eden-emu/mbedtls
15
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Merge pull request #8182 from daverodgman/asn1write-size

Browse source 
Reduce code size in mbedtls_asn1_write_len
This commit is contained in:
Dave Rodgman 2023-09-18 10:27:23 +00:00 • committed by GitHub
commit 25c271a035
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 55 additions and 99 deletions
Download patch file Download diff file Expand all files Collapse all files

154
library/asn1write.c
View file

@ -28,68 +28,40 @@
#include "mbedtls/platform.h" #include "mbedtls/platform.h"
#if defined(MBEDTLS_ASN1_PARSE_C)
#include "mbedtls/asn1.h"
#endif
int mbedtls_asn1_write_len(unsigned char **p, const unsigned char *start, size_t len) int mbedtls_asn1_write_len(unsigned char **p, const unsigned char *start, size_t len)
{ {
if (len < 0x80) {
if (*p - start < 1) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*--(*p) = (unsigned char) len;
return 1;
}
if (len <= 0xFF) {
if (*p - start < 2) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*--(*p) = (unsigned char) len;
*--(*p) = 0x81;
return 2;
}
if (len <= 0xFFFF) {
if (*p - start < 3) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*--(*p) = MBEDTLS_BYTE_0(len);
*--(*p) = MBEDTLS_BYTE_1(len);
*--(*p) = 0x82;
return 3;
}
if (len <= 0xFFFFFF) {
if (*p - start < 4) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*--(*p) = MBEDTLS_BYTE_0(len);
*--(*p) = MBEDTLS_BYTE_1(len);
*--(*p) = MBEDTLS_BYTE_2(len);
*--(*p) = 0x83;
return 4;
}
int len_is_valid = 1;
#if SIZE_MAX > 0xFFFFFFFF #if SIZE_MAX > 0xFFFFFFFF
len_is_valid = (len <= 0xFFFFFFFF); if (len > 0xFFFFFFFF) {
return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
}
#endif #endif
if (len_is_valid) {
if (*p - start < 5) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
*--(*p) = MBEDTLS_BYTE_0(len); int required = 1;
*--(*p) = MBEDTLS_BYTE_1(len);
*--(*p) = MBEDTLS_BYTE_2(len); if (len >= 0x80) {
*--(*p) = MBEDTLS_BYTE_3(len); for (size_t l = len; l != 0; l >>= 8) {
*--(*p) = 0x84; required++;
return 5; }
} }
return MBEDTLS_ERR_ASN1_INVALID_LENGTH; if (required > (*p - start)) {
return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
}
do {
*--(*p) = MBEDTLS_BYTE_0(len);
len >>= 8;
} while (len);
if (required > 1) {
*--(*p) = (unsigned char) (0x80 + required - 1);
}
return required;
} }
int mbedtls_asn1_write_tag(unsigned char **p, const unsigned char *start, unsigned char tag) int mbedtls_asn1_write_tag(unsigned char **p, const unsigned char *start, unsigned char tag)
@ -105,6 +77,19 @@ int mbedtls_asn1_write_tag(unsigned char **p, const unsigned char *start, unsign
#endif /* MBEDTLS_ASN1_WRITE_C || MBEDTLS_X509_USE_C */ #endif /* MBEDTLS_ASN1_WRITE_C || MBEDTLS_X509_USE_C */
#if defined(MBEDTLS_ASN1_WRITE_C) #if defined(MBEDTLS_ASN1_WRITE_C)
static int mbedtls_asn1_write_len_and_tag(unsigned char **p,
const unsigned char *start,
size_t len,
unsigned char tag)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));
return (int) len;
}
int mbedtls_asn1_write_raw_buffer(unsigned char **p, const unsigned char *start, int mbedtls_asn1_write_raw_buffer(unsigned char **p, const unsigned char *start,
const unsigned char *buf, size_t size) const unsigned char *buf, size_t size)
{ {
@ -156,10 +141,7 @@ int mbedtls_asn1_write_mpi(unsigned char **p, const unsigned char *start, const
len += 1; len += 1;
} }
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); ret = mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_INTEGER);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_INTEGER));
ret = (int) len;
cleanup: cleanup:
return ret; return ret;
@ -168,15 +150,9 @@ cleanup:
int mbedtls_asn1_write_null(unsigned char **p, const unsigned char *start) int mbedtls_asn1_write_null(unsigned char **p, const unsigned char *start)
{ {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
// Write NULL // Write NULL
// //
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, 0)); return mbedtls_asn1_write_len_and_tag(p, start, 0, MBEDTLS_ASN1_NULL);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_NULL));
return (int) len;
} }
int mbedtls_asn1_write_oid(unsigned char **p, const unsigned char *start, int mbedtls_asn1_write_oid(unsigned char **p, const unsigned char *start,
@ -187,10 +163,7 @@ int mbedtls_asn1_write_oid(unsigned char **p, const unsigned char *start,
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start,
(const unsigned char *) oid, oid_len)); (const unsigned char *) oid, oid_len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OID);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OID));
return (int) len;
} }
int mbedtls_asn1_write_algorithm_identifier(unsigned char **p, const unsigned char *start, int mbedtls_asn1_write_algorithm_identifier(unsigned char **p, const unsigned char *start,
@ -217,17 +190,12 @@ int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char **p, const unsigne
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len,
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE);
MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE));
return (int) len;
} }
int mbedtls_asn1_write_bool(unsigned char **p, const unsigned char *start, int boolean) int mbedtls_asn1_write_bool(unsigned char **p, const unsigned char *start, int boolean)
{ {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0; size_t len = 0;
if (*p - start < 1) { if (*p - start < 1) {
@ -237,15 +205,11 @@ int mbedtls_asn1_write_bool(unsigned char **p, const unsigned char *start, int b
*--(*p) = (boolean) ? 255 : 0; *--(*p) = (boolean) ? 255 : 0;
len++; len++;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BOOLEAN);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BOOLEAN));
return (int) len;
} }
static int asn1_write_tagged_int(unsigned char **p, const unsigned char *start, int val, int tag) static int asn1_write_tagged_int(unsigned char **p, const unsigned char *start, int val, int tag)
{ {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0; size_t len = 0;
do { do {
@ -265,10 +229,7 @@ static int asn1_write_tagged_int(unsigned char **p, const unsigned char *start,
len += 1; len += 1;
} }
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));
return (int) len;
} }
int mbedtls_asn1_write_int(unsigned char **p, const unsigned char *start, int val) int mbedtls_asn1_write_int(unsigned char **p, const unsigned char *start, int val)
@ -291,10 +252,7 @@ int mbedtls_asn1_write_tagged_string(unsigned char **p, const unsigned char *sta
(const unsigned char *) text, (const unsigned char *) text,
text_len)); text_len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len, tag);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, tag));
return (int) len;
} }
int mbedtls_asn1_write_utf8_string(unsigned char **p, const unsigned char *start, int mbedtls_asn1_write_utf8_string(unsigned char **p, const unsigned char *start,
@ -363,7 +321,6 @@ int mbedtls_asn1_write_named_bitstring(unsigned char **p,
int mbedtls_asn1_write_bitstring(unsigned char **p, const unsigned char *start, int mbedtls_asn1_write_bitstring(unsigned char **p, const unsigned char *start,
const unsigned char *buf, size_t bits) const unsigned char *buf, size_t bits)
{ {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0; size_t len = 0;
size_t unused_bits, byte_len; size_t unused_bits, byte_len;
@ -387,10 +344,7 @@ int mbedtls_asn1_write_bitstring(unsigned char **p, const unsigned char *start,
/* Write unused bits */ /* Write unused bits */
*--(*p) = (unsigned char) unused_bits; *--(*p) = (unsigned char) unused_bits;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_BIT_STRING);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_BIT_STRING));
return (int) len;
} }
int mbedtls_asn1_write_octet_string(unsigned char **p, const unsigned char *start, int mbedtls_asn1_write_octet_string(unsigned char **p, const unsigned char *start,
@ -401,13 +355,11 @@ int mbedtls_asn1_write_octet_string(unsigned char **p, const unsigned char *star
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, buf, size)); MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_raw_buffer(p, start, buf, size));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); return mbedtls_asn1_write_len_and_tag(p, start, len, MBEDTLS_ASN1_OCTET_STRING);
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING));
return (int) len;
} }
#if !defined(MBEDTLS_ASN1_PARSE_C)
/* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(), /* This is a copy of the ASN.1 parsing function mbedtls_asn1_find_named_data(),
* which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */ * which is replicated to avoid a dependency ASN1_WRITE_C on ASN1_PARSE_C. */
static mbedtls_asn1_named_data *asn1_find_named_data( static mbedtls_asn1_named_data *asn1_find_named_data(
@ -425,6 +377,10 @@ static mbedtls_asn1_named_data *asn1_find_named_data(
return list; return list;
} }
#else
#define asn1_find_named_data(list, oid, len) \
((mbedtls_asn1_named_data *) mbedtls_asn1_find_named_data(list, oid, len))
#endif
mbedtls_asn1_named_data *mbedtls_asn1_store_named_data( mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(
mbedtls_asn1_named_data **head, mbedtls_asn1_named_data **head,