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| author | Michael Brown | 2012-05-20 17:38:57 +0200 |
|---|---|---|
| committer | Michael Brown | 2012-05-20 17:47:57 +0200 |
| commit | 40e68e1119ed45ed27c586836d4cb9400a96db1c (patch) | |
| tree | 1d7640bd5a31ed0e81bcb13dbe9b4b1ea799b115 /src/core/base64.c | |
| parent | [efi] Work around platforms which choke on EFI_PCI_DEVICE_ENABLE (diff) | |
| download | ipxe-40e68e1119ed45ed27c586836d4cb9400a96db1c.tar.gz ipxe-40e68e1119ed45ed27c586836d4cb9400a96db1c.tar.xz ipxe-40e68e1119ed45ed27c586836d4cb9400a96db1c.zip | |
[base64] Avoid overrunning input data buffer
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/core/base64.c')
| -rw-r--r-- | src/core/base64.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/core/base64.c b/src/core/base64.c index 7514c1fa..761b42f2 100644 --- a/src/core/base64.c +++ b/src/core/base64.c @@ -54,11 +54,16 @@ void base64_encode ( const uint8_t *raw, size_t len, char *encoded ) { uint8_t *encoded_bytes = ( ( uint8_t * ) encoded ); size_t raw_bit_len = ( 8 * len ); unsigned int bit; + unsigned int byte; + unsigned int shift; unsigned int tmp; for ( bit = 0 ; bit < raw_bit_len ; bit += 6 ) { - tmp = ( ( raw_bytes[ bit / 8 ] << ( bit % 8 ) ) | - ( raw_bytes[ bit / 8 + 1 ] >> ( 8 - ( bit % 8 ) ) ) ); + byte = ( bit / 8 ); + shift = ( bit % 8 ); + tmp = ( raw_bytes[byte] << shift ); + if ( ( byte + 1 ) < len ) + tmp |= ( raw_bytes[ byte + 1 ] >> ( 8 - shift ) ); tmp = ( ( tmp >> 2 ) & 0x3f ); *(encoded_bytes++) = base64[tmp]; } |