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HashString

function HashString(aPlaintext: string): string

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := Hash.HashString('nonempty content');
end;

Usage​

HashString returns a 96-character uppercase SHA-384 hexadecimal digest for nonempty UTF-8 text. It does not change RowHash.

Additional Technical Info​

HashString returns Velox's string representation of a SHA-384 digest.

For nonempty input, LockBox converts the Delphi string to UTF-8, hashes those bytes with SHA-384, and exposes a 48-byte digest stream. Velox rewinds the stream and converts each byte to two uppercase hexadecimal characters, yielding exactly 96 characters with no prefix/separators.

After copying the result, Velox calls FHash.Burn, clearing the internal hash output. It does not assign RowHash; that property remains whatever the most recent HasChanged stored, or empty on a new object.

Empty-input divergence

The vendored LockBox HashString skips its complete begin/hash/end sequence when aPlaintext = ''. The result depends on existing object state:

  • on a new object, or after a prior HashString burned the output, it returns '';
  • immediately after a nonempty HasChanged, whose output is retained, it returns that previous digest and then burns it.

Neither case returns the standard 96-character SHA-384 digest of an empty message.

Do not pass empty when a standards-compatible digest is required. The global HashString wrapper creates the same class and has the same empty result.

Meaning and safe use

This is an unkeyed digest. It is suitable for ordinary deterministic fingerprints of nonempty text, not passwords, authentication or signatures. Input normalization is entirely the caller's responsibility: case, whitespace, Unicode normalization and line endings all change the UTF-8 byte sequence.

The method is synchronous, allocates the UTF-8 byte array and iterates the digest stream. The object is mutable and not thread-safe; serialize calls on the action-shared Hash object. Allocation/algorithm failures can raise.

External references

Created 2026-07-15