peass-ng/PEASS-ng · error · ArgumentException

Hash size is not recommended. Use 256/384/512 instead

Error message

Hash size is not recommended. Use 256/384/512 instead

What it means

DSTU 7564 (Ukrainian Kubeh hash) is only standardized for 256-, 384-, and 512-bit outputs; other sizes would require untested round/column parameters. The Dstu7564Digest(int hashSizeBits) constructor throws ArgumentException for any hashSizeBits other than 256, 384, or 512.

Solutions

1. Pass exactly 256, 384, or 512 (bits) to the constructor.
2. If a 128- or 224-bit output is needed, choose another algorithm (e.g. SHA-256 truncated, or a different digest).
3. Validate the configured hash size against the allowed set before constructing.

Example fix

// before
var digest = new Dstu7564Digest(32); // bytes, not bits
// after
var digest = new Dstu7564Digest(256); // bits: 256|384|512

int[] allowed = { 256, 384, 512 };
if (Array.IndexOf(allowed, hashSizeBits) < 0)
    throw new ArgumentOutOfRangeException(nameof(hashSizeBits), "DSTU 7564 requires 256/384/512 bits");
var digest = new Dstu7564Digest(hashSizeBits);

static bool IsValidDstu7564Size(int bits) => bits == 256 || bits == 384 || bits == 512;

try { var d = new Dstu7564Digest(bits); }
catch (ArgumentException ex) { /* default to 512 or report config error */ }

When it happens

Trigger: Calling new Dstu7564Digest(hashSizeBits) with a value other than 256/384/512 — e.g. 128, 224, or a bit/byte confusion such as passing 32 instead of 256.

Common situations: Passing bit sizes from SHA-2 family configs (224); passing byte sizes (32/64) where bits are expected; guessing that smaller variants exist like in other hash families.

Related errors

• Invalid digest length (required: 1 - 32)
• invalid S-box passed to GOST28147 init
• Key length not 128/192/256 bits.
• Keys > 32 are not supported
• Keys > 32 bytes are not supported

AI-assisted analysis of peass-ng/PEASS-ng@53fb989abc (2026-09-02). Data as JSON: /api/errors/69cb6fb082df1e56. Report an issue: GitHub.

Appendix: source

Thrown at winPEAS/winPEASexe/winPEAS/3rdParty/BouncyCastle/crypto/digests/DSTU7564Digest.cs:71

                this.state = Arrays.Clone(digest.state);
                this.tempState1 = new ulong[columns];
                this.tempState2 = new ulong[columns];
                this.buf = Arrays.Clone(digest.buf);
            }

            this.inputBlocks = digest.inputBlocks;
            this.bufOff = digest.bufOff;
        }

        public Dstu7564Digest(int hashSizeBits)
        {
            if (hashSizeBits == 256 || hashSizeBits == 384 || hashSizeBits == 512)
            {
                this.hashSize = hashSizeBits / 8;
            }
            else
            {
                throw new ArgumentException("Hash size is not recommended. Use 256/384/512 instead");
            }

            if (hashSizeBits > 256)
            {
                this.columns = NB_1024;
                this.rounds = NR_1024;
            }
            else
            {
                this.columns = NB_512;
                this.rounds = NR_512;
            }

            this.blockSize = columns << 3;

            this.state = new ulong[columns];
            this.state[0] = (ulong)blockSize;

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