refactor(crypto): remove circular dependency

bluesky-social · Dec 8, 2023 · 9917a4f · 9917a4f
1 parent 842e183
commit 9917a4f
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Showing 4 changed files with 48 additions and 28 deletions.
diff --git a/packages/crypto/src/did.ts b/packages/crypto/src/did.ts
@@ -1,27 +1,23 @@
 import * as uint8arrays from 'uint8arrays'
-import * as p256 from './p256/encoding'
-import * as secp from './secp256k1/encoding'
-import plugins from './plugins'
+
 import {
   BASE58_MULTIBASE_PREFIX,
   DID_KEY_PREFIX,
   P256_JWT_ALG,
   SECP256K1_JWT_ALG,
 } from './const'
+import * as p256 from './p256/encoding'
+import plugins from './plugins'
+import * as secp from './secp256k1/encoding'
+import { extractMultikey, extractPrefixedBytes, hasPrefix } from './utils'
 
 export type ParsedMultikey = {
   jwtAlg: string
   keyBytes: Uint8Array
 }
 
 export const parseMultikey = (multikey: string): ParsedMultikey => {
-  if (!multikey.startsWith(BASE58_MULTIBASE_PREFIX)) {
-    throw new Error(`Incorrect prefix for multikey: ${multikey}`)
-  }
-  const prefixedBytes = uint8arrays.fromString(
-    multikey.slice(BASE58_MULTIBASE_PREFIX.length),
-    'base58btc',
-  )
+  const prefixedBytes = extractPrefixedBytes(multikey)
   const plugin = plugins.find((p) => hasPrefix(prefixedBytes, p.prefix))
   if (!plugin) {
     throw new Error('Unsupported key type')
@@ -58,16 +54,10 @@ export const formatMultikey = (
 }
 
 export const parseDidKey = (did: string): ParsedMultikey => {
-  if (!did.startsWith(DID_KEY_PREFIX)) {
-    throw new Error(`Incorrect prefix for did:key: ${did}`)
-  }
-  return parseMultikey(did.slice(DID_KEY_PREFIX.length))
+  const multikey = extractMultikey(did)
+  return parseMultikey(multikey)
 }
 
 export const formatDidKey = (jwtAlg: string, keyBytes: Uint8Array): string => {
   return DID_KEY_PREFIX + formatMultikey(jwtAlg, keyBytes)
 }
-
-const hasPrefix = (bytes: Uint8Array, prefix: Uint8Array): boolean => {
-  return uint8arrays.equals(prefix, bytes.subarray(0, prefix.byteLength))
-}
diff --git a/packages/crypto/src/p256/operations.ts b/packages/crypto/src/p256/operations.ts
@@ -1,20 +1,22 @@
 import { p256 } from '@noble/curves/p256'
 import { sha256 } from '@noble/hashes/sha256'
-import * as ui8 from 'uint8arrays'
-import { P256_JWT_ALG } from '../const'
-import { parseDidKey } from '../did'
+import { equals as ui8equals } from 'uint8arrays'
+
+import { P256_DID_PREFIX } from '../const'
 import { VerifyOptions } from '../types'
+import { extractMultikey, extractPrefixedBytes, hasPrefix } from '../utils'
 
 export const verifyDidSig = async (
   did: string,
   data: Uint8Array,
   sig: Uint8Array,
   opts?: VerifyOptions,
 ): Promise<boolean> => {
-  const { jwtAlg, keyBytes } = parseDidKey(did)
-  if (jwtAlg !== P256_JWT_ALG) {
+  const prefixedBytes = extractPrefixedBytes(extractMultikey(did))
+  if (!hasPrefix(prefixedBytes, P256_DID_PREFIX)) {
     throw new Error(`Not a P-256 did:key: ${did}`)
   }
+  const keyBytes = prefixedBytes.slice(P256_DID_PREFIX.length)
   return verifySig(keyBytes, data, sig, opts)
 }
 
@@ -39,7 +41,7 @@ export const verifySig = async (
 export const isCompactFormat = (sig: Uint8Array) => {
   try {
     const parsed = p256.Signature.fromCompact(sig)
-    return ui8.equals(parsed.toCompactRawBytes(), sig)
+    return ui8equals(parsed.toCompactRawBytes(), sig)
   } catch {
     return false
   }

diff --git a/packages/crypto/src/secp256k1/operations.ts b/packages/crypto/src/secp256k1/operations.ts
@@ -1,20 +1,22 @@
 import { secp256k1 as k256 } from '@noble/curves/secp256k1'
 import { sha256 } from '@noble/hashes/sha256'
 import * as ui8 from 'uint8arrays'
-import { SECP256K1_JWT_ALG } from '../const'
-import { parseDidKey } from '../did'
+
+import { SECP256K1_DID_PREFIX } from '../const'
 import { VerifyOptions } from '../types'
+import { extractMultikey, extractPrefixedBytes, hasPrefix } from '../utils'
 
 export const verifyDidSig = async (
   did: string,
   data: Uint8Array,
   sig: Uint8Array,
   opts?: VerifyOptions,
 ): Promise<boolean> => {
-  const { jwtAlg, keyBytes } = parseDidKey(did)
-  if (jwtAlg !== SECP256K1_JWT_ALG) {
+  const prefixedBytes = extractPrefixedBytes(extractMultikey(did))
+  if (!hasPrefix(prefixedBytes, SECP256K1_DID_PREFIX)) {
     throw new Error(`Not a secp256k1 did:key: ${did}`)
   }
+  const keyBytes = prefixedBytes.slice(SECP256K1_DID_PREFIX.length)
   return verifySig(keyBytes, data, sig, opts)
 }
 

diff --git a/packages/crypto/src/utils.ts b/packages/crypto/src/utils.ts
@@ -0,0 +1,26 @@
+import * as uint8arrays from 'uint8arrays'
+import {
+  BASE58_MULTIBASE_PREFIX,
+  DID_KEY_PREFIX
+} from './const'
+
+export const extractMultikey = (did: string): string => {
+  if (!did.startsWith(DID_KEY_PREFIX)) {
+    throw new Error(`Incorrect prefix for did:key: ${did}`)
+  }
+  return did.slice(DID_KEY_PREFIX.length)
+}
+
+export const extractPrefixedBytes = (multikey: string): Uint8Array => {
+  if (!multikey.startsWith(BASE58_MULTIBASE_PREFIX)) {
+    throw new Error(`Incorrect prefix for multikey: ${multikey}`)
+  }
+  return uint8arrays.fromString(
+    multikey.slice(BASE58_MULTIBASE_PREFIX.length),
+    'base58btc',
+  )
+}
+
+export const hasPrefix = (bytes: Uint8Array, prefix: Uint8Array): boolean => {
+  return uint8arrays.equals(prefix, bytes.subarray(0, prefix.byteLength))
+}