From 503ac614ea91b4fdd9d5f6f467a2efcad900a7e1 Mon Sep 17 00:00:00 2001
From: Uros Majstorovic <majstor@majstor.org>
Date: Tue, 23 Apr 2024 18:07:21 +0200
Subject: added string key utilities

---
 ecp/src/ecp/cr.h            |  3 +++
 ecp/src/ecp/crypto/crypto.c | 37 +++++++++++++++++++++++++++++++++++++
 ecp/src/ecp/crypto/crypto.h |  2 ++
 3 files changed, 42 insertions(+)

(limited to 'ecp/src')

diff --git a/ecp/src/ecp/cr.h b/ecp/src/ecp/cr.h
index f5a617d..84f9bf1 100644
--- a/ecp/src/ecp/cr.h
+++ b/ecp/src/ecp/cr.h
@@ -16,3 +16,6 @@ int ecp_ecdsa_sign(ecp_ecdsa_signature_t *sig, unsigned char *m, size_t ml, ecp_
 int ecp_ecdsa_verify(unsigned char *m, size_t ml, ecp_ecdsa_signature_t *sig, ecp_ecdsa_public_t *p);
 
 void ecp_hmac(unsigned char *hd, ecp_hmac_key_t *k, unsigned char *m, size_t ml);
+
+int ecp_str2key(uint8_t *key, char *str);
+void ecp_key2str(char *str, uint8_t *key);
diff --git a/ecp/src/ecp/crypto/crypto.c b/ecp/src/ecp/crypto/crypto.c
index 2909f47..1b801ab 100644
--- a/ecp/src/ecp/crypto/crypto.c
+++ b/ecp/src/ecp/crypto/crypto.c
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <string.h>
+#include <stdio.h>
 
 #include <ecp/core.h>
 #include <ecp/cr.h>
@@ -131,3 +132,39 @@ void ecp_hmac(unsigned char *hd, ecp_hmac_key_t *k, unsigned char *m, size_t ml)
     SHA1_Update(&ctx, d, sizeof(d));
     SHA1_Final(hd, &ctx);
 }
+
+int ecp_str2key(uint8_t *key, char *str) {
+    unsigned int u[8];
+    int i, rv;
+
+    if (str[ECP_SIZE_ECDH_KEY_BUF - 1] != '\0') return ECP_ERR;
+
+    rv = sscanf(str, "%X:%X:%X:%X:%X:%X:%X:%X", &u[0], &u[1], &u[2], &u[3], &u[4], &u[5], &u[6], &u[7]);
+    if (rv != 8) return ECP_ERR;
+
+    for (i=0; i<8; i++) {
+        key[0] = u[i] >> 24;
+        key[1] = u[i] >> 16;
+        key[2] = u[i] >> 8;
+        key[3] = u[i];
+        key += 4;
+    }
+
+    return ECP_OK;
+}
+
+void ecp_key2str(char *str, uint8_t *key) {
+    unsigned int u[8];
+    int i;
+
+    for (i=0; i<8; i++) {
+        u[i]  = (unsigned int)key[0] << 24;
+        u[i] |= (unsigned int)key[1] << 16;
+        u[i] |= (unsigned int)key[2] << 8;
+        u[i] |= (unsigned int)key[3];
+        key += 4;
+    }
+
+    sprintf(str, "%.8X:%.8X:%.8X:%.8X:%.8X:%.8X:%.8X:%.8X", u[0], u[1], u[2], u[3], u[4], u[5], u[6], u[7]);
+    str[ECP_SIZE_ECDH_KEY_BUF - 1] = '\0';
+}
diff --git a/ecp/src/ecp/crypto/crypto.h b/ecp/src/ecp/crypto/crypto.h
index 1320fb8..1fd63a2 100644
--- a/ecp/src/ecp/crypto/crypto.h
+++ b/ecp/src/ecp/crypto/crypto.h
@@ -18,6 +18,8 @@
 #define ECP_SIZE_HMAC_KEY       32
 #define ECP_SIZE_HMAC_DIGEST    SHA_DIGEST_LENGTH
 
+#define ECP_SIZE_ECDH_KEY_BUF   72
+
 typedef uint8_t ecp_ecdh_public_t[ECP_SIZE_ECDH_PUB];
 typedef uint8_t ecp_ecdh_private_t[ECP_SIZE_ECDH_SEC];
 typedef uint8_t ecp_aead_key_t[ECP_SIZE_AEAD_KEY];
-- 
cgit v1.2.3