chacha/asm/chacha*: ensure that zero length is handled (without crash).

[openssl.git] / crypto / chacha / asm / chacha-armv4.pl

diff --git a/crypto/chacha/asm/chacha-armv4.pl b/crypto/chacha/asm/chacha-armv4.pl
index 4d234b727562ffc1eb20ad2bafc53af178dc7c38..55ebc9e586475a35e313b74483eb4b8d5b6f2b03 100755 (executable)
--- a/crypto/chacha/asm/chacha-armv4.pl
+++ b/crypto/chacha/asm/chacha-armv4.pl
@@ -200,6 +200,12 @@ ChaCha20_ctr32:
 #else
        adr     r14,.LChaCha20_ctr32
 #endif
+       cmp     r2,#0                   @ len==0?
+#ifdef __thumb2__
+       itt     eq
+#endif
+       addeq   sp,sp,#4*3
+       beq     .Lno_data
 #if __ARM_MAX_ARCH__>=7
        cmp     r2,#192                 @ test len
        bls     .Lshort
@@ -605,6 +611,7 @@ $code.=<<___;
 
 .Ldone:
        add     sp,sp,#4*(32+3)
+.Lno_data:
        ldmia   sp!,{r4-r11,pc}
 .size  ChaCha20_ctr32,.-ChaCha20_ctr32
 ___