Added NaCl crypto library.

13 files changed, 480 insertions, 0 deletions

diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/checksum b/nacl/crypto_box/curve25519xsalsa20poly1305/checksum
new file mode 100644
index 00000000..56a20083
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/checksum
@@ -0,0 +1 @@
+5fac7400caabc14a99c5c0bc13fb1df5e468e870382a3a1c
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/ref/after.c b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/after.c
new file mode 100644
index 00000000..eb243e22
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/after.c
@@ -0,0 +1,22 @@
+#include "crypto_secretbox_xsalsa20poly1305.h"
+#include "crypto_box.h"
+
+int crypto_box_afternm(
+  unsigned char *c,
+  const unsigned char *m,unsigned long long mlen,
+  const unsigned char *n,
+  const unsigned char *k
+)
+{
+  return crypto_secretbox_xsalsa20poly1305(c,m,mlen,n,k);
+}
+
+int crypto_box_open_afternm(
+  unsigned char *m,
+  const unsigned char *c,unsigned long long clen,
+  const unsigned char *n,
+  const unsigned char *k
+)
+{
+  return crypto_secretbox_xsalsa20poly1305_open(m,c,clen,n,k);
+}
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/ref/api.h b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/api.h
new file mode 100644
index 00000000..ce7762df
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/api.h
@@ -0,0 +1,6 @@
+#define CRYPTO_PUBLICKEYBYTES 32
+#define CRYPTO_SECRETKEYBYTES 32
+#define CRYPTO_BEFORENMBYTES 32
+#define CRYPTO_NONCEBYTES 24
+#define CRYPTO_ZEROBYTES 32
+#define CRYPTO_BOXZEROBYTES 16
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/ref/before.c b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/before.c
new file mode 100644
index 00000000..279bb12a
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/before.c
@@ -0,0 +1,17 @@
+#include "crypto_core_hsalsa20.h"
+#include "crypto_scalarmult_curve25519.h"
+#include "crypto_box.h"
+
+static const unsigned char sigma[16] = "expand 32-byte k";
+static const unsigned char n[16] = {0};
+
+int crypto_box_beforenm(
+  unsigned char *k,
+  const unsigned char *pk,
+  const unsigned char *sk
+)
+{
+  unsigned char s[32];
+  crypto_scalarmult_curve25519(s,sk,pk);
+  return crypto_core_hsalsa20(k,n,s,sigma);
+}
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/ref/box.c b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/box.c
new file mode 100644
index 00000000..81ff72e2
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/box.c
@@ -0,0 +1,27 @@
+#include "crypto_box.h"
+
+int crypto_box(
+  unsigned char *c,
+  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];
+  crypto_box_beforenm(k,pk,sk);
+  return crypto_box_afternm(c,m,mlen,n,k);
+}
+
+int crypto_box_open(
+  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];
+  crypto_box_beforenm(k,pk,sk);
+  return crypto_box_open_afternm(m,c,clen,n,k);
+}
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/ref/keypair.c b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/keypair.c
new file mode 100644
index 00000000..233bc950
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/ref/keypair.c
@@ -0,0 +1,12 @@
+#include "crypto_scalarmult_curve25519.h"
+#include "crypto_box.h"
+#include "randombytes.h"
+
+int crypto_box_keypair(
+  unsigned char *pk,
+  unsigned char *sk
+)
+{
+  randombytes(sk,32);
+  return crypto_scalarmult_curve25519_base(pk,sk);
+}
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/selected b/nacl/crypto_box/curve25519xsalsa20poly1305/selected
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/selected
diff --git a/nacl/crypto_box/curve25519xsalsa20poly1305/used b/nacl/crypto_box/curve25519xsalsa20poly1305/used
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/nacl/crypto_box/curve25519xsalsa20poly1305/used
diff --git a/nacl/crypto_box/measure.c b/nacl/crypto_box/measure.c
new file mode 100644
index 00000000..08df1e39
--- /dev/null
+++ b/nacl/crypto_box/measure.c
@@ -0,0 +1,137 @@
+#include <stdlib.h>
+#include "randombytes.h"
+#include "cpucycles.h"
+#include "crypto_box.h"
+
+extern void printentry(long long,const char *,long long *,long long);
+extern unsigned char *alignedcalloc(unsigned long long);
+extern const char *primitiveimplementation;
+extern const char *implementationversion;
+extern const char *sizenames[];
+extern const long long sizes[];
+extern void allocate(void);
+extern void measure(void);
+
+const char *primitiveimplementation = crypto_box_IMPLEMENTATION;
+const char *implementationversion = crypto_box_VERSION;
+const char *sizenames[] = { "publickeybytes", "secretkeybytes", "beforenmbytes", "noncebytes", "zerobytes", "boxzerobytes", 0 };
+const long long sizes[] = { crypto_box_PUBLICKEYBYTES, crypto_box_SECRETKEYBYTES, crypto_box_BEFORENMBYTES, crypto_box_NONCEBYTES, crypto_box_ZEROBYTES, crypto_box_BOXZEROBYTES };
+
+#define MAXTEST_BYTES 4096
+
+static unsigned char *ska;
+static unsigned char *pka;
+static unsigned char *skb;
+static unsigned char *pkb;
+static unsigned char *n;
+static unsigned char *m;
+static unsigned char *c;
+static unsigned char *sa;
+static unsigned char *sb;
+
+void preallocate(void)
+{
+}
+
+void allocate(void)
+{
+  ska = alignedcalloc(crypto_box_SECRETKEYBYTES);
+  pka = alignedcalloc(crypto_box_PUBLICKEYBYTES);
+  skb = alignedcalloc(crypto_box_SECRETKEYBYTES);
+  pkb = alignedcalloc(crypto_box_PUBLICKEYBYTES);
+  n = alignedcalloc(crypto_box_NONCEBYTES);
+  m = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  c = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  sa = alignedcalloc(crypto_box_BEFORENMBYTES);
+  sb = alignedcalloc(crypto_box_BEFORENMBYTES);
+}
+
+#define TIMINGS 15
+static long long cycles[TIMINGS + 1];
+
+void measure(void)
+{
+  int i;
+  int loop;
+  int mlen;
+
+  for (loop = 0;loop < LOOPS;++loop) {
+    for (i = 0;i <= TIMINGS;++i) {
+      cycles[i] = cpucycles();
+      crypto_box_keypair(pka,ska);
+    }
+    for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+    printentry(-1,"keypair_cycles",cycles,TIMINGS);
+
+    for (i = 0;i <= TIMINGS;++i) {
+      cycles[i] = cpucycles();
+      crypto_box_keypair(pkb,skb);
+    }
+    for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+    printentry(-1,"keypair_cycles",cycles,TIMINGS);
+
+    for (i = 0;i <= TIMINGS;++i) {
+      cycles[i] = cpucycles();
+      crypto_box_beforenm(sa,pkb,ska);
+    }
+    for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+    printentry(-1,"beforenm_cycles",cycles,TIMINGS);
+
+    for (i = 0;i <= TIMINGS;++i) {
+      cycles[i] = cpucycles();
+      crypto_box_beforenm(sb,pka,skb);
+    }
+    for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+    printentry(-1,"beforenm_cycles",cycles,TIMINGS);
+
+    for (mlen = 0;mlen <= MAXTEST_BYTES;mlen += 1 + mlen / 8) {
+      randombytes(n,crypto_box_NONCEBYTES);
+      randombytes(m + crypto_box_ZEROBYTES,mlen);
+      randombytes(c,mlen + crypto_box_ZEROBYTES);
+
+      for (i = 0;i <= TIMINGS;++i) {
+        cycles[i] = cpucycles();
+        crypto_box(c,m,mlen + crypto_box_ZEROBYTES,n,pka,skb);
+      }
+      for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+      printentry(mlen,"cycles",cycles,TIMINGS);
+
+      for (i = 0;i <= TIMINGS;++i) {
+        cycles[i] = cpucycles();
+        crypto_box_open(m,c,mlen + crypto_box_ZEROBYTES,n,pkb,ska);
+      }
+      for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+      printentry(mlen,"open_cycles",cycles,TIMINGS);
+
+      ++c[crypto_box_ZEROBYTES];
+      for (i = 0;i <= TIMINGS;++i) {
+        cycles[i] = cpucycles();
+        crypto_box_open(m,c,mlen + crypto_box_ZEROBYTES,n,pkb,ska);
+      }
+      for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+      printentry(mlen,"forgery_open_cycles",cycles,TIMINGS);
+
+      for (i = 0;i <= TIMINGS;++i) {
+        cycles[i] = cpucycles();
+        crypto_box_afternm(c,m,mlen + crypto_box_ZEROBYTES,n,sb);
+      }
+      for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+      printentry(mlen,"afternm_cycles",cycles,TIMINGS);
+
+      for (i = 0;i <= TIMINGS;++i) {
+        cycles[i] = cpucycles();
+        crypto_box_open_afternm(m,c,mlen + crypto_box_ZEROBYTES,n,sa);
+      }
+      for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+      printentry(mlen,"open_afternm_cycles",cycles,TIMINGS);
+
+      ++c[crypto_box_ZEROBYTES];
+      for (i = 0;i <= TIMINGS;++i) {
+        cycles[i] = cpucycles();
+        crypto_box_open_afternm(m,c,mlen + crypto_box_ZEROBYTES,n,sa);
+      }
+      for (i = 0;i < TIMINGS;++i) cycles[i] = cycles[i + 1] - cycles[i];
+      printentry(mlen,"forgery_open_afternm_cycles",cycles,TIMINGS);
+    }
+  }
+}
diff --git a/nacl/crypto_box/try.c b/nacl/crypto_box/try.c
new file mode 100644
index 00000000..f7029909
--- /dev/null
+++ b/nacl/crypto_box/try.c
@@ -0,0 +1,195 @@
+/*
+ * crypto_box/try.c version 20090118
+ * D. J. Bernstein
+ * Public domain.
+ */
+
+#include "crypto_box.h"
+
+extern unsigned char *alignedcalloc(unsigned long long);
+
+const char *primitiveimplementation = crypto_box_IMPLEMENTATION;
+
+#define MAXTEST_BYTES 10000
+#define CHECKSUM_BYTES 4096
+#define TUNE_BYTES 1536
+
+static unsigned char *ska;
+static unsigned char *pka;
+static unsigned char *skb;
+static unsigned char *pkb;
+static unsigned char *s;
+static unsigned char *n;
+static unsigned char *m;
+static unsigned char *c;
+static unsigned char *t;
+static unsigned char *ska2;
+static unsigned char *pka2;
+static unsigned char *skb2;
+static unsigned char *pkb2;
+static unsigned char *s2;
+static unsigned char *n2;
+static unsigned char *m2;
+static unsigned char *c2;
+static unsigned char *t2;
+
+#define sklen crypto_box_SECRETKEYBYTES
+#define pklen crypto_box_PUBLICKEYBYTES
+#define nlen crypto_box_NONCEBYTES
+#define slen crypto_box_BEFORENMBYTES
+
+void preallocate(void)
+{
+}
+
+void allocate(void)
+{
+  ska = alignedcalloc(sklen);
+  pka = alignedcalloc(pklen);
+  skb = alignedcalloc(sklen);
+  pkb = alignedcalloc(pklen);
+  n = alignedcalloc(nlen);
+  m = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  c = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  t = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  s = alignedcalloc(slen);
+  ska2 = alignedcalloc(sklen);
+  pka2 = alignedcalloc(pklen);
+  skb2 = alignedcalloc(sklen);
+  pkb2 = alignedcalloc(pklen);
+  n2 = alignedcalloc(nlen);
+  m2 = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  c2 = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  t2 = alignedcalloc(MAXTEST_BYTES + crypto_box_ZEROBYTES);
+  s2 = alignedcalloc(slen);
+}
+
+void predoit(void)
+{
+}
+
+void doit(void)
+{
+  crypto_box(c,m,TUNE_BYTES + crypto_box_ZEROBYTES,n,pka,skb);
+  crypto_box_open(t,c,TUNE_BYTES + crypto_box_ZEROBYTES,n,pkb,ska);
+}
+
+char checksum[nlen * 2 + 1];
+
+const char *checksum_compute(void)
+{
+  long long i;
+  long long j;
+
+  if (crypto_box_keypair(pka,ska) != 0) return "crypto_box_keypair returns nonzero";
+  if (crypto_box_keypair(pkb,skb) != 0) return "crypto_box_keypair returns nonzero";
+
+  for (j = 0;j < crypto_box_ZEROBYTES;++j) m[j] = 0;
+
+  for (i = 0;i < CHECKSUM_BYTES;++i) {
+    long long mlen = i + crypto_box_ZEROBYTES;
+    long long tlen = i + crypto_box_ZEROBYTES;
+    long long clen = i + crypto_box_ZEROBYTES;
+
+    for (j = -16;j < 0;++j) ska[j] = random();
+    for (j = -16;j < 0;++j) skb[j] = random();
+    for (j = -16;j < 0;++j) pka[j] = random();
+    for (j = -16;j < 0;++j) pkb[j] = random();
+    for (j = -16;j < 0;++j) m[j] = random();
+    for (j = -16;j < 0;++j) n[j] = random();
+
+    for (j = sklen;j < sklen + 16;++j) ska[j] = random();
+    for (j = sklen;j < sklen + 16;++j) skb[j] = random();
+    for (j = pklen;j < pklen + 16;++j) pka[j] = random();
+    for (j = pklen;j < pklen + 16;++j) pkb[j] = random();
+    for (j = mlen;j < mlen + 16;++j) m[j] = random();
+    for (j = nlen;j < nlen + 16;++j) n[j] = random();
+
+    for (j = -16;j < sklen + 16;++j) ska2[j] = ska[j];
+    for (j = -16;j < sklen + 16;++j) skb2[j] = skb[j];
+    for (j = -16;j < pklen + 16;++j) pka2[j] = pka[j];
+    for (j = -16;j < pklen + 16;++j) pkb2[j] = pkb[j];
+    for (j = -16;j < mlen + 16;++j) m2[j] = m[j];
+    for (j = -16;j < nlen + 16;++j) n2[j] = n[j];
+    for (j = -16;j < clen + 16;++j) c2[j] = c[j] = random();
+
+    if (crypto_box(c,m,mlen,n,pkb,ska) != 0) return "crypto_box returns nonzero";
+
+    for (j = -16;j < mlen + 16;++j) if (m2[j] != m[j]) return "crypto_box overwrites m";
+    for (j = -16;j < nlen + 16;++j) if (n2[j] != n[j]) return "crypto_box overwrites n";
+    for (j = -16;j < 0;++j) if (c2[j] != c[j]) return "crypto_box writes before output";
+    for (j = clen;j < clen + 16;++j) if (c2[j] != c[j]) return "crypto_box writes after output";
+    for (j = 0;j < crypto_box_BOXZEROBYTES;++j)
+      if (c[j] != 0) return "crypto_box does not clear extra bytes";
+
+    for (j = -16;j < sklen + 16;++j) if (ska2[j] != ska[j]) return "crypto_box overwrites ska";
+    for (j = -16;j < sklen + 16;++j) if (skb2[j] != skb[j]) return "crypto_box overwrites skb";
+    for (j = -16;j < pklen + 16;++j) if (pka2[j] != pka[j]) return "crypto_box overwrites pka";
+    for (j = -16;j < pklen + 16;++j) if (pkb2[j] != pkb[j]) return "crypto_box overwrites pkb";
+
+    for (j = -16;j < 0;++j) c[j] = random();
+    for (j = clen;j < clen + 16;++j) c[j] = random();
+    for (j = -16;j < clen + 16;++j) c2[j] = c[j];
+    for (j = -16;j < tlen + 16;++j) t2[j] = t[j] = random();
+
+    if (crypto_box_open(t,c,clen,n,pka,skb) != 0) return "crypto_box_open returns nonzero";
+
+    for (j = -16;j < clen + 16;++j) if (c2[j] != c[j]) return "crypto_box_open overwrites c";
+    for (j = -16;j < nlen + 16;++j) if (n2[j] != n[j]) return "crypto_box_open overwrites n";
+    for (j = -16;j < 0;++j) if (t2[j] != t[j]) return "crypto_box_open writes before output";
+    for (j = tlen;j < tlen + 16;++j) if (t2[j] != t[j]) return "crypto_box_open writes after output";
+    for (j = 0;j < crypto_box_ZEROBYTES;++j)
+      if (t[j] != 0) return "crypto_box_open does not clear extra bytes";
+
+    for (j = -16;j < sklen + 16;++j) if (ska2[j] != ska[j]) return "crypto_box_open overwrites ska";
+    for (j = -16;j < sklen + 16;++j) if (skb2[j] != skb[j]) return "crypto_box_open overwrites skb";
+    for (j = -16;j < pklen + 16;++j) if (pka2[j] != pka[j]) return "crypto_box_open overwrites pka";
+    for (j = -16;j < pklen + 16;++j) if (pkb2[j] != pkb[j]) return "crypto_box_open overwrites pkb";
+
+    for (j = 0;j < mlen;++j) if (t[j] != m[j]) return "plaintext does not match";
+
+    for (j = -16;j < slen + 16;++j) s2[j] = s[j] = random();
+    if (crypto_box_beforenm(s,pkb,ska) != 0) return "crypto_box_beforenm returns nonzero";
+    for (j = -16;j < pklen + 16;++j) if (pka2[j] != pka[j]) return "crypto_box_open overwrites pk";
+    for (j = -16;j < sklen + 16;++j) if (skb2[j] != skb[j]) return "crypto_box_open overwrites sk";
+    for (j = -16;j < 0;++j) if (s2[j] != s[j]) return "crypto_box_beforenm writes before output";
+    for (j = slen;j < slen + 16;++j) if (s2[j] != s[j]) return "crypto_box_beforenm writes after output";
+
+    for (j = -16;j < slen + 16;++j) s2[j] = s[j];
+    for (j = -16;j < tlen + 16;++j) t2[j] = t[j] = random();
+    if (crypto_box_afternm(t,m,mlen,n,s) != 0) return "crypto_box_afternm returns nonzero";
+    for (j = -16;j < slen + 16;++j) if (s2[j] != s[j]) return "crypto_box_afternm overwrites s";
+    for (j = -16;j < mlen + 16;++j) if (m2[j] != m[j]) return "crypto_box_afternm overwrites m";
+    for (j = -16;j < nlen + 16;++j) if (n2[j] != n[j]) return "crypto_box_afternm overwrites n";
+    for (j = -16;j < 0;++j) if (t2[j] != t[j]) return "crypto_box_afternm writes before output";
+    for (j = tlen;j < tlen + 16;++j) if (t2[j] != t[j]) return "crypto_box_afternm writes after output";
+    for (j = 0;j < crypto_box_BOXZEROBYTES;++j)
+      if (t[j] != 0) return "crypto_box_afternm does not clear extra bytes";
+    for (j = 0;j < mlen;++j) if (t[j] != c[j]) return "crypto_box_afternm does not match crypto_box";
+
+    if (crypto_box_beforenm(s,pka,skb) != 0) return "crypto_box_beforenm returns nonzero";
+
+    for (j = -16;j < tlen + 16;++j) t2[j] = t[j] = random();
+    if (crypto_box_open_afternm(t,c,clen,n,s) != 0) return "crypto_box_open_afternm returns nonzero";
+    for (j = -16;j < slen + 16;++j) if (s2[j] != s[j]) return "crypto_box_open_afternm overwrites s";
+    for (j = -16;j < mlen + 16;++j) if (m2[j] != m[j]) return "crypto_box_open_afternm overwrites m";
+    for (j = -16;j < nlen + 16;++j) if (n2[j] != n[j]) return "crypto_box_open_afternm overwrites n";
+    for (j = -16;j < 0;++j) if (t2[j] != t[j]) return "crypto_box_open_afternm writes before output";
+    for (j = tlen;j < tlen + 16;++j) if (t2[j] != t[j]) return "crypto_box_open_afternm writes after output";
+    for (j = 0;j < crypto_box_ZEROBYTES;++j)
+      if (t[j] != 0) return "crypto_box_open_afternm does not clear extra bytes";
+    for (j = 0;j < mlen;++j) if (t[j] != m[j]) return "crypto_box_open_afternm does not match crypto_box_open";
+
+    for (j = 0;j < i;++j) n[j % nlen] ^= c[j + crypto_box_BOXZEROBYTES];
+    if (i == 0) m[crypto_box_ZEROBYTES] = 0;
+    m[i + crypto_box_ZEROBYTES] = m[crypto_box_ZEROBYTES];
+    for (j = 0;j < i;++j) m[j + crypto_box_ZEROBYTES] ^= c[j + crypto_box_BOXZEROBYTES];
+  }
+
+  for (i = 0;i < nlen;++i) {
+    checksum[2 * i] = "0123456789abcdef"[15 & (n[i] >> 4)];
+    checksum[2 * i + 1] = "0123456789abcdef"[15 & n[i]];
+  }
+  checksum[2 * i] = 0;
+  return 0;
+}
diff --git a/nacl/crypto_box/wrapper-box.cpp b/nacl/crypto_box/wrapper-box.cpp
new file mode 100644
index 00000000..f0429295
--- /dev/null
+++ b/nacl/crypto_box/wrapper-box.cpp
@@ -0,0 +1,24 @@
+#include <string>
+using std::string;
+#include "crypto_box.h"
+
+string crypto_box(const string &m,const string &n,const string &pk,const string &sk)
+{
+  if (pk.size() != crypto_box_PUBLICKEYBYTES) throw "incorrect public-key length";
+  if (sk.size() != crypto_box_SECRETKEYBYTES) throw "incorrect secret-key length";
+  if (n.size() != crypto_box_NONCEBYTES) throw "incorrect nonce length";
+  size_t mlen = m.size() + crypto_box_ZEROBYTES;
+  unsigned char mpad[mlen];
+  for (int i = 0;i < crypto_box_ZEROBYTES;++i) mpad[i] = 0;
+  for (int i = crypto_box_ZEROBYTES;i < mlen;++i) mpad[i] = m[i - crypto_box_ZEROBYTES];
+  unsigned char cpad[mlen];
+  crypto_box(cpad,mpad,mlen,
+    (const unsigned char *) n.c_str(),
+    (const unsigned char *) pk.c_str(),
+    (const unsigned char *) sk.c_str()
+    );
+  return string(
+    (char *) cpad + crypto_box_BOXZEROBYTES,
+    mlen - crypto_box_BOXZEROBYTES
+  );
+}
diff --git a/nacl/crypto_box/wrapper-keypair.cpp b/nacl/crypto_box/wrapper-keypair.cpp
new file mode 100644
index 00000000..b59f92d9
--- /dev/null
+++ b/nacl/crypto_box/wrapper-keypair.cpp
@@ -0,0 +1,12 @@
+#include <string>
+using std::string;
+#include "crypto_box.h"
+
+string crypto_box_keypair(string *sk_string)
+{
+  unsigned char pk[crypto_box_PUBLICKEYBYTES];
+  unsigned char sk[crypto_box_SECRETKEYBYTES];
+  crypto_box_keypair(pk,sk);
+  *sk_string = string((char *) sk,sizeof sk);
+  return string((char *) pk,sizeof pk);
+}
diff --git a/nacl/crypto_box/wrapper-open.cpp b/nacl/crypto_box/wrapper-open.cpp
new file mode 100644
index 00000000..67663a21
--- /dev/null
+++ b/nacl/crypto_box/wrapper-open.cpp
@@ -0,0 +1,27 @@
+#include <string>
+using std::string;
+#include "crypto_box.h"
+
+string crypto_box_open(const string &c,const string &n,const string &pk,const string &sk)
+{
+  if (pk.size() != crypto_box_PUBLICKEYBYTES) throw "incorrect public-key length";
+  if (sk.size() != crypto_box_SECRETKEYBYTES) throw "incorrect secret-key length";
+  if (n.size() != crypto_box_NONCEBYTES) throw "incorrect nonce length";
+  size_t clen = c.size() + crypto_box_BOXZEROBYTES;
+  unsigned char cpad[clen];
+  for (int i = 0;i < crypto_box_BOXZEROBYTES;++i) cpad[i] = 0;
+  for (int i = crypto_box_BOXZEROBYTES;i < clen;++i) cpad[i] = c[i - crypto_box_BOXZEROBYTES];
+  unsigned char mpad[clen];
+  if (crypto_box_open(mpad,cpad,clen,
+                       (const unsigned char *) n.c_str(),
+                       (const unsigned char *) pk.c_str(),
+                       (const unsigned char *) sk.c_str()
+                     ) != 0)
+    throw "ciphertext fails verification";
+  if (clen < crypto_box_ZEROBYTES)
+    throw "ciphertext too short"; // should have been caught by _open
+  return string(
+    (char *) mpad + crypto_box_ZEROBYTES,
+    clen - crypto_box_ZEROBYTES
+  );
+}