update base64 implementation to newer crate (#7739)

# Description

This PR updates the base64 crate, which has changed significantly, so
all the base64 implementations had to be changed too. Tests pass. I hope
that's enough.

# User-Facing Changes

None, except added a new character encoding imap-mutf7 as mutf7.

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/src/network/fetch.rs

@@ -1,19 +1,16 @@
-use base64::encode;
+use base64::{alphabet, engine::general_purpose::PAD, engine::GeneralPurpose, Engine};
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::util::BufferedReader;
 use nu_protocol::RawStream;
-
 use nu_protocol::{
     Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use reqwest::blocking::Response;
-
+use reqwest::StatusCode;
 use std::collections::HashMap;
 use std::io::BufReader;
-
-use reqwest::StatusCode;
 use std::path::PathBuf;
 use std::str::FromStr;
 use std::time::Duration;
@@ -165,10 +162,24 @@ fn helper(
     let timeout = args.timeout;
     let headers = args.headers;
     let raw = args.raw;
+    let base64_engine = GeneralPurpose::new(&alphabet::STANDARD, PAD);
+
     let login = match (user, password) {
-        (Some(user), Some(password)) => Some(encode(format!("{}:{}", user, password))),
-        (Some(user), _) => Some(encode(format!("{}:", user))),
-        (_, Some(password)) => Some(encode(format!(":{}", password))),
+        (Some(user), Some(password)) => {
+            let mut enc_str = String::new();
+            base64_engine.encode_string(&format!("{}:{}", user, password), &mut enc_str);
+            Some(enc_str)
+        }
+        (Some(user), _) => {
+            let mut enc_str = String::new();
+            base64_engine.encode_string(&format!("{}:", user), &mut enc_str);
+            Some(enc_str)
+        }
+        (_, Some(password)) => {
+            let mut enc_str = String::new();
+            base64_engine.encode_string(&format!(":{}", password), &mut enc_str);
+            Some(enc_str)
+        }
         _ => None,
     };
 

crates/nu-command/src/network/post.rs

@@ -1,19 +1,18 @@
 use crate::formats::value_to_json_value;
-use base64::encode;
+use base64::{alphabet, engine::general_purpose::PAD, engine::GeneralPurpose, Engine};
 use nu_engine::CallExt;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::util::BufferedReader;
 use nu_protocol::RawStream;
-use reqwest::{blocking::Response, StatusCode};
-use std::path::PathBuf;
-use std::str::FromStr;
-
 use nu_protocol::{
     Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
+use reqwest::{blocking::Response, StatusCode};
 use std::collections::HashMap;
 use std::io::BufReader;
+use std::path::PathBuf;
+use std::str::FromStr;
 
 #[derive(Clone)]
 pub struct SubCommand;
@@ -186,9 +185,19 @@ fn helper(
     let headers = args.headers;
     let location = url;
     let raw = args.raw;
+    let base64_engine = GeneralPurpose::new(&alphabet::STANDARD, PAD);
+
     let login = match (user, password) {
-        (Some(user), Some(password)) => Some(encode(&format!("{}:{}", user, password))),
-        (Some(user), _) => Some(encode(&format!("{}:", user))),
+        (Some(user), Some(password)) => {
+            let mut enc_str = String::new();
+            base64_engine.encode_string(&format!("{}:{}", user, password), &mut enc_str);
+            Some(enc_str)
+        }
+        (Some(user), _) => {
+            let mut enc_str = String::new();
+            base64_engine.encode_string(&format!("{}:", user), &mut enc_str);
+            Some(enc_str)
+        }
         _ => None,
     };