Shadow File Hash Prefix Identifier
Bounded shadow hash prefix recognition; locked prefixes retained, no password or full hash validity inference.
Description
Recognize supported modular-crypt prefix families and locked-record markers.
Unix-style password records can include modular-crypt prefix markers that identify a stored verifier family. Recognizing a marker describes the record format without verifying a password.
When to use this tool
Recognize supported modular-crypt prefix families and locked-record markers. Use it when the input measurements and conventions below match the operation you need.
- Prepare storedHash, respecting the measurement basis and boundaries below.
- Compare the worked example with your intended operation before reusing its result.
How to use the tool and how it works
- Enter every field in the input table using the stated units and exact supported selector spelling where applicable.
- Run the tool. Correct input errors before interpreting an output.
- Read the result fields below; use accompanying flags and the stated sign, boundary or model convention when interpreting a number.
The tool checks whether the record begins with a dollar sign and looks up the first dollar-delimited marker. It recognizes 1, 2a, 2b, 2y, 5, 6, y and gy as its stored families, otherwise reports unknown. A separate flag notes an initial exclamation mark or asterisk as locked, and hashVerified is always false.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| storedHash | Stored hash. | Text |
| Output field | Interpretation |
|---|---|
| result | Object containing the following named result fields. |
| result.prefixFamily | Prefix family; use the stated units and sign convention. |
| result.lockedMarker | Locked marker flag under the exact conditions described above. |
| result.hashVerified | Always false; only a prefix is classified. |
{
"input": {
"storedHash": "$6$salt$hash"
},
"output": {
"result": {
"prefixFamily": "SHA-512-crypt",
"lockedMarker": false,
"hashVerified": false
}
}
}Limitations and assumptions
- No full hash syntax, work factor, salt or password is verified. A locked record can obscure an embedded format; a recognized marker is not evidence that the algorithm is suitable for new password storage.
- Every declared field is required and unexpected fields are rejected. Numeric inputs must be finite; input errors are distinct from a valid false result or an explicitly qualified output.
- Extremely large inputs and nonfinite or excessively large outputs are rejected. List positions reported by the tool use zero-based indices unless stated otherwise.
Alternative or Complementary methods
Use the applicable protocol specification and a reviewed implementation for real verification, hashing or key management. A format label, probability model or tentative text mapping does not replace that operation. Compare the scope of the nearby tools below before substituting one.
References
Similar or alternative tools
- api key prefix separability checker
Prefix-based dispatch becomes ambiguous when one registered prefix begins with another.
- Cipher Identifier Heuristic Scorer
Overlapping syntax heuristic flags only, not cryptographic identification or proof of encryption.