Implement a PEM-like format for Ed25519 keys.

[tinc] / src / ed25519 / ecdsa.c

diff --git a/src/ed25519/ecdsa.c b/src/ed25519/ecdsa.c
index 4515131..bfdabc1 100644 (file)
--- a/src/ed25519/ecdsa.c
+++ b/src/ed25519/ecdsa.c
@@ -62,9 +62,52 @@ char *ecdsa_get_base64_public_key(ecdsa_t *ecdsa) {
 
 // Read PEM ECDSA keys
 
+static bool read_pem(FILE *fp, const char *type, void *buf, size_t size) {
+       char line[1024];
+       bool data = false;
+       size_t typelen = strlen(type);
+
+       while(fgets(line, sizeof line, fp)) {
+               if(!data) {
+                       if(strncmp(line, "-----BEGIN ", 11))
+                               continue;
+                       if(strncmp(line + 11, type, typelen))
+                               continue;
+                       data = true;
+                       continue;
+               }
+
+               if(!strncmp(line, "-----END ", 9))
+                       break;
+
+               size_t linelen = strcspn(line, "\r\n");
+               size_t len = b64decode(line, line, linelen);
+               if(!len) {
+                       logger(DEBUG_ALWAYS, LOG_ERR, "Invalid base64 data in PEM file\n");
+                       return false;
+               }
+
+               if(len > size) {
+                       logger(DEBUG_ALWAYS, LOG_ERR, "Too much base64 data in PEM file\n");
+                       return false;
+               }
+
+               memcpy(buf, line, len);
+               buf += len;
+               size -= len;
+       }
+
+       if(size) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Too little base64 data in PEM file\n");
+               return false;
+       }
+
+       return true;
+}
+
 ecdsa_t *ecdsa_read_pem_public_key(FILE *fp) {
        ecdsa_t *ecdsa = xzalloc(sizeof *ecdsa);
-       if(fread(ecdsa->public, sizeof ecdsa->public, 1, fp) == 1)
+       if(read_pem(fp, "ED25519 PUBLIC KEY", ecdsa->public, sizeof ecdsa->public))
                return ecdsa;
        free(ecdsa);
        return 0;
@@ -72,7 +115,7 @@ ecdsa_t *ecdsa_read_pem_public_key(FILE *fp) {
 
 ecdsa_t *ecdsa_read_pem_private_key(FILE *fp) {
        ecdsa_t *ecdsa = xmalloc(sizeof *ecdsa);
-       if(fread(ecdsa, sizeof *ecdsa, 1, fp) == 1)
+       if(read_pem(fp, "ED25519 PRIVATE KEY", ecdsa->private, sizeof *ecdsa))
                return ecdsa;
        free(ecdsa);
        return 0;