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Diffstat (limited to 'libtomcrypt/src/misc/base64/base64_decode.c')
-rw-r--r--libtomcrypt/src/misc/base64/base64_decode.c160
1 files changed, 126 insertions, 34 deletions
diff --git a/libtomcrypt/src/misc/base64/base64_decode.c b/libtomcrypt/src/misc/base64/base64_decode.c
index 6fd0ba2..4c58c68 100644
--- a/libtomcrypt/src/misc/base64/base64_decode.c
+++ b/libtomcrypt/src/misc/base64/base64_decode.c
@@ -5,20 +5,20 @@
*
* The library is free for all purposes without any express
* guarantee it works.
- *
- * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
*/
#include "tomcrypt.h"
/**
@file base64_decode.c
Compliant base64 code donated by Wayne Scott (wscott@bitmover.com)
+ base64 URL Safe variant (RFC 4648 section 5) by Karel Miko
*/
-#ifdef LTC_BASE64
+#if defined(LTC_BASE64) || defined (LTC_BASE64_URL)
-static const unsigned char map[256] = {
+#if defined(LTC_BASE64)
+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,
@@ -41,17 +41,43 @@ static const unsigned char map[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 };
+#endif /* LTC_BASE64 */
-/**
- 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[] = {
+#if defined(LTC_BASE64_URL)
+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
+#endif /* LTC_BASE64_URL */
+};
+
+enum {
+ relaxed = 0,
+ strict = 1
+};
+
+static int _base64_decode_internal(const unsigned char *in, unsigned long inlen,
+ unsigned char *out, unsigned long *outlen,
+ const unsigned char *map, int is_strict)
{
unsigned long t, x, y, z;
unsigned char c;
@@ -61,44 +87,110 @@ int base64_decode(const unsigned char *in, unsigned long inlen,
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
- g = 3;
+ g = 0; /* '=' counter */
for (x = y = z = t = 0; x < inlen; x++) {
c = map[in[x]&0xFF];
- if (c == 255) continue;
- /* the final = symbols are read and used to trim the remaining bytes */
- if (c == 254) {
- c = 0;
- /* prevent g < 0 which would potentially allow an overflow later */
- if (--g < 0) {
- return CRYPT_INVALID_PACKET;
- }
- } else if (g != 3) {
- /* we only allow = to be at the end */
+ if (c == 254) {
+ g++;
+ continue;
+ }
+ else if (is_strict && g > 0) {
+ /* we only allow '=' to be at the end */
return CRYPT_INVALID_PACKET;
}
+ if (c == 255) {
+ if (is_strict)
+ return CRYPT_INVALID_PACKET;
+ else
+ continue;
+ }
t = (t<<6)|c;
if (++y == 4) {
- if (z + g > *outlen) {
- return CRYPT_BUFFER_OVERFLOW;
- }
+ if (z + 3 > *outlen) return CRYPT_BUFFER_OVERFLOW;
out[z++] = (unsigned char)((t>>16)&255);
- if (g > 1) out[z++] = (unsigned char)((t>>8)&255);
- if (g > 2) out[z++] = (unsigned char)(t&255);
+ out[z++] = (unsigned char)((t>>8)&255);
+ out[z++] = (unsigned char)(t&255);
y = t = 0;
}
}
+
if (y != 0) {
- return CRYPT_INVALID_PACKET;
+ if (y == 1) return CRYPT_INVALID_PACKET;
+ if ((y + g) != 4 && is_strict && map != map_base64url) return CRYPT_INVALID_PACKET;
+ t = t << (6 * (4 - y));
+ if (z + y - 1 > *outlen) return CRYPT_BUFFER_OVERFLOW;
+ if (y >= 2) out[z++] = (unsigned char) ((t >> 16) & 255);
+ if (y == 3) out[z++] = (unsigned char) ((t >> 8) & 255);
}
*outlen = z;
return CRYPT_OK;
}
+#if defined(LTC_BASE64)
+/**
+ Relaxed 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, relaxed);
+}
+
+/**
+ Strict 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_strict_decode(const unsigned char *in, unsigned long inlen,
+ unsigned char *out, unsigned long *outlen)
+{
+ return _base64_decode_internal(in, inlen, out, outlen, map_base64, strict);
+}
+#endif /* LTC_BASE64 */
+
+#if defined(LTC_BASE64_URL)
+/**
+ Relaxed 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, relaxed);
+}
+
+/**
+ Strict 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_strict_decode(const unsigned char *in, unsigned long inlen,
+ unsigned char *out, unsigned long *outlen)
+{
+ return _base64_decode_internal(in, inlen, out, outlen, map_base64url, strict);
+}
+#endif /* LTC_BASE64_URL */
+
#endif
-/* $Source$ */
-/* $Revision$ */
-/* $Date$ */
+/* ref: $Format:%D$ */
+/* git commit: $Format:%H$ */
+/* commit time: $Format:%ai$ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 17:32:07 +0000