From ddb8e4fdf2e366ccbe81cc2a4607ed9427f4285b Mon Sep 17 00:00:00 2001
From: Elichai Turkel <elichai.turkel@gmail.com>
Date: Thu, 8 Aug 2019 16:01:08 -0400
Subject: [PATCH] Explicit checks for empty slices

---
 src/key.rs          | 2 ++
 src/lib.rs          | 4 ++++
 src/recovery/mod.rs | 2 ++
 3 files changed, 8 insertions(+)

diff --git a/src/key.rs b/src/key.rs
index 25c898b..2e64df0 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -232,6 +232,8 @@ impl PublicKey {
     /// Creates a public key directly from a slice
     #[inline]
     pub fn from_slice(data: &[u8]) -> Result<PublicKey, Error> {
+        if data.is_empty() {return Err(Error::InvalidPublicKey);}
+
         let mut pk = ffi::PublicKey::new();
         unsafe {
             if ffi::secp256k1_ec_pubkey_parse(
diff --git a/src/lib.rs b/src/lib.rs
index 165a2d5..0863ded 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -247,6 +247,8 @@ impl Signature {
 #[inline]
     /// Converts a DER-encoded byte slice to a signature
     pub fn from_der(data: &[u8]) -> Result<Signature, Error> {
+        if data.is_empty() {return Err(Error::InvalidSignature);}
+
         let mut ret = ffi::Signature::new();
 
         unsafe {
@@ -290,6 +292,8 @@ impl Signature {
     /// 2016. It should never be used in new applications. This library does not
     /// support serializing to this "format"
     pub fn from_der_lax(data: &[u8]) -> Result<Signature, Error> {
+        if data.is_empty() {return Err(Error::InvalidSignature);}
+
         unsafe {
             let mut ret = ffi::Signature::new();
             if ffi::ecdsa_signature_parse_der_lax(
diff --git a/src/recovery/mod.rs b/src/recovery/mod.rs
index d0d92e3..1cad4e6 100644
--- a/src/recovery/mod.rs
+++ b/src/recovery/mod.rs
@@ -58,6 +58,8 @@ impl RecoverableSignature {
     /// representation is nonstandard and defined by the libsecp256k1
     /// library.
     pub fn from_compact(data: &[u8], recid: RecoveryId) -> Result<RecoverableSignature, Error> {
+        if data.is_empty() {return Err(Error::InvalidSignature);}
+
         let mut ret = ffi::RecoverableSignature::new();
 
         unsafe {