Support memorable passwords (#571)

* Improve password generator API.

* Move ChangePassword to vault module.

* feat: implement memorable password generator

* feat: Add logging to memorable password generation test

* feat: update `generate_memorable_password` to include uppercase and numeric characters

* feat: update memorable password function to allow digit on either side of hyphen or as last character

* feat: Implement memorable password generation

* fix: Resolve moved compiler errors in memorable password test spec

* feat: Add digit check to memorable password generation

* feat: Update memorable password function

* feat: create syllables by placing vowels between consonants

* fix: Update memorable_password function and test case to ensure consonant at index 4

* Rewrite memorable password function manually.

* Add memorable passwords to the builder.

* Fix bug with hard-coded syllables length.

Author: tmpfs

crates/sdk/src/account/account.rs

@@ -1032,7 +1032,7 @@ impl LocalAccount {
         vault_id: &VaultId,
         new_key: AccessKey,
     ) -> Result<Vec<u8>> {
-        use crate::passwd::ChangePassword;
+        use crate::vault::ChangePassword;
         let paths = self.paths().clone();
         // Get the current vault passphrase from the identity vault
         let current_key = self

crates/sdk/src/passwd/diceware.rs

@@ -0,0 +1,53 @@
+//! Helper functions for generating diceware passwords.
+use crate::{Error, Result};
+use chbs::{
+    config::{BasicConfig, BasicConfigBuilder},
+    prelude::*,
+    probability::Probability,
+    word::{WordList, WordSampler},
+};
+use secrecy::{Secret, SecretString};
+
+use once_cell::sync::Lazy;
+
+static WORD_LIST: Lazy<WordList> = Lazy::new(WordList::builtin_eff_large);
+
+/// Generate a passphrase using the given config.
+pub fn generate_passphrase_config(
+    config: &BasicConfig<WordSampler>,
+) -> Result<(SecretString, f64)> {
+    if config.words < 6 {
+        return Err(Error::DicewareWordsTooFew(config.words, 6));
+    }
+
+    let scheme = config.to_scheme();
+    Ok((Secret::new(scheme.generate()), scheme.entropy().bits()))
+}
+
+/// Generate a diceware passphrase with the given number of words.
+///
+/// The number of words must be at least six.
+pub fn generate_passphrase_words(
+    words: usize,
+) -> Result<(SecretString, f64)> {
+    let config = default_config(words);
+    generate_passphrase_config(&config)
+}
+
+/// Generate a diceware passphrase with six words which is ~171 bits of entropy.
+pub fn generate_passphrase() -> Result<(SecretString, f64)> {
+    generate_passphrase_words(6)
+}
+
+/// Get the default config for diceware passphrase generation.
+pub fn default_config(words: usize) -> BasicConfig<WordSampler> {
+    let config = BasicConfigBuilder::default()
+        .word_provider(WORD_LIST.sampler())
+        .words(words)
+        .separator(' ')
+        .capitalize_first(Probability::Never)
+        .capitalize_words(Probability::Never)
+        .build()
+        .unwrap();
+    config
+}