Initial commit of BoringSSL for Android.

1 files changed, 218 insertions, 0 deletions

diff --git a/src/crypto/cipher/e_chacha20poly1305.c b/src/crypto/cipher/e_chacha20poly1305.c
new file mode 100644
index 0000000..1cdcbca
--- /dev/null
+++ b/src/crypto/cipher/e_chacha20poly1305.c
@@ -0,0 +1,218 @@
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/aead.h>
+
+#include <string.h>
+
+#include <openssl/chacha.h>
+#include <openssl/cipher.h>
+#include <openssl/err.h>
+#include <openssl/mem.h>
+#include <openssl/poly1305.h>
+
+#include "internal.h"
+
+
+#define POLY1305_TAG_LEN 16
+#define CHACHA20_NONCE_LEN 8
+
+struct aead_chacha20_poly1305_ctx {
+  unsigned char key[32];
+  unsigned char tag_len;
+};
+
+static int aead_chacha20_poly1305_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
+                                       size_t key_len, size_t tag_len) {
+  struct aead_chacha20_poly1305_ctx *c20_ctx;
+
+  if (tag_len == 0) {
+    tag_len = POLY1305_TAG_LEN;
+  }
+
+  if (tag_len > POLY1305_TAG_LEN) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_init, CIPHER_R_TOO_LARGE);
+    return 0;
+  }
+
+  if (key_len != sizeof(c20_ctx->key)) {
+    return 0; /* internal error - EVP_AEAD_CTX_init should catch this. */
+  }
+
+  c20_ctx = OPENSSL_malloc(sizeof(struct aead_chacha20_poly1305_ctx));
+  if (c20_ctx == NULL) {
+    return 0;
+  }
+
+  memcpy(c20_ctx->key, key, key_len);
+  c20_ctx->tag_len = tag_len;
+  ctx->aead_state = c20_ctx;
+
+  return 1;
+}
+
+static void aead_chacha20_poly1305_cleanup(EVP_AEAD_CTX *ctx) {
+  struct aead_chacha20_poly1305_ctx *c20_ctx = ctx->aead_state;
+  OPENSSL_cleanse(c20_ctx->key, sizeof(c20_ctx->key));
+  OPENSSL_free(c20_ctx);
+}
+
+static void poly1305_update_with_length(poly1305_state *poly1305,
+                                        const uint8_t *data, size_t data_len) {
+  size_t j = data_len;
+  uint8_t 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));
+}
+
+#if defined(__arm__)
+#define ALIGNED __attribute__((aligned(16)))
+#else
+#define ALIGNED
+#endif
+
+static int aead_chacha20_poly1305_seal(const EVP_AEAD_CTX *ctx, uint8_t *out,
+                                       size_t *out_len, size_t max_out_len,
+                                       const uint8_t *nonce, size_t nonce_len,
+                                       const uint8_t *in, size_t in_len,
+                                       const uint8_t *ad, size_t ad_len) {
+  const struct aead_chacha20_poly1305_ctx *c20_ctx = ctx->aead_state;
+  uint8_t poly1305_key[32] ALIGNED;
+  poly1305_state poly1305;
+  const uint64_t in_len_64 = in_len;
+
+  /* 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 256GB 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. */
+  if (in_len_64 >= (1ull << 32) * 64 - 64) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_seal, CIPHER_R_TOO_LARGE);
+    return 0;
+  }
+
+  if (in_len + c20_ctx->tag_len < in_len) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_seal, CIPHER_R_TOO_LARGE);
+    return 0;
+  }
+
+  if (max_out_len < in_len + c20_ctx->tag_len) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_seal,
+                      CIPHER_R_BUFFER_TOO_SMALL);
+    return 0;
+  }
+
+  if (nonce_len != CHACHA20_NONCE_LEN) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_seal, CIPHER_R_IV_TOO_LARGE);
+    return 0;
+  }
+
+  memset(poly1305_key, 0, sizeof(poly1305_key));
+  CRYPTO_chacha_20(poly1305_key, poly1305_key, sizeof(poly1305_key),
+                   c20_ctx->key, nonce, 0);
+
+  CRYPTO_poly1305_init(&poly1305, poly1305_key);
+  poly1305_update_with_length(&poly1305, ad, ad_len);
+  CRYPTO_chacha_20(out, in, in_len, c20_ctx->key, nonce, 1);
+  poly1305_update_with_length(&poly1305, out, in_len);
+
+  uint8_t tag[POLY1305_TAG_LEN] ALIGNED;
+  CRYPTO_poly1305_finish(&poly1305, tag);
+  memcpy(out + in_len, tag, c20_ctx->tag_len);
+  *out_len = in_len + c20_ctx->tag_len;
+  return 1;
+}
+
+static int aead_chacha20_poly1305_open(const EVP_AEAD_CTX *ctx, uint8_t *out,
+                                       size_t *out_len, size_t max_out_len,
+                                       const uint8_t *nonce, size_t nonce_len,
+                                       const uint8_t *in, size_t in_len,
+                                       const uint8_t *ad, size_t ad_len) {
+  const struct aead_chacha20_poly1305_ctx *c20_ctx = ctx->aead_state;
+  uint8_t mac[POLY1305_TAG_LEN];
+  uint8_t poly1305_key[32] ALIGNED;
+  size_t plaintext_len;
+  poly1305_state poly1305;
+  const uint64_t in_len_64 = in_len;
+
+  if (in_len < c20_ctx->tag_len) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_open, CIPHER_R_BAD_DECRYPT);
+    return 0;
+  }
+
+  /* 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 256GB 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. */
+  if (in_len_64 >= (1ull << 32) * 64 - 64) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_open, CIPHER_R_TOO_LARGE);
+    return 0;
+  }
+
+  if (nonce_len != CHACHA20_NONCE_LEN) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_open, CIPHER_R_IV_TOO_LARGE);
+    return 0;
+  }
+
+  plaintext_len = in_len - c20_ctx->tag_len;
+
+  if (max_out_len < plaintext_len) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_open,
+                      CIPHER_R_BUFFER_TOO_SMALL);
+    return 0;
+  }
+
+  memset(poly1305_key, 0, sizeof(poly1305_key));
+  CRYPTO_chacha_20(poly1305_key, poly1305_key, sizeof(poly1305_key),
+                   c20_ctx->key, nonce, 0);
+
+  CRYPTO_poly1305_init(&poly1305, poly1305_key);
+  poly1305_update_with_length(&poly1305, ad, ad_len);
+  poly1305_update_with_length(&poly1305, in, plaintext_len);
+  CRYPTO_poly1305_finish(&poly1305, mac);
+
+  if (CRYPTO_memcmp(mac, in + plaintext_len, c20_ctx->tag_len) != 0) {
+    OPENSSL_PUT_ERROR(CIPHER, aead_chacha20_poly1305_open, CIPHER_R_BAD_DECRYPT);
+    return 0;
+  }
+
+  CRYPTO_chacha_20(out, in, plaintext_len, c20_ctx->key, nonce, 1);
+  *out_len = plaintext_len;
+  return 1;
+}
+
+static const EVP_AEAD aead_chacha20_poly1305 = {
+    32,                 /* key len */
+    CHACHA20_NONCE_LEN, /* nonce len */
+    POLY1305_TAG_LEN,   /* overhead */
+    POLY1305_TAG_LEN,   /* max tag length */
+    aead_chacha20_poly1305_init, aead_chacha20_poly1305_cleanup,
+    aead_chacha20_poly1305_seal, aead_chacha20_poly1305_open,
+};
+
+const EVP_AEAD *EVP_aead_chacha20_poly1305(void) {
+  return &aead_chacha20_poly1305;
+}