extend base64 api with url safe versions

1 files changed, 193 insertions, 26 deletions

diff --git a/src/base64.c b/src/base64.c
index c11364f..79909ea 100644
--- a/src/base64.c
+++ b/src/base64.c
@@ -21,22 +21,112 @@
 
 #include "nsutils/base64.h"
 
-static uint8_t decoding_table[256];
-static uint8_t encoding_table[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
-                                'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
-                                'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
-                                'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
-                                'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
-                                'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
-                                'w', 'x', 'y', 'z', '0', '1', '2', '3',
-                                '4', '5', '6', '7', '8', '9', '+', '/'};
+static const uint8_t b64_decoding_table[256] = {
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /*  0 -  7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /*  8 -  F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 10 - 17 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 18 - 1F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 20 - 27 */
+    0xff, 0xff, 0xff,   62, 0xff, 0xff, 0xff,   63, /* 28 - 2F */
+      52,   53,   54,   55,   56,   57,   58,   59, /* 30 - 37 */
+      60,   61, 0xff, 0xff, 0xff,   64, 0xff, 0xff, /* 38 - 3F */
+    0xff,    0,    1,    2,    3,    4,    5,    6, /* 40 - 47 */
+       7,    8,    9,   10,   11,   12,   13,   14, /* 48 - 4F */
+      15,   16,   17,   18,   19,   20,   21,   22, /* 50 - 57 */
+      23,   24,   25, 0xff, 0xff, 0xff, 0xff, 0xff, /* 58 - 5F */
+    0xff,   26,   27,   28,   29,   30,   31,   32, /* 60 - 67 */
+      33,   34,   35,   36,   37,   38,   39,   40, /* 68 - 6F */
+      41,   42,   43,   44,   45,   46,   47,   48, /* 70 - 77 */
+      49,   50,   51, 0xff, 0xff, 0xff, 0xff, 0xff, /* 78 - 7F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 80 - 87 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 88 - 8F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 90 - 97 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 98 - 9F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* A0 - A7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* A8 - AF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* B0 - B7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* B8 - BF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* C0 - C7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* C8 - CF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* D0 - D7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* D8 - DF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* E0 - E7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* E8 - EF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* F0 - F7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* F8 - FF */
+};
+static const uint8_t b64_encoding_table[] = {
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+    'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+    'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+    'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+    'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+    'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+    'w', 'x', 'y', 'z', '0', '1', '2', '3',
+    '4', '5', '6', '7', '8', '9', '+', '/'};
+static const uint8_t b64url_decoding_table[256] = {
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /*  0 -  7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /*  8 -  F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 10 - 17 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 18 - 1F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 20 - 27 */
+    0xff, 0xff, 0xff, 0xff, 0xff,   62, 0xff, 0xff, /* 28 - 2F */
+      52,   53,   54,   55,   56,   57,   58,   59, /* 30 - 37 */
+      60,   61, 0xff, 0xff, 0xff,   64, 0xff, 0xff, /* 38 - 3F */
+    0xff,    0,    1,    2,    3,    4,    5,    6, /* 40 - 47 */
+       7,    8,    9,   10,   11,   12,   13,   14, /* 48 - 4F */
+      15,   16,   17,   18,   19,   20,   21,   22, /* 50 - 57 */
+      23,   24,   25, 0xff, 0xff, 0xff, 0xff,   63, /* 58 - 5F */
+    0xff,   26,   27,   28,   29,   30,   31,   32, /* 60 - 67 */
+      33,   34,   35,   36,   37,   38,   39,   40, /* 68 - 6F */
+      41,   42,   43,   44,   45,   46,   47,   48, /* 70 - 77 */
+      49,   50,   51, 0xff, 0xff, 0xff, 0xff, 0xff, /* 78 - 7F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 80 - 87 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 88 - 8F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 90 - 97 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 98 - 9F */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* A0 - A7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* A8 - AF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* B0 - B7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* B8 - BF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* C0 - C7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* C8 - CF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* D0 - D7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* D8 - DF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* E0 - E7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* E8 - EF */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* F0 - F7 */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* F8 - FF */
+};
+static const uint8_t b64url_encoding_table[] = {
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+    'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+    'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+    'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+    'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+    'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+    'w', 'x', 'y', 'z', '0', '1', '2', '3',
+    '4', '5', '6', '7', '8', '9', '-', '_'};
 static unsigned int mod_table[] = {0, 2, 1};
 
-/* exported interface documented in nsutils/base64.h */
-nsuerror nsu_base64_encode_alloc(const uint8_t *input,
-                            size_t input_length,
-                            uint8_t **output,
-                            size_t *output_length)
+
+/**
+ * Base 64 encode data using a given encoding table.
+ *
+ * allocate a buffer and encode source data into it using the Base64 encoding.
+ *
+ * \param input The source data to encode.
+ * \param input_length The length of the source data.
+ * \param output The buffer to recive data into, the caller must free.
+ * \param output_length The length of data placed in \a output
+ * \return NSERROR_OK on success and \a output updated else error code.
+ */
+static nsuerror
+table_encode_alloc(const uint8_t *encoding_table,
+                   const uint8_t *input,
+                   size_t input_length,
+                   uint8_t **output,
+                   size_t *output_length)
 {
         uint8_t *encoded;
         size_t encoded_len;
@@ -74,14 +164,62 @@ nsuerror nsu_base64_encode_alloc(const uint8_t *input,
         return NSUERROR_OK;
 }
 
+/*
+ * standard base64 encoding
+ *
+ * exported interface documented in nsutils/base64.h
+ */
+nsuerror
+nsu_base64_encode_alloc(const uint8_t *input,
+                        size_t input_length,
+                        uint8_t **output,
+                        size_t *output_length)
+{
+        return table_encode_alloc(b64_encoding_table,
+                                  input,
+                                  input_length,
+                                  output,
+                                  output_length);
+}
 
-/* exported interface documented in nsutils/base64.h */
-nsuerror nsu_base64_decode_alloc(const uint8_t *input,
+/*
+ * url base64 encoding
+ *
+ * exported interface documented in nsutils/base64.h
+ */
+nsuerror
+nsu_base64_encode_alloc_url(const uint8_t *input,
                             size_t input_length,
                             uint8_t **output,
                             size_t *output_length)
 {
-        static bool decode_initialised = false;
+        return table_encode_alloc(b64url_encoding_table,
+                                  input,
+                                  input_length,
+                                  output,
+                                  output_length);
+}
+
+
+/**
+ * Base 64 decode data with a given decoding table.
+ *
+ * Allocate a buffer and decode source data into it using the Base64 decoding
+ * table.
+ *
+ * \param input The source data to decode.
+ * \param input_length The length of the source data.
+ * \param output The buffer to recive data into, the caller must free.
+ * \param output_length The length of data placed in \a output
+ * \return NSERROR_OK on success and \a output updated else error code.
+ */
+static nsuerror
+base64_decode_alloc(const uint8_t *decoding_table,
+                    const uint8_t *input,
+                    size_t input_length,
+                    uint8_t **output,
+                    size_t *output_length)
+{
         uint8_t *decoded;
         size_t decoded_len;
         size_t idx;
@@ -89,15 +227,6 @@ nsuerror nsu_base64_decode_alloc(const uint8_t *input,
         uint8_t sextet[4];
         int sextet_idx;
 
-        if (!decode_initialised) {
-                memset(decoding_table, 0xff, sizeof(decoding_table));
-                for (idx = 0; idx < 64; idx++) {
-                        decoding_table[encoding_table[idx]] = idx;
-                }
-                decoding_table['='] = 64;
-                decode_initialised = true;
-        }
-
         decoded_len = ((input_length + 3) / 4) * 3;
         if (input[input_length - 1] == '=') (decoded_len)--;
         if (input[input_length - 2] == '=') (decoded_len)--;
@@ -179,3 +308,41 @@ nsuerror nsu_base64_decode_alloc(const uint8_t *input,
 
         return NSUERROR_OK;
 }
+
+
+/*
+ * standard base64 decoding
+ *
+ * exported interface documented in nsutils/base64.h
+ */
+nsuerror
+nsu_base64_decode_alloc(const uint8_t *input,
+                        size_t input_length,
+                        uint8_t **output,
+                        size_t *output_length)
+{
+        return base64_decode_alloc(b64_decoding_table,
+                                   input,
+                                   input_length,
+                                   output,
+                                   output_length);
+}
+
+
+/*
+ * standard base64 decoding
+ *
+ * exported interface documented in nsutils/base64.h
+ */
+nsuerror
+nsu_base64_decode_alloc_url(const uint8_t *input,
+                            size_t input_length,
+                            uint8_t **output,
+                            size_t *output_length)
+{
+        return base64_decode_alloc(b64url_decoding_table,
+                                   input,
+                                   input_length,
+                                   output,
+                                   output_length);
+}