Reduce size of mbedtls_asn1_get_len

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
This commit is contained in:
Dave Rodgman 2023-09-12 14:42:46 +01:00
parent d3450da98d
commit ef6795d2a9

View file

@ -47,47 +47,18 @@ int mbedtls_asn1_get_len(unsigned char **p,
if ((**p & 0x80) == 0) { if ((**p & 0x80) == 0) {
*len = *(*p)++; *len = *(*p)++;
} else { } else {
switch (**p & 0x7F) { int n = (**p) & 0x7F;
case 1: if (n == 0 || n > 4) {
if ((end - *p) < 2) { return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
return MBEDTLS_ERR_ASN1_OUT_OF_DATA; }
} if ((end - *p) <= n) {
return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
*len = (*p)[1]; }
(*p) += 2; *len = 0;
break; (*p)++;
while (n--) {
case 2: *len = (*len << 8) | **p;
if ((end - *p) < 3) { (*p)++;
return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
}
*len = ((size_t) (*p)[1] << 8) | (*p)[2];
(*p) += 3;
break;
case 3:
if ((end - *p) < 4) {
return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
}
*len = ((size_t) (*p)[1] << 16) |
((size_t) (*p)[2] << 8) | (*p)[3];
(*p) += 4;
break;
case 4:
if ((end - *p) < 5) {
return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
}
*len = ((size_t) (*p)[1] << 24) | ((size_t) (*p)[2] << 16) |
((size_t) (*p)[3] << 8) | (*p)[4];
(*p) += 5;
break;
default:
return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
} }
} }