Add URL safe base64 de-/encoding

src/headers/tomcrypt_misc.h

@@ -7,6 +7,12 @@ int base64_decode(const unsigned char *in,  unsigned long len,
                         unsigned char *out, unsigned long *outlen);
 #endif
 
+int base64url_encode(const unsigned char *in,  unsigned long len,
+                        unsigned char *out, unsigned long *outlen);
+
+int base64url_decode(const unsigned char *in,  unsigned long len,
+                        unsigned char *out, unsigned long *outlen);
+
 /* ===> LTC_HKDF -- RFC5869 HMAC-based Key Derivation Function <=== */
 #ifdef LTC_HKDF
 

src/misc/base64/base64_decode.c

@@ -13,12 +13,13 @@
 /**
   @file base64_decode.c
   Compliant base64 code donated by Wayne Scott ([email protected])
+  base64 URL Safe variant (RFC 4648 section 5) by Karel Miko
 */
 
 
 #ifdef LTC_BASE64
 
-static const unsigned char map[256] = {
+static const unsigned char map_base64[256] = {
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
@@ -42,16 +43,33 @@ static const unsigned char map[256] = {
 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 255, 255, 255, 255 };
 
-/**
-   base64 decode a block of memory
-   @param in       The base64 data to decode
-   @param inlen    The length of the base64 data
-   @param out      [out] The destination of the binary decoded data
-   @param outlen   [in/out] The max size and resulting size of the decoded data
-   @return CRYPT_OK if successful
-*/
-int base64_decode(const unsigned char *in,  unsigned long inlen, 
-                        unsigned char *out, unsigned long *outlen)
+static const unsigned char map_base64url[256] = {
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255,  62, 255, 255,
+ 52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,
+255, 254, 255, 255, 255,   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, 255, 255, 255, 255,  63,
+255,  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, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+255, 255, 255, 255 };
+
+int base64_decode_internal(const unsigned char *in,  unsigned long inlen,
+                                 unsigned char *out, unsigned long *outlen,
+                           const unsigned char *map)
 {
    unsigned long t, x, y, z;
    unsigned char c;
@@ -96,6 +114,34 @@ int base64_decode(const unsigned char *in,  unsigned long inlen,
    return CRYPT_OK;
 }
 
+/**
+   base64 decode a block of memory
+   @param in       The base64 data to decode
+   @param inlen    The length of the base64 data
+   @param out      [out] The destination of the binary decoded data
+   @param outlen   [in/out] The max size and resulting size of the decoded data
+   @return CRYPT_OK if successful
+*/
+int base64_decode(const unsigned char *in,  unsigned long inlen,
+                        unsigned char *out, unsigned long *outlen)
+{
+    return base64_decode_internal(in, inlen, out, outlen, map_base64);
+}
+
+/**
+   base64 (URL Safe, RFC 4648 section 5) decode a block of memory
+   @param in       The base64 data to decode
+   @param inlen    The length of the base64 data
+   @param out      [out] The destination of the binary decoded data
+   @param outlen   [in/out] The max size and resulting size of the decoded data
+   @return CRYPT_OK if successful
+*/
+int base64url_decode(const unsigned char *in,  unsigned long inlen,
+                           unsigned char *out, unsigned long *outlen)
+{
+    return base64_decode_internal(in, inlen, out, outlen, map_base64url);
+}
+
 #endif
 
 

src/misc/base64/base64_encode.c

@@ -13,24 +13,21 @@
 /**
   @file base64_encode.c
   Compliant base64 encoder donated by Wayne Scott ([email protected])
+  base64 URL Safe variant (RFC 4648 section 5) by Karel Miko
 */
 
 
 #ifdef LTC_BASE64
 
-static const char *codes = 
+static const char *codes_base64 =
 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
-/**
-   base64 Encode a buffer (NUL terminated)
-   @param in      The input buffer to encode
-   @param inlen   The length of the input buffer
-   @param out     [out] The destination of the base64 encoded data
-   @param outlen  [in/out] The max size and resulting size
-   @return CRYPT_OK if successful
-*/
-int base64_encode(const unsigned char *in,  unsigned long inlen, 
-                        unsigned char *out, unsigned long *outlen)
+static const char *codes_base64url =
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+
+int base64_encode_internal(const unsigned char *in,  unsigned long inlen,
+                                 unsigned char *out, unsigned long *outlen,
+                                 const char *codes, int pad)
 {
    unsigned long i, len2, leven;
    unsigned char *p;
@@ -61,8 +58,13 @@ int base64_encode(const unsigned char *in,  unsigned long inlen,
 
        *p++ = codes[(a >> 2) & 0x3F];
        *p++ = codes[(((a & 3) << 4) + (b >> 4)) & 0x3F];
-       *p++ = (i+1 < inlen) ? codes[(((b & 0xf) << 2)) & 0x3F] : '=';
-       *p++ = '=';
+       if (pad) {
+         *p++ = (i+1 < inlen) ? codes[(((b & 0xf) << 2)) & 0x3F] : '=';
+         *p++ = '=';
+       }
+       else {
+         if (i+1 < inlen) *p++ = codes[(((b & 0xf) << 2)) & 0x3F];
+       }
    }
 
    /* append a NULL byte */
@@ -73,6 +75,35 @@ int base64_encode(const unsigned char *in,  unsigned long inlen,
    return CRYPT_OK;
 }
 
+/**
+   base64 Encode a buffer (NUL terminated)
+   @param in      The input buffer to encode
+   @param inlen   The length of the input buffer
+   @param out     [out] The destination of the base64 encoded data
+   @param outlen  [in/out] The max size and resulting size
+   @return CRYPT_OK if successful
+*/
+int base64_encode(const unsigned char *in,  unsigned long inlen,
+                        unsigned char *out, unsigned long *outlen)
+{
+    return base64_encode_internal(in, inlen, out, outlen, codes_base64, 1);
+}
+
+
+/**
+   base64 (URL Safe, RFC 4648 section 5) Encode a buffer (NUL terminated)
+   @param in      The input buffer to encode
+   @param inlen   The length of the input buffer
+   @param out     [out] The destination of the base64 encoded data
+   @param outlen  [in/out] The max size and resulting size
+   @return CRYPT_OK if successful
+*/
+int base64url_encode(const unsigned char *in,  unsigned long inlen,
+                           unsigned char *out, unsigned long *outlen)
+{
+    return base64_encode_internal(in, inlen, out, outlen, codes_base64url, 0);
+}
+
 #endif