--- /dev/null
+/* 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 <cassert>
+
+#include "olm/base64.h"
+#include "olm/base64.hh"
+
+namespace {
+
+static const std::uint8_t ENCODE_BASE64[64] = {
+ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
+ 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
+ 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+ 0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
+ 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E,
+ 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76,
+ 0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33,
+ 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2F,
+};
+
+static const std::uint8_t E = -1;
+
+static const std::uint8_t DECODE_BASE64[128] = {
+/* 0x0 0x1 0x2 0x3 0x4 0x5 0x6 0x7 0x8 0x9 0xA 0xB 0xC 0xD 0xE 0xF */
+ E, E, E, E, E, E, E, E, E, E, E, E, E, E, E, E,
+ E, E, E, E, E, E, E, E, E, E, E, E, E, E, E, E,
+ E, E, E, E, E, E, E, E, E, E, E, 62, E, E, E, 63,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, E, E, E, E, E, E,
+ E, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, E, E, E, E, E,
+ E, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, E, E, E, E, E,
+};
+
+} // namespace
+
+
+std::size_t olm::encode_base64_length(
+ std::size_t input_length
+) {
+ return 4 * ((input_length + 2) / 3) + (input_length + 2) % 3 - 2;
+}
+
+std::uint8_t * olm::encode_base64(
+ std::uint8_t const * input, std::size_t input_length,
+ std::uint8_t * output
+) {
+ std::uint8_t const * end = input + (input_length / 3) * 3;
+ std::uint8_t const * pos = input;
+ while (pos != end) {
+ unsigned value = pos[0];
+ value <<= 8; value |= pos[1];
+ value <<= 8; value |= pos[2];
+ pos += 3;
+ output[3] = ENCODE_BASE64[value & 0x3F];
+ value >>= 6; output[2] = ENCODE_BASE64[value & 0x3F];
+ value >>= 6; output[1] = ENCODE_BASE64[value & 0x3F];
+ value >>= 6; output[0] = ENCODE_BASE64[value];
+ output += 4;
+ }
+ unsigned remainder = input + input_length - pos;
+ std::uint8_t * result = output;
+ if (remainder) {
+ unsigned value = pos[0];
+ if (remainder == 2) {
+ value <<= 8; value |= pos[1];
+ value <<= 2;
+ output[2] = ENCODE_BASE64[value & 0x3F];
+ value >>= 6;
+ result += 3;
+ } else {
+ value <<= 4;
+ result += 2;
+ }
+ output[1] = ENCODE_BASE64[value & 0x3F];
+ value >>= 6;
+ output[0] = ENCODE_BASE64[value];
+ }
+ return result;
+}
+
+
+std::size_t olm::decode_base64_length(
+ std::size_t input_length
+) {
+ if (input_length % 4 == 1) {
+ return std::size_t(-1);
+ } else {
+ return 3 * ((input_length + 2) / 4) + (input_length + 2) % 4 - 2;
+ }
+}
+
+
+std::size_t olm::decode_base64(
+ std::uint8_t const * input, std::size_t input_length,
+ std::uint8_t * output
+) {
+ size_t raw_length = olm::decode_base64_length(input_length);
+
+ if (raw_length == std::size_t(-1)) {
+ return std::size_t(-1);
+ }
+
+ std::uint8_t const * end = input + (input_length / 4) * 4;
+ std::uint8_t const * pos = input;
+
+ while (pos != end) {
+ unsigned value = DECODE_BASE64[pos[0] & 0x7F];
+ value <<= 6; value |= DECODE_BASE64[pos[1] & 0x7F];
+ value <<= 6; value |= DECODE_BASE64[pos[2] & 0x7F];
+ value <<= 6; value |= DECODE_BASE64[pos[3] & 0x7F];
+ pos += 4;
+ output[2] = value;
+ value >>= 8; output[1] = value;
+ value >>= 8; output[0] = value;
+ output += 3;
+ }
+
+ unsigned remainder = input + input_length - pos;
+ if (remainder) {
+ /* A base64 payload with a single byte remainder cannot occur because
+ * a single base64 character only encodes 6 bits, which is less than
+ * a full byte. Therefore, a minimum of two base64 characters are
+ * required to construct a single output byte and payloads with
+ * a remainder of 1 are illegal.
+ *
+ * Should never be the case due to length check above.
+ */
+ assert(remainder != 1);
+
+ unsigned value = DECODE_BASE64[pos[0] & 0x7F];
+ value <<= 6; value |= DECODE_BASE64[pos[1] & 0x7F];
+ if (remainder == 3) {
+ value <<= 6; value |= DECODE_BASE64[pos[2] & 0x7F];
+ value >>= 2;
+ output[1] = value;
+ value >>= 8;
+ } else {
+ value >>= 4;
+ }
+ output[0] = value;
+ }
+
+ return raw_length;
+}
+
+
+// implementations of base64.h
+
+size_t _olm_encode_base64_length(
+ size_t input_length
+) {
+ return olm::encode_base64_length(input_length);
+}
+
+size_t _olm_encode_base64(
+ uint8_t const * input, size_t input_length,
+ uint8_t * output
+) {
+ uint8_t * r = olm::encode_base64(input, input_length, output);
+ return r - output;
+}
+
+size_t _olm_decode_base64_length(
+ size_t input_length
+) {
+ return olm::decode_base64_length(input_length);
+}
+
+size_t _olm_decode_base64(
+ uint8_t const * input, size_t input_length,
+ uint8_t * output
+) {
+ return olm::decode_base64(input, input_length, output);
+}
projects / matrix_esp_thesis / blobdiff