openpgp: Introduce crypto::Hash.

  - This trait formalizes the hashing of OpenPGP packets and related
    types.

  - Fixes #183.

8 files changed, 46 insertions, 24 deletions

diff --git a/openpgp/src/crypto/hash.rs b/openpgp/src/crypto/hash.rs
index 26f9fda6..fdde1976 100644
--- a/openpgp/src/crypto/hash.rs
+++ b/openpgp/src/crypto/hash.rs
@@ -134,9 +134,15 @@ impl nettle::Hash for HashDumper {
     }
 }
 
-impl UserID {
+/// Hashes OpenPGP packets and related types.
+pub trait Hash {
+    /// Updates the given hash with this object.
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H);
+}
+
+impl Hash for UserID {
     /// Update the Hash with a hash of the user id.
-    pub fn hash<H: nettle::Hash>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         let mut header = [0; 5];
 
         header[0] = 0xB4;
@@ -151,9 +157,9 @@ impl UserID {
     }
 }
 
-impl UserAttribute {
+impl Hash for UserAttribute {
     /// Update the Hash with a hash of the user attribute.
-    pub fn hash<H: nettle::Hash>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         let mut header = [0; 5];
 
         header[0] = 0xD1;
@@ -168,9 +174,9 @@ impl UserAttribute {
     }
 }
 
-impl Key {
+impl Hash for Key {
     /// Update the Hash with a hash of the key.
-    pub fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         // We hash 8 bytes plus the MPIs.  But, the len doesn't
         // include the tag (1 byte) or the length (2 bytes).
         let len = (9 - 3) + self.mpis().serialized_len();
@@ -205,16 +211,16 @@ impl Key {
     }
 }
 
-impl Signature {
+impl Hash for Signature {
     /// Adds the `Signature` to the provided hash context.
-    pub fn hash<H: nettle::Hash>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         self.fields.hash(hash);
     }
 }
 
-impl signature::Builder {
+impl Hash for signature::Builder {
     /// Adds the `Signature` to the provided hash context.
-    pub fn hash<H: nettle::Hash>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         // A version 4 signature packet is laid out as follows:
         //
         //   version - 1 byte                    \
diff --git a/openpgp/src/crypto/mod.rs b/openpgp/src/crypto/mod.rs
index 5f94e3b4..052be2d4 100644
--- a/openpgp/src/crypto/mod.rs
+++ b/openpgp/src/crypto/mod.rs
@@ -25,6 +25,8 @@ pub use self::asymmetric::{
     KeyPair,
 };
 
+pub use self::hash::Hash;
+
 /// Holds a session key.
 ///
 /// The session key is cleared when dropped.
diff --git a/openpgp/src/crypto/mpis.rs b/openpgp/src/crypto/mpis.rs
index f749d90f..24e4d479 100644
--- a/openpgp/src/crypto/mpis.rs
+++ b/openpgp/src/crypto/mpis.rs
@@ -13,6 +13,7 @@ use constants::{
     PublicKeyAlgorithm,
     SymmetricAlgorithm,
 };
+use crypto::Hash;
 use serialize::Serialize;
 
 use nettle;
@@ -48,14 +49,6 @@ impl MPI {
         }
     }
 
-    /// Update the Hash with a hash of the MPIs.
-    pub fn hash<H: nettle::Hash>(&self, hash: &mut H) {
-        let len = &[(self.bits >> 8) as u8 & 0xFF, self.bits as u8];
-
-        hash.update(len);
-        hash.update(&self.value);
-    }
-
     fn secure_memzero(&mut self) {
         unsafe {
             ::memsec::memzero(self.value.as_mut_ptr(), self.value.len());
@@ -87,6 +80,16 @@ impl fmt::Debug for MPI {
     }
 }
 
+impl Hash for MPI {
+    /// Update the Hash with a hash of the MPIs.
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
+        let len = &[(self.bits >> 8) as u8 & 0xFF, self.bits as u8];
+
+        hash.update(len);
+        hash.update(&self.value);
+    }
+}
+
 impl Arbitrary for MPI {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         loop {
@@ -254,9 +257,11 @@ impl PublicKey {
             &Unknown { .. } => 0,
         }
     }
+}
 
+impl Hash for PublicKey {
     /// Update the Hash with a hash of the MPIs.
-    pub fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         self.serialize(hash).expect("hashing does not fail")
     }
 }
@@ -554,9 +559,11 @@ impl SecretKey {
                 + rest.len(),
         }
     }
+}
 
+impl Hash for SecretKey {
     /// Update the Hash with a hash of the MPIs.
-    pub fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         self.serialize(hash).expect("hashing does not fail")
     }
 }
@@ -674,9 +681,11 @@ impl Ciphertext {
             &Unknown { .. } => None,
         }
     }
+}
 
+impl Hash for Ciphertext {
     /// Update the Hash with a hash of the MPIs.
-    pub fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         self.serialize(hash).expect("hashing does not fail")
     }
 }
@@ -784,9 +793,11 @@ impl Signature {
                 + rest.len(),
         }
     }
+}
 
+impl Hash for Signature {
     /// Update the Hash with a hash of the MPIs.
-    pub fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
+    fn hash<H: nettle::Hash + Write>(&self, hash: &mut H) {
         self.serialize(hash).expect("hashing does not fail")
     }
 }
diff --git a/openpgp/src/packet/signature/mod.rs b/openpgp/src/packet/signature/mod.rs
index 0a3f7cba..6c216c92 100644
--- a/openpgp/src/packet/signature/mod.rs
+++ b/openpgp/src/packet/signature/mod.rs
@@ -8,6 +8,7 @@ use Error;
 use Result;
 use crypto::{
     mpis,
+    Hash,
     Signer,
 };
 use HashAlgorithm;
diff --git a/openpgp/src/parse/key.rs b/openpgp/src/parse/key.rs
index 76afeb01..36c252ba 100644
--- a/openpgp/src/parse/key.rs
+++ b/openpgp/src/parse/key.rs
@@ -4,6 +4,7 @@ use nettle::Hash as NettleHash;
 use nettle::hash::insecure_do_not_use::Sha1;
 
 use {
+    crypto::Hash,
     packet::Key,
     KeyID,
     Fingerprint,
diff --git a/openpgp/src/parse/parse.rs b/openpgp/src/parse/parse.rs
index be146c2e..ce0ffa86 100644
--- a/openpgp/src/parse/parse.rs
+++ b/openpgp/src/parse/parse.rs
@@ -15,7 +15,7 @@ use nettle;
 use ::buffered_reader::*;
 
 use {
-    crypto::aead,
+    crypto::{aead, Hash},
     Result,
     CTB,
     BodyLength,
diff --git a/openpgp/src/tpk/mod.rs b/openpgp/src/tpk/mod.rs
index 15cbf2ab..789c5114 100644
--- a/openpgp/src/tpk/mod.rs
+++ b/openpgp/src/tpk/mod.rs
@@ -11,7 +11,7 @@ use time;
 use failure;
 
 use {
-    crypto::Signer,
+    crypto::{Hash, Signer},
     Error,
     Result,
     RevocationStatus,
diff --git a/sqv/src/sqv.rs b/sqv/src/sqv.rs
index fc8a98a3..c9cc65c6 100644
--- a/sqv/src/sqv.rs
+++ b/sqv/src/sqv.rs
@@ -16,6 +16,7 @@ use std::collections::{HashMap, HashSet};
 
 use openpgp::{TPK, Packet, packet::Signature, KeyID, RevocationStatus};
 use openpgp::constants::HashAlgorithm;
+use openpgp::crypto::Hash;
 use openpgp::parse::{Parse, PacketParserResult, PacketParser};
 use openpgp::tpk::TPKParser;