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Add the SM4 block cipher, also a no-padding option for block ciphers.

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This adds an implementation of the SM4 block cipher, and operations
to encrypt and decrypt using it with CBC,ECB,CFB,OFB,CTR modes.

Also, a "no padding" option is added for AES,DES,3DES and SM4
decryption in ECB/CBC modes. This variant does not attempt to
validate the last block as being PKCS#7 padded.

This is useful, both since other padding schemes exist, and also
for decrypting data where the final block is missing.
This commit is contained in:
swesven 2021-03-24 00:58:54 +01:00
parent 5029356514
commit 6155634d3b
9 changed files with 821 additions and 7 deletions
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18
src/core/operations/AESDecrypt.mjs
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@ -22,7 +22,7 @@ class AESDecrypt extends Operation {
this.name = "AES Decrypt";
this.module = "Ciphers";
this.description = "Advanced Encryption Standard (AES) is a U.S. Federal Information Processing Standard (FIPS). It was selected after a 5-year process where 15 competing designs were evaluated.<br><br><b>Key:</b> The following algorithms will be used based on the size of the key:<ul><li>16 bytes = AES-128</li><li>24 bytes = AES-192</li><li>32 bytes = AES-256</li></ul><br><br><b>IV:</b> The Initialization Vector should be 16 bytes long. If not entered, it will default to 16 null bytes.<br><br><b>Padding:</b> In CBC and ECB mode, PKCS#7 padding will be used.<br><br><b>GCM Tag:</b> This field is ignored unless 'GCM' mode is used.";
this.description = "Advanced Encryption Standard (AES) is a U.S. Federal Information Processing Standard (FIPS). It was selected after a 5-year process where 15 competing designs were evaluated.<br><br><b>Key:</b> The following algorithms will be used based on the size of the key:<ul><li>16 bytes = AES-128</li><li>24 bytes = AES-192</li><li>32 bytes = AES-256</li></ul><br><br><b>IV:</b> The Initialization Vector should be 16 bytes long. If not entered, it will default to 16 null bytes.<br><br><b>Padding:</b> In CBC and ECB mode, PKCS#7 padding will be used as a default.<br><br><b>GCM Tag:</b> This field is ignored unless 'GCM' mode is used.";
this.infoURL = "https://wikipedia.org/wiki/Advanced_Encryption_Standard";
this.inputType = "string";
this.outputType = "string";
@ -66,6 +66,14 @@ class AESDecrypt extends Operation {
{
name: "ECB",
off: [5, 6]
},
{
name: "CBC/NoPadding",
off: [5, 6]
},
{
name: "ECB/NoPadding",
off: [5, 6]
}
]
},
@ -104,7 +112,7 @@ class AESDecrypt extends Operation {
run(input, args) {
const key = Utils.convertToByteString(args[0].string, args[0].option),
iv = Utils.convertToByteString(args[1].string, args[1].option),
mode = args[2],
mode = args[2].substring(0, 3),
inputType = args[3],
outputType = args[4],
gcmTag = Utils.convertToByteString(args[5].string, args[5].option),
@ -122,6 +130,12 @@ The following algorithms will be used based on the size of the key:
input = Utils.convertToByteString(input, inputType);
const decipher = forge.cipher.createDecipher("AES-" + mode, key);
/* Allow for a "no padding" mode */
if (args[2].endsWith("NoPadding")) {
decipher.mode.unpad = function(output, options) {
return true;
};
}
decipher.start({
iv: iv.length === 0 ? "" : iv,
tag: mode === "GCM" ? gcmTag : undefined,