a

libsec/hmac.c

@@ -0,0 +1,56 @@
+#include "os.h"
+#include <libsec.h>
+
+/* rfc2104 */
+static DigestState*
+hmac_x(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s,
+	DigestState*(*x)(uchar*, ulong, uchar*, DigestState*), int xlen)
+{
+	int i;
+	uchar pad[65], innerdigest[256];
+
+	if(xlen > sizeof(innerdigest))
+		return nil;
+
+	if(klen>64)
+		return nil;
+
+	/* first time through */
+	if(s == nil){
+		for(i=0; i<64; i++)
+			pad[i] = 0x36;
+		pad[64] = 0;
+		for(i=0; i<klen; i++)
+			pad[i] ^= key[i];
+		s = (*x)(pad, 64, nil, nil);
+		if(s == nil)
+			return nil;
+	}
+
+	s = (*x)(p, len, nil, s);
+	if(digest == nil)
+		return s;
+
+	/* last time through */
+	for(i=0; i<64; i++)
+		pad[i] = 0x5c;
+	pad[64] = 0;
+	for(i=0; i<klen; i++)
+		pad[i] ^= key[i];
+	(*x)(nil, 0, innerdigest, s);
+	s = (*x)(pad, 64, nil, nil);
+	(*x)(innerdigest, xlen, digest, s);
+	return nil;
+}
+
+DigestState*
+hmac_sha1(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s)
+{
+	return hmac_x(p, len, key, klen, digest, s, sha1, SHA1dlen);
+}
+
+DigestState*
+hmac_md5(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s)
+{
+	return hmac_x(p, len, key, klen, digest, s, md5, MD5dlen);
+}