zzstoatzz.io
+2
languages/ziglang/0.15/README.md
+2
languages/ziglang/0.15/README.md
···
9
9
- [build](./build.md) - createModule + imports, hash trick
10
10
- [comptime](./comptime.md) - type generation, tuple synthesis, validation
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11
- [concurrency](./concurrency.md) - atomics vs mutex, callback pattern
12
+
- [crypto](./crypto.md) - ecdsa paths, signature verification
13
+
- [testing](./testing.md) - zig test vs build test, arena for leaky apis
+44
languages/ziglang/0.15/crypto.md
+44
languages/ziglang/0.15/crypto.md
···
1
+
# crypto
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zig 0.15 crypto paths and patterns.
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## ecdsa
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the ecdsa types are under `std.crypto.sign.ecdsa`, not `std.crypto.ecdsa`:
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```zig
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const crypto = std.crypto;
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// correct (0.15)
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const Secp256k1 = crypto.sign.ecdsa.EcdsaSecp256k1Sha256;
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const P256 = crypto.sign.ecdsa.EcdsaP256Sha256;
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+
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// wrong - will error "has no member named 'ecdsa'"
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// const Secp256k1 = crypto.ecdsa.EcdsaSecp256k1Sha256;
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```
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## verifying signatures
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```zig
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const Scheme = std.crypto.sign.ecdsa.EcdsaSecp256k1Sha256;
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// signature is r || s (64 bytes for 256-bit curves)
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const sig = Scheme.Signature.fromBytes(sig_bytes[0..64].*);
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// public key from SEC1 compressed format (33 bytes)
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const public_key = try Scheme.PublicKey.fromSec1(key_bytes);
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// verify - returns error.SignatureVerificationFailed on mismatch
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try sig.verify(message, public_key);
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```
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## key sizes
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| curve | compressed pubkey | uncompressed pubkey | signature (r\|\|s) |
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|-------|-------------------|---------------------|-------------------|
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| P-256 | 33 bytes | 65 bytes | 64 bytes |
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| secp256k1 | 33 bytes | 65 bytes | 64 bytes |
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+
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compressed keys start with 0x02 or 0x03. uncompressed start with 0x04.
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+
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see: [zat/jwt.zig](https://tangled.sh/@zzstoatzz.io/zat/tree/main/src/internal/jwt.zig)
+16
languages/ziglang/0.15/testing.md
+16
languages/ziglang/0.15/testing.md
···
1
+
# testing
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+
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`zig build test` compiles tests but may not run them if your build.zig doesn't wire it up correctly. to actually run tests:
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```bash
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zig test src/foo.zig # runs tests in foo.zig and its imports
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zig test src/foo.zig --test-filter "parse" # only tests matching "parse"
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```
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+
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the testing allocator catches leaks. if you use `parseFromValueLeaky` or similar "leaky" apis, wrap in an arena:
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+
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```zig
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var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
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defer arena.deinit();
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const result = try leakyFunction(arena.allocator(), input);
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```
+2
-1
languages/ziglang/README.md
+2
-1
languages/ziglang/README.md
···
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4
5
5
## topics
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6
7
-
- [0.15](./0.15/) - version-specific patterns (i/o overhaul, arraylist, concurrency)
7
+
- [0.15](./0.15/) - version-specific patterns (i/o, arraylist, crypto, testing)
8
8
- [build](./build/) - build system patterns from large projects
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9
10
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## sources
···
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17
| [find-bufo](https://tangled.sh/@zzstoatzz.io/find-bufo) | bluesky bot |
18
18
| [leaflet-search](https://tangled.sh/@zzstoatzz.io/leaflet-search) | fts search backend |
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19
| [zql](https://tangled.sh/@zzstoatzz.io/zql) | comptime sql parsing |
20
+
| [zat](https://tangled.sh/@zzstoatzz.io/zat) | atproto primitives (jwt, crypto) |
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21
| [ghostty](https://github.com/ghostty-org/ghostty) | terminal emulator (build system) |
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| [bun](https://github.com/oven-sh/bun) | javascript runtime (build system) |
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