsasig.len == 0) {
-+ /* Error set by checkedSignatureLen */
-+ return SECFailure;
-+ }
-+ if (rsasig.len > sizeof(cx->u)) {
-+ PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
- return SECFailure;
- }
- if (sig) {
- if (sig->len != rsasig.len) {
- PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
- return SECFailure;
- }
- PORT_Memcpy(rsasig.data, sig->data, rsasig.len);
-@@ -744,37 +789,42 @@ VFY_End(VFYContext *cx)
- static SECStatus
- vfy_VerifyDigest(const SECItem *digest, const SECKEYPublicKey *key,
- const SECItem *sig, SECOidTag encAlg, SECOidTag hashAlg,
- void *wincx)
- {
- SECStatus rv;
- VFYContext *cx;
- SECItem dsasig; /* also used for ECDSA */
--
- rv = SECFailure;
-
- cx = vfy_CreateContext(key, sig, encAlg, hashAlg, NULL, wincx);
- if (cx != NULL) {
- switch (key->keyType) {
- case rsaKey:
- rv = verifyPKCS1DigestInfo(cx, digest);
-+ /* Error (if any) set by verifyPKCS1DigestInfo */
- break;
-- case dsaKey:
- case ecKey:
-+ case dsaKey:
- dsasig.data = cx->u.buffer;
-- dsasig.len = SECKEY_SignatureLen(cx->key);
-+ dsasig.len = checkedSignatureLen(cx->key);
- if (dsasig.len == 0) {
-+ /* Error set by checkedSignatureLen */
-+ rv = SECFailure;
- break;
- }
-- if (PK11_Verify(cx->key, &dsasig, (SECItem *)digest, cx->wincx) !=
-- SECSuccess) {
-+ if (dsasig.len > sizeof(cx->u)) {
- PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
-- } else {
-- rv = SECSuccess;
-+ rv = SECFailure;
-+ break;
-+ }
-+ rv = PK11_Verify(cx->key, &dsasig, (SECItem *)digest, cx->wincx);
-+ if (rv != SECSuccess) {
-+ PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
- }
- break;
- default:
- break;
- }
- VFY_DestroyContext(cx, PR_TRUE);
- }
- return rv;
-