From c8dfd0d211993a5b408cdde22f8eacf0b243b387 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Thu, 26 Jun 2014 15:54:03 -0700
Subject: [PATCH] _detached versions of crypto_box

---
 src/libsodium/crypto_box/crypto_box_easy.c | 48 ++++++++++++++++------
 src/libsodium/include/sodium/crypto_box.h  | 13 ++++++
 2 files changed, 49 insertions(+), 12 deletions(-)

diff --git a/src/libsodium/crypto_box/crypto_box_easy.c b/src/libsodium/crypto_box/crypto_box_easy.c
index a01b4961..70648c09 100644
--- a/src/libsodium/crypto_box/crypto_box_easy.c
+++ b/src/libsodium/crypto_box/crypto_box_easy.c
@@ -4,9 +4,10 @@
 #include "utils.h"
 
 int
-crypto_box_easy(unsigned char *c, const unsigned char *m,
-                unsigned long long mlen, const unsigned char *n,
-                const unsigned char *pk, const unsigned char *sk)
+crypto_box_easy_detached(unsigned char *c, unsigned char *mac,
+                         const unsigned char *m, unsigned long long mlen,
+                         const unsigned char *n, const unsigned char *pk,
+                         const unsigned char *sk)
 {
     unsigned char k[crypto_box_BEFORENMBYTES];
     int           ret;
@@ -14,7 +15,32 @@ crypto_box_easy(unsigned char *c, const unsigned char *m,
     (void) sizeof(int[crypto_box_BEFORENMBYTES >=
                       crypto_secretbox_KEYBYTES ? 1 : -1]);
     crypto_box_beforenm(k, pk, sk);
-    ret = crypto_secretbox_easy(c, m, mlen, n, k);
+    ret = crypto_secretbox_easy_detached(c, mac, m, mlen, n, k);
+    sodium_memzero(k, sizeof k);
+
+    return ret;
+}
+
+int
+crypto_box_easy(unsigned char *c, const unsigned char *m,
+                unsigned long long mlen, const unsigned char *n,
+                const unsigned char *pk, const unsigned char *sk)
+{
+    return crypto_box_easy_detached(c + crypto_box_MACBYTES, c, m, mlen, n,
+                                    pk, sk);
+}
+
+int
+crypto_box_open_easy_detached(unsigned char *m, const unsigned char *c,
+                              const unsigned char *mac,
+                              unsigned long long clen, const unsigned char *n,
+                              const unsigned char *pk, const unsigned char *sk)
+{
+    unsigned char k[crypto_box_BEFORENMBYTES];
+    int           ret;
+
+    crypto_box_beforenm(k, pk, sk);
+    ret = crypto_secretbox_open_easy_detached(m, c, mac, clen, n, k);
     sodium_memzero(k, sizeof k);
 
     return ret;
@@ -25,12 +51,10 @@ crypto_box_open_easy(unsigned char *m, const unsigned char *c,
                      unsigned long long clen, const unsigned char *n,
                      const unsigned char *pk, const unsigned char *sk)
 {
-    unsigned char k[crypto_box_BEFORENMBYTES];
-    int           ret;
-
-    crypto_box_beforenm(k, pk, sk);
-    ret = crypto_secretbox_open_easy(m, c, clen, n, k);
-    sodium_memzero(k, sizeof k);
-
-    return ret;
+    if (clen < crypto_box_MACBYTES) {
+        return -1;
+    }
+    return crypto_box_open_easy_detached(m, c + crypto_box_MACBYTES, c,
+                                         clen - crypto_box_MACBYTES,
+                                         n, pk, sk);
 }
diff --git a/src/libsodium/include/sodium/crypto_box.h b/src/libsodium/include/sodium/crypto_box.h
index 9c1a64bf..17f7b516 100644
--- a/src/libsodium/include/sodium/crypto_box.h
+++ b/src/libsodium/include/sodium/crypto_box.h
@@ -97,6 +97,19 @@ int crypto_box_open_easy(unsigned char *m, const unsigned char *c,
                          unsigned long long clen, const unsigned char *n,
                          const unsigned char *pk, const unsigned char *sk);
 
+SODIUM_EXPORT
+int crypto_box_easy_detached(unsigned char *c, unsigned char *mac,
+                             const unsigned char *m, unsigned long long mlen,
+                             const unsigned char *n, const unsigned char *pk,
+                             const unsigned char *sk);
+
+SODIUM_EXPORT
+int crypto_box_open_easy_detached(unsigned char *m, const unsigned char *c,
+                                  const unsigned char *mac,
+                                  unsigned long long clen,
+                                  const unsigned char *n,
+                                  const unsigned char *pk,
+                                  const unsigned char *sk);
 #ifdef __cplusplus
 }
 #endif