1 files changed, 145 insertions, 0 deletions
diff --git a/src/util/support/base64.c b/src/util/support/base64.c
new file mode 100644
index 000000000000..e964a389e60d
--- /dev/null
+++ b/src/util/support/base64.c
@@ -0,0 +1,145 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/* util/support/base64.c - base64 encoder and decoder */
+/*
+ * Copyright (c) 1995-2001 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <k5-platform.h>
+#include <k5-base64.h>
+
+static const char base64_chars[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+char *
+k5_base64_encode(const void *data, size_t len)
+{
+    char *s, *p;
+    size_t i;
+    unsigned int c;
+    const unsigned char *q;
+
+    if (len > SIZE_MAX / 4)
+        return NULL;
+
+    p = s = malloc(len * 4 / 3 + 4);
+    if (p == NULL)
+        return NULL;
+    q = (const unsigned char *)data;
+
+    for (i = 0; i < len;) {
+        c = q[i++];
+        c *= 256;
+        if (i < len)
+            c += q[i];
+        i++;
+        c *= 256;
+        if (i < len)
+            c += q[i];
+        i++;
+        p[0] = base64_chars[(c & 0x00fc0000) >> 18];
+        p[1] = base64_chars[(c & 0x0003f000) >> 12];
+        p[2] = base64_chars[(c & 0x00000fc0) >> 6];
+        p[3] = base64_chars[(c & 0x0000003f) >> 0];
+        if (i > len)
+            p[3] = '=';
+        if (i > len + 1)
+            p[2] = '=';
+        p += 4;
+    }
+    *p = '\0';
+    return s;
+}
+
+#define DECODE_ERROR 0xffffffff
+
+/* Decode token, which must be four bytes long. */
+static unsigned int
+decode_token(const char *token)
+{
+    int i, marker = 0;
+    unsigned int val = 0;
+    const char *p;
+
+    for (i = 0; i < 4; i++) {
+        val *= 64;
+        if (token[i] == '=') {
+            marker++;
+        } else if (marker > 0) {
+            return DECODE_ERROR;
+        } else {
+            p = strchr(base64_chars, token[i]);
+            if (p == NULL)
+                return DECODE_ERROR;
+            val += p - base64_chars;
+        }
+    }
+    if (marker > 2)
+        return DECODE_ERROR;
+    return (marker << 24) | val;
+}
+
+void *
+k5_base64_decode(const char *str, size_t *len_out)
+{
+    unsigned char *data, *q;
+    unsigned int val, marker;
+    size_t len;
+
+    *len_out = SIZE_MAX;
+
+    /* Allocate the output buffer. */
+    len = strlen(str);
+    if (len % 4)
+        return NULL;
+    q = data = malloc(len / 4 * 3);
+    if (data == NULL) {
+        *len_out = 0;
+        return NULL;
+    }
+
+    /* Decode the string. */
+    for (; *str != '\0'; str += 4) {
+        val = decode_token(str);
+        if (val == DECODE_ERROR) {
+            free(data);
+            return NULL;
+        }
+        marker = (val >> 24) & 0xff;
+        *q++ = (val >> 16) & 0xff;
+        if (marker < 2)
+            *q++ = (val >> 8) & 0xff;
+        if (marker < 1)
+            *q++ = val & 0xff;
+    }
+    *len_out = q - data;
+    return data;
+}