scd: Extend ISO binary and record reading functions.

* scd/iso7816.c (iso7816_read_binary_ext): Add optional arg r_sw and
change callers.
(iso7816_read_record): Factor all code out to ...
(iso7816_read_record_ext): New.

Signed-off-by: Werner Koch <[email protected]>

3 files changed, 38 insertions, 10 deletions

diff --git a/scd/app-p15.c b/scd/app-p15.c
index 53e122206..21f7726cd 100644
--- a/scd/app-p15.c
+++ b/scd/app-p15.c
@@ -2917,7 +2917,7 @@ readcert_by_cdf (app_t app, cdf_object_t cdf,
     goto leave;
 
   err = iso7816_read_binary_ext (app_get_slot (app), 1, cdf->off, cdf->len,
-                                 &buffer, &buflen);
+                                 &buffer, &buflen, NULL);
   if (!err && (!buflen || *buffer == 0xff))
     err = gpg_error (GPG_ERR_NOT_FOUND);
   if (err)
diff --git a/scd/iso7816.c b/scd/iso7816.c
index 20706706c..d996eef39 100644
--- a/scd/iso7816.c
+++ b/scd/iso7816.c
@@ -786,13 +786,15 @@ iso7816_get_challenge (int slot, int length, unsigned char *buffer)
 }
 
 /* Perform a READ BINARY command requesting a maximum of NMAX bytes
-   from OFFSET.  With NMAX = 0 the entire file is read. The result is
-   stored in a newly allocated buffer at the address passed by RESULT.
-   Returns the length of this data at the address of RESULTLEN. */
+ * from OFFSET.  With NMAX = 0 the entire file is read. The result is
+ * stored in a newly allocated buffer at the address passed by RESULT.
+ * Returns the length of this data at the address of RESULTLEN.  If
+ * R_SW is not NULL the last status word is stored there. */
 gpg_error_t
 iso7816_read_binary_ext (int slot, int extended_mode,
                          size_t offset, size_t nmax,
-                         unsigned char **result, size_t *resultlen)
+                         unsigned char **result, size_t *resultlen,
+                         int *r_sw)
 {
   int sw;
   unsigned char *buffer;
@@ -800,6 +802,9 @@ iso7816_read_binary_ext (int slot, int extended_mode,
   int read_all = !nmax;
   size_t n;
 
+  if (r_sw)
+    *r_sw = 0;
+
   if (!result || !resultlen)
     return gpg_error (GPG_ERR_INV_VALUE);
   *result = NULL;
@@ -825,6 +830,8 @@ iso7816_read_binary_ext (int slot, int extended_mode,
                              ((offset>>8) & 0xff), (offset & 0xff) , -1, NULL,
                              n, &buffer, &bufferlen);
         }
+      if (r_sw)
+        *r_sw = sw;
 
       if (*result && sw == SW_BAD_P0_P1)
         {
@@ -885,7 +892,8 @@ gpg_error_t
 iso7816_read_binary (int slot, size_t offset, size_t nmax,
                      unsigned char **result, size_t *resultlen)
 {
-  return iso7816_read_binary_ext (slot, 0, offset, nmax, result, resultlen);
+  return iso7816_read_binary_ext (slot, 0, offset, nmax,
+                                  result, resultlen, NULL);
 }
 
 
@@ -895,15 +903,20 @@ iso7816_read_binary (int slot, size_t offset, size_t nmax,
    should be 0 to read the current EF or contain a short EF. The
    result is stored in a newly allocated buffer at the address passed
    by RESULT.  Returns the length of this data at the address of
-   RESULTLEN. */
+   RESULTLEN.  If R_SW is not NULL the last status word is stored
+   there.  */
 gpg_error_t
-iso7816_read_record (int slot, int recno, int reccount, int short_ef,
-                     unsigned char **result, size_t *resultlen)
+iso7816_read_record_ext (int slot, int recno, int reccount, int short_ef,
+                         unsigned char **result, size_t *resultlen,
+                         int *r_sw)
 {
   int sw;
   unsigned char *buffer;
   size_t bufferlen;
 
+  if (r_sw)
+    *r_sw = 0;
+
   if (!result || !resultlen)
     return gpg_error (GPG_ERR_INV_VALUE);
   *result = NULL;
@@ -922,6 +935,8 @@ iso7816_read_record (int slot, int recno, int reccount, int short_ef,
                      short_ef? short_ef : 0x04,
                      -1, NULL,
                      0, &buffer, &bufferlen);
+  if (r_sw)
+    *r_sw = sw;
 
   if (sw != SW_SUCCESS && sw != SW_EOF_REACHED)
     {
@@ -937,3 +952,11 @@ iso7816_read_record (int slot, int recno, int reccount, int short_ef,
 
   return 0;
 }
+
+gpg_error_t
+iso7816_read_record (int slot, int recno, int reccount, int short_ef,
+                     unsigned char **result, size_t *resultlen)
+{
+  return iso7816_read_record_ext (slot, recno, reccount, short_ef,
+                                  result, resultlen, NULL);
+}
diff --git a/scd/iso7816.h b/scd/iso7816.h
index bad558d0a..2cbfe6185 100644
--- a/scd/iso7816.h
+++ b/scd/iso7816.h
@@ -135,9 +135,14 @@ gpg_error_t iso7816_get_challenge (int slot,
 
 gpg_error_t iso7816_read_binary_ext (int slot, int extended_mode,
                                      size_t offset, size_t nmax,
-                                     unsigned char **result, size_t *resultlen);
+                                     unsigned char **result, size_t *resultlen,
+                                     int *r_sw);
 gpg_error_t iso7816_read_binary (int slot, size_t offset, size_t nmax,
                                  unsigned char **result, size_t *resultlen);
+gpg_error_t iso7816_read_record_ext (int slot, int recno, int reccount,
+                                     int short_ef,
+                                     unsigned char **result, size_t *resultlen,
+                                     int *r_sw);
 gpg_error_t iso7816_read_record (int slot, int recno, int reccount,
                                  int short_ef,
                                  unsigned char **result, size_t *resultlen);