Add key_gen_type config option

deltachat-ffi/deltachat.h

@@ -364,6 +364,12 @@ char*           dc_get_blobdir               (const dc_context_t* context);
  *                    also show all mails of confirmed contacts,
  *                    DC_SHOW_EMAILS_ALL (2)=
  *                    also show mails of unconfirmed contacts in the deaddrop.
+ * - `key_gen_type` = DC_KEY_GEN_DEFAULT (0)=
+ *                    generate recommended key type (default),
+ *                    DC_KEY_GEN_RSA2048 (1)=
+ *                    generate RSA 2048 keypair
+ *                    DC_KEY_GEN_ED25519 (2)=
+ *                    generate Ed25519 keypair
  * - `save_mime_headers` = 1=save mime headers
  *                    and make dc_get_mime_headers() work for subsequent calls,
  *                    0=do not save mime headers (default)
@@ -4529,6 +4535,13 @@ void            dc_array_add_id              (dc_array_t*, uint32_t); // depreca
 #define DC_SHOW_EMAILS_ACCEPTED_CONTACTS 1
 #define DC_SHOW_EMAILS_ALL               2
 
+/*
+ * Values for dc_get|set_config("key_gen_type")
+ */
+#define DC_KEY_GEN_DEFAULT 0
+#define DC_KEY_GEN_RSA2048 1
+#define DC_KEY_GEN_ED25519 2
+
 
 /**
  * @defgroup DC_PROVIDER_STATUS DC_PROVIDER_STATUS

python/src/deltachat/const.py

@@ -103,6 +103,9 @@ DC_EVENT_FILE_COPIED = 2055
 DC_EVENT_IS_OFFLINE = 2081
 DC_EVENT_GET_STRING = 2091
 DC_STR_SELFNOTINGRP = 21
+DC_KEY_GEN_DEFAULT = 0
+DC_KEY_GEN_RSA2048 = 1
+DC_KEY_GEN_ED25519 = 2
 DC_PROVIDER_STATUS_OK = 1
 DC_PROVIDER_STATUS_PREPARATION = 2
 DC_PROVIDER_STATUS_BROKEN = 3
@@ -161,7 +164,7 @@ DC_STR_COUNT = 68
 
 def read_event_defines(f):
     rex = re.compile(r'#define\s+((?:DC_EVENT|DC_QR|DC_MSG|DC_LP|DC_EMPTY|DC_CERTCK|DC_STATE|DC_STR|'
-                     r'DC_CONTACT_ID|DC_GCL|DC_CHAT|DC_PROVIDER)_\S+)\s+([x\d]+).*')
+                     r'DC_CONTACT_ID|DC_GCL|DC_CHAT|DC_PROVIDER|DC_KEY_GEN)_\S+)\s+([x\d]+).*')
     for line in f:
         m = rex.match(line)
         if m:

src/config.rs

@@ -62,6 +62,9 @@ pub enum Config {
     #[strum(props(default = "0"))] // also change ShowEmails.default() on changes
     ShowEmails,
 
+    #[strum(props(default = "0"))]
+    KeyGenType,
+
     SaveMimeHeaders,
     ConfiguredAddr,
     ConfiguredMailServer,

src/constants.rs

@@ -57,6 +57,20 @@ impl Default for ShowEmails {
     }
 }
 
+#[derive(Debug, Display, Clone, Copy, PartialEq, Eq, FromPrimitive, ToPrimitive, FromSql, ToSql)]
+#[repr(u8)]
+pub enum KeyGenType {
+    Default = 0,
+    Rsa2048 = 1,
+    Ed25519 = 2,
+}
+
+impl Default for KeyGenType {
+    fn default() -> Self {
+        KeyGenType::Default
+    }
+}
+
 pub const DC_HANDSHAKE_CONTINUE_NORMAL_PROCESSING: i32 = 0x01;
 pub const DC_HANDSHAKE_STOP_NORMAL_PROCESSING: i32 = 0x02;
 pub const DC_HANDSHAKE_ADD_DELETE_JOB: i32 = 0x04;

src/e2ee.rs

@@ -8,6 +8,7 @@ use num_traits::FromPrimitive;
 
 use crate::aheader::*;
 use crate::config::Config;
+use crate::constants::KeyGenType;
 use crate::context::Context;
 use crate::dc_tools::EmailAddress;
 use crate::error::*;
@@ -211,11 +212,11 @@ fn load_or_generate_self_public_key(
     }
 
     let start = std::time::Instant::now();
-    info!(
-        context,
-        "Generating keypair with {} bits, e={} ...", 2048, 65537,
-    );
-    let keypair = pgp::create_keypair(EmailAddress::new(self_addr.as_ref())?)?;
+
+    let keygen_type =
+        KeyGenType::from_i32(context.get_config_int(Config::KeyGenType)).unwrap_or_default();
+    info!(context, "Generating keypair with type {}", keygen_type);
+    let keypair = pgp::create_keypair(EmailAddress::new(self_addr.as_ref())?, keygen_type)?;
     key::store_self_keypair(context, &keypair, KeyPairUse::Default)?;
     info!(
         context,

src/pgp.rs

@@ -16,6 +16,7 @@ use pgp::types::{
 };
 use rand::{thread_rng, CryptoRng, Rng};
 
+use crate::constants::KeyGenType;
 use crate::dc_tools::EmailAddress;
 use crate::error::Result;
 use crate::key::*;
@@ -147,10 +148,18 @@ pub struct KeyPair {
 }
 
 /// Create a new key pair.
-pub(crate) fn create_keypair(addr: EmailAddress) -> std::result::Result<KeyPair, PgpKeygenError> {
+pub(crate) fn create_keypair(
+    addr: EmailAddress,
+    keygen_type: KeyGenType,
+) -> std::result::Result<KeyPair, PgpKeygenError> {
+    let (secret_key_type, public_key_type) = match keygen_type {
+        KeyGenType::Rsa2048 => (PgpKeyType::Rsa(2048), PgpKeyType::Rsa(2048)),
+        KeyGenType::Ed25519 | KeyGenType::Default => (PgpKeyType::EdDSA, PgpKeyType::ECDH),
+    };
+
     let user_id = format!("<{}>", addr);
     let key_params = SecretKeyParamsBuilder::default()
-        .key_type(PgpKeyType::EdDSA)
+        .key_type(secret_key_type)
         .can_create_certificates(true)
         .can_sign(true)
         .primary_user_id(user_id)
@@ -173,7 +182,7 @@ pub(crate) fn create_keypair(addr: EmailAddress) -> std::result::Result<KeyPair,
         ])
         .subkey(
             SubkeyParamsBuilder::default()
-                .key_type(PgpKeyType::ECDH)
+                .key_type(public_key_type)
                 .can_encrypt(true)
                 .passphrase(None)
                 .build()
@@ -387,8 +396,16 @@ mod tests {
     #[test]
     #[ignore] // is too expensive
     fn test_create_keypair() {
-        let keypair0 = create_keypair(EmailAddress::new("foo@bar.de").unwrap()).unwrap();
-        let keypair1 = create_keypair(EmailAddress::new("two@zwo.de").unwrap()).unwrap();
+        let keypair0 = create_keypair(
+            EmailAddress::new("foo@bar.de").unwrap(),
+            KeyGenType::Default,
+        )
+        .unwrap();
+        let keypair1 = create_keypair(
+            EmailAddress::new("two@zwo.de").unwrap(),
+            KeyGenType::Default,
+        )
+        .unwrap();
         assert_ne!(keypair0.public, keypair1.public);
     }