Fixed configure.ac again (I broke it with my last change). Added first cut at gpg decryption routine.

git-svn-id: file:///home/mbr/svn/fwknop/trunk@45 510a4753-2344-4c79-9c09-4d669213fbeb

configure.ac

@@ -56,33 +56,23 @@ AC_CHECK_FUNCS([bzero gettimeofday memmove memset strchr strcspn strdup strndup
 
 # Check for gpgme
 #AM_PATH_GPGME
-#GPGME_SUPPORT="yes"
-
 AC_ARG_WITH([gpgme],
   [AS_HELP_STRING([--with-gpgme],
     [support for gpg encryption using libgpgme @<:@default=check@:>@])],
   [],
   [with_gpgme=check])
 
-LIBGPGME=
+have_gpgme=yes
 AS_IF([test "x$with_gpgme" != xno],
   [AC_CHECK_LIB([gpgme], [gpgme_check_version],
-    [AC_SUBST([LIBGPGME], ["-lgpgme"])
-     AC_DEFINE([HAVE_LIBGPGME], [1],
-               [Define if you have libgpgme])
-    ],
+  [],
     [if test "x$with_gpgme" != xcheck; then
        AC_MSG_FAILURE(
          [--with-gpgme was given, but test for gpgme failed])
-     fi
-    ])])
-
-have_gpgme=
-if test "x$LIBGPGME" == "x"; then
-  have_gpgme=no
      else
-  have_gpgme=yes
+       have_gpgme=no
      fi
+    ])], [have_gpgme=no])
 
 AC_CONFIG_FILES([Makefile
                  fko/Makefile

fko/fko_encryption.c

@@ -208,6 +208,53 @@ _gpg_encrypt(fko_ctx_t ctx, const char *enc_key)
     return(FKO_SUCCESS);
 }
 
+/* Prep and encrypt using gpgme
+*/
+int
+_gpg_decrypt(fko_ctx_t ctx, const char *dec_key, int b64_len)
+{
+    unsigned char  *cipher;
+    size_t          cipher_len, pt_len;
+
+    /* First make sure we have signer and recipient keys set.
+    if(ctx->gpg_signer == NULL || ctx->gpg_recipient == NULL)
+        return(FKO_ERROR_MISSING_GPG_KEY_DATA);
+    */
+
+    /* Create a bucket for the (base64) decoded encrypted data and get the
+     * raw cipher data.
+    */
+    cipher = malloc(strlen(ctx->encrypted_msg));
+    if(cipher == NULL)
+        return(FKO_ERROR_MEMORY_ALLOCATION);
+ 
+    cipher_len = b64_decode(ctx->encrypted_msg, cipher, b64_len);
+
+    /* Create a bucket for the plaintext data and decrypt the message
+     * data into it.
+    */
+    ctx->encoded_msg = malloc(cipher_len);
+    if(ctx->encoded_msg == NULL)
+        return(FKO_ERROR_MEMORY_ALLOCATION);
+
+    pt_len = gpgme_decrypt(cipher, cipher_len,
+        ctx->gpg_signer, ctx->gpg_recipient,
+        dec_key,  (unsigned char**)&ctx->encoded_msg, &cipher_len
+    );
+ 
+    /* Done with cipher...
+    */
+    free(cipher);
+
+    /* XXX: We could put some kind of sanity check  of the decrypted
+     *      data here
+    */
+
+    /* Call fko_decode and return the results.
+    */
+    return(fko_decode_spa_data(ctx));
+}
+
 #endif /* HAVE_LIBGPGME */
 
 /* Set the SPA encryption type.
@@ -314,8 +361,7 @@ fko_decrypt_spa_data(fko_ctx_t ctx, const char *dec_key)
     {
         ctx->encryption_type = FKO_ENCRYPTION_GPG;
 #if HAVE_LIBGPGME
-        return(FKO_ERROR_UNSUPPORTED_FEATURE);
-        //return(_gpg_decrypt(ctx, dec_key));
+        return(_gpg_decrypt(ctx, dec_key, b64_len));
 #else
         return(FKO_ERROR_UNSUPPORTED_FEATURE);
 #endif

fko/gpgme_funcs.c

@@ -28,17 +28,17 @@
 
 #if HAVE_LIBGPGME
 
+//#include <locale.h>
 #include <gpgme.h>
 #include "gpgme_funcs.h"
 
 /* Callback function that supplies the password when gpgme needs it.
 */
 gpgme_error_t
-get_gpg_pw(
+passphrase_cb(
   void *hook, const char *uid_hint, const char *passphrase_info,
   int prev_was_bad, int fd)
 {
-
     /* We only need to try once as it is fed by the program
      * (for now --DSS).
     */
@@ -250,7 +250,7 @@ gpgme_encrypt(
 
     /* Set the passphrase callback.
     */
-    gpgme_set_passphrase_cb(gpg_ctx, get_gpg_pw, pw);
+    gpgme_set_passphrase_cb(gpg_ctx, passphrase_cb, (void*)pw);
 
     err = gpgme_op_encrypt_sign(gpg_ctx, key, GPGME_ENCRYPT_ALWAYS_TRUST, plaintext, data);
     if(gpg_err_code(err) != GPG_ERR_NO_ERROR)
@@ -261,6 +261,8 @@ gpgme_encrypt(
         return(gpg_err_code(err));
     }
 
+    gpgme_data_release(plaintext);
+
     /* Get the encrypted data and its length from the gpgme data object.
     */
     tmp_buf = gpgme_data_release_and_get_mem(data, out_len);
@@ -282,6 +284,113 @@ gpgme_encrypt(
     return(res);
 }
 
+/* The main GPG encryption routine for libfko.
+*/
+int
+gpgme_decrypt(
+  unsigned char *indata, size_t in_len, const char *signer, const char *recip,
+  const char *pw, unsigned char **out, size_t *out_len)
+{
+    char                   *tmp_buf;
+    int                     res;
+
+    gpgme_ctx_t             gpg_ctx;
+    gpgme_error_t           err;
+    gpgme_data_t            cipher, plaintext;
+    gpgme_decrypt_result_t  decrypt_result;
+    gpgme_verify_result_t   verify_result;
+
+    /* Because the gpgme manual says you should.
+    */
+    gpgme_check_version(NULL);
+    //setlocale(LC_ALL, "");
+    //gpgme_set_locale(NULL, LC_CTYPE, setlocale(LC_CTYPE, NULL));
+
+    /* Check for OpenPGP support
+    */
+    err = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
+    if(gpg_err_code(err) != GPG_ERR_NO_ERROR)
+    {
+        /* GPG engine is not available. */
+        return(gpg_err_code(err));
+    }
+
+    /* Create our gpgme context
+    */
+    err = gpgme_new(&gpg_ctx);
+    if(gpg_err_code(err) != GPG_ERR_NO_ERROR)
+    {
+        return(gpg_err_code(err));
+    }
+
+    //gpgme_set_armor(gpg_ctx, 0);
+
+    err = gpgme_data_new(&plaintext);
+    if(gpg_err_code(err) != GPG_ERR_NO_ERROR)
+    {
+        gpgme_release(gpg_ctx);
+        return(gpg_err_code(err));
+    }
+
+    
+    /* Initialize the cipher data (place into gpgme_data object)
+    */
+    err = gpgme_data_new_from_mem(&cipher, (char*)indata, in_len, 0);
+    if(gpg_err_code(err) != GPG_ERR_NO_ERROR)
+    {
+        gpgme_release(gpg_ctx);
+        return(gpg_err_code(err));
+    }
+
+    /* Set the passphrase callback.
+    */
+    gpgme_set_passphrase_cb(gpg_ctx, passphrase_cb, (void*)pw);
+
+    /* Now decrypt and verify.
+    */
+    err = gpgme_op_decrypt_verify(gpg_ctx, cipher, plaintext);
+    if(gpg_err_code(err) != GPG_ERR_NO_ERROR)
+    {
+        gpgme_release(gpg_ctx);
+        return(gpg_err_code(err));
+    }
+
+    gpgme_data_release(cipher);
+
+    decrypt_result = gpgme_op_decrypt_result (gpg_ctx);
+
+    /* TODO: Do something with this (like the sample below)
+    if (decrypt_result->unsupported_algorithm)
+    {
+        fprintf (stderr, "%s:%i: unsupported algorithm: %s\n",
+	        __FILE__, __LINE__, decrypt_result->unsupported_algorithm);
+    }    
+    */
+
+    verify_result = gpgme_op_verify_result (gpg_ctx);
+    //TODO: Do something with this too (or not)
+
+    /* Get the encrypted data and its length from the gpgme data object.
+    */
+    tmp_buf = gpgme_data_release_and_get_mem(plaintext, out_len);
+
+    *out = malloc(*out_len); /* Note: this is freed when the context is destroyed */
+    if(*out == NULL)
+    {
+        res = -2;
+    }
+    else
+    {
+        res = 0;
+        memcpy(*out, tmp_buf, *out_len);
+    }
+
+    gpgme_free(tmp_buf);
+    gpgme_release(gpg_ctx);
+
+    return(res);
+}
+
 #endif /* HAVE_LIBGPGME */
 
 /***EOF***/

fko/gpgme_funcs.h

@@ -27,7 +27,7 @@
 #include "fko_common.h"
 
 int gpgme_encrypt(unsigned char *in, size_t len, const char *signer, const char *recip, const char *pw, unsigned char **out, size_t *out_len);
-int gpgme_decrypt(unsigned char *in, size_t len, const char *pw, unsigned char **out, size_t *out_len);
+int gpgme_decrypt(unsigned char *in, size_t len, const char *signer, const char *recip, const char *pw, unsigned char **out, size_t *out_len);
 
 #endif /* GPGME_FUNCS_H */