From: Timo Sirainen <tss@iki.fi>
Date: Thu, 30 May 2013 14:45:27 +0000 (+0300)
Subject: var_expand(): Added %N, which is the same as %H except based on MD5.
X-Git-Tag: 2.2.3~105
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e95bc848767afa2e52cb988a6d3f5e5cc5933885;p=thirdparty%2Fdovecot%2Fcore.git

var_expand(): Added %N, which is the same as %H except based on MD5.
This gives a better distribution of values than %H.
---

diff --git a/src/lib/var-expand.c b/src/lib/var-expand.c
index baec1e250c..0e8ec6aa04 100644
--- a/src/lib/var-expand.c
+++ b/src/lib/var-expand.c
@@ -87,6 +87,29 @@ static const char *m_str_hash(const char *str, struct var_expand_context *ctx)
 	return str_c(hash);
 }
 
+static const char *
+m_str_newhash(const char *str, struct var_expand_context *ctx)
+{
+	string_t *hash = t_str_new(20);
+	unsigned char result[MD5_RESULTLEN];
+	unsigned int value;
+
+	md5_get_digest(str, strlen(str), result);
+	memcpy(&value, result, sizeof(value));
+
+	if (ctx->width != 0) {
+		value %= ctx->width;
+		ctx->width = 0;
+	}
+
+	str_printfa(hash, "%x", value);
+	while ((int)str_len(hash) < ctx->offset)
+		str_insert(hash, 0, "0");
+        ctx->offset = 0;
+
+	return str_c(hash);
+}
+
 static const char *
 m_str_md5(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
 {
@@ -132,6 +155,7 @@ static const struct var_expand_modifier modifiers[] = {
 	{ 'X', m_str_hex },
 	{ 'R', m_str_reverse },
 	{ 'H', m_str_hash },
+	{ 'N', m_str_newhash },
 	{ 'M', m_str_md5 },
 	{ 'D', m_str_ldap_dn },
 	{ 'T', m_str_trim },