Updater

- The updater looks for updates to certificates from the certificate
  store.
- The updates are spaced by random time intervals so that the
  reconstruction of the content of the cert store is made more
  difficult.
- The updater can be send into the background - start, stop and status
  are implemented.
- The state of the updater is persisted to disk so that the update
  procedure survives a restart.

Cargo.lock

@@ -99,7 +99,7 @@ checksum = "3c3610892ee6e0cbce8ae2700349fcf8f98adb0dbfbee85aec3c9179d29cc072"
 dependencies = [
  "base64ct",
  "blake2",
- "cpufeatures",
+ "cpufeatures 0.2.17",
  "password-hash",
 ]
 
@@ -333,6 +333,17 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "chacha20"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d524456ba66e72eb8b115ff89e01e497f8e6d11d78b70b1aa13c0fbd97540a81"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.0",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.45"
@@ -447,6 +458,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "cpufeatures"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b2a41393f66f16b0823bb79094d54ac5fbd34ab292ddafb9a0456ac9f87d201"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -1055,6 +1075,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "r-efi 6.0.0",
+ "rand_core 0.10.1",
 ]
 
 [[package]]
@@ -1270,6 +1291,7 @@ dependencies = [
  "lettre",
  "log",
  "log4rs",
+ "rand 0.10.2",
  "sequoia-cert-store",
  "sequoia-directories",
  "sequoia-keystore",
@@ -1614,7 +1636,7 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb26cec98cce3a3d96cbb7bced3c4b16e3d13f27ec56dbd62cbc8f39cfb9d653"
 dependencies = [
- "cpufeatures",
+ "cpufeatures 0.2.17",
 ]
 
 [[package]]
@@ -2290,6 +2312,17 @@ dependencies = [
  "rand_core 0.9.5",
 ]
 
+[[package]]
+name = "rand"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7f5fa3a058cd35567ef9bfa5e75732bee0f9e4c55fa90477bef2dfcdbc4be80"
+dependencies = [
+ "chacha20",
+ "getrandom 0.4.3",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.3.1"
@@ -2328,6 +2361,12 @@ dependencies = [
  "getrandom 0.3.4",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
 [[package]]
 name = "rayon"
 version = "1.12.0"
@@ -2940,7 +2979,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
 dependencies = [
  "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.17",
  "digest",
 ]