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authorAdam Langley <agl@google.com>2015-01-22 14:27:53 -0800
committerAdam Langley <agl@google.com>2015-01-30 16:52:14 -0800
commitd9e397b599b13d642138480a28c14db7a136bf05 (patch)
tree34bab61dc4ce323b123ad4614dbc07e86ea2f9ef /src/crypto/cipher/e_ssl3.c
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Initial commit of BoringSSL for Android.
Diffstat (limited to 'src/crypto/cipher/e_ssl3.c')
-rw-r--r--src/crypto/cipher/e_ssl3.c437
1 files changed, 437 insertions, 0 deletions
diff --git a/src/crypto/cipher/e_ssl3.c b/src/crypto/cipher/e_ssl3.c
new file mode 100644
index 0000000..d9dec68
--- /dev/null
+++ b/src/crypto/cipher/e_ssl3.c
@@ -0,0 +1,437 @@
+/* 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 <assert.h>
+#include <limits.h>
+#include <string.h>
+
+#include <openssl/aead.h>
+#include <openssl/cipher.h>
+#include <openssl/err.h>
+#include <openssl/hmac.h>
+#include <openssl/md5.h>
+#include <openssl/mem.h>
+#include <openssl/sha.h>
+
+#include "internal.h"
+
+
+typedef struct {
+ EVP_CIPHER_CTX cipher_ctx;
+ EVP_MD_CTX md_ctx;
+ /* enc_key is the portion of the key used for the stream or block cipher. It
+ * is retained separately to allow the EVP_CIPHER_CTX to be initialized once
+ * the direction is known. */
+ uint8_t enc_key[EVP_MAX_KEY_LENGTH];
+ uint8_t enc_key_len;
+ /* iv is the portion of the key used for the fixed IV. It is retained
+ * separately to allow the EVP_CIPHER_CTX to be initialized once the direction
+ * is known. */
+ uint8_t iv[EVP_MAX_IV_LENGTH];
+ uint8_t iv_len;
+ char initialized;
+} AEAD_SSL3_CTX;
+
+static int ssl3_mac(AEAD_SSL3_CTX *ssl3_ctx, uint8_t *out, unsigned *out_len,
+ const uint8_t *ad, size_t ad_len, const uint8_t *in,
+ size_t in_len) {
+ size_t md_size = EVP_MD_CTX_size(&ssl3_ctx->md_ctx);
+ size_t pad_len = (md_size == 20) ? 40 : 48;
+
+ /* To allow for CBC mode which changes cipher length, |ad| doesn't include the
+ * length for legacy ciphers. */
+ uint8_t ad_extra[2];
+ ad_extra[0] = (uint8_t)(in_len >> 8);
+ ad_extra[1] = (uint8_t)(in_len & 0xff);
+
+ EVP_MD_CTX md_ctx;
+ EVP_MD_CTX_init(&md_ctx);
+
+ uint8_t pad[48];
+ uint8_t tmp[EVP_MAX_MD_SIZE];
+ memset(pad, 0x36, pad_len);
+ if (!EVP_MD_CTX_copy_ex(&md_ctx, &ssl3_ctx->md_ctx) ||
+ !EVP_DigestUpdate(&md_ctx, pad, pad_len) ||
+ !EVP_DigestUpdate(&md_ctx, ad, ad_len) ||
+ !EVP_DigestUpdate(&md_ctx, ad_extra, sizeof(ad_extra)) ||
+ !EVP_DigestUpdate(&md_ctx, in, in_len) ||
+ !EVP_DigestFinal_ex(&md_ctx, tmp, NULL)) {
+ EVP_MD_CTX_cleanup(&md_ctx);
+ return 0;
+ }
+
+ memset(pad, 0x5c, pad_len);
+ if (!EVP_MD_CTX_copy_ex(&md_ctx, &ssl3_ctx->md_ctx) ||
+ !EVP_DigestUpdate(&md_ctx, pad, pad_len) ||
+ !EVP_DigestUpdate(&md_ctx, tmp, md_size) ||
+ !EVP_DigestFinal_ex(&md_ctx, out, out_len)) {
+ EVP_MD_CTX_cleanup(&md_ctx);
+ return 0;
+ }
+ EVP_MD_CTX_cleanup(&md_ctx);
+ return 1;
+}
+
+static void aead_ssl3_cleanup(EVP_AEAD_CTX *ctx) {
+ AEAD_SSL3_CTX *ssl3_ctx = (AEAD_SSL3_CTX *)ctx->aead_state;
+ EVP_CIPHER_CTX_cleanup(&ssl3_ctx->cipher_ctx);
+ EVP_MD_CTX_cleanup(&ssl3_ctx->md_ctx);
+ OPENSSL_cleanse(&ssl3_ctx->enc_key, sizeof(ssl3_ctx->enc_key));
+ OPENSSL_cleanse(&ssl3_ctx->iv, sizeof(ssl3_ctx->iv));
+ OPENSSL_free(ssl3_ctx);
+ ctx->aead_state = NULL;
+}
+
+static int aead_ssl3_init(EVP_AEAD_CTX *ctx, const uint8_t *key, size_t key_len,
+ size_t tag_len, const EVP_CIPHER *cipher,
+ const EVP_MD *md) {
+ if (tag_len != EVP_AEAD_DEFAULT_TAG_LENGTH &&
+ tag_len != EVP_MD_size(md)) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_init, CIPHER_R_UNSUPPORTED_TAG_SIZE);
+ return 0;
+ }
+
+ if (key_len != EVP_AEAD_key_length(ctx->aead)) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_init, CIPHER_R_BAD_KEY_LENGTH);
+ return 0;
+ }
+
+ size_t mac_key_len = EVP_MD_size(md);
+ size_t enc_key_len = EVP_CIPHER_key_length(cipher);
+ size_t iv_len = EVP_CIPHER_iv_length(cipher);
+ assert(mac_key_len + enc_key_len + iv_len == key_len);
+ assert(mac_key_len < 256);
+ assert(enc_key_len < 256);
+ assert(iv_len < 256);
+ /* Although EVP_rc4() is a variable-length cipher, the default key size is
+ * correct for SSL3. */
+
+ AEAD_SSL3_CTX *ssl3_ctx = OPENSSL_malloc(sizeof(AEAD_SSL3_CTX));
+ if (ssl3_ctx == NULL) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_init, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ EVP_CIPHER_CTX_init(&ssl3_ctx->cipher_ctx);
+ EVP_MD_CTX_init(&ssl3_ctx->md_ctx);
+ memcpy(ssl3_ctx->enc_key, &key[mac_key_len], enc_key_len);
+ ssl3_ctx->enc_key_len = (uint8_t)enc_key_len;
+ memcpy(ssl3_ctx->iv, &key[mac_key_len + enc_key_len], iv_len);
+ ssl3_ctx->iv_len = (uint8_t)iv_len;
+ ssl3_ctx->initialized = 0;
+
+ ctx->aead_state = ssl3_ctx;
+ if (!EVP_CipherInit_ex(&ssl3_ctx->cipher_ctx, cipher, NULL, NULL, NULL, 0) ||
+ !EVP_DigestInit_ex(&ssl3_ctx->md_ctx, md, NULL) ||
+ !EVP_DigestUpdate(&ssl3_ctx->md_ctx, key, mac_key_len)) {
+ aead_ssl3_cleanup(ctx);
+ return 0;
+ }
+ EVP_CIPHER_CTX_set_padding(&ssl3_ctx->cipher_ctx, 0);
+
+ return 1;
+}
+
+/* aead_ssl3_ensure_cipher_init initializes |ssl3_ctx| for encryption (or
+ * decryption, if |encrypt| is zero). If it has already been initialized, it
+ * ensures the direction matches and fails otherwise. It returns one on success
+ * and zero on failure.
+ *
+ * Note that, unlike normal AEADs, legacy SSL3 AEADs may not be used concurrently
+ * due to this (and bulk-cipher-internal) statefulness. */
+static int aead_ssl3_ensure_cipher_init(AEAD_SSL3_CTX *ssl3_ctx, int encrypt) {
+ if (!ssl3_ctx->initialized) {
+ /* Finish initializing the EVP_CIPHER_CTX now that the direction is
+ * known. */
+ if (!EVP_CipherInit_ex(&ssl3_ctx->cipher_ctx, NULL, NULL, ssl3_ctx->enc_key,
+ ssl3_ctx->iv, encrypt)) {
+ return 0;
+ }
+ ssl3_ctx->initialized = 1;
+ } else if (ssl3_ctx->cipher_ctx.encrypt != encrypt) {
+ /* Unlike a normal AEAD, using an SSL3 AEAD once freezes the direction. */
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_ensure_cipher_init,
+ CIPHER_R_INVALID_OPERATION);
+ return 0;
+ }
+ return 1;
+}
+
+static int aead_ssl3_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) {
+ AEAD_SSL3_CTX *ssl3_ctx = (AEAD_SSL3_CTX *)ctx->aead_state;
+ size_t total = 0;
+
+ if (in_len + EVP_AEAD_max_overhead(ctx->aead) < in_len ||
+ in_len > INT_MAX) {
+ /* EVP_CIPHER takes int as input. */
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_seal, CIPHER_R_TOO_LARGE);
+ return 0;
+ }
+
+ if (max_out_len < in_len + EVP_AEAD_max_overhead(ctx->aead)) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_seal, CIPHER_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+
+ if (nonce_len != 0) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_seal, CIPHER_R_IV_TOO_LARGE);
+ return 0;
+ }
+
+ if (ad_len != 11 - 2 /* length bytes */) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_seal, CIPHER_R_INVALID_AD_SIZE);
+ return 0;
+ }
+
+ if (!aead_ssl3_ensure_cipher_init(ssl3_ctx, 1)) {
+ return 0;
+ }
+
+ /* Compute the MAC. This must be first in case the operation is being done
+ * in-place. */
+ uint8_t mac[EVP_MAX_MD_SIZE];
+ unsigned mac_len;
+ if (!ssl3_mac(ssl3_ctx, mac, &mac_len, ad, ad_len, in, in_len)) {
+ return 0;
+ }
+
+ /* Encrypt the input. */
+ int len;
+ if (!EVP_EncryptUpdate(&ssl3_ctx->cipher_ctx, out, &len, in,
+ (int)in_len)) {
+ return 0;
+ }
+ total = len;
+
+ /* Feed the MAC into the cipher. */
+ if (!EVP_EncryptUpdate(&ssl3_ctx->cipher_ctx, out + total, &len, mac,
+ (int)mac_len)) {
+ return 0;
+ }
+ total += len;
+
+ unsigned block_size = EVP_CIPHER_CTX_block_size(&ssl3_ctx->cipher_ctx);
+ if (block_size > 1) {
+ assert(block_size <= 256);
+ assert(EVP_CIPHER_CTX_mode(&ssl3_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE);
+
+ /* Compute padding and feed that into the cipher. */
+ uint8_t padding[256];
+ unsigned padding_len = block_size - ((in_len + mac_len) % block_size);
+ memset(padding, 0, padding_len - 1);
+ padding[padding_len - 1] = padding_len - 1;
+ if (!EVP_EncryptUpdate(&ssl3_ctx->cipher_ctx, out + total, &len, padding,
+ (int)padding_len)) {
+ return 0;
+ }
+ total += len;
+ }
+
+ if (!EVP_EncryptFinal_ex(&ssl3_ctx->cipher_ctx, out + total, &len)) {
+ return 0;
+ }
+ total += len;
+
+ *out_len = total;
+ return 1;
+}
+
+static int aead_ssl3_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) {
+ AEAD_SSL3_CTX *ssl3_ctx = (AEAD_SSL3_CTX *)ctx->aead_state;
+
+ size_t mac_len = EVP_MD_CTX_size(&ssl3_ctx->md_ctx);
+ if (in_len < mac_len) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_BAD_DECRYPT);
+ return 0;
+ }
+
+ if (max_out_len < in_len) {
+ /* This requires that the caller provide space for the MAC, even though it
+ * will always be removed on return. */
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+
+ if (nonce_len != 0) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_TOO_LARGE);
+ return 0;
+ }
+
+ if (ad_len != 11 - 2 /* length bytes */) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_INVALID_AD_SIZE);
+ return 0;
+ }
+
+ if (in_len > INT_MAX) {
+ /* EVP_CIPHER takes int as input. */
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_TOO_LARGE);
+ return 0;
+ }
+
+ if (!aead_ssl3_ensure_cipher_init(ssl3_ctx, 0)) {
+ return 0;
+ }
+
+ /* Decrypt to get the plaintext + MAC + padding. */
+ size_t total = 0;
+ int len;
+ if (!EVP_DecryptUpdate(&ssl3_ctx->cipher_ctx, out, &len, in, (int)in_len)) {
+ return 0;
+ }
+ total += len;
+ if (!EVP_DecryptFinal_ex(&ssl3_ctx->cipher_ctx, out + total, &len)) {
+ return 0;
+ }
+ total += len;
+ assert(total == in_len);
+
+ /* Remove CBC padding and MAC. This would normally be timing-sensitive, but SSLv3 CBC
+ * ciphers are already broken. Support will be removed eventually.
+ * https://www.openssl.org/~bodo/ssl-poodle.pdf */
+ unsigned data_len;
+ if (EVP_CIPHER_CTX_mode(&ssl3_ctx->cipher_ctx) == EVP_CIPH_CBC_MODE) {
+ unsigned padding_length = out[total - 1];
+ if (total < padding_length + 1 + mac_len) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_BAD_DECRYPT);
+ return 0;
+ }
+ /* The padding must be minimal. */
+ if (padding_length + 1 > EVP_CIPHER_CTX_block_size(&ssl3_ctx->cipher_ctx)) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_BAD_DECRYPT);
+ return 0;
+ }
+ data_len = total - padding_length - 1 - mac_len;
+ } else {
+ data_len = total - mac_len;
+ }
+
+ /* Compute the MAC and compare against the one in the record. */
+ uint8_t mac[EVP_MAX_MD_SIZE];
+ if (!ssl3_mac(ssl3_ctx, mac, NULL, ad, ad_len, out, data_len)) {
+ return 0;
+ }
+ if (CRYPTO_memcmp(&out[data_len], mac, mac_len) != 0) {
+ OPENSSL_PUT_ERROR(CIPHER, aead_ssl3_open, CIPHER_R_BAD_DECRYPT);
+ return 0;
+ }
+
+ *out_len = data_len;
+ return 1;
+}
+
+static int aead_rc4_md5_ssl3_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
+ size_t key_len, size_t tag_len) {
+ return aead_ssl3_init(ctx, key, key_len, tag_len, EVP_rc4(), EVP_md5());
+}
+
+static int aead_rc4_sha1_ssl3_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
+ size_t key_len, size_t tag_len) {
+ return aead_ssl3_init(ctx, key, key_len, tag_len, EVP_rc4(), EVP_sha1());
+}
+
+static int aead_aes_128_cbc_sha1_ssl3_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
+ size_t key_len, size_t tag_len) {
+ return aead_ssl3_init(ctx, key, key_len, tag_len, EVP_aes_128_cbc(),
+ EVP_sha1());
+}
+
+static int aead_aes_256_cbc_sha1_ssl3_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
+ size_t key_len, size_t tag_len) {
+ return aead_ssl3_init(ctx, key, key_len, tag_len, EVP_aes_256_cbc(),
+ EVP_sha1());
+}
+static int aead_des_ede3_cbc_sha1_ssl3_init(EVP_AEAD_CTX *ctx,
+ const uint8_t *key, size_t key_len,
+ size_t tag_len) {
+ return aead_ssl3_init(ctx, key, key_len, tag_len, EVP_des_ede3_cbc(),
+ EVP_sha1());
+}
+
+static const EVP_AEAD aead_rc4_md5_ssl3 = {
+ MD5_DIGEST_LENGTH + 16, /* key len (MD5 + RC4) */
+ 0, /* nonce len */
+ MD5_DIGEST_LENGTH, /* overhead */
+ MD5_DIGEST_LENGTH, /* max tag length */
+ aead_rc4_md5_ssl3_init,
+ aead_ssl3_cleanup,
+ aead_ssl3_seal,
+ aead_ssl3_open,
+};
+
+static const EVP_AEAD aead_rc4_sha1_ssl3 = {
+ SHA_DIGEST_LENGTH + 16, /* key len (SHA1 + RC4) */
+ 0, /* nonce len */
+ SHA_DIGEST_LENGTH, /* overhead */
+ SHA_DIGEST_LENGTH, /* max tag length */
+ aead_rc4_sha1_ssl3_init,
+ aead_ssl3_cleanup,
+ aead_ssl3_seal,
+ aead_ssl3_open,
+};
+
+static const EVP_AEAD aead_aes_128_cbc_sha1_ssl3 = {
+ SHA_DIGEST_LENGTH + 16 + 16, /* key len (SHA1 + AES128 + IV) */
+ 0, /* nonce len */
+ 16 + SHA_DIGEST_LENGTH, /* overhead (padding + SHA1) */
+ SHA_DIGEST_LENGTH, /* max tag length */
+ aead_aes_128_cbc_sha1_ssl3_init,
+ aead_ssl3_cleanup,
+ aead_ssl3_seal,
+ aead_ssl3_open,
+};
+
+static const EVP_AEAD aead_aes_256_cbc_sha1_ssl3 = {
+ SHA_DIGEST_LENGTH + 32 + 16, /* key len (SHA1 + AES256 + IV) */
+ 0, /* nonce len */
+ 16 + SHA_DIGEST_LENGTH, /* overhead (padding + SHA1) */
+ SHA_DIGEST_LENGTH, /* max tag length */
+ aead_aes_256_cbc_sha1_ssl3_init,
+ aead_ssl3_cleanup,
+ aead_ssl3_seal,
+ aead_ssl3_open,
+};
+
+static const EVP_AEAD aead_des_ede3_cbc_sha1_ssl3 = {
+ SHA_DIGEST_LENGTH + 24 + 8, /* key len (SHA1 + 3DES + IV) */
+ 0, /* nonce len */
+ 8 + SHA_DIGEST_LENGTH, /* overhead (padding + SHA1) */
+ SHA_DIGEST_LENGTH, /* max tag length */
+ aead_des_ede3_cbc_sha1_ssl3_init,
+ aead_ssl3_cleanup,
+ aead_ssl3_seal,
+ aead_ssl3_open,
+};
+
+const EVP_AEAD *EVP_aead_rc4_md5_ssl3(void) { return &aead_rc4_md5_ssl3; }
+
+const EVP_AEAD *EVP_aead_rc4_sha1_ssl3(void) { return &aead_rc4_sha1_ssl3; }
+
+const EVP_AEAD *EVP_aead_aes_128_cbc_sha1_ssl3(void) {
+ return &aead_aes_128_cbc_sha1_ssl3;
+}
+
+const EVP_AEAD *EVP_aead_aes_256_cbc_sha1_ssl3(void) {
+ return &aead_aes_256_cbc_sha1_ssl3;
+}
+
+const EVP_AEAD *EVP_aead_des_ede3_cbc_sha1_ssl3(void) {
+ return &aead_des_ede3_cbc_sha1_ssl3;
+}