openpgp: Implement FromStr for some types.

  - This implements std::str::FromStr for types that have
    string-representations and are reasonably likely to be encountered
    by downstream users, e.g. fingerprints or messages.  This allows
    us to do `"xxx".parse()?`.

  - Fixes #320.

6 files changed, 48 insertions, 0 deletions

diff --git a/openpgp/src/crypto/keygrip.rs b/openpgp/src/crypto/keygrip.rs
index 9bf4bf5b..66240b92 100644
--- a/openpgp/src/crypto/keygrip.rs
+++ b/openpgp/src/crypto/keygrip.rs
@@ -29,6 +29,14 @@ impl fmt::Display for Keygrip {
     }
 }
 
+impl std::str::FromStr for Keygrip {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_hex(s)
+    }
+}
+
 impl Keygrip {
     /// Parses a keygrip.
     pub fn from_hex(hex: &str) -> Result<Self> {
diff --git a/openpgp/src/fingerprint.rs b/openpgp/src/fingerprint.rs
index 9c4a57cf..a12ec118 100644
--- a/openpgp/src/fingerprint.rs
+++ b/openpgp/src/fingerprint.rs
@@ -18,6 +18,14 @@ impl fmt::Debug for Fingerprint {
     }
 }
 
+impl std::str::FromStr for Fingerprint {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_hex(s)
+    }
+}
+
 impl Fingerprint {
     /// Reads a binary fingerprint.
     pub fn from_bytes(raw: &[u8]) -> Fingerprint {
diff --git a/openpgp/src/keyid.rs b/openpgp/src/keyid.rs
index 799bf4fd..2e77c962 100644
--- a/openpgp/src/keyid.rs
+++ b/openpgp/src/keyid.rs
@@ -20,6 +20,14 @@ impl fmt::Debug for KeyID {
     }
 }
 
+impl std::str::FromStr for KeyID {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_hex(s)
+    }
+}
+
 impl From<KeyID> for Vec<u8> {
     fn from(id: KeyID) -> Self {
         let mut r = Vec::with_capacity(8);
diff --git a/openpgp/src/message/mod.rs b/openpgp/src/message/mod.rs
index d36ddb3c..30f8268d 100644
--- a/openpgp/src/message/mod.rs
+++ b/openpgp/src/message/mod.rs
@@ -338,6 +338,14 @@ impl<'a> Parse<'a, Message> for Message {
     }
 }
 
+impl std::str::FromStr for Message {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_bytes(s.as_bytes())
+    }
+}
+
 impl Message {
     /// Converts the `PacketPile` to a `Message`.
     ///
diff --git a/openpgp/src/packet_pile.rs b/openpgp/src/packet_pile.rs
index e14a541d..275c0dba 100644
--- a/openpgp/src/packet_pile.rs
+++ b/openpgp/src/packet_pile.rs
@@ -64,6 +64,14 @@ impl<'a> Parse<'a, PacketPile> for PacketPile {
     }
 }
 
+impl std::str::FromStr for PacketPile {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_bytes(s.as_bytes())
+    }
+}
+
 impl From<Vec<Packet>> for PacketPile {
     fn from(p: Vec<Packet>) -> Self {
         PacketPile { top_level: Container { packets: p } }
diff --git a/openpgp/src/tpk/mod.rs b/openpgp/src/tpk/mod.rs
index fb1ae43e..29f59da2 100644
--- a/openpgp/src/tpk/mod.rs
+++ b/openpgp/src/tpk/mod.rs
@@ -368,6 +368,14 @@ impl<'a> Parse<'a, TPKParser<'a, vec::IntoIter<Packet>>>
     }
 }
 
+impl std::str::FromStr for TPK {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_bytes(s.as_bytes())
+    }
+}
+
 impl<'a, I: Iterator<Item=Packet>> TPKParser<'a, I> {
     /// Initializes a TPKParser from an iterator over Packets.
     pub fn from_iter(iter: I) -> Self {