crypto: add support for ChaCha20/Policy1305 AEAD cipher

4 files changed, 200 insertions, 9 deletions

diff --git a/lib/crypto/c_src/crypto.c b/lib/crypto/c_src/crypto.c
index d08f0ae26b..27b4e7abbd 100644
--- a/lib/crypto/c_src/crypto.c
+++ b/lib/crypto/c_src/crypto.c
@@ -93,13 +93,28 @@
 # define HAVE_GCM
 #endif
 
+#if defined(NID_chacha20) && !defined(OPENSSL_NO_CHACHA) && !defined(OPENSSL_NO_POLY1305)
+# define HAVE_CHACHA20_POLY1305
+#endif
+
 #if defined(HAVE_EC)
 #include <openssl/ec.h>
 #include <openssl/ecdh.h>
 #include <openssl/ecdsa.h>
 #endif
 
+#if defined(HAVE_CHACHA20_POLY1305)
+#include <openssl/chacha.h>
+#include <openssl/poly1305.h>
+
+#if !defined(CHACHA20_NONCE_LEN)
+# define CHACHA20_NONCE_LEN 8
+#endif
+#if !defined(POLY1305_TAG_LEN)
+# define POLY1305_TAG_LEN 16
+#endif
 
+#endif
 
 #ifdef VALGRIND
     #  include <valgrind/memcheck.h>
@@ -268,6 +283,9 @@ static ERL_NIF_TERM rand_seed_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM a
 static ERL_NIF_TERM aes_gcm_encrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
 static ERL_NIF_TERM aes_gcm_decrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
 
+static ERL_NIF_TERM chacha20_poly1305_encrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM chacha20_poly1305_decrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+
 /* helpers */
 static void init_algorithms_types(ErlNifEnv*);
 static void init_digest_types(ErlNifEnv* env);
@@ -400,7 +418,11 @@ static ErlNifFunc nif_funcs[] = {
     {"rand_seed_nif", 1, rand_seed_nif},
 
     {"aes_gcm_encrypt", 4, aes_gcm_encrypt},
-    {"aes_gcm_decrypt", 5, aes_gcm_decrypt}
+    {"aes_gcm_decrypt", 5, aes_gcm_decrypt},
+
+    {"chacha20_poly1305_encrypt", 4, chacha20_poly1305_encrypt},
+    {"chacha20_poly1305_decrypt", 5, chacha20_poly1305_decrypt}
+
 
 };
 
@@ -717,7 +739,7 @@ static ERL_NIF_TERM algo_hash[8];   /* increase when extending the list */
 static int algo_pubkey_cnt;
 static ERL_NIF_TERM algo_pubkey[3]; /* increase when extending the list */
 static int algo_cipher_cnt;
-static ERL_NIF_TERM algo_cipher[3]; /* increase when extending the list */
+static ERL_NIF_TERM algo_cipher[4]; /* increase when extending the list */
 
 static void init_algorithms_types(ErlNifEnv* env)
 {
@@ -758,6 +780,9 @@ static void init_algorithms_types(ErlNifEnv* env)
 #if defined(HAVE_GCM)
     algo_cipher[algo_cipher_cnt++] = enif_make_atom(env,"aes_gcm");
 #endif
+#if defined(HAVE_CHACHA20_POLY1305)
+    algo_cipher[algo_cipher_cnt++] = enif_make_atom(env,"chacha20_poly1305");
+#endif
 
     ASSERT(algo_hash_cnt <= sizeof(algo_hash)/sizeof(ERL_NIF_TERM));
     ASSERT(algo_pubkey_cnt <= sizeof(algo_pubkey)/sizeof(ERL_NIF_TERM));
@@ -1856,6 +1881,135 @@ out_err:
 #endif
 }
 
+#if defined(HAVE_CHACHA20_POLY1305)
+static void
+poly1305_update_with_length(poly1305_state *poly1305,
+			    const unsigned char *data, size_t data_len)
+{
+        size_t j = data_len;
+        unsigned char length_bytes[8];
+        unsigned i;
+
+        for (i = 0; i < sizeof(length_bytes); i++) {
+                length_bytes[i] = j;
+                j >>= 8;
+        }
+
+        CRYPTO_poly1305_update(poly1305, data, data_len);
+        CRYPTO_poly1305_update(poly1305, length_bytes, sizeof(length_bytes));
+}
+#endif
+
+static ERL_NIF_TERM chacha20_poly1305_encrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{/* (Key,Iv,AAD,In) */
+#if defined(HAVE_CHACHA20_POLY1305)
+    ErlNifBinary key, iv, aad, in;
+    unsigned char *outp;
+    ERL_NIF_TERM out, out_tag;
+    ErlNifUInt64 in_len_64;
+    unsigned char poly1305_key[32];
+    poly1305_state poly1305;
+
+    CHECK_OSE_CRYPTO();
+
+    if (!enif_inspect_iolist_as_binary(env, argv[0], &key) || key.size != 32
+	|| !enif_inspect_binary(env, argv[1], &iv) || iv.size != CHACHA20_NONCE_LEN
+	|| !enif_inspect_iolist_as_binary(env, argv[2], &aad)
+	|| !enif_inspect_iolist_as_binary(env, argv[3], &in)) {
+	return enif_make_badarg(env);
+    }
+
+    /* Take from OpenSSL patch set/LibreSSL:
+     *
+     * The underlying ChaCha implementation may not overflow the block
+     * counter into the second counter word. Therefore we disallow
+     * individual operations that work on more than 2TB at a time.
+     * in_len_64 is needed because, on 32-bit platforms, size_t is only
+     * 32-bits and this produces a warning because it's always false.
+     * Casting to uint64_t inside the conditional is not sufficient to stop
+     * the warning. */
+    in_len_64 = in.size;
+    if (in_len_64 >= (1ULL << 32) * 64 - 64)
+	return enif_make_badarg(env);
+
+    memset(poly1305_key, 0, sizeof(poly1305_key));
+    CRYPTO_chacha_20(poly1305_key, poly1305_key, sizeof(poly1305_key), key.data, iv.data, 0);
+
+    outp = enif_make_new_binary(env, in.size, &out);
+
+    CRYPTO_poly1305_init(&poly1305, poly1305_key);
+    poly1305_update_with_length(&poly1305, aad.data, aad.size);
+    CRYPTO_chacha_20(outp, in.data, in.size, key.data, iv.data, 1);
+    poly1305_update_with_length(&poly1305, outp, in.size);
+
+    CRYPTO_poly1305_finish(&poly1305, enif_make_new_binary(env, POLY1305_TAG_LEN, &out_tag));
+
+    CONSUME_REDS(env, in);
+
+    return enif_make_tuple2(env, out, out_tag);
+
+#else
+    return atom_notsup;
+#endif
+}
+
+static ERL_NIF_TERM chacha20_poly1305_decrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{/* (Key,Iv,AAD,In,Tag) */
+#if defined(HAVE_CHACHA20_POLY1305)
+    ErlNifBinary key, iv, aad, in, tag;
+    unsigned char *outp;
+    ERL_NIF_TERM out;
+    ErlNifUInt64 in_len_64;
+    unsigned char poly1305_key[32];
+    unsigned char mac[POLY1305_TAG_LEN];
+    poly1305_state poly1305;
+
+    CHECK_OSE_CRYPTO();
+
+    if (!enif_inspect_iolist_as_binary(env, argv[0], &key) || key.size != 32
+	|| !enif_inspect_binary(env, argv[1], &iv) || iv.size != CHACHA20_NONCE_LEN
+	|| !enif_inspect_iolist_as_binary(env, argv[2], &aad)
+	|| !enif_inspect_iolist_as_binary(env, argv[3], &in)
+	|| !enif_inspect_iolist_as_binary(env, argv[4], &tag) || tag.size != POLY1305_TAG_LEN) {
+	return enif_make_badarg(env);
+    }
+
+    /* Take from OpenSSL patch set/LibreSSL:
+     *
+     * The underlying ChaCha implementation may not overflow the block
+     * counter into the second counter word. Therefore we disallow
+     * individual operations that work on more than 2TB at a time.
+     * in_len_64 is needed because, on 32-bit platforms, size_t is only
+     * 32-bits and this produces a warning because it's always false.
+     * Casting to uint64_t inside the conditional is not sufficient to stop
+     * the warning. */
+    in_len_64 = in.size;
+    if (in_len_64 >= (1ULL << 32) * 64 - 64)
+	return enif_make_badarg(env);
+
+    memset(poly1305_key, 0, sizeof(poly1305_key));
+    CRYPTO_chacha_20(poly1305_key, poly1305_key, sizeof(poly1305_key), key.data, iv.data, 0);
+
+    CRYPTO_poly1305_init(&poly1305, poly1305_key);
+    poly1305_update_with_length(&poly1305, aad.data, aad.size);
+    poly1305_update_with_length(&poly1305, in.data, in.size);
+    CRYPTO_poly1305_finish(&poly1305, mac);
+
+    if (memcmp(mac, tag.data, POLY1305_TAG_LEN) != 0)
+	return atom_error;
+
+    outp = enif_make_new_binary(env, in.size, &out);
+
+    CRYPTO_chacha_20(outp, in.data, in.size, key.data, iv.data, 1);
+
+    CONSUME_REDS(env, in);
+
+    return out;
+#else
+    return atom_notsup;
+#endif
+}
+
 static ERL_NIF_TERM rand_bytes_1(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {/* (Bytes) */     
     unsigned bytes;
diff --git a/lib/crypto/doc/src/crypto.xml b/lib/crypto/doc/src/crypto.xml
index 5f19c5cce3..cdeeaaaf43 100644
--- a/lib/crypto/doc/src/crypto.xml
+++ b/lib/crypto/doc/src/crypto.xml
@@ -136,7 +136,9 @@
 
      <p><code>block_cipher() =  aes_cbc128 | aes_cfb8 | aes_cfb128 | aes_ige256 | blowfish_cbc |
      blowfish_cfb64 | des_cbc | des_cfb | des3_cbc | des3_cbf
-     | des_ede3 | rc2_cbc | aes_gcm </code></p>
+     | des_ede3 | rc2_cbc </code></p>
+
+     <p><code>aead_cipher() =  aes_gcm | chacha20_poly1305 </code></p>
 
      <p><code>stream_key() =  aes_key() | rc4_key() </code></p>
 
@@ -158,7 +160,7 @@
      Note that both md4 and md5 are recommended only for compatibility with existing applications.
      </p>
      <p><code> cipher_algorithms() = des_cbc | des_cfb |  des3_cbc | des3_cbf | des_ede3 |
-     blowfish_cbc | blowfish_cfb64 | aes_cbc128 | aes_cfb8 | aes_cfb128| aes_cbc256 | aes_ige256 | aes_gcm | rc2_cbc | aes_ctr| rc4  </code> </p>
+     blowfish_cbc | blowfish_cfb64 | aes_cbc128 | aes_cfb8 | aes_cfb128| aes_cbc256 | aes_ige256 | aes_gcm | chacha20_poly1305 | rc2_cbc | aes_ctr| rc4  </code> </p>
      <p><code> public_key_algorithms() =   rsa |dss | ecdsa | dh | ecdh | ec_gf2m</code>
      Note that ec_gf2m is not strictly a public key algorithm, but a restriction on what curves are supported
      with ecdsa and ecdh.
@@ -169,10 +171,11 @@
   <funcs>
     <func>
       <name>block_encrypt(Type, Key, Ivec, PlainText) -> CipherText</name>
-      <name>block_encrypt(aes_gcm, Key, Ivec, {AAD, PlainText}) -> {CipherText, CipherTag}</name>
+      <name>block_encrypt(AeadType, Key, Ivec, {AAD, PlainText}) -> {CipherText, CipherTag}</name>
       <fsummary>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher</fsummary>
       <type>
 	<v>Type = block_cipher() </v>
+	<v>AeadType = aead_cipher() </v>
 	<v>Key = block_key() </v>
         <v>PlainText = iodata() </v>
         <v>AAD = IVec = CipherText = CipherTag = binary()</v>
@@ -190,10 +193,11 @@
 
     <func>
       <name>block_decrypt(Type, Key, Ivec, CipherText) -> PlainText</name>
-      <name>block_decrypt(aes_gcm, Key, Ivec, {AAD, CipherText, CipherTag}) -> PlainText | error</name>
+      <name>block_decrypt(AeadType, Key, Ivec, {AAD, CipherText, CipherTag}) -> PlainText | error</name>
       <fsummary>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher</fsummary>
       <type>
 	<v>Type = block_cipher() </v>
+	<v>AeadType = aead_cipher() </v>
 	<v>Key = block_key() </v>
         <v>PlainText = iodata() </v>
         <v>AAD = IVec = CipherText = CipherTag = binary()</v>
diff --git a/lib/crypto/src/crypto.erl b/lib/crypto/src/crypto.erl
index e4ec4f4d19..7f82fa83fd 100644
--- a/lib/crypto/src/crypto.erl
+++ b/lib/crypto/src/crypto.erl
@@ -283,7 +283,7 @@ hmac_final_n(_Context, _HashLen) -> ? nif_stub.
 -spec block_encrypt(des_cbc | des_cfb | des3_cbc | des3_cbf | des_ede3 | blowfish_cbc |
 		    blowfish_cfb64 | aes_cbc128 | aes_cfb8 | aes_cfb128 | aes_cbc256 | rc2_cbc,
 		    Key::iodata(), Ivec::binary(), Data::iodata()) -> binary();
-		   (aes_gcm, Key::iodata(), Ivec::binary(), {AAD::binary(), Data::iodata()}) -> {binary(), binary()}.
+		   (aes_gcm | chacha20_poly1305, Key::iodata(), Ivec::binary(), {AAD::binary(), Data::iodata()}) -> {binary(), binary()}.
 
 block_encrypt(des_cbc, Key, Ivec, Data) ->
     des_cbc_encrypt(Key, Ivec, Data);
@@ -316,6 +316,11 @@ block_encrypt(aes_gcm, Key, Ivec, {AAD, Data}) ->
 	notsup -> erlang:error(notsup);
 	Return -> Return
     end;
+block_encrypt(chacha20_poly1305, Key, Ivec, {AAD, Data}) ->
+    case chacha20_poly1305_encrypt(Key, Ivec, AAD, Data) of
+	notsup -> erlang:error(notsup);
+	Return -> Return
+    end;
 block_encrypt(rc2_cbc, Key, Ivec, Data) ->
     rc2_cbc_encrypt(Key, Ivec, Data).
 
@@ -323,7 +328,7 @@ block_encrypt(rc2_cbc, Key, Ivec, Data) ->
 		    blowfish_cfb64 | blowfish_ofb64  | aes_cbc128 | aes_cbc256 | aes_ige256 |
 		    aes_cfb8 | aes_cfb128 | rc2_cbc,
 		    Key::iodata(), Ivec::binary(), Data::iodata()) -> binary();
-		   (aes_gcm, Key::iodata(), Ivec::binary(),
+		   (aes_gcm | chacha20_poly1305, Key::iodata(), Ivec::binary(),
 		    {AAD::binary(), Data::iodata(), Tag::binary()}) -> binary() | error.
 block_decrypt(des_cbc, Key, Ivec, Data) ->
     des_cbc_decrypt(Key, Ivec, Data);
@@ -356,6 +361,11 @@ block_decrypt(aes_gcm, Key, Ivec, {AAD, Data, Tag}) ->
 	notsup -> erlang:error(notsup);
 	Return -> Return
     end;
+block_decrypt(chacha20_poly1305, Key, Ivec, {AAD, Data, Tag}) ->
+    case chacha20_poly1305_decrypt(Key, Ivec, AAD, Data, Tag) of
+	notsup -> erlang:error(notsup);
+	Return -> Return
+    end;
 block_decrypt(rc2_cbc, Key, Ivec, Data) ->
     rc2_cbc_decrypt(Key, Ivec, Data).
 -spec block_encrypt(des_ecb | blowfish_ecb, Key::iodata(), Data::iodata()) -> binary().
@@ -1208,6 +1218,12 @@ aes_gcm_encrypt(_Key, _Ivec, _AAD, _In) -> ?nif_stub.
 aes_gcm_decrypt(_Key, _Ivec, _AAD, _In, _Tag) -> ?nif_stub.
 
 %%
+%% Chacha20/Ppoly1305
+%%
+chacha20_poly1305_encrypt(_Key, _Ivec, _AAD, _In) -> ?nif_stub.
+chacha20_poly1305_decrypt(_Key, _Ivec, _AAD, _In, _Tag) -> ?nif_stub.
+
+%%
 %% DES - in cipher block chaining mode (CBC)
 %%
 -spec des_cbc_encrypt(iodata(), binary(), iodata()) -> binary().
diff --git a/lib/crypto/test/crypto_SUITE.erl b/lib/crypto/test/crypto_SUITE.erl
index f3ec20b11e..1031e6403f 100644
--- a/lib/crypto/test/crypto_SUITE.erl
+++ b/lib/crypto/test/crypto_SUITE.erl
@@ -63,6 +63,7 @@ all() ->
      {group, rc4}, 
      {group, aes_ctr},
      {group, aes_gcm},
+     {group, chacha20_poly1305},
      mod_pow,
      exor,
      rand_uniform
@@ -102,7 +103,8 @@ groups() ->
      {blowfish_ofb64,[], [block]},
      {rc4, [], [stream]}, 
      {aes_ctr, [], [stream]},
-     {aes_gcm, [], [aead]}
+     {aes_gcm, [], [aead]},
+     {chacha20_poly1305, [], [aead]}
     ].
 
 %%-------------------------------------------------------------------
@@ -777,6 +779,9 @@ group_config(aes_ctr, Config) ->
 group_config(aes_gcm, Config) ->
     AEAD = aes_gcm(),
     [{aead, AEAD} | Config];
+group_config(chacha20_poly1305, Config) ->
+    AEAD = chacha20_poly1305(),
+    [{aead, AEAD} | Config];
 group_config(_, Config) ->
     Config.
 
@@ -1657,6 +1662,18 @@ aes_gcm() ->
       hexstr2bin("a44a8266ee1c8eb0c8b5d4cf5ae9f19a")}                    %% CipherTag
     ].
 
+%% http://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-04
+chacha20_poly1305() ->
+    [
+     {chacha20_poly1305, hexstr2bin("4290bcb154173531f314af57f3be3b500"  %% Key
+				    "6da371ece272afa1b5dbdd1100a1007"),
+      hexstr2bin("86d09974840bded2a5ca"),                                %% PlainText
+      hexstr2bin("cd7cf67be39c794a"),                                    %% Nonce
+      hexstr2bin("87e229d4500845a079c0"),                                %% AAD
+      hexstr2bin("e3e446f7ede9a19b62a4"),                                %% CipherText
+      hexstr2bin("677dabf4e3d24b876bb284753896e1d6")}                   %% CipherTag
+    ].
+
 rsa_plain() ->
     <<"7896345786348756234 Hejsan Svejsan, erlang crypto debugger"
       "09812312908312378623487263487623412039812 huagasd">>.