Update the android keystore attestation encoding format

Author: QZHelen

app/src/main/java/com/credman/cmwallet/Utils.kt

@@ -106,6 +106,11 @@ fun ByteArray.toBase64UrlNoPadding(): String {
     return Base64.UrlSafe.withPadding(Base64.PaddingOption.ABSENT).encode(this)
 }
 
+@OptIn(ExperimentalEncodingApi::class)
+fun ByteArray.toBase64NoPadding(): String {
+    return Base64.Default.withPadding(Base64.PaddingOption.ABSENT).encode(this)
+}
+
 @OptIn(ExperimentalEncodingApi::class)
 fun String.decodeBase64UrlNoPadding(): ByteArray {
     return Base64.UrlSafe.withPadding(kotlin.io.encoding.Base64.PaddingOption.ABSENT).decode(this)

app/src/main/java/com/credman/cmwallet/openid4vci/OpenId4VCI.kt

@@ -21,6 +21,7 @@ import com.credman.cmwallet.openid4vci.data.ParResponse
 import com.credman.cmwallet.openid4vci.data.Proofs
 import com.credman.cmwallet.openid4vci.data.TokenRequest
 import com.credman.cmwallet.openid4vci.data.TokenResponse
+import com.credman.cmwallet.toBase64NoPadding
 import com.credman.cmwallet.toBase64UrlNoPadding
 import com.credman.cmwallet.toJWK
 import io.ktor.client.HttpClient
@@ -423,7 +424,7 @@ class OpenId4VCI(val credentialOfferJson: String) {
         return Pair(
             first = Proofs(
                 androidKeystoreAttestation = certificates.map { certificateArray ->
-                    certificateArray.map { certificate -> certificate.encoded.toBase64UrlNoPadding() }
+                    certificateArray.map { certificate -> certificate.encoded.toBase64NoPadding() }
                 }
             ),
             second = deviceKeys