Merge pull request #402 from bbatha/feat/dsa-ffi

DSA bindings

2 files changed, 352 insertions, 0 deletions

diff --git a/openssl/src/crypto/dsa.rs b/openssl/src/crypto/dsa.rs
new file mode 100644
index 00000000..7e384ae3
--- /dev/null
+++ b/openssl/src/crypto/dsa.rs
@@ -0,0 +1,351 @@
+use ffi;
+use std::fmt;
+use ssl::error::{SslError, StreamError};
+use std::ptr;
+use std::io::{self, Read, Write};
+use libc::{c_uint, c_int};
+
+use bn::BigNum;
+use bio::MemBio;
+use crypto::hash;
+use crypto::HashTypeInternals;
+
+#[cfg(feature = "catch_unwind")]
+use libc::{c_char, c_void};
+#[cfg(feature = "catch_unwind")]
+use crypto::util::{CallbackState, invoke_passwd_cb};
+
+/// Builder for upfront DSA parameter generateration
+pub struct DSAParams(*mut ffi::DSA);
+
+impl DSAParams {
+    pub fn with_size(size: usize) -> Result<DSAParams, SslError> {
+        unsafe {
+            // Wrap it so that if we panic we'll call the dtor
+            let dsa = DSAParams(try_ssl_null!(ffi::DSA_new()));
+            try_ssl!(ffi::DSA_generate_parameters_ex(dsa.0, size as c_int, ptr::null(), 0,
+                                                 ptr::null_mut(), ptr::null_mut(), ptr::null()));
+            Ok(dsa)
+        }
+    }
+
+    /// Generate a key pair from the initialized parameters
+    pub fn generate(self) -> Result<DSA, SslError> {
+        unsafe {
+            try_ssl!(ffi::DSA_generate_key(self.0));
+            let dsa = DSA(self.0);
+            ::std::mem::forget(self);
+            Ok(dsa)
+        }
+    }
+}
+
+impl Drop for DSAParams {
+    fn drop(&mut self) {
+        unsafe {
+            ffi::DSA_free(self.0);
+        }
+    }
+}
+
+pub struct DSA(*mut ffi::DSA);
+
+impl Drop for DSA {
+    fn drop(&mut self) {
+        unsafe {
+            ffi::DSA_free(self.0);
+        }
+    }
+}
+
+impl DSA {
+    /// the caller should assert that the dsa pointer is valid.
+    pub unsafe fn from_raw(dsa: *mut ffi::DSA) -> DSA {
+        DSA(dsa)
+    }
+
+    /// Generate a DSA key pair
+    /// For more complicated key generation scenarios see the `DSAParams` type
+    pub fn generate(size: usize) -> Result<DSA, SslError> {
+        let params = try!(DSAParams::with_size(size));
+        params.generate()
+    }
+
+    /// Reads a DSA private key from PEM formatted data.
+    pub fn private_key_from_pem<R>(reader: &mut R) -> Result<DSA, SslError>
+        where R: Read
+    {
+        let mut mem_bio = try!(MemBio::new());
+        try!(io::copy(reader, &mut mem_bio).map_err(StreamError));
+
+        unsafe {
+            let dsa = try_ssl_null!(ffi::PEM_read_bio_DSAPrivateKey(mem_bio.get_handle(),
+                                                                    ptr::null_mut(),
+                                                                    None,
+                                                                    ptr::null_mut()));
+            let dsa = DSA(dsa);
+            assert!(dsa.has_private_key());
+            Ok(dsa)
+        }
+    }
+
+    /// Read a private key from PEM supplying a password callback to be invoked if the private key
+    /// is encrypted.
+    ///
+    /// The callback will be passed the password buffer and should return the number of characters
+    /// placed into the buffer.
+    ///
+    /// Requires the `catch_unwind` feature.
+    #[cfg(feature = "catch_unwind")]
+    pub fn private_key_from_pem_cb<R, F>(reader: &mut R, pass_cb: F) -> Result<DSA, SslError>
+        where R: Read, F: FnOnce(&mut [c_char]) -> usize
+    {
+        let mut cb = CallbackState::new(pass_cb);
+        let mut mem_bio = try!(MemBio::new());
+        try!(io::copy(reader, &mut mem_bio).map_err(StreamError));
+
+        unsafe {
+            let cb_ptr = &mut cb as *mut _ as *mut c_void;
+            let dsa = try_ssl_null!(ffi::PEM_read_bio_DSAPrivateKey(mem_bio.get_handle(),
+                                                                    ptr::null_mut(),
+                                                                    Some(invoke_passwd_cb::<F>),
+                                                                    cb_ptr));
+            let dsa = DSA(dsa);
+            assert!(dsa.has_private_key());
+            Ok(dsa)
+        }
+    }
+
+    /// Writes an DSA private key as unencrypted PEM formatted data
+    pub fn private_key_to_pem<W>(&self, writer: &mut W) -> Result<(), SslError>
+        where W: Write
+    {
+        assert!(self.has_private_key());
+        let mut mem_bio = try!(MemBio::new());
+
+        unsafe {
+            try_ssl!(ffi::PEM_write_bio_DSAPrivateKey(mem_bio.get_handle(), self.0,
+                                              ptr::null(), ptr::null_mut(), 0,
+                                              None, ptr::null_mut()))
+        };
+
+
+        try!(io::copy(&mut mem_bio, writer).map_err(StreamError));
+        Ok(())
+    }
+
+    /// Reads an DSA public key from PEM formatted data.
+    pub fn public_key_from_pem<R>(reader: &mut R) -> Result<DSA, SslError>
+        where R: Read
+    {
+        let mut mem_bio = try!(MemBio::new());
+        try!(io::copy(reader, &mut mem_bio).map_err(StreamError));
+
+        unsafe {
+            let dsa = try_ssl_null!(ffi::PEM_read_bio_DSA_PUBKEY(mem_bio.get_handle(),
+                                                                 ptr::null_mut(),
+                                                                 None,
+                                                                 ptr::null_mut()));
+            Ok(DSA(dsa))
+        }
+    }
+
+    /// Writes an DSA public key as PEM formatted data
+    pub fn public_key_to_pem<W>(&self, writer: &mut W) -> Result<(), SslError>
+        where W: Write
+    {
+        let mut mem_bio = try!(MemBio::new());
+
+        unsafe { try_ssl!(ffi::PEM_write_bio_DSA_PUBKEY(mem_bio.get_handle(), self.0)) };
+
+        try!(io::copy(&mut mem_bio, writer).map_err(StreamError));
+        Ok(())
+    }
+
+    pub fn size(&self) -> Result<isize, SslError> {
+        if self.has_q() {
+            unsafe { Ok(ffi::DSA_size(self.0) as isize) }
+        } else {
+            Err(SslError::OpenSslErrors(vec![]))
+        }
+    }
+
+    pub fn sign(&self, hash: hash::Type, message: &[u8]) -> Result<Vec<u8>, SslError> {
+        let k_len = try!(self.size()) as c_uint;
+        let mut sig = vec![0;k_len as usize];
+        let mut sig_len = k_len;
+        assert!(self.has_private_key());
+
+        unsafe {
+            try_ssl!(ffi::DSA_sign(hash.as_nid() as c_int,
+                                   message.as_ptr(),
+                                   message.len() as c_int,
+                                   sig.as_mut_ptr(),
+                                   &mut sig_len,
+                                   self.0));
+            sig.set_len(sig_len as usize);
+            sig.shrink_to_fit();
+            Ok(sig)
+        }
+    }
+
+    pub fn verify(&self, hash: hash::Type, message: &[u8], sig: &[u8]) -> Result<bool, SslError> {
+        unsafe {
+            let result = ffi::DSA_verify(hash.as_nid() as c_int,
+                                         message.as_ptr(),
+                                         message.len() as c_int,
+                                         sig.as_ptr(),
+                                         sig.len() as c_int,
+                                         self.0);
+
+            try_ssl_if!(result == -1);
+            Ok(result == 1)
+        }
+    }
+
+    pub fn as_ptr(&self) -> *mut ffi::DSA {
+        self.0
+    }
+
+    // The following getters are unsafe, since BigNum::new_from_ffi fails upon null pointers
+    pub fn p(&self) -> Result<BigNum, SslError> {
+        unsafe { BigNum::new_from_ffi((*self.0).p) }
+    }
+
+    pub fn has_p(&self) -> bool {
+        unsafe { !(*self.0).p.is_null() }
+    }
+
+    pub fn q(&self) -> Result<BigNum, SslError> {
+        unsafe { BigNum::new_from_ffi((*self.0).q) }
+    }
+
+    pub fn has_q(&self) -> bool {
+        unsafe { !(*self.0).q.is_null() }
+    }
+
+    pub fn g(&self) -> Result<BigNum, SslError> {
+        unsafe { BigNum::new_from_ffi((*self.0).g) }
+    }
+
+    pub fn has_g(&self) -> bool {
+        unsafe { !(*self.0).q.is_null() }
+    }
+
+    pub fn has_public_key(&self) -> bool {
+        unsafe { !(*self.0).pub_key.is_null() }
+    }
+
+    pub fn has_private_key(&self) -> bool {
+        unsafe { !(*self.0).priv_key.is_null() }
+    }
+}
+
+impl fmt::Debug for DSA {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "DSA")
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use std::fs::File;
+    use std::io::{Write, Cursor};
+    use super::*;
+    use crypto::hash::*;
+
+    #[test]
+    pub fn test_generate() {
+        let key = DSA::generate(1024).unwrap();
+        let mut priv_buf = Cursor::new(vec![]);
+        let mut pub_buf = Cursor::new(vec![]);
+
+        key.public_key_to_pem(&mut pub_buf).unwrap();
+        key.private_key_to_pem(&mut priv_buf).unwrap();
+
+        let input: Vec<u8> = (0..25).cycle().take(1024).collect();
+
+        let digest = {
+            let mut sha = Hasher::new(Type::SHA1);
+            sha.write_all(&input).unwrap();
+            sha.finish()
+        };
+
+        let sig = key.sign(Type::SHA1, &digest).unwrap();
+        let verified = key.verify(Type::SHA1, &digest, &sig).unwrap();
+        assert!(verified);
+    }
+
+    #[test]
+    pub fn test_sign_verify() {
+        let input: Vec<u8> = (0..25).cycle().take(1024).collect();
+
+        let private_key = {
+            let mut buffer = File::open("test/dsa.pem").unwrap();
+            DSA::private_key_from_pem(&mut buffer).unwrap()
+        };
+
+        let public_key = {
+            let mut buffer = File::open("test/dsa.pem.pub").unwrap();
+            DSA::public_key_from_pem(&mut buffer).unwrap()
+        };
+
+        let digest = {
+            let mut sha = Hasher::new(Type::SHA1);
+            sha.write_all(&input).unwrap();
+            sha.finish()
+        };
+
+        let sig = private_key.sign(Type::SHA1, &digest).unwrap();
+        let verified = public_key.verify(Type::SHA1, &digest, &sig).unwrap();
+        assert!(verified);
+    }
+
+    #[test]
+    pub fn test_sign_verify_fail() {
+        let input: Vec<u8> = (0..25).cycle().take(128).collect();
+        let private_key = {
+            let mut buffer = File::open("test/dsa.pem").unwrap();
+            DSA::private_key_from_pem(&mut buffer).unwrap()
+        };
+
+        let public_key = {
+            let mut buffer = File::open("test/dsa.pem.pub").unwrap();
+            DSA::public_key_from_pem(&mut buffer).unwrap()
+        };
+
+        let digest = {
+            let mut sha = Hasher::new(Type::SHA1);
+            sha.write_all(&input).unwrap();
+            sha.finish()
+        };
+
+        let mut sig = private_key.sign(Type::SHA1, &digest).unwrap();
+        // tamper with the sig this should cause a failure
+        let len = sig.len();
+        sig[len / 2] = 0;
+        sig[len - 1] = 0;
+        if let Ok(true) = public_key.verify(Type::SHA1, &digest, &sig) {
+            panic!("Tampered with signatures should not verify!");
+        }
+    }
+
+    #[test]
+    #[cfg(feature = "catch_unwind")]
+    pub fn test_password() {
+        let mut password_queried = false;
+        let mut buffer = File::open("test/dsa-encrypted.pem").unwrap();
+        DSA::private_key_from_pem_cb(&mut buffer, |password| {
+            password_queried = true;
+            password[0] = b'm' as _;
+            password[1] = b'y' as _;
+            password[2] = b'p' as _;
+            password[3] = b'a' as _;
+            password[4] = b's' as _;
+            password[5] = b's' as _;
+            6
+        }).unwrap();
+
+        assert!(password_queried);
+    }
+}
diff --git a/openssl/src/crypto/mod.rs b/openssl/src/crypto/mod.rs
index 481eb05c..6a34bd59 100644
--- a/openssl/src/crypto/mod.rs
+++ b/openssl/src/crypto/mod.rs
@@ -24,6 +24,7 @@ pub mod rand;
 pub mod symm;
 pub mod memcmp;
 pub mod rsa;
+pub mod dsa;
 #[cfg(feature = "catch_unwind")]
 mod util;