Clean up and expose base64 implementation

7 files changed, 187 insertions, 65 deletions

diff --git a/serd/serd.h b/serd/serd.h
index e764d069..d87896ea 100644
--- a/serd/serd.h
+++ b/serd/serd.h
@@ -378,18 +378,59 @@ double
 serd_strtod(const char* str, size_t* end);
 
 /**
+   @}
+   @name Base64
+   @{
+*/
+
+/**
+   Return the number of bytes required to encode `size` bytes in base64.
+
+   @param size The number of input (binary) bytes to encode.
+   @param wrap_lines Wrap lines at 76 characters to conform to RFC 2045.
+   @return The length of the base64 encoding, excluding null terminator.
+*/
+SERD_API
+size_t
+serd_base64_encoded_length(size_t size, bool wrap_lines);
+
+/**
+   Return the maximum number of bytes required to decode `size` bytes of base64.
+
+   @param len The number of input (text) bytes to decode.
+   @return The required buffer size to decode `size` bytes of base64.
+*/
+SERD_API
+size_t
+serd_base64_decoded_size(size_t len);
+
+/**
+   Encode `size` bytes of `buf` into `str`, which must be large enough.
+
+   @param str Output buffer of at least serd_base64_encoded_length(size) bytes.
+   @param buf Input binary data.
+   @param size Number of bytes to encode from `buf`.
+   @param wrap_lines Wrap lines at 76 characters to conform to RFC 2045.
+   @return True iff `str` contains newlines.
+*/
+SERD_API
+bool
+serd_base64_encode(char* str, const void* buf, size_t size, bool wrap_lines);
+
+/**
    Decode a base64 string.
+
    This function can be used to deserialise a blob node created with
    serd_new_blob().
 
+   @param buf Output buffer of at least serd_base64_decoded_size(size) bytes.
+   @param size Set to the size of the decoded data in bytes.
    @param str Base64 string to decode.
    @param len The length of `str`.
-   @param size Set to the size of the returned blob in bytes.
-   @return A newly allocated blob which must be freed with serd_free().
 */
 SERD_API
-void*
-serd_base64_decode(const char* str, size_t len, size_t* size);
+SerdStatus
+serd_base64_decode(void* buf, size_t* size, const char* str, size_t len);
 
 /**
    @}
diff --git a/src/base64.c b/src/base64.c
index b82f0389..e557fdf8 100644
--- a/src/base64.c
+++ b/src/base64.c
@@ -14,8 +14,6 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
-#include "base64.h"
-
 #include "serd_internal.h"
 #include "string_utils.h"
 
@@ -59,11 +57,17 @@ encode_chunk(uint8_t out[4], const uint8_t in[3], size_t n_in)
 }
 
 size_t
-serd_base64_get_length(const size_t size, const bool wrap_lines)
+serd_base64_encoded_length(const size_t size, const bool wrap_lines)
 {
 	return (size + 2) / 3 * 4 + (wrap_lines * ((size - 1) / 57));
 }
 
+size_t
+serd_base64_decoded_size(const size_t len)
+{
+	return (len * 3) / 4 + 2;
+}
+
 bool
 serd_base64_encode(char* const       str,
                    const void* const buf,
@@ -104,13 +108,12 @@ decode_chunk(const uint8_t in[4], uint8_t out[3])
 	return 1 + (in[2] != '=') + ((in[2] != '=') && (in[3] != '='));
 }
 
-void*
-serd_base64_decode(const char* str, size_t len, size_t* size)
+SerdStatus
+serd_base64_decode(void* buf, size_t* size, const char* str, size_t len)
 {
 	const uint8_t* ustr = (const uint8_t*)str;
 
-	void* buf = malloc((len * 3) / 4 + 2);
-	*size     = 0;
+	*size = 0;
 	for (size_t i = 0, j = 0; i < len; j += 3) {
 		uint8_t in[] = "====";
 		size_t  n_in = 0;
@@ -122,5 +125,6 @@ serd_base64_decode(const char* str, size_t len, size_t* size)
 			*size += decode_chunk(in, (uint8_t*)buf + j);
 		}
 	}
-	return buf;
+
+	return SERD_SUCCESS;
 }
diff --git a/src/base64.h b/src/base64.h
deleted file mode 100644
index cb89491c..00000000
--- a/src/base64.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
-  Copyright 2011-2018 David Robillard <http://drobilla.net>
-
-  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.
-
-  THIS 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.
-*/
-
-#ifndef SERD_BASE64_H
-#define SERD_BASE64_H
-
-#include <stdbool.h>
-#include <stddef.h>
-
-/**
-   Return the number of bytes required to encode `size` bytes in base64.
-
-   @param size The number of input (binary) bytes to encode.
-   @param wrap_lines Wrap lines at 76 characters to conform to RFC 2045.
-   @return The length of the base64 encoding, excluding null terminator.
-*/
-size_t
-serd_base64_get_length(size_t size, bool wrap_lines);
-
-/**
-   Encode `size` bytes of `buf` into `str`, which must be large enough.
-
-   @param str Output string buffer.
-   @param buf Input binary data.
-   @param size Number of bytes to encode from `buf`.
-   @param wrap_lines Wrap lines at 76 characters to conform to RFC 2045.
-   @return True iff `str` contains newlines.
-*/
-bool
-serd_base64_encode(char* str, const void* buf, size_t size, bool wrap_lines);
-
-#endif  // SERD_BASE64_H
diff --git a/src/node.c b/src/node.c
index 20312815..af18d095 100644
--- a/src/node.c
+++ b/src/node.c
@@ -16,7 +16,6 @@
 
 #include "node.h"
 
-#include "base64.h"
 #include "serd_internal.h"
 #include "string_utils.h"
 
@@ -623,7 +622,7 @@ serd_new_blob(const void*     buf,
 	}
 
 	const SerdNode* type      = datatype ? datatype : &serd_xsd_base64Binary.node;
-	const size_t    len       = serd_base64_get_length(size, wrap_lines);
+	const size_t    len       = serd_base64_encoded_length(size, wrap_lines);
 	const size_t    type_len  = serd_node_total_size(type);
 	const size_t    total_len = len + 1 + type_len;
 
diff --git a/tests/base64_test.c b/tests/base64_test.c
new file mode 100644
index 00000000..b279b46b
--- /dev/null
+++ b/tests/base64_test.c
@@ -0,0 +1,120 @@
+/*
+  Copyright 2011-2019 David Robillard <http://drobilla.net>
+
+  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.
+
+  THIS 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.
+*/
+
+#undef NDEBUG
+
+#include "serd/serd.h"
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int
+test_round_trip(void)
+{
+	for (size_t size = 1; size < 1024; ++size) {
+		const size_t len = serd_base64_encoded_length(size, true);
+
+		char* buf = (char*)malloc(size);
+		for (size_t i = 0; i < size; ++i) {
+			buf[i] = (char)i;
+		}
+
+		char* str = (char*)calloc(1, len + 1);
+		serd_base64_encode(str, buf, size, true);
+
+		const size_t max_size  = serd_base64_decoded_size(len);
+		size_t       copy_size = 0;
+		char*        copy      = (char*)malloc(max_size);
+		serd_base64_decode(copy, &copy_size, str, len);
+		assert(copy_size == size);
+		assert(!memcmp(buf, copy, size));
+
+		free(copy);
+		free(str);
+		free(buf);
+	}
+
+	return 0;
+}
+
+static void
+test_encoding_equals(const char* const input, const char* const expected)
+{
+	const size_t size = strlen(input);
+	const size_t len  = serd_base64_encoded_length(size, true);
+
+	char* str = (char*)calloc(1, len + 1);
+	serd_base64_encode(str, input, size, true);
+
+	assert(!strcmp(str, expected));
+
+	free(str);
+}
+
+static int
+test_rfc4648_vectors(void)
+{
+	test_encoding_equals("f", "Zg==");
+	test_encoding_equals("fo", "Zm8=");
+	test_encoding_equals("foo", "Zm9v");
+	test_encoding_equals("foob", "Zm9vYg==");
+	test_encoding_equals("fooba", "Zm9vYmE=");
+	test_encoding_equals("foobar", "Zm9vYmFy");
+	return 0;
+}
+
+static void
+test_decoding_equals(const char* const base64, const char* const expected)
+{
+	const size_t len  = strlen(base64);
+	const size_t size = serd_base64_decoded_size(len);
+
+	size_t buf_size = 0;
+	char*  buf      = (char*)malloc(size);
+	serd_base64_decode(buf, &buf_size, base64, len);
+
+	assert(buf_size <= size);
+	assert(!memcmp(buf, expected, buf_size));
+
+	free(buf);
+}
+
+static int
+test_junk(void)
+{
+	test_decoding_equals("?Zm9vYmFy", "foobar");
+	test_decoding_equals("Z?m9vYmFy", "foobar");
+	test_decoding_equals("?Z?m9vYmFy", "foobar");
+	test_decoding_equals("?Z??m9vYmFy", "foobar");
+	test_decoding_equals("?Z???m9vYmFy", "foobar");
+	test_decoding_equals("?Z????m9vYmFy", "foobar");
+
+	test_decoding_equals("Zm9vYmFy?", "foobar");
+	test_decoding_equals("Zm9vYmF?y?", "foobar");
+	test_decoding_equals("Zm9vYmF?y??", "foobar");
+	test_decoding_equals("Zm9vYmF?y???", "foobar");
+	test_decoding_equals("Zm9vYmF?y????", "foobar");
+
+	return 0;
+}
+
+int
+main(void)
+{
+	return test_round_trip() || test_rfc4648_vectors() || test_junk();
+}
diff --git a/tests/serd_test.c b/tests/serd_test.c
index d6c2d1fc..a461e22a 100644
--- a/tests/serd_test.c
+++ b/tests/serd_test.c
@@ -212,12 +212,13 @@ main(void)
 			data[i] = (uint8_t)(rand() % 256);
 		}
 
-		size_t      out_size;
-		SerdNode*   blob     = serd_new_blob(data, size, size % 5, NULL);
-		const char* blob_str = serd_node_get_string(blob);
-		uint8_t*    out      = (uint8_t*)serd_base64_decode(
-			blob_str, serd_node_get_length(blob), &out_size);
+		size_t       out_size = 0;
+		SerdNode*    blob     = serd_new_blob(data, size, size % 5, NULL);
+		const char*  blob_str = serd_node_get_string(blob);
+		const size_t len      = serd_node_get_length(blob);
 
+		uint8_t* out = (uint8_t*)malloc(serd_base64_decoded_size(len));
+		assert(!serd_base64_decode(out, &out_size, blob_str, len));
 		assert(serd_node_get_length(blob) == strlen(blob_str));
 		assert(out_size == size);
 
@@ -229,7 +230,7 @@ main(void)
 		               NS_XSD "base64Binary"));
 
 		serd_node_free(blob);
-		serd_free(out);
+		free(out);
 		free(data);
 	}
 
diff --git a/wscript b/wscript
index 95cb0c86..e8abe917 100644
--- a/wscript
+++ b/wscript
@@ -148,6 +148,7 @@ def build(bld):
 
         # Test programs
         for prog in [('serdi_static', 'src/serdi.c'),
+                     ('base64_test', 'tests/base64_test.c'),
                      ('cursor_test', 'tests/cursor_test.c'),
                      ('serd_test', 'tests/serd_test.c'),
                      ('read_chunk_test', 'tests/read_chunk_test.c'),
@@ -422,6 +423,7 @@ def test(tst):
     srcdir = tst.path.abspath()
 
     with tst.group('Unit') as check:
+        check(['./base64_test'])
         check(['./cursor_test'])
         check(['./nodes_test'])
         check(['./overflow_test'])