Ken Johnson
e2ac43f9d2
Carved out of fpc-comet's cm.crypto.pas. Both are pure crypto primitives that belong in fpc-crypto regardless of whether there's a second consumer yet -- the "wait for a third consumer" rule that was appropriate for MD5 doesn't apply the same way to clearly-cryptographic surfaces like X25519 + ChaCha20 where pre-carving now avoids a coordinated release later. cr.x25519 -- Curve25519 scalar multiplication (RFC 7748). Shares field arithmetic with cr.ed25519 since the two schemes ride on the same curve. Exposes X25519Keypair, X25519ScalarMult (exported for testability), and X25519SharedSecret with zero-point rejection. cr.chacha20 -- ChaCha20 stream cipher (RFC 8439). Standalone, no deps beyond SysUtils. Exposes ChaCha20Init and ChaCha20Crypt over a TChacha20State record (256-bit key + 96-bit nonce + 64-bit counter + 64-byte keystream buffer). Known-answer tests added for both -- RFC 7748 §5.2 vectors + DH round-trip for X25519, RFC 8439 §2.4.2 vector + round- trip for ChaCha20. All 5 tests PASS, all 6 targets still green. Existing v0.1.0 API (MD5 / SHA / Ed25519) unchanged. Pure additive release; no ABI break. CRYPTO_MIN_COMPATIBLE_VERSION stays at 0.1.0.
fpc-crypto
Pure-Pascal cryptographic primitives shared across the FidoNet / Comet / Fimail ecosystem. One source of truth for the hash and signature algorithms used by fpc-binkp (CRAM-MD5), fpc-comet (pre-auth hash + Ed25519 peer auth), and fpc-emsi (FSC-0056 shared-secret auth).
What's in v0.2.0
| Unit | Primitive | Spec |
|---|---|---|
cr.md5 |
MD5 | RFC 1321 |
cr.sha |
SHA-256 + SHA-384 + SHA-512 | FIPS 180-4 |
cr.ed25519 |
Ed25519 sign/verify | RFC 8032 |
cr.ed25519.sc |
Scalar arithmetic | (internal to Ed25519) |
cr.ed25519.ge |
Group element ops | (internal to Ed25519) |
cr.ed25519.bp |
Precomputed base | (internal to Ed25519) |
cr.x25519 |
X25519 DH key exchange | RFC 7748 |
cr.chacha20 |
ChaCha20 stream cipher | RFC 8439 |
v0.2.0 carves X25519 + ChaCha20 out of fpc-comet's
cm.crypto — they're crypto primitives that belong in the
crypto library even with a single consumer today.
The go32v2 MD5 subtlety
cr.md5 is the go32v2-safe standalone MD5 implementation
originally carved from Comet's cm.md5. It is not a wrapper
over the FPC RTL md5.ppu, because the RTL unit has a
sysutils-checksum bug that corrupts MD5 output on i386-go32v2.
Consumers who need MD5 on DOS (or anywhere else) should call
cr.md5 directly and avoid the RTL.
Building
./build.sh # all seven targets
./build.sh x86_64-linux # single target
./run_tests.sh # host-side known-answer tests
Target matrix
x86_64-linux, i386-linux, i386-freebsd, i386-go32v2,
i386-os2, i386-win32 — same matrix as fpc-emsi / fpc-log.
Consumers
Vendor via cp -r src into the downstream tree, or pin at a
tag and git submodule. Downstream libraries currently
vendoring fpc-crypto:
fpc-binkpv0.3.0+ (CRAM-MD5)fpc-cometv0.2.0+ (pre-auth + Ed25519)fpc-emsiv0.2.0+ (FSC-0056)
Dependencies
- FPC RTL only (SysUtils).
- No external crypto library.
- No linkage against OpenSSL / libsodium / any other native lib.
License
GPL-2.0, same as the rest of the ecosystem.