ceph: aes crypto and base64 encode/decode helpers
Helpers to encrypt/decrypt AES and base64.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/armor.c b/fs/ceph/armor.c
new file mode 100644
index 0000000..67b2c03
--- /dev/null
+++ b/fs/ceph/armor.c
@@ -0,0 +1,99 @@
+
+#include <linux/errno.h>
+
+/*
+ * base64 encode/decode.
+ */
+
+const char *pem_key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static int encode_bits(int c)
+{
+ return pem_key[c];
+}
+
+static int decode_bits(char c)
+{
+ if (c >= 'A' && c <= 'Z')
+ return c - 'A';
+ if (c >= 'a' && c <= 'z')
+ return c - 'a' + 26;
+ if (c >= '0' && c <= '9')
+ return c - '0' + 52;
+ if (c == '+')
+ return 62;
+ if (c == '/')
+ return 63;
+ if (c == '=')
+ return 0; /* just non-negative, please */
+ return -EINVAL;
+}
+
+int ceph_armor(char *dst, const char *src, const char *end)
+{
+ int olen = 0;
+ int line = 0;
+
+ while (src < end) {
+ unsigned char a, b, c;
+
+ a = *src++;
+ *dst++ = encode_bits(a >> 2);
+ if (src < end) {
+ b = *src++;
+ *dst++ = encode_bits(((a & 3) << 4) | (b >> 4));
+ if (src < end) {
+ c = *src++;
+ *dst++ = encode_bits(((b & 15) << 2) |
+ (c >> 6));
+ *dst++ = encode_bits(c & 63);
+ } else {
+ *dst++ = encode_bits((b & 15) << 2);
+ *dst++ = '=';
+ }
+ } else {
+ *dst++ = encode_bits(((a & 3) << 4));
+ *dst++ = '=';
+ *dst++ = '=';
+ }
+ olen += 4;
+ line += 4;
+ if (line == 64) {
+ line = 0;
+ *(dst++) = '\n';
+ olen++;
+ }
+ }
+ return olen;
+}
+
+int ceph_unarmor(char *dst, const char *src, const char *end)
+{
+ int olen = 0;
+
+ while (src < end) {
+ int a, b, c, d;
+
+ if (src < end && src[0] == '\n')
+ src++;
+ if (src + 4 > end)
+ return -EINVAL;
+ a = decode_bits(src[0]);
+ b = decode_bits(src[1]);
+ c = decode_bits(src[2]);
+ d = decode_bits(src[3]);
+ if (a < 0 || b < 0 || c < 0 || d < 0)
+ return -EINVAL;
+
+ *dst++ = (a << 2) | (b >> 4);
+ if (src[2] == '=')
+ return olen + 1;
+ *dst++ = ((b & 15) << 4) | (c >> 2);
+ if (src[3] == '=')
+ return olen + 2;
+ *dst++ = ((c & 3) << 6) | d;
+ olen += 3;
+ src += 4;
+ }
+ return olen;
+}