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AES cipher: make padding optional

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Fixes #5152
This commit is contained in:
Rob Wu 2014-08-08 12:36:29 +02:00
parent c3fb7ee79a
commit 58cd3349db
1 changed files with 25 additions and 5 deletions
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30
src/core/crypto.js
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@ -978,8 +978,18 @@ var AES128Cipher = (function AES128CipherClosure() {
if (finalize) { if (finalize) {
// undo a padding that is described in RFC 2898 // undo a padding that is described in RFC 2898
var lastBlock = result[result.length - 1]; var lastBlock = result[result.length - 1];
outputLength -= lastBlock[15]; var psLen = lastBlock[15];
result[result.length - 1] = lastBlock.subarray(0, 16 - lastBlock[15]); if (psLen <= 16) {
for (i = 15, ii = 16 - psLen; i >= ii; --i) {
if (lastBlock[i] !== psLen) {
// Invalid padding, assume that the block has no padding.
psLen = 0;
break;
}
}
outputLength -= psLen;
result[result.length - 1] = lastBlock.subarray(0, 16 - psLen);
}
} }
var output = new Uint8Array(outputLength); var output = new Uint8Array(outputLength);
for (i = 0, j = 0, ii = result.length; i < ii; ++i, j += 16) { for (i = 0, j = 0, ii = result.length; i < ii; ++i, j += 16) {
@ -1394,7 +1404,7 @@ var AES256Cipher = (function AES256CipherClosure() {
if (bufferLength < 16) { if (bufferLength < 16) {
continue; continue;
} }
// buffer is full, encrypting // buffer is full, decrypting
var plain = decrypt256(buffer, this.key); var plain = decrypt256(buffer, this.key);
// xor-ing the IV vector to get plain text // xor-ing the IV vector to get plain text
for (j = 0; j < 16; ++j) { for (j = 0; j < 16; ++j) {
@ -1417,8 +1427,18 @@ var AES256Cipher = (function AES256CipherClosure() {
if (finalize) { if (finalize) {
// undo a padding that is described in RFC 2898 // undo a padding that is described in RFC 2898
var lastBlock = result[result.length - 1]; var lastBlock = result[result.length - 1];
outputLength -= lastBlock[15]; var psLen = lastBlock[15];
result[result.length - 1] = lastBlock.subarray(0, 16 - lastBlock[15]); if (psLen <= 16) {
for (i = 15, ii = 16 - psLen; i >= ii; --i) {
if (lastBlock[i] !== psLen) {
// Invalid padding, assume that the block has no padding.
psLen = 0;
break;
}
}
outputLength -= psLen;
result[result.length - 1] = lastBlock.subarray(0, 16 - psLen);
}
} }
var output = new Uint8Array(outputLength); var output = new Uint8Array(outputLength);
for (i = 0, j = 0, ii = result.length; i < ii; ++i, j += 16) { for (i = 0, j = 0, ii = result.length; i < ii; ++i, j += 16) {