Introduce support for user-provided extensions

This change introduces support for discovering and executing
user-provided extensions to the program. Extensions are useful for
allowing users to provide additional functionality on top of the
nitrocli proper. Implementation wise we stick to an approach similar to
git or cargo subcommands in nature: we find executables in the PATH
environment variable whose file name starts with "nitrocli-" and allow
for them to be invoked as a nitrocli command.

1 files changed, 104 insertions, 0 deletions

diff --git a/nitrocli/Cargo.lock b/nitrocli/Cargo.lock
index 45f8090..9ae9299 100644
--- a/nitrocli/Cargo.lock
+++ b/nitrocli/Cargo.lock
@@ -22,6 +22,15 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "c2-chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 1.2.0",
+ "ppv-lite86 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "cc"
 version = "1.0.40"
 
@@ -53,6 +62,16 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "getrandom"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62",
+ "wasi 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "lazy_static"
 version = "1.2.0"
 
@@ -80,6 +99,7 @@ dependencies = [
  "nitrokey-test 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "nitrokey-test-state 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -116,6 +136,11 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "ppv-lite86"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "proc-macro2"
 version = "0.4.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -132,10 +157,47 @@ dependencies = [
 ]
 
 [[package]]
+name = "rand"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "getrandom 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62",
+ "rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "c2-chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "rand_core"
 version = "0.3.0"
 
 [[package]]
+name = "rand_core"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "getrandom 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "rand_os"
 version = "0.1.1"
 dependencies = [
@@ -156,6 +218,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "redox_syscall"
+version = "0.1.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "regex"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -176,6 +243,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "remove_dir_all"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "syn"
 version = "0.15.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -186,6 +261,19 @@ dependencies = [
 ]
 
 [[package]]
+name = "tempfile"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.62",
+ "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "thread_local"
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -209,6 +297,11 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "wasi"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "winapi"
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -230,23 +323,34 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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+"checksum c2-chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7d64d04786e0f528460fc884753cf8dddcc466be308f6026f8e355c41a0e4101"
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