C bindings for base64 functions

1 files changed, 77 insertions, 0 deletions

diff --git a/include/olm/base64.h b/include/olm/base64.h
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+/* Copyright 2015, 2016 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.
+ */
+
+/* C bindings for base64 functions */
+
+
+#ifndef OLM_BASE64_H_
+#define OLM_BASE64_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/**
+ * The number of bytes of unpadded base64 needed to encode a length of input.
+ */
+size_t olm_encode_base64_length(
+    size_t input_length
+);
+
+/**
+ * Encode the raw input as unpadded base64.
+ * Writes encode_base64_length(input_length) bytes to the output buffer.
+ * The input can overlap with the last three quarters of the output buffer.
+ * That is, the input pointer may be output + output_length - input_length.
+ *
+ * Returns number of bytes encoded
+ */
+size_t olm_encode_base64(
+    uint8_t const * input, size_t input_length,
+    uint8_t * output
+);
+
+/**
+ * The number of bytes of raw data a length of unpadded base64 will encode to.
+ * Returns size_t(-1) if the length is not a valid length for base64.
+ */
+size_t olm_decode_base64_length(
+    size_t input_length
+);
+
+/**
+ * Decodes the unpadded base64 input to raw bytes.
+ * Writes decode_base64_length(input_length) bytes to the output buffer.
+ * The output can overlap with the first three quarters of the input buffer.
+ * That is, the input pointers and output pointer may be the same.
+ *
+ * Returns number of bytes decoded
+ */
+size_t olm_decode_base64(
+    uint8_t const * input, size_t input_length,
+    uint8_t * output
+);
+
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+
+#endif /* OLM_BASE64_H_ */