Add base32 encoding utility.

diff --git a/src/libutil/util.c b/src/libutil/util.c
index f06b7a62d86db5dfaef575a1e83ece0ff6285720..a4117d3c36aff686a8545e65c4026bd0d03c89ed 100644 (file)
--- a/src/libutil/util.c
+++ b/src/libutil/util.c
@@ -2246,3 +2246,67 @@ rspamd_inet_address_connect (rspamd_inet_addr_t *addr, gint type,
 
        return fd;
 }
+
+/*
+ * We use here z-base32 encoding described here:
+ * http://philzimmermann.com/docs/human-oriented-base-32-encoding.txt
+ */
+
+gchar *
+rspamd_encode_base32(guchar *in, gsize inlen)
+{
+       gint remain = -1, r, x;
+       gsize i;
+       gsize outlen = inlen * 8 / 5 + 1;
+       gchar *out;
+       static const char b32[]="ybndrfg8ejkmcpqxot1uwisza345h769";
+
+       out = g_malloc (outlen);
+       for (i = 0, r = 0; i < inlen; i++) {
+               switch (i % 5) {
+               case 0:
+                       /* 8 bits of input and 3 to remain */
+                       x = in[i];
+                       remain = in[i] >> 5;
+                       out[r++] = b32[x & 0x1F];
+                       break;
+               case 1:
+                       /* 11 bits of input, 1 to remain */
+                       x = remain | in[i] << 3;
+                       out[r++] = b32[x & 0x1F];
+                       out[r++] = b32[x >> 5 & 0x1F];
+                       remain = x >> 10;
+                       break;
+               case 2:
+                       /* 9 bits of input, 4 to remain */
+                       x = remain | in[i] << 1;
+                       out[r++] = b32[x & 0x1F];
+                       remain = x >> 5;
+                       break;
+               case 3:
+                       /* 12 bits of input, 2 to remain */
+                       x = remain | in[i] << 4;
+                       out[r++] = b32[x & 0x1F];
+                       out[r++] = b32[x >> 5 & 0x1F];
+                       remain = x >> 10 & 0x3;
+                       break;
+               case 4:
+                       /* 10 bits of output, nothing to remain */
+                       x = remain | in[i] << 2;
+                       out[r++] = b32[x & 0x1F];
+                       out[r++] = b32[x >> 5 & 0x1F];
+                       remain = -1;
+                       break;
+               default:
+                       /* Not to be happen */
+                       break;
+               }
+
+       }
+       if (remain >= 0)
+               out[r++] = b32[remain];
+
+       out[r] = 0;
+
+       return out;
+}

diff --git a/src/libutil/util.h b/src/libutil/util.h
index 3a44cb1d83ee7072fa730c7a873e8fbbdf494068..e2e20da62aa83e1f8089a1818ea53196edc940e4 100644 (file)
--- a/src/libutil/util.h
+++ b/src/libutil/util.h
@@ -489,4 +489,12 @@ void rspamd_inet_address_set_port (rspamd_inet_addr_t *addr, uint16_t port);
 int rspamd_inet_address_connect (rspamd_inet_addr_t *addr, gint type,
        gboolean async);
 
+/**
+ * Encode string using base32 encoding
+ * @param in input
+ * @param inlen input length
+ * @return freshly allocated base32 encoding of a specified string
+ */
+gchar * rspamd_encode_base32(guchar *in, gsize inlen);
+
 #endif