diff options
Diffstat (limited to 'scd/iso7816.c')
| -rw-r--r-- | scd/iso7816.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/scd/iso7816.c b/scd/iso7816.c index d7d3c126b..24361d148 100644 --- a/scd/iso7816.c +++ b/scd/iso7816.c @@ -488,6 +488,8 @@ iso7816_read_binary (int slot, size_t offset, size_t nmax, int sw; unsigned char *buffer; size_t bufferlen; + int read_all = !nmax; + size_t n; if (!result || !resultlen) return gpg_error (GPG_ERR_INV_VALUE); @@ -496,18 +498,22 @@ iso7816_read_binary (int slot, size_t offset, size_t nmax, /* We can only encode 15 bits in p0,p1 to indicate an offset. Thus we check for this limit. */ - if (offset > 32767 || nmax > 254) + if (offset > 32767) return gpg_error (GPG_ERR_INV_VALUE); do { buffer = NULL; bufferlen = 0; - /* Fixme: Either the ccid driver of the TCOS cards have problems + /* Fixme: Either the ccid driver or the TCOS cards have problems with an Le of 0. */ + if (read_all || nmax > 254) + n = 254; + else + n = nmax; sw = apdu_send_le (slot, 0x00, CMD_READ_BINARY, - ((offset>>8) & 0xff), (offset & 0xff) , -1, NULL, - nmax? nmax : 254, &buffer, &bufferlen); + ((offset>>8) & 0xff), (offset & 0xff) , -1, NULL, + n, &buffer, &bufferlen); if (sw != SW_SUCCESS && sw != SW_EOF_REACHED) { @@ -545,8 +551,12 @@ iso7816_read_binary (int slot, size_t offset, size_t nmax, if (offset > 32767) break; /* We simply truncate the result for too large files. */ + if (nmax > bufferlen) + nmax -= bufferlen; + else + nmax = 0; } - while (!nmax && sw != SW_EOF_REACHED); + while ((read_all && sw != SW_EOF_REACHED) || (!read_all && nmax)); return 0; } |