sha1 Reference

SHA-1 hashing helpers for whole-input and incremental hashing.

sha1
ShaCounter
Accepted sources
Digest format
Whole-input and incremental relation
Sha1Internal
Examples
Example: incremental and direct hashing agree
Example: digest bytes of abc
See also

sha1 `(source -- digest)`

Computes one SHA-1 digest for one complete source span.

ShaCounter

Incremental SHA-1 state that accepts appended input chunks and produces one final digest.

Fields

state: five-word SHA-1 state.
buffer: pending input buffer.
bufferProcessed: number of bytes currently stored in the buffer.
bitSize: total processed bit count.

Methods

append (source --): appends one source span to the current hashing state.
finish (-- digest): finalizes the digest and returns one Nat8 20 array.

Remarks

append accepts the same source classes as sha1.
finish uses the buffered partial block together with the accumulated bit count.

Accepted sources

sha1 and ShaCounter.append convert their input through toSpan.
Text inputs are accepted directly.
Homogeneous non-Ref combined values are accepted directly.
Objects with a span member are accepted through that member.

Digest format

The digest schema is Nat8 20 array.
The digest bytes are returned in the assembled order produced by Sha1Internal.finish.

Whole-input and incremental relation

sha1 hashes the whole accepted source in one call.
ShaCounter allows the same byte sequence to be supplied in chunks.
Both paths produce the same digest for the same byte sequence.

Sha1Internal

Low-level helpers used by ShaCounter and sha1.

rol: left-rotation helper.
f1, f2, f3, f4: SHA-1 round helpers.
m and r: message-schedule and round helpers.
finish: final padding and digest assembly helper.
transform: one 64-byte block transform helper.

Examples

Incremental and direct hashing agree

"sha1" use
"control" use

{} () {} [
  direct: "abc" sha1;
  counter: ShaCounter;
  "ab" @counter.append
  "c" @counter.append
  incremental: @counter.finish;
  direct incremental same printStack _:;
] "main" exportFunction

Expected Output During Compilation

TRUE

Digest bytes of "abc"

"sha1" use
"String" use
"control" use

{} Int32 {} [
  digest: "abc" sha1;
  out: String;

  20 [
    byte: i digest @;
    i 0 > [" " @out.catString] when
    byte 16n8 < ["0" @out.catString] when
    byte @out.catHex
  ] times

  @out.getStringView print
  0
] "main" exportFunction

Expected Output

A9 99 3E 36 47 06 81 6A BA 3E 25 71 78 50 C2 6C 9C D0 D8 9D

sha1 (source -- digest)