fix: base64url encoding / decoding isn't always available

Signed-off-by: Tom Lanser <[email protected]>
openwallet-foundation-labs · Nov 21, 2024 · beb95bc · beb95bc
1 parent 9757fbd
commit beb95bc
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Showing 6 changed files with 17 additions and 11 deletions.
diff --git a/packages/core/src/jsonWeb/createJsonWebToken.ts b/packages/core/src/jsonWeb/createJsonWebToken.ts
@@ -1,4 +1,5 @@
 import { Buffer } from 'buffer'
+import { base64ToBase64URL } from '../utils/encoding'
 
 /**
  *
@@ -10,10 +11,10 @@ export const createJsonWebToken = (
   payload: Record<string, unknown>,
   signature: Uint8Array
 ) => {
-  const encodedHeader = Buffer.from(JSON.stringify(header)).toString('base64url')
-  const encodedPayload = Buffer.from(JSON.stringify(payload)).toString('base64url')
+  const encodedHeader = base64ToBase64URL(Buffer.from(JSON.stringify(header)).toString('base64'))
+  const encodedPayload = base64ToBase64URL(Buffer.from(JSON.stringify(payload)).toString('base64'))
 
-  const encodedSignature = Buffer.from(signature).toString('base64url')
+  const encodedSignature = base64ToBase64URL(Buffer.from(signature).toString('base64'))
 
   return `${encodedHeader}.${encodedPayload}.${encodedSignature}`
 }
diff --git a/packages/core/src/jsonWeb/createJsonWebTokenSignableInput.ts b/packages/core/src/jsonWeb/createJsonWebTokenSignableInput.ts
@@ -1,4 +1,5 @@
 import { Buffer } from 'buffer'
+import { base64ToBase64URL } from '../utils/encoding'
 
 /**
  *
@@ -14,8 +15,8 @@ export const createJwtSignableInput = (header: Record<string, unknown>, payload:
     throw new Error('Can not create JWT with an empty payload')
   }
 
-  const encodedHeader = Buffer.from(JSON.stringify(header)).toString('base64url')
-  const encodedPayload = Buffer.from(JSON.stringify(payload)).toString('base64url')
+  const encodedHeader = base64ToBase64URL(Buffer.from(JSON.stringify(header)).toString('base64'))
+  const encodedPayload = base64ToBase64URL(Buffer.from(JSON.stringify(payload)).toString('base64'))
 
   const toBeSignedString = `${encodedHeader}.${encodedPayload}`
 

diff --git a/packages/core/src/jsonWeb/jsonWebToken.ts b/packages/core/src/jsonWeb/jsonWebToken.ts
@@ -52,9 +52,9 @@ export const jsonWebTokenSchema = <
       return z.NEVER
     }
 
-    const decodedHeader = Buffer.from(header, 'base64url').toString()
-    const decodedClaims = Buffer.from(claims, 'base64url').toString()
-    const decodedSignature = Buffer.from(signature, 'base64url')
+    const decodedHeader = Buffer.from(header, 'base64').toString()
+    const decodedClaims = Buffer.from(claims, 'base64').toString()
+    const decodedSignature = Buffer.from(signature, 'base64')
 
     const validatedHeader = validate({
       schema: headerSchema,

diff --git a/packages/core/src/jsonWeb/parseJsonWebToken.ts b/packages/core/src/jsonWeb/parseJsonWebToken.ts
@@ -22,9 +22,9 @@ export const parseJsonWebToken = (jwt: string): JsonWebTokenParts => {
     throw new Error('could not find the signature in the JWT')
   }
 
-  const header = JSON.parse(Buffer.from(encodedHeader, 'base64url').toString())
-  const claims = JSON.parse(Buffer.from(encodedClaims, 'base64url').toString())
-  const signature = new Uint8Array(Buffer.from(encodedSignature, 'base64url'))
+  const header = JSON.parse(Buffer.from(encodedHeader, 'base64').toString())
+  const claims = JSON.parse(Buffer.from(encodedClaims, 'base64').toString())
+  const signature = new Uint8Array(Buffer.from(encodedSignature, 'base64'))
 
   return {
     header,

diff --git a/packages/core/src/utils/encoding.ts b/packages/core/src/utils/encoding.ts
@@ -0,0 +1,3 @@
+export function base64ToBase64URL(base64: string) {
+  return base64.replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '')
+}
diff --git a/packages/core/src/utils/index.ts b/packages/core/src/utils/index.ts
@@ -2,3 +2,4 @@ export * from './dateSchema'
 export * from './url'
 export * from './fetch'
 export * from './types'
+export * from './encoding'