From 9761e0e66467a77628f4db9c4b15dd35a9ce3a6b Mon Sep 17 00:00:00 2001
From: Heiko Schaefer <heiko@schaefer.name>
Date: Tue, 29 Aug 2023 15:07:31 +0200
Subject: [PATCH] openpgp-card: internal API cleanup, continued

---
 openpgp-card/src/algorithm.rs | 19 ++++++++++---------
 openpgp-card/src/lib.rs       |  9 +++------
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/openpgp-card/src/algorithm.rs b/openpgp-card/src/algorithm.rs
index 590723d..9be5a35 100644
--- a/openpgp-card/src/algorithm.rs
+++ b/openpgp-card/src/algorithm.rs
@@ -12,7 +12,6 @@
 use std::convert::TryFrom;
 use std::fmt;
 
-use crate::card_do::ApplicationRelatedData;
 use crate::crypto_data::EccType;
 use crate::{keys, oid, Error, KeyType};
 
@@ -77,38 +76,40 @@ impl AlgoSimple {
 
     /// Return the appropriate Algo for this AlgoSimple.
     ///
-    /// This mapping differs between cards, based on `ard` and `algo_info`
-    /// (e.g. the exact Algo variant can have a different size for e, in RSA;
-    /// also, the import_format can differ).
+    /// This mapping depends on the actual card in use
+    /// (e.g.: the size of "e", in RSA can differ;
+    /// or a different `import_format` can be selected).
+    ///
+    /// These card-specific settings are derived from `algorithm_attributes` and `algo_info`.
     pub(crate) fn determine_algo_attributes(
         &self,
         key_type: KeyType,
-        ard: &ApplicationRelatedData,
+        algorithm_attributes: AlgorithmAttributes,
         algo_info: Option<AlgoInfo>,
     ) -> Result<AlgorithmAttributes, Error> {
         let algo = match self {
             Self::RSA1k => AlgorithmAttributes::Rsa(keys::determine_rsa_attrs(
                 1024,
                 key_type,
-                ard.algorithm_attributes(key_type)?,
+                algorithm_attributes,
                 algo_info,
             )?),
             Self::RSA2k => AlgorithmAttributes::Rsa(keys::determine_rsa_attrs(
                 2048,
                 key_type,
-                ard.algorithm_attributes(key_type)?,
+                algorithm_attributes,
                 algo_info,
             )?),
             Self::RSA3k => AlgorithmAttributes::Rsa(keys::determine_rsa_attrs(
                 3072,
                 key_type,
-                ard.algorithm_attributes(key_type)?,
+                algorithm_attributes,
                 algo_info,
             )?),
             Self::RSA4k => AlgorithmAttributes::Rsa(keys::determine_rsa_attrs(
                 4096,
                 key_type,
-                ard.algorithm_attributes(key_type)?,
+                algorithm_attributes,
                 algo_info,
             )?),
             Self::NIST256 => AlgorithmAttributes::Ecc(keys::determine_ecc_attrs(
diff --git a/openpgp-card/src/lib.rs b/openpgp-card/src/lib.rs
index 9a84926..fcb3844 100644
--- a/openpgp-card/src/lib.rs
+++ b/openpgp-card/src/lib.rs
@@ -1242,14 +1242,11 @@ impl<'a> Transaction<'a> {
         simple: AlgoSimple,
     ) -> Result<(PublicKeyMaterial, KeyGenerationTime), Error> {
         let ard = self.application_related_data()?;
-        let algo_info = if let Ok(ai) = self.algorithm_information() {
-            ai
-        } else {
-            None
-        };
+        let algorithm_attributes = ard.algorithm_attributes(key_type)?;
 
-        let algo = simple.determine_algo_attributes(key_type, &ard, algo_info)?;
+        let algo_info = self.algorithm_information().ok().flatten();
 
+        let algo = simple.determine_algo_attributes(key_type, algorithm_attributes, algo_info)?;
         Self::generate_key(self, fp_from_pub, key_type, Some(&algo))
     }