size_t
encode_base64 (const void*source, void *target, size_t source_size)
{
int
nb_block; /* Total number of blocks */
const byte
*p_source, /* Pointer to source buffer */
*source_start;
byte
*p_target, /* Pointer to target buffer */
value; /* Value of Base64 byte */
ASSERT (source);
ASSERT (target);
source_start = (const byte *)source;
if (source_size == 0)
return (0);
if (!tables_initialised)
init_conversion_tables ();
/* Bit positions
| byte 1 | byte 2 | byte 3 |
source block 87654321 87654321 87654321 -> 3 bytes of 8 bits
| byte 1 | byte 2 | byte 3 | byte 4 |
Encoded block 876543 218765 432187 654321 -> 4 bytes of 6 bits
*/
nb_block = (int) ((source_size + 2) / 3);
p_source = (const byte *) source; /* Point to start of buffers */
p_target = (byte *) target;
while (nb_block--)
{
/* Byte 1 */
value = *p_source >> 2;
*p_target++ = base64_to_char [value];
/* Byte 2 */
value = (*p_source++ & 0x03) << 4;
if ((size_t) (p_source - source_start) < source_size)
value |= (*p_source & 0xF0) >> 4;
*p_target++ = base64_to_char [value];
/* Byte 3 - pad the buffer with '=' if block not completed */
if ((size_t) (p_source - source_start) < source_size)
{
value = (*p_source++ & 0x0F) << 2;
if ((size_t) (p_source - source_start) < source_size)
value |= (*p_source & 0xC0) >> 6;
*p_target++ = base64_to_char [value];
}
else
size_t
encode_base64 (const byte *source, byte *target, size_t source_size)
{
size_t
target_size = 0; /* Length of target buffer */
int
nb_block; /* Total number of blocks */
byte
*p_source, /* Pointer to source buffer */
*p_target, /* Pointer to target buffer */
value; /* Value of Base64 byte */
ASSERT (source);
ASSERT (target);
if (source_size == 0)
return (0);
if (!tables_initialised)
init_conversion_tables ();
/* Bit positions
| byte 1 | byte 2 | byte 3 |
source block 87654321 87654321 87654321 -> 3 bytes of 8 bits
| byte 1 | byte 2 | byte 3 | byte 4 |
Encoded block 876543 218765 432187 654321 -> 4 bytes of 6 bits
*/
nb_block = (int) (source_size / 3);
/* Check if we have a partially-filled block */
if (nb_block * 3 != (int) source_size)
nb_block++;
target_size = (size_t) nb_block * 4;
target [target_size] = '\0';
p_source = (byte *) source; /* Point to start of buffers */
p_target = target;
while (nb_block--)
{
/* Byte 1 */
value = *p_source >> 2;
*p_target++ = base64_to_char [value];
/* Byte 2 */
value = (*p_source++ & 0x03) << 4;
if ((size_t) (p_source - source) < source_size)
value |= (*p_source & 0xF0) >> 4;
*p_target++ = base64_to_char [value];
/* Byte 3 - pad the buffer with '=' if block not completed */
if ((size_t) (p_source - source) < source_size)
{
value = (*p_source++ & 0x0F) << 2;
if ((size_t) (p_source - source) < source_size)
value |= (*p_source & 0xC0) >> 6;
*p_target++ = base64_to_char [value];
}
else
