sysadmin/ipxe
1
0
Fork 0
mirror of https://github.com/ipxe/ipxe synced 2026-01-22 03:32:59 +03:00
Code Issues Packages Projects Releases Wiki Activity

[crypto] Allow for zero-length big integer literals

Browse Source 
Ensure that zero-length big integer literals are treated as containing
a zero value.  Avoid tests on every big integer arithmetic operation
by ensuring that bigint_required_size() always returns a non-zero
value: the zero-length tests can therefore be restricted to only
bigint_init() and bigint_done().

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown
2025-12-29 14:01:46 +00:00
parent 01038893a3
commit 7c39c04a53
3 changed files with 15 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
src/arch/x86/include/bits/bigint.h
View File

@@ -32,10 +32,12 @@ bigint_init_raw ( uint32_t *value0, unsigned int size,
long discard_c;
/* Copy raw data in reverse order, padding with zeros */
__asm__ __volatile__ ( "\n1:\n\t"
__asm__ __volatile__ ( "jecxz 2f\n\t"
"\n1:\n\t"
"movb -1(%3,%1), %%al\n\t"
"stosb\n\t"
"loop 1b\n\t"
"\n2:\n\t"
"xorl %%eax, %%eax\n\t"
"mov %4, %1\n\t"
"rep stosb\n\t"
@@ -308,10 +310,12 @@ bigint_done_raw ( const uint32_t *value0, unsigned int size __unused,
long discard_c;
/* Copy raw data in reverse order */
__asm__ __volatile__ ( "\n1:\n\t"
__asm__ __volatile__ ( "jecxz 2f\n\t"
"\n1:\n\t"
"movb -1(%3,%1), %%al\n\t"
"stosb\n\t"
"loop 1b\n\t"
"\n2:\n\t"
: "=&D" ( discard_D ), "=&c" ( discard_c ),
"+m" ( *out_bytes )
: "r" ( value0 ), "0" ( out ), "1" ( len )