DKIM: Ed25519 signatures (GnuTLS 3.6.0 and later)

[users/jgh/exim.git] / test / src / ed25519_privkey_pem_to_pubkey_raw_b64.c

diff --git a/test/src/ed25519_privkey_pem_to_pubkey_raw_b64.c b/test/src/ed25519_privkey_pem_to_pubkey_raw_b64.c
new file mode 100644 (file)
index 0000000..f6639b7
--- /dev/null
+++ b/test/src/ed25519_privkey_pem_to_pubkey_raw_b64.c
@@ -0,0 +1,139 @@
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Unix includes */
+
+typedef unsigned char uschar;
+
+#define CS   (char *)
+#define US   (unsigned char *)
+
+#define FALSE         0
+#define TRUE          1
+
+
+
+#ifdef HAVE_GNUTLS
+
+
+#include <gnutls/gnutls.h>
+#include <gnutls/abstract.h>
+#include <gnutls/x509.h>
+
+#if GNUTLS_VERSION_NUMBER >= 0x030600
+# define SIGN_HAVE_ED25519
+#endif
+
+
+
+static uschar *enc64table =
+  US"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+uschar *
+b64encode(uschar *clear, int len)
+{
+uschar *code = malloc(4*((len+2)/3) + 2);
+uschar *p = code;
+
+while (len-- >0)
+  {
+  int x, y;
+
+  x = *clear++;
+  *p++ = enc64table[(x >> 2) & 63];
+
+  if (len-- <= 0)
+    {
+    *p++ = enc64table[(x << 4) & 63];
+    *p++ = '=';
+    *p++ = '=';
+    break;
+    }
+
+  y = *clear++;
+  *p++ = enc64table[((x << 4) | ((y >> 4) & 15)) & 63];
+
+  if (len-- <= 0)
+    {
+    *p++ = enc64table[(y << 2) & 63];
+    *p++ = '=';
+    break;
+    }
+
+  x = *clear++;
+  *p++ = enc64table[((y << 2) | ((x >> 6) & 3)) & 63];
+
+  *p++ = enc64table[x & 63];
+  }
+
+*p = 0;
+
+return code;
+}
+
+/*************************************************
+*                 Main Program                   *
+*************************************************/
+
+
+int
+main(int argc, char **argv)
+{
+uschar * pemfile = argv[1];
+int fd;
+uschar buf[1024];
+int len, rc;
+gnutls_privkey_t privkey;
+gnutls_datum_t k;
+gnutls_pubkey_t pubkey;
+uschar * b64;
+
+#ifdef SIGN_HAVE_ED25519
+if ((fd = open(CS pemfile, O_RDONLY)) < 0)
+  exit(1);
+
+if ((len = read(fd, buf, sizeof(buf)-1)) < 0)
+  exit(2);
+
+k.data = buf;
+k.size = len;
+
+if (  (rc = gnutls_privkey_init(&privkey))
+   || (rc = gnutls_privkey_import_x509_raw(privkey, &k, GNUTLS_X509_FMT_PEM, NULL, GNUTLS_PKCS_PLAIN))
+   || (rc = gnutls_pubkey_init(&pubkey))
+   || (rc = gnutls_pubkey_import_privkey(pubkey, privkey, GNUTLS_KEY_DIGITAL_SIGNATURE, 0))
+   || (rc = gnutls_pubkey_export_ecc_raw2(pubkey, NULL, &k, NULL, GNUTLS_EXPORT_FLAG_NO_LZ))
+   )
+  fprintf(stderr, "%s\n", gnutls_strerror(rc));
+
+b64 = b64encode(k.data, k.size);
+
+printf("%s\n", b64);
+exit(0);
+
+#else
+fprintf(stderr, "No support for ed25519 signing in GnuTLS (version %s)\n", gnutls_check_version(NULL));
+exit(3);
+#endif
+}
+
+#endif
+
+#ifdef HAVE_OPENSSL
+int
+main(int argc, char **argv)
+{
+fprintf(stderr, "No support for ed25519 signing in OpenSSL\n");
+exit(3);
+}
+
+#endif