sqlmapproject/sqlmap · error · ValueError

Kerberos integrity check failed (wrong key or corrupted…

Error message

Kerberos integrity check failed (wrong key or corrupted ciphertext)

What it means

decrypt decrypted the body fine but the trailing HMAC-SHA1 (truncated to macsize) computed with ki does not match the MAC carried in the ciphertext, so integrity verification under RFC 3961 5.3 failed. With a valid Kerberos exchange this means the derived key or key usage is wrong, or the data was altered/corrupted in transit.

Solutions

1. Verify the password/salt used to derive the base key.
2. Confirm the key usage number passed to decrypt matches the one used at encryption (RFC 3961 usage derivation).
3. Check for transmission corruption; re-fetch the message.
4. If comparing two implementations, ensure both derive ke/ki with the same usage bytes (0xAA/0x55).

When it happens

Trigger: Thrown at extra/kerberos/crypto.py:192 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of sqlmapproject/sqlmap@0a35b20e39 (2026-08-26). Data as JSON: /api/errors/4b1a6a453caeae49. Report an issue: GitHub.

Appendix: source

Thrown at extra/kerberos/crypto.py:192

        ke = self.dk(key, struct.pack(">IB", usage, 0xAA))
        ki = self.dk(key, struct.pack(">IB", usage, 0x55))
        return ke, ki

    def encrypt(self, key, usage, plaintext, confounder=None):
        ke, ki = self._keys(key, usage)
        if confounder is None:
            confounder = os.urandom(self.blocksize)
        basic = confounder + plaintext
        return self._basicEncrypt(ke, basic) + hmac.new(ki, basic, hashlib.sha1).digest()[:self.macsize]

    def decrypt(self, key, usage, ciphertext):
        if len(ciphertext) < self.blocksize + self.macsize:   # confounder block + HMAC; guards a hostile short reply
            raise ValueError("Kerberos ciphertext too short")
        ke, ki = self._keys(key, usage)
        ct, mac = ciphertext[:-self.macsize], ciphertext[-self.macsize:]
        basic = self._basicDecrypt(ke, ct)
        if not _eq(mac, hmac.new(ki, basic, hashlib.sha1).digest()[:self.macsize]):
            raise ValueError("Kerberos integrity check failed (wrong key or corrupted ciphertext)")
        return basic[self.blocksize:]

def _rc4(key, data):
    """RC4 (ARCFOUR) stream cipher."""

    key, data = bytearray(key), bytearray(data)
    if not key:
        raise ValueError("RC4 requires a non-empty key")
    s = list(range(256))
    j = 0
    for i in range(256):
        j = (j + s[i] + key[i % len(key)]) & 0xff
        s[i], s[j] = s[j], s[i]

    out = bytearray(len(data))
    i = j = 0
    for n in range(len(data)):
        i = (i + 1) & 0xff

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