Add signature basics

Add a way to sign and verify keys. Still need to figure out the
keyserver situation and how to make that shit work

Cargo.lock

@@ -8,6 +8,18 @@ version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 
+[[package]]
+name = "autocfg"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
+
+[[package]]
+name = "base64ct"
+version = "1.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2af50177e190e07a26ab74f8b1efbfe2ef87da2116221318cb1c2e82baf7de06"
+
 [[package]]
 name = "bitflags"
 version = "2.11.1"
@@ -26,6 +38,22 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "const-oid"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
+
+[[package]]
+name = "der"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
+dependencies = [
+ "const-oid",
+ "zeroize",
+]
+
 [[package]]
 name = "deranged"
 version = "0.5.8"
@@ -36,6 +64,16 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "ed25519"
+version = "2.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "115531babc129696a58c64a4fef0a8bf9e9698629fb97e9e40767d235cfbcd53"
+dependencies = [
+ "pkcs8",
+ "signature",
+]
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -46,8 +84,11 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 name = "fedichat"
 version = "0.1.0"
 dependencies = [
+ "ed25519",
+ "rmp-serde",
  "serde",
  "serde_bytes",
+ "thiserror",
  "time",
  "uuid",
 ]
@@ -82,6 +123,17 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.4.2"
@@ -182,6 +234,15 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6673768db2d862beb9b39a78fdcb1a69439615d5794a1be50caa9bc92c81967"
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.4"
@@ -194,6 +255,16 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 
+[[package]]
+name = "pkcs8"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
+dependencies = [
+ "der",
+ "spki",
+]
+
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -234,6 +305,34 @@ version = "6.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom 0.2.17",
+]
+
+[[package]]
+name = "rmp"
+version = "0.8.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ba8be72d372b2c9b35542551678538b562e7cf86c3315773cae48dfbfe7790c"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72f81bee8c8ef9b577d1681a70ebbc962c232461e397b22c208c43c04b67a155"
+dependencies = [
+ "rmp",
+ "serde",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.22"
@@ -299,12 +398,31 @@ dependencies = [
  "zmij",
 ]
 
+[[package]]
+name = "signature"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
+dependencies = [
+ "rand_core",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c790de23124f9ab44544d7ac05d60440adc586479ce501c1d6d7da3cd8c9cf5"
 
+[[package]]
+name = "spki"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
+dependencies = [
+ "base64ct",
+ "der",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.117"
@@ -316,6 +434,26 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "thiserror"
+version = "2.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4288b5bcbc7920c07a1149a35cf9590a2aa808e0bc1eafaade0b80947865fbc4"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "2.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebc4ee7f67670e9b64d05fa4253e753e016c6c95ff35b89b7941d6b856dec1d5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "time"
 version = "0.3.47"
@@ -364,12 +502,18 @@ version = "1.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ddd74a9687298c6858e9b88ec8935ec45d22e8fd5e6394fa1bd4e99a87789c76"
 dependencies = [
- "getrandom",
+ "getrandom 0.4.2",
  "js-sys",
  "serde_core",
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
 [[package]]
 name = "wasip2"
 version = "1.0.3+wasi-0.2.9"
@@ -561,6 +705,12 @@ dependencies = [
  "wasmparser",
 ]
 
+[[package]]
+name = "zeroize"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
+
 [[package]]
 name = "zmij"
 version = "1.0.21"

Cargo.toml

@@ -4,8 +4,12 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+# This is kinda an old version but the dalek side of v3 is still in prerelease
+ed25519 = "2.2.3"
+rmp-serde = "1.3.1"
 serde = { version = "1.0", features = ["derive"] } 
 serde_bytes = "0.11.19"
+thiserror = "2.0.18"
 time = {version = "0.3.47", features = ["serde"]}
 
 [dependencies.uuid]

src/client.rs

@@ -1,9 +1,13 @@
 use uuid::Uuid;
-use crate::message::{MessageId,TaggedMessage,VerificationError,Relevance};
+use crate::message::{MessageId,TaggedMessage,Relevance};
 use crate::state::{self,StateValue,StatePath,StatePermission,StatePermissionKey};
 use crate::{RoomId,Group,Role,User,GroupPower,ServerAddr};
+use ed25519::signature::{Signer,Verifier};
+use ed25519::Signature;
+use rmp_serde::encode::Serializer;
 use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
+use thiserror::Error;
 
 //StatePath [String]
 //octal is fine for now
@@ -61,9 +65,38 @@ impl SignedClientMessage {
             target: self.target.unwrap_or(servername)
         }
     }
-    pub fn verify(&self) -> Result<bool,VerificationError> {
+    // Canonical way to sign messages. Glue the message, target, and timestamp together. Serialize
-        unimplemented!()
+    // them, then sign those bytes. It is slightly ambiguous how target=None messages should
+    // by signed vs target=Some(local_server) especially if rewriting of the target happens.
+    // This makes signature verification harder as you would have to check both
+    // cases to see if either correctly verifies.
+    pub fn sign<S: Signer<ed25519::Signature>>(&mut self, signer: S) -> Result<(),SignatureError> {
+
+        let mut bytes = Vec::new();
+        (&self.message,&self.target,&self.timestamp).serialize(&mut Serializer::new(&mut bytes).with_struct_map())?;
+        let result = signer.try_sign(&bytes)?;
+                
+
+        self.signature = Box::new(result.to_bytes());
+        Ok(())
     }
+    pub fn verify<V: Verifier<ed25519::Signature>>(&self, verifier: V) -> Result<(),SignatureError> {
+
+        let mut bytes = Vec::new();
+        (&self.message,&self.target,&self.timestamp).serialize(&mut Serializer::new(&mut bytes).with_struct_map())?;
+        
+
+        let sig = Signature::from_slice(&self.signature)?;
+        Ok(verifier.verify(&bytes,&sig)?)
+    }
+}
+
+#[derive(Debug,Error)]
+pub enum SignatureError {
+    #[error("Problem while making eliptic curve {0}")]
+    Ed25519(#[from] ed25519::Error),
+    #[error("Serialization error: {0}")]
+    Serialization(#[from] rmp_serde::encode::Error),
 }
 #[derive(Serialize,Deserialize,Clone,Debug)]
 pub enum AuthMethod {