Merge pull request #71 from matrix-org/js_sanitising

zero buffers in the JavaScript bindings
This commit is contained in:
Hubert Chathi 2018-10-19 11:34:55 -04:00 committed by GitHub
commit c4c3055f83
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GPG key ID: 4AEE18F83AFDEB23
4 changed files with 260 additions and 90 deletions

View file

@ -29,9 +29,17 @@ InboundGroupSession.prototype['pickle'] = restore_stack(function(key) {
)(this.ptr);
var key_buffer = stack(key_array);
var pickle_buffer = stack(pickle_length + NULL_BYTE_PADDING_LENGTH);
inbound_group_session_method(Module['_olm_pickle_inbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
try {
inbound_group_session_method(Module['_olm_pickle_inbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
return Pointer_stringify(pickle_buffer);
});
@ -40,28 +48,52 @@ InboundGroupSession.prototype['unpickle'] = restore_stack(function(key, pickle)
var key_buffer = stack(key_array);
var pickle_array = array_from_string(pickle);
var pickle_buffer = stack(pickle_array);
inbound_group_session_method(Module['_olm_unpickle_inbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
try {
inbound_group_session_method(Module['_olm_unpickle_inbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
});
InboundGroupSession.prototype['create'] = restore_stack(function(session_key) {
var key_array = array_from_string(session_key);
var key_buffer = stack(key_array);
inbound_group_session_method(Module['_olm_init_inbound_group_session'])(
this.ptr, key_buffer, key_array.length
);
try {
inbound_group_session_method(Module['_olm_init_inbound_group_session'])(
this.ptr, key_buffer, key_array.length
);
} finally {
// clear out copies of the key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
});
InboundGroupSession.prototype['import_session'] = restore_stack(function(session_key) {
var key_array = array_from_string(session_key);
var key_buffer = stack(key_array);
inbound_group_session_method(Module['_olm_import_inbound_group_session'])(
this.ptr, key_buffer, key_array.length
);
try {
inbound_group_session_method(Module['_olm_import_inbound_group_session'])(
this.ptr, key_buffer, key_array.length
);
} finally {
// clear out copies of the key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
});
InboundGroupSession.prototype['decrypt'] = restore_stack(function(
@ -140,7 +172,9 @@ InboundGroupSession.prototype['export_session'] = restore_stack(function(message
outbound_group_session_method(Module['_olm_export_inbound_group_session'])(
this.ptr, key, key_length, message_index
);
return Pointer_stringify(key);
var key_str = Pointer_stringify(key);
bzero(key, key_length); // clear out a copy of the key
return key_str;
});
olm_exports['InboundGroupSession'] = InboundGroupSession;

View file

@ -29,9 +29,17 @@ OutboundGroupSession.prototype['pickle'] = restore_stack(function(key) {
)(this.ptr);
var key_buffer = stack(key_array);
var pickle_buffer = stack(pickle_length + NULL_BYTE_PADDING_LENGTH);
outbound_group_session_method(Module['_olm_pickle_outbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
try {
outbound_group_session_method(Module['_olm_pickle_outbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
return Pointer_stringify(pickle_buffer);
});
@ -40,10 +48,18 @@ OutboundGroupSession.prototype['unpickle'] = restore_stack(function(key, pickle)
var key_buffer = stack(key_array);
var pickle_array = array_from_string(pickle);
var pickle_buffer = stack(pickle_array);
outbound_group_session_method(Module['_olm_unpickle_outbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
try {
outbound_group_session_method(Module['_olm_unpickle_outbound_group_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
});
OutboundGroupSession.prototype['create'] = restore_stack(function() {
@ -116,7 +132,9 @@ OutboundGroupSession.prototype['session_key'] = restore_stack(function() {
outbound_group_session_method(Module['_olm_outbound_group_session_key'])(
this.ptr, key, key_length
);
return Pointer_stringify(key);
var key_str = Pointer_stringify(key);
bzero(key, key_length); // clear out our copy of the key
return key_str;
});
OutboundGroupSession.prototype['message_index'] = function() {

View file

@ -33,15 +33,15 @@ PkEncryption.prototype['set_recipient_key'] = restore_stack(function(key) {
PkEncryption.prototype['encrypt'] = restore_stack(function(
plaintext
) {
var plaintext_buffer, ciphertext_buffer, plaintext_length;
var plaintext_buffer, ciphertext_buffer, plaintext_length, random, random_length;
try {
plaintext_length = lengthBytesUTF8(plaintext)
plaintext_buffer = malloc(plaintext_length + 1);
stringToUTF8(plaintext, plaintext_buffer, plaintext_length + 1);
var random_length = pk_encryption_method(
random_length = pk_encryption_method(
Module['_olm_pk_encrypt_random_length']
)();
var random = random_stack(random_length);
random = random_stack(random_length);
var ciphertext_length = pk_encryption_method(
Module['_olm_pk_ciphertext_length']
)(this.ptr, plaintext_length);
@ -82,6 +82,10 @@ PkEncryption.prototype['encrypt'] = restore_stack(function(
"ephemeral": Pointer_stringify(ephemeral_buffer)
};
} finally {
if (random !== undefined) {
// clear out the random buffer, since it is key data
bzero(random, random_length);
}
if (plaintext_buffer !== undefined) {
// don't leave a copy of the plaintext in the heap.
bzero(plaintext_buffer, plaintext_length + 1);
@ -126,11 +130,16 @@ PkDecryption.prototype['init_with_private_key'] = restore_stack(function (privat
Module['_olm_pk_key_length']
)();
var pubkey_buffer = stack(pubkey_length + NULL_BYTE_PADDING_LENGTH);
pk_decryption_method(Module['_olm_pk_key_from_private'])(
this.ptr,
pubkey_buffer, pubkey_length,
private_key_buffer, private_key.length
);
try {
pk_decryption_method(Module['_olm_pk_key_from_private'])(
this.ptr,
pubkey_buffer, pubkey_length,
private_key_buffer, private_key.length
);
} finally {
// clear out our copy of the private key
bzero(private_key_buffer, private_key.length);
}
return Pointer_stringify(pubkey_buffer);
});
@ -143,11 +152,16 @@ PkDecryption.prototype['generate_key'] = restore_stack(function () {
Module['_olm_pk_key_length']
)();
var pubkey_buffer = stack(pubkey_length + NULL_BYTE_PADDING_LENGTH);
pk_decryption_method(Module['_olm_pk_key_from_private'])(
this.ptr,
pubkey_buffer, pubkey_length,
random_buffer, random_length
);
try {
pk_decryption_method(Module['_olm_pk_key_from_private'])(
this.ptr,
pubkey_buffer, pubkey_length,
random_buffer, random_length
);
} finally {
// clear out the random buffer (= private key)
bzero(random_buffer, random_length);
}
return Pointer_stringify(pubkey_buffer);
});
@ -160,7 +174,14 @@ PkDecryption.prototype['get_private_key'] = restore_stack(function () {
this.ptr,
privkey_buffer, privkey_length
);
return new Uint8Array(Module['HEAPU8'].buffer, privkey_buffer, privkey_length);
// The inner Uint8Array creates a view of the buffer. The outer Uint8Array
// copies it to a new array to return, since the original buffer will get
// deallocated from the stack and could get overwritten.
var key_arr = new Uint8Array(
new Uint8Array(Module['HEAPU8'].buffer, privkey_buffer, privkey_length)
);
bzero(privkey_buffer, privkey_length); // clear out our copy of the key
return key_arr;
});
PkDecryption.prototype['pickle'] = restore_stack(function (key) {
@ -170,9 +191,17 @@ PkDecryption.prototype['pickle'] = restore_stack(function (key) {
)(this.ptr);
var key_buffer = stack(key_array);
var pickle_buffer = stack(pickle_length + NULL_BYTE_PADDING_LENGTH);
pk_decryption_method(Module['_olm_pickle_pk_decryption'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
try {
pk_decryption_method(Module['_olm_pickle_pk_decryption'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
return Pointer_stringify(pickle_buffer);
});
@ -185,10 +214,18 @@ PkDecryption.prototype['unpickle'] = restore_stack(function (key, pickle) {
Module["_olm_pk_key_length"]
)();
var ephemeral_buffer = stack(ephemeral_length + NULL_BYTE_PADDING_LENGTH);
pk_decryption_method(Module['_olm_unpickle_pk_decryption'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length, ephemeral_buffer, ephemeral_length
);
try {
pk_decryption_method(Module['_olm_unpickle_pk_decryption'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length, ephemeral_buffer, ephemeral_length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
return Pointer_stringify(ephemeral_buffer);
});

View file

@ -91,11 +91,19 @@ Account.prototype['sign'] = restore_stack(function(message) {
var message_array = array_from_string(message);
var message_buffer = stack(message_array);
var signature_buffer = stack(signature_length + NULL_BYTE_PADDING_LENGTH);
account_method(Module['_olm_account_sign'])(
this.ptr,
message_buffer, message_array.length,
signature_buffer, signature_length
);
try {
account_method(Module['_olm_account_sign'])(
this.ptr,
message_buffer, message_array.length,
signature_buffer, signature_length
);
} finally {
// clear out copies of the message, which may be plaintext
bzero(message_buffer, message_array.length);
for (var i = 0; i < message_array.length; i++) {
message_array[i] = 0;
}
}
return Pointer_stringify(signature_buffer);
});
@ -145,9 +153,17 @@ Account.prototype['pickle'] = restore_stack(function(key) {
)(this.ptr);
var key_buffer = stack(key_array);
var pickle_buffer = stack(pickle_length + NULL_BYTE_PADDING_LENGTH);
account_method(Module['_olm_pickle_account'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
try {
account_method(Module['_olm_pickle_account'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
return Pointer_stringify(pickle_buffer);
});
@ -156,10 +172,18 @@ Account.prototype['unpickle'] = restore_stack(function(key, pickle) {
var key_buffer = stack(key_array);
var pickle_array = array_from_string(pickle);
var pickle_buffer = stack(pickle_array);
account_method(Module['_olm_unpickle_account'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
try {
account_method(Module['_olm_unpickle_account'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
});
function Session() {
@ -193,9 +217,17 @@ Session.prototype['pickle'] = restore_stack(function(key) {
)(this.ptr);
var key_buffer = stack(key_array);
var pickle_buffer = stack(pickle_length + NULL_BYTE_PADDING_LENGTH);
session_method(Module['_olm_pickle_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
try {
session_method(Module['_olm_pickle_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
return Pointer_stringify(pickle_buffer);
});
@ -204,10 +236,18 @@ Session.prototype['unpickle'] = restore_stack(function(key, pickle) {
var key_buffer = stack(key_array);
var pickle_array = array_from_string(pickle);
var pickle_buffer = stack(pickle_array);
session_method(Module['_olm_unpickle_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
try {
session_method(Module['_olm_unpickle_session'])(
this.ptr, key_buffer, key_array.length, pickle_buffer,
pickle_array.length
);
} finally {
// clear out copies of the pickle key
bzero(key_buffer, key_array.length)
for (var i = 0; i < key_array.length; i++) {
key_array[i] = 0;
}
}
});
Session.prototype['create_outbound'] = restore_stack(function(
@ -221,12 +261,17 @@ Session.prototype['create_outbound'] = restore_stack(function(
var one_time_key_array = array_from_string(their_one_time_key);
var identity_key_buffer = stack(identity_key_array);
var one_time_key_buffer = stack(one_time_key_array);
session_method(Module['_olm_create_outbound_session'])(
this.ptr, account.ptr,
identity_key_buffer, identity_key_array.length,
one_time_key_buffer, one_time_key_array.length,
random, random_length
);
try {
session_method(Module['_olm_create_outbound_session'])(
this.ptr, account.ptr,
identity_key_buffer, identity_key_array.length,
one_time_key_buffer, one_time_key_array.length,
random, random_length
);
} finally {
// clear the random buffer, which is key data
bzero(random, random_length);
}
});
Session.prototype['create_inbound'] = restore_stack(function(
@ -234,9 +279,17 @@ Session.prototype['create_inbound'] = restore_stack(function(
) {
var message_array = array_from_string(one_time_key_message);
var message_buffer = stack(message_array);
session_method(Module['_olm_create_inbound_session'])(
this.ptr, account.ptr, message_buffer, message_array.length
);
try {
session_method(Module['_olm_create_inbound_session'])(
this.ptr, account.ptr, message_buffer, message_array.length
);
} finally {
// clear out copies of the key
bzero(message_buffer, message_array.length);
for (var i = 0; i < message_array.length; i++) {
message_array[i] = 0;
}
}
});
Session.prototype['create_inbound_from'] = restore_stack(function(
@ -246,11 +299,19 @@ Session.prototype['create_inbound_from'] = restore_stack(function(
var identity_key_buffer = stack(identity_key_array);
var message_array = array_from_string(one_time_key_message);
var message_buffer = stack(message_array);
session_method(Module['_olm_create_inbound_session_from'])(
this.ptr, account.ptr,
identity_key_buffer, identity_key_array.length,
message_buffer, message_array.length
);
try {
session_method(Module['_olm_create_inbound_session_from'])(
this.ptr, account.ptr,
identity_key_buffer, identity_key_array.length,
message_buffer, message_array.length
);
} finally {
// clear out copies of the key
bzero(message_buffer, message_array.length);
for (var i = 0; i < message_array.length; i++) {
message_array[i] = 0;
}
}
});
Session.prototype['session_id'] = restore_stack(function() {
@ -296,9 +357,9 @@ Session.prototype['matches_inbound_from'] = restore_stack(function(
Session.prototype['encrypt'] = restore_stack(function(
plaintext
) {
var plaintext_buffer, message_buffer, plaintext_length;
var plaintext_buffer, message_buffer, plaintext_length, random, random_length;
try {
var random_length = session_method(
random_length = session_method(
Module['_olm_encrypt_random_length']
)(this.ptr);
var message_type = session_method(
@ -310,7 +371,7 @@ Session.prototype['encrypt'] = restore_stack(function(
Module['_olm_encrypt_message_length']
)(this.ptr, plaintext_length);
var random = random_stack(random_length);
random = random_stack(random_length);
// need to allow space for the terminator (which stringToUTF8 always
// writes), hence + 1.
@ -338,6 +399,10 @@ Session.prototype['encrypt'] = restore_stack(function(
"body": UTF8ToString(message_buffer),
};
} finally {
if (random !== undefined) {
// clear out the random buffer, since it is the private key
bzero(random, random_length);
}
if (plaintext_buffer !== undefined) {
// don't leave a copy of the plaintext in the heap.
bzero(plaintext_buffer, plaintext_length + 1);
@ -423,11 +488,19 @@ Utility.prototype['sha256'] = restore_stack(function(input) {
var input_array = array_from_string(input);
var input_buffer = stack(input_array);
var output_buffer = stack(output_length + NULL_BYTE_PADDING_LENGTH);
utility_method(Module['_olm_sha256'])(
this.ptr,
input_buffer, input_array.length,
output_buffer, output_length
);
try {
utility_method(Module['_olm_sha256'])(
this.ptr,
input_buffer, input_array.length,
output_buffer, output_length
);
} finally {
// clear out copies of the input buffer, which may be plaintext
bzero(input_buffer, input_array.length);
for (var i = 0; i < input_array.length; i++) {
input_array[i] = 0;
}
}
return Pointer_stringify(output_buffer);
});
@ -440,12 +513,20 @@ Utility.prototype['ed25519_verify'] = restore_stack(function(
var message_buffer = stack(message_array);
var signature_array = array_from_string(signature);
var signature_buffer = stack(signature_array);
utility_method(Module['_olm_ed25519_verify'])(
this.ptr,
key_buffer, key_array.length,
message_buffer, message_array.length,
signature_buffer, signature_array.length
);
try {
utility_method(Module['_olm_ed25519_verify'])(
this.ptr,
key_buffer, key_array.length,
message_buffer, message_array.length,
signature_buffer, signature_array.length
);
} finally {
// clear out copies of the input buffer, which may be plaintext
bzero(message_buffer, message_array.length);
for (var i = 0; i < message_array.length; i++) {
message_array[i] = 0;
}
}
});
olm_exports["Account"] = Account;