From 39c1f3b3559d7fe659a6fe05d5ac5c752501ed37 Mon Sep 17 00:00:00 2001
From: Mark Haines <mark.haines@matrix.org>
Date: Fri, 24 Jul 2015 14:29:52 +0100
Subject: [PATCH] Add methods for computing sha256 hashes and validating
ed25519 signatures
---
include/olm/olm.hh | 43 ++++++++++++++
include/olm/utility.hh | 52 +++++++++++++++++
src/olm.cpp | 109 +++++++++++++++++++++++++++++++++--
src/utility.cpp | 57 ++++++++++++++++++
tests/test_olm_sha256.cpp | 20 +++++++
tests/test_olm_signature.cpp | 81 ++++++++++++++++++++++++++
6 files changed, 357 insertions(+), 5 deletions(-)
create mode 100644 include/olm/utility.hh
create mode 100644 src/utility.cpp
create mode 100644 tests/test_olm_sha256.cpp
create mode 100644 tests/test_olm_signature.cpp
diff --git a/include/olm/olm.hh b/include/olm/olm.hh
index a5a50de..34d84fd 100644
--- a/include/olm/olm.hh
+++ b/include/olm/olm.hh
@@ -27,6 +27,7 @@ static const size_t OLM_MESSAGE_TYPE_MESSAGE = 1;
struct OlmAccount;
struct OlmSession;
+struct OlmUtility;
/** The size of an account object in bytes */
size_t olm_account_size();
@@ -34,6 +35,9 @@ size_t olm_account_size();
/** The size of a session object in bytes */
size_t olm_session_size();
+/** The size of a utility object in bytes */
+size_t olm_utility_size();
+
/** Initialise an account object using the supplied memory
* The supplied memory must be at least olm_account_size() bytes */
OlmAccount * olm_account(
@@ -46,6 +50,12 @@ OlmSession * olm_session(
void * memory
);
+/** Initialise a utility object using the supplied memory
+ * The supplied memory must be at least olm_session_size() bytes */
+OlmUtility * olm_utility(
+ void * memory
+);
+
/** The value that olm will return from a function if there was an error */
size_t olm_error();
@@ -61,6 +71,12 @@ const char * olm_session_last_error(
OlmSession * session
);
+/** A null terminated string describing the most recent error to happen to a
+ * utility */
+const char * olm_utility_last_error(
+ OlmUtility * utility
+);
+
/** Clears the memory used to back this account */
size_t olm_clear_account(
OlmAccount * account
@@ -71,6 +87,11 @@ size_t olm_clear_session(
OlmSession * session
);
+/** Clears the memory used to back this utility */
+size_t olm_clear_utility(
+ OlmUtility * utility
+);
+
/** Returns the number of bytes needed to store an account */
size_t olm_pickle_account_length(
OlmAccount * account
@@ -370,7 +391,29 @@ size_t olm_decrypt(
void * plaintext, size_t max_plaintext_length
);
+/** The length of the buffer needed to hold the SHA-256 hash. */
+size_t olm_sha256_length(
+ OlmUtility * utility
+);
+
+/** Calculates the SHA-256 hash of the input and encodes it as base64. If the
+ * output buffer is smaller than olm_sha256_length() then
+ * olm_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL". */
+size_t olm_sha256(
+ OlmUtility * utility,
+ void const * input, size_t input_length,
+ void * output, size_t output_length
+);
+/** Verify an ed25519 signature. If the key was too small then
+ * olm_session_last_error will be "INVALID_BASE64". If the signature was invalid
+ * then olm_session_last_error() will be "BAD_MESSAGE_MAC". */
+size_t olm_ed25519_verify(
+ OlmUtility * utility,
+ void const * key, size_t key_length,
+ void const * message, size_t message_length,
+ void * signature, size_t signature_length
+);
#ifdef __cplusplus
}
diff --git a/include/olm/utility.hh b/include/olm/utility.hh
new file mode 100644
index 0000000..241d7e0
--- /dev/null
+++ b/include/olm/utility.hh
@@ -0,0 +1,52 @@
+/* Copyright 2015 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef UTILITY_HH_
+#define UTILITY_HH_
+
+#include "olm/error.hh"
+
+#include <cstddef>
+#include <cstdint>
+
+namespace olm {
+
+class Ed25519PublicKey;
+
+struct Utility {
+
+ Utility();
+
+ ErrorCode last_error;
+
+ std::size_t sha256_length();
+
+ std::size_t sha256(
+ std::uint8_t const * input, std::size_t input_length,
+ std::uint8_t * output, std::size_t output_length
+ );
+
+ std::size_t ed25519_verify(
+ Ed25519PublicKey const & key,
+ std::uint8_t const * message, std::size_t message_length,
+ std::uint8_t const * signature, std::size_t signature_length
+ );
+
+};
+
+
+} // namespace olm
+
+#endif /* UTILITY_HH_ */
diff --git a/src/olm.cpp b/src/olm.cpp
index cb4291e..28b194f 100644
--- a/src/olm.cpp
+++ b/src/olm.cpp
@@ -15,6 +15,7 @@
#include "olm/olm.hh"
#include "olm/session.hh"
#include "olm/account.hh"
+#include "olm/utility.hh"
#include "olm/base64.hh"
#include "olm/cipher.hh"
#include "olm/memory.hh"
@@ -28,16 +29,24 @@ static OlmAccount * to_c(olm::Account * account) {
return reinterpret_cast<OlmAccount *>(account);
}
-static OlmSession * to_c(olm::Session * account) {
- return reinterpret_cast<OlmSession *>(account);
+static OlmSession * to_c(olm::Session * session) {
+ return reinterpret_cast<OlmSession *>(session);
+}
+
+static OlmUtility * to_c(olm::Utility * utility) {
+ return reinterpret_cast<OlmUtility *>(utility);
}
static olm::Account * from_c(OlmAccount * account) {
return reinterpret_cast<olm::Account *>(account);
}
-static olm::Session * from_c(OlmSession * account) {
- return reinterpret_cast<olm::Session *>(account);
+static olm::Session * from_c(OlmSession * session) {
+ return reinterpret_cast<olm::Session *>(session);
+}
+
+static olm::Utility * from_c(OlmUtility * utility) {
+ return reinterpret_cast<olm::Utility *>(utility);
}
static std::uint8_t * from_c(void * bytes) {
@@ -200,6 +209,16 @@ const char * olm_session_last_error(
}
}
+const char * olm_utility_last_error(
+ OlmUtility * utility
+) {
+ unsigned error = unsigned(from_c(utility)->last_error);
+ if (error < sizeof(ERRORS)) {
+ return ERRORS[error];
+ } else {
+ return "UNKNOWN_ERROR";
+ }
+}
size_t olm_account_size() {
return sizeof(olm::Account);
@@ -210,6 +229,9 @@ size_t olm_session_size() {
return sizeof(olm::Session);
}
+size_t olm_utility_size() {
+ return sizeof(olm::Utility);
+}
OlmAccount * olm_account(
void * memory
@@ -227,6 +249,14 @@ OlmSession * olm_session(
}
+OlmUtility * olm_utility(
+ void * memory
+) {
+ olm::unset(memory, sizeof(olm::Utility));
+ return to_c(new(memory) olm::Utility());
+}
+
+
size_t olm_clear_account(
OlmAccount * account
) {
@@ -249,6 +279,17 @@ size_t olm_clear_session(
}
+size_t olm_clear_utility(
+ OlmUtility * utility
+) {
+ /* Clear the memory backing the session */
+ olm::unset(utility, sizeof(olm::Utility));
+ /* Initialise a fresh session object in case someone tries to use it */
+ new(utility) olm::Utility();
+ return sizeof(olm::Utility);
+}
+
+
size_t olm_pickle_account_length(
OlmAccount * account
) {
@@ -558,7 +599,6 @@ size_t olm_session_id_length(
return b64_output_length(from_c(session)->session_id_length());
}
-
size_t olm_session_id(
OlmSession * session,
void * id, size_t id_length
@@ -724,4 +764,63 @@ size_t olm_decrypt(
);
}
+
+size_t olm_sha256_length(
+ OlmUtility * utility
+) {
+ return b64_output_length(from_c(utility)->sha256_length());
+}
+
+
+size_t olm_sha256(
+ OlmUtility * utility,
+ void const * input, size_t input_length,
+ void * output, size_t output_length
+) {
+ std::size_t raw_length = from_c(utility)->sha256_length();
+ if (output_length < b64_output_length(raw_length)) {
+ from_c(utility)->last_error =
+ olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+ return std::size_t(-1);
+ }
+ std::size_t result = from_c(utility)->sha256(
+ from_c(input), input_length,
+ b64_output_pos(from_c(output), raw_length), raw_length
+ );
+ if (result == std::size_t(-1)) {
+ return result;
+ }
+ return b64_output(from_c(output), raw_length);
+}
+
+
+size_t olm_ed25519_verify(
+ OlmUtility * utility,
+ void const * key, size_t key_length,
+ void const * message, size_t message_length,
+ void * signature, size_t signature_length
+) {
+ if (olm::decode_base64_length(key_length) != 32) {
+ from_c(utility)->last_error = olm::ErrorCode::INVALID_BASE64;
+ return std::size_t(-1);
+ }
+ olm::Ed25519PublicKey verify_key;
+ olm::decode_base64(
+ from_c(key), key_length,
+ verify_key.public_key
+ );
+ std::size_t raw_signature_length = b64_input(
+ from_c(signature), signature_length, from_c(utility)->last_error
+ );
+ if (raw_signature_length == std::size_t(-1)) {
+ return std::size_t(-1);
+ }
+ return from_c(utility)->ed25519_verify(
+ verify_key,
+ from_c(message), message_length,
+ from_c(signature), raw_signature_length
+ );
+}
+
+
}
diff --git a/src/utility.cpp b/src/utility.cpp
new file mode 100644
index 0000000..1d8c5c1
--- /dev/null
+++ b/src/utility.cpp
@@ -0,0 +1,57 @@
+/* Copyright 2015 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm/utility.hh"
+#include "olm/crypto.hh"
+
+
+olm::Utility::Utility(
+) : last_error(olm::ErrorCode::SUCCESS) {
+}
+
+
+size_t olm::Utility::sha256_length() {
+ return olm::HMAC_SHA256_OUTPUT_LENGTH;
+}
+
+
+size_t olm::Utility::sha256(
+ std::uint8_t const * input, std::size_t input_length,
+ std::uint8_t * output, std::size_t output_length
+) {
+ if (output_length < sha256_length()) {
+ last_error = olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+ return std::size_t(-1);
+ }
+ olm::sha256(input, input_length, output);
+ return 32;
+}
+
+
+size_t olm::Utility::ed25519_verify(
+ Ed25519PublicKey const & key,
+ std::uint8_t const * message, std::size_t message_length,
+ std::uint8_t const * signature, std::size_t signature_length
+) {
+ if (signature_length < 64) {
+ last_error = olm::ErrorCode::BAD_MESSAGE_MAC;
+ return std::size_t(-1);
+ }
+ if (!olm::ed25519_verify(key, message, message_length, signature)) {
+ last_error = olm::ErrorCode::BAD_MESSAGE_MAC;
+ return std::size_t(-1);
+ }
+ return std::size_t(0);
+}
diff --git a/tests/test_olm_sha256.cpp b/tests/test_olm_sha256.cpp
new file mode 100644
index 0000000..fe5bf42
--- /dev/null
+++ b/tests/test_olm_sha256.cpp
@@ -0,0 +1,20 @@
+#include "olm/olm.hh"
+#include "unittest.hh"
+
+int main() {
+{
+TestCase("Olm sha256 test");
+
+
+std::uint8_t utility_buffer[::olm_utility_size()];
+::OlmUtility * utility = ::olm_utility(utility_buffer);
+
+assert_equals(std::size_t(43), ::olm_sha256_length(utility));
+std::uint8_t output[43];
+::olm_sha256(utility, "Hello, World", 12, output, 43);
+
+std::uint8_t expected_output[] = "A2daxT/5zRU1zMffzfosRYxSGDcfQY3BNvLRmsH76KU";
+assert_equals(output, expected_output, 43);
+
+}
+}
diff --git a/tests/test_olm_signature.cpp b/tests/test_olm_signature.cpp
new file mode 100644
index 0000000..a7cce63
--- /dev/null
+++ b/tests/test_olm_signature.cpp
@@ -0,0 +1,81 @@
+#include "olm/olm.hh"
+#include "unittest.hh"
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+
+struct MockRandom {
+ MockRandom(std::uint8_t tag, std::uint8_t offset = 0)
+ : tag(tag), current(offset) {}
+ void operator()(
+ void * buf, std::size_t length
+ ) {
+ std::uint8_t * bytes = (std::uint8_t *) buf;
+ while (length > 32) {
+ bytes[0] = tag;
+ std::memset(bytes + 1, current, 31);
+ length -= 32;
+ bytes += 32;
+ current += 1;
+ }
+ if (length) {
+ bytes[0] = tag;
+ std::memset(bytes + 1, current, length - 1);
+ current += 1;
+ }
+ }
+ std::uint8_t tag;
+ std::uint8_t current;
+};
+
+std::uint8_t * check_malloc(std::size_t size) {
+ if (size == std::size_t(-1)) {
+ assert_not_equals(std::size_t(-1), size);
+ }
+ return (std::uint8_t *)::malloc(size);
+}
+
+
+int main() {
+
+{ /** Signing Test */
+TestCase test_case("Signing test");
+
+MockRandom mock_random_a('A', 0x00);
+
+void * account_buffer = check_malloc(::olm_account_size());
+::OlmAccount * account = ::olm_account(account_buffer);
+
+std::size_t random_size = ::olm_create_account_random_length(account);
+void * random = check_malloc(random_size);
+mock_random_a(random, random_size);
+::olm_create_account(account, random, random_size);
+::free(random);
+
+std::size_t message_size = 12;
+void * message = check_malloc(message_size);
+::memcpy(message, "Hello, World", message_size);
+
+std::size_t signature_size = ::olm_account_signature_length(account);
+void * signature = check_malloc(signature_size);
+assert_not_equals(std::size_t(-1), ::olm_account_sign(
+ account, message, message_size, signature, signature_size
+));
+
+std::size_t id_keys_size = ::olm_account_identity_keys_length(account);
+std::uint8_t * id_keys = (std::uint8_t *) check_malloc(id_keys_size);
+assert_not_equals(std::size_t(-1), ::olm_account_identity_keys(
+ account, id_keys, id_keys_size
+));
+
+void * utility_buffer = check_malloc(::olm_utility_size());
+::OlmUtility * utility = ::olm_utility(utility_buffer);
+
+assert_not_equals(std::size_t(-1), ::olm_ed25519_verify(
+ utility, id_keys + 71, 43, message, message_size, signature, signature_size
+));
+
+}
+
+}
--
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