New. Based on code from ../sm/base64.c.

common/ChangeLog

@@ -1,3 +1,7 @@
+2004-02-10  Werner Koch  <wk@gnupg.org>
+
+	* b64enc.c: New.  Based on code from ../sm/base64.c.
+
 2004-01-30  Marcus Brinkmann  <marcus@g10code.de>
 
 	* Makefile.am (libcommon_a_SOURCES): Add xasprintf.c.

common/Makefile.am

@@ -34,6 +34,7 @@ libcommon_a_SOURCES = \
 	sysutils.c sysutils.h \
 	gettime.c \
 	yesno.c \
+	b64enc.c \
 	miscellaneous.c \
 	xasprintf.c \
 	membuf.c membuf.h \

common/b64enc.c

@@ -0,0 +1,211 @@
+/* b64enc.c - Simple Base64 encoder.
+ *	Copyright (C) 2001, 2003, 2004 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "i18n.h"
+#include "util.h"
+
+#define B64ENC_DID_HEADER   1
+#define B64ENC_DID_TRAILER  2
+#define B64ENC_NO_LINEFEEDS 16
+
+
+/* The base-64 character list */
+static unsigned char bintoasc[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" 
+                                    "abcdefghijklmnopqrstuvwxyz" 
+                                    "0123456789+/"; 
+
+/* Prepare for base-64 writing to the stream FP.  If TITLE is not NULL
+   and not an empty string, this string will be used as the title for
+   the armor lines, with TITLE being an empty string, we don't write
+   the header lines and furthermore even don't write any linefeeds.
+   With TITLE beeing NULL, we merely don't write header but make sure
+   that lines are not too long. Note, that we don't write any output
+   unless at least one byte get written using b64enc_write. */
+gpg_error_t
+b64enc_start (struct b64state *state, FILE *fp, const char *title)
+{
+  memset (state, 0, sizeof *state);
+  state->fp = fp;
+  if (title && !*title)
+    state->flags |= B64ENC_NO_LINEFEEDS;
+  else if (title)
+    {
+      state->title = xtrystrdup (title);
+      if (!state->title)
+        return  gpg_error_from_errno (errno);
+    }
+  return 0;
+}
+
+
+/* Write NBYTES from BUFFER to the Base 64 stream identified by
+   STATE. With BUFFER and NBYTES being 0, merely do a fflush on the
+   stream. */
+gpg_error_t
+b64enc_write (struct b64state *state, const void *buffer, size_t nbytes)
+{
+  unsigned char radbuf[4];
+  int idx, quad_count;
+  const unsigned char *p;
+  FILE *fp = state->fp;
+
+
+  if (!nbytes)
+    {
+      if (buffer && fflush (fp))
+        goto write_error;
+      return 0;
+    }
+
+  if (!(state->flags & B64ENC_DID_HEADER))
+    {
+      if (state->title)
+        {
+          if ( fputs ("-----BEGIN ", fp) == EOF
+               || fputs (state->title, fp) == EOF
+               || fputs ("-----\n", fp) == EOF)
+            goto write_error;
+        }
+      state->flags |= B64ENC_DID_HEADER;
+    }
+
+  idx = state->idx;
+  quad_count = state->quad_count;
+  assert (idx < 4);
+  memcpy (radbuf, state->radbuf, idx);
+  
+  for (p=buffer; nbytes; p++, nbytes--)
+    {
+      radbuf[idx++] = *p;
+      if (idx > 2)
+        {
+          char tmp[4];
+
+          tmp[0] = bintoasc[(*radbuf >> 2) & 077];
+          tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077];
+          tmp[2] = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077];
+          tmp[3] = bintoasc[radbuf[2]&077];
+          for (idx=0; idx < 4; idx++)
+            putc (tmp[idx], fp);
+          idx = 0;
+          if (ferror (fp))
+            goto write_error;
+          if (++quad_count >= (64/4)) 
+            {
+              quad_count = 0;
+              if (!(state->flags & B64ENC_NO_LINEFEEDS)
+                  && fputs ("\n", fp) == EOF)
+                goto write_error;
+            }
+        }
+    }
+  memcpy (state->radbuf, radbuf, idx);
+  state->idx = idx;
+  state->quad_count = quad_count;
+  return 0;
+
+ write_error:
+  return gpg_error_from_errno (errno);
+}
+
+gpg_error_t
+b64enc_finish (struct b64state *state)
+{
+  gpg_error_t err = 0;
+  unsigned char radbuf[4];
+  int idx, quad_count;
+  FILE *fp;
+
+  if (!(state->flags & B64ENC_DID_HEADER))
+    goto cleanup;
+
+  /* Flush the base64 encoding */
+  fp = state->fp;
+  idx = state->idx;
+  quad_count = state->quad_count;
+  assert (idx < 4);
+  memcpy (radbuf, state->radbuf, idx);
+
+  if (idx)
+    {
+      char tmp[4];
+      
+      tmp[0] = bintoasc[(*radbuf>>2)&077];
+      if (idx == 1)
+        {
+          tmp[1] = bintoasc[((*radbuf << 4) & 060) & 077];
+          tmp[2] = '=';
+          tmp[3] = '=';
+        }
+      else 
+        { 
+          tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077];
+          tmp[2] = bintoasc[((radbuf[1] << 2) & 074) & 077];
+          tmp[3] = '=';
+        }
+      for (idx=0; idx < 4; idx++)
+        putc (tmp[idx], fp);
+      idx = 0;
+      if (ferror (fp))
+        goto write_error;
+      
+      if (++quad_count >= (64/4)) 
+        {
+          quad_count = 0;
+          if (!(state->flags & B64ENC_NO_LINEFEEDS)
+              && fputs ("\n", fp) == EOF)
+            goto write_error;
+        }
+    }
+
+  /* Finish the last line and write the trailer. */
+  if (quad_count
+      && !(state->flags & B64ENC_NO_LINEFEEDS)
+      && fputs ("\n", fp) == EOF)
+    goto write_error;
+
+  if (state->title)
+    {
+      if ( fputs ("-----END ", fp) == EOF
+           || fputs (state->title, fp) == EOF
+           || fputs ("-----\n", fp) == EOF)
+        goto write_error;
+    }
+
+  goto cleanup;
+
+ write_error:
+  err = gpg_error_from_errno (errno);
+
+ cleanup:
+  if (state->title)
+    {
+      xfree (state->title);
+      state->title = NULL;
+    }
+  state->fp = NULL;
+  return err;
+}
+

common/util.h

@@ -1,5 +1,5 @@
-/* util.h - Utility functions for Gnupg
- *	Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
+/* util.h - Utility functions for GnuPG
+ * Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
  *
  * This file is part of GnuPG.
  *
@@ -98,6 +98,22 @@ int answer_is_yes_no_default (const char *s, int def_answer);
 int answer_is_yes_no_quit (const char *s);
 
 
+/*-- b64enc.c --*/
+struct b64state 
+{ 
+  unsigned int flags;
+  int idx;
+  int quad_count;
+  FILE *fp;
+  char *title;
+  unsigned char radbuf[4];
+};
+gpg_error_t b64enc_start (struct b64state *state, FILE *fp, const char *title);
+gpg_error_t b64enc_write (struct b64state *state,
+                          const void *buffer, size_t nbytes);
+gpg_error_t b64enc_finish (struct b64state *state);
+
+
 /*-- miscellaneous.c --*/
 
 /* Same as asprintf but return an allocated buffer suitable to be