Created initial prototype.

Makefile

@@ -0,0 +1,12 @@
+CC = gcc
+CFLAGS = -O2 -Wall -I.
+DEPS = iprs_types.h sign.h validity.h
+OBJECTS = sign.o validity.o
+
+%.o: %.c $(DEPS)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+all: $(OBJECTS)
+
+clean:
+	rm -f $(OBJECTS)

iprs.h

@@ -0,0 +1,12 @@
+#ifndef IPRS_H
+   #define IPRS_H
+
+   #define TRUE			1
+   #define FALSE		0
+
+   typedef struct Record_struct {
+      uint8_t*    Value;
+      uint32_t    Expires;
+      uint8_t*    Signature;
+   } Record;
+#endif /* IPRS_H */

sign.c

@@ -0,0 +1,21 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include "iprs.h"
+#include "sign.h"
+
+uint8_t* signablePart(Record *r) {
+   uint8_t* sigbuf = NULL;
+   /* TODO */
+   return sigbuf;
+}
+
+uint8_t* authorKey_Sign(uint8_t *v) {
+   uint8_t* sign = NULL;
+   /* TODO */
+   return sign;
+}
+
+int authorKey_Verify(uint8_t *sign, uint8_t *value) {
+   /* TODO */
+   return TRUE;
+}

sign.h

@@ -0,0 +1,8 @@
+#ifndef SIGN_H
+   #define SIGN_H
+   uint8_t* signablePart(Record *r);
+
+   uint8_t* authorKey_Sign(uint8_t *v);
+
+   int authorKey_Verify(uint8_t *sign, uint8_t *value);
+#endif /* SIGN_H */

validity.c

@@ -0,0 +1,50 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <sys/time.h>
+#include "iprs.h"
+#include "validity.h"
+#include "sign.h"
+
+Record* MakeRecord(uint8_t* value, uint8_t* authorKey) {
+   struct timeval tv;
+   Record* r = calloc(1, sizeof(Record));
+
+   if (r) {
+      if (gettimeofday(&tv, NULL) != 0) {
+          // gettimeofday failed, cannot continue.
+          return NULL;
+      }
+      r->Value = value;
+
+      /* establish an expiration date */
+      r->Expires = tv.tv_sec + EXPIRATION_SECS;
+
+      /* cryptographically sign the record */
+      r->Signature = authorKey_Sign(signablePart(r));
+   }
+
+   return r;
+}
+
+int VerifyRecord(Record* r, uint8_t* authorKey) {
+   /* always check the signature first */
+   int sigok = authorKey_Verify(r->Signature, signablePart(r));
+   struct timeval tv;
+
+   if (!sigok || !r) {
+      return FALSE; /* sig did not check out! forged record? */
+   }
+
+   if (gettimeofday(&tv, NULL) != 0) {
+       // gettimeofday failed, cannot continue.
+       return FALSE;
+   }
+
+   /* check the expiration. */
+   if (r->Expires < tv.tv_sec) {
+      return FALSE; /* not valid anymore :( */
+   }
+
+   /* everything seems ok! */
+   return TRUE;
+}

validity.h

@@ -0,0 +1,9 @@
+#ifndef VALIDITY_H
+   #define VALIDITY_H
+
+   #define EXPIRATION_SECS	(24 * 60 * 60)	/* Record valide for a day */
+
+   uint8_t* signablePart(Record *r);
+   Record* MakeRecord(uint8_t* value, uint8_t* authorKey);
+   int VerifyRecord(Record* rec, uint8_t* authorKey);
+#endif /* VALIDITY_H */