cosmopolitan/third_party/mbedtls/pem.c
Justine Tunney ae5d06dc53 Unbloat build config
- 10.5% reduction of o//depend dependency graph
- 8.8% reduction in latency of make command
- Fix issue with temporary file cleanup

There's a new -w option in compile.com that turns off the recent
Landlock output path workaround for "good commands" which do not
unlink() the output file like GNU tooling does.

Our new GNU Make unveil sandboxing appears to have zero overhead
in the grand scheme of things. Full builds are pretty fast since
the only thing that's actually slowed us down is probably libcxx

    make -j16 MODE=rel
    RL: took 85,732,063µs wall time
    RL: ballooned to 323,612kb in size
    RL: needed 828,560,521µs cpu (11% kernel)
    RL: caused 39,080,670 page faults (99% memcpy)
    RL: 350,073 context switches (72% consensual)
    RL: performed 0 reads and 11,494,960 write i/o operations

pledge() and unveil() no longer consider ENOSYS to be an error.
These functions have also been added to Python's cosmo module.

This change also removes some WIN32 APIs and System Five magnums
which we're not using and it's doubtful anyone else would be too
2022-08-10 04:43:09 -07:00

409 lines
15 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright The Mbed TLS Contributors │
│ │
│ Licensed under the Apache License, Version 2.0 (the "License"); │
│ you may not use this file except in compliance with the License. │
│ You may obtain a copy of the License at │
│ │
│ http://www.apache.org/licenses/LICENSE-2.0 │
│ │
│ Unless required by applicable law or agreed to in writing, software │
│ distributed under the License is distributed on an "AS IS" BASIS, │
│ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. │
│ See the License for the specific language governing permissions and │
│ limitations under the License. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "third_party/mbedtls/aes.h"
#include "third_party/mbedtls/base64.h"
#include "third_party/mbedtls/chk.h"
#include "third_party/mbedtls/cipher.h"
#include "third_party/mbedtls/common.h"
#include "third_party/mbedtls/des.h"
#include "third_party/mbedtls/error.h"
#include "third_party/mbedtls/md5.h"
#include "third_party/mbedtls/pem.h"
#include "third_party/mbedtls/platform.h"
/* clang-format off */
asm(".ident\t\"\\n\\n\
Mbed TLS (Apache 2.0)\\n\
Copyright ARM Limited\\n\
Copyright Mbed TLS Contributors\"");
asm(".include \"libc/disclaimer.inc\"");
/**
* @fileoverview Privacy Enhanced Mail (PEM) decoding
*/
#if defined(MBEDTLS_PEM_PARSE_C) || defined(MBEDTLS_PEM_WRITE_C)
#if defined(MBEDTLS_PEM_PARSE_C)
void mbedtls_pem_init( mbedtls_pem_context *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pem_context ) );
}
#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
/*
* Read a 16-byte hex string and convert it to binary
*/
static int pem_get_iv( const unsigned char *s, unsigned char *iv,
size_t iv_len )
{
size_t i, j, k;
mbedtls_platform_zeroize( iv, iv_len );
for( i = 0; i < iv_len * 2; i++, s++ )
{
if( *s >= '0' && *s <= '9' ) j = *s - '0'; else
if( *s >= 'A' && *s <= 'F' ) j = *s - '7'; else
if( *s >= 'a' && *s <= 'f' ) j = *s - 'W'; else
return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
k = ( ( i & 1 ) != 0 ) ? j : j << 4;
iv[i >> 1] = (unsigned char)( iv[i >> 1] | k );
}
return( 0 );
}
static int pem_pbkdf1( unsigned char *key, size_t keylen,
unsigned char *iv,
const unsigned char *pwd, size_t pwdlen )
{
mbedtls_md5_context md5_ctx;
unsigned char md5sum[16];
size_t use_len;
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_md5_init( &md5_ctx );
/*
* key[ 0..15] = MD5(pwd || IV)
*/
MBEDTLS_CHK( mbedtls_md5_starts_ret( &md5_ctx ) );
MBEDTLS_CHK( mbedtls_md5_update_ret( &md5_ctx, pwd, pwdlen ) );
MBEDTLS_CHK( mbedtls_md5_update_ret( &md5_ctx, iv, 8 ) );
MBEDTLS_CHK( mbedtls_md5_finish_ret( &md5_ctx, md5sum ) );
if( keylen <= 16 )
{
memcpy( key, md5sum, keylen );
goto cleanup;
}
memcpy( key, md5sum, 16 );
/*
* key[16..23] = MD5(key[ 0..15] || pwd || IV])
*/
MBEDTLS_CHK( mbedtls_md5_starts_ret( &md5_ctx ) );
MBEDTLS_CHK( mbedtls_md5_update_ret( &md5_ctx, md5sum, 16 ) );
MBEDTLS_CHK( mbedtls_md5_update_ret( &md5_ctx, pwd, pwdlen ) );
MBEDTLS_CHK( mbedtls_md5_update_ret( &md5_ctx, iv, 8 ) );
MBEDTLS_CHK( mbedtls_md5_finish_ret( &md5_ctx, md5sum ) );
use_len = 16;
if( keylen < 32 )
use_len = keylen - 16;
memcpy( key + 16, md5sum, use_len );
cleanup:
mbedtls_md5_free( &md5_ctx );
mbedtls_platform_zeroize( md5sum, 16 );
return( ret );
}
#if defined(MBEDTLS_DES_C)
/*
* Decrypt with DES-CBC, using PBKDF1 for key derivation
*/
static int pem_des_decrypt( unsigned char des_iv[8],
unsigned char *buf, size_t buflen,
const unsigned char *pwd, size_t pwdlen )
{
mbedtls_des_context des_ctx;
unsigned char des_key[8];
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_des_init( &des_ctx );
if( ( ret = pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_des_setkey_dec( &des_ctx, des_key ) ) != 0 )
goto exit;
ret = mbedtls_des_crypt_cbc( &des_ctx, MBEDTLS_DES_DECRYPT, buflen,
des_iv, buf, buf );
exit:
mbedtls_des_free( &des_ctx );
mbedtls_platform_zeroize( des_key, 8 );
return( ret );
}
/*
* Decrypt with 3DES-CBC, using PBKDF1 for key derivation
*/
static int pem_des3_decrypt( unsigned char des3_iv[8],
unsigned char *buf, size_t buflen,
const unsigned char *pwd, size_t pwdlen )
{
mbedtls_des3_context des3_ctx;
unsigned char des3_key[24];
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_des3_init( &des3_ctx );
if( ( ret = pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_des3_set3key_dec( &des3_ctx, des3_key ) ) != 0 )
goto exit;
ret = mbedtls_des3_crypt_cbc( &des3_ctx, MBEDTLS_DES_DECRYPT, buflen,
des3_iv, buf, buf );
exit:
mbedtls_des3_free( &des3_ctx );
mbedtls_platform_zeroize( des3_key, 24 );
return( ret );
}
#endif /* MBEDTLS_DES_C */
#if defined(MBEDTLS_AES_C)
/*
* Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation
*/
static int pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen,
unsigned char *buf, size_t buflen,
const unsigned char *pwd, size_t pwdlen )
{
mbedtls_aes_context aes_ctx;
unsigned char aes_key[32];
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_aes_init( &aes_ctx );
if( ( ret = pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen ) ) != 0 )
goto exit;
if( ( ret = mbedtls_aes_setkey_dec( &aes_ctx, aes_key, keylen * 8 ) ) != 0 )
goto exit;
ret = mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_DECRYPT, buflen,
aes_iv, buf, buf );
exit:
mbedtls_aes_free( &aes_ctx );
mbedtls_platform_zeroize( aes_key, keylen );
return( ret );
}
#endif /* MBEDTLS_AES_C */
#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const char *footer,
const unsigned char *data, const unsigned char *pwd,
size_t pwdlen, size_t *use_len )
{
int ret, enc;
size_t len;
unsigned char *buf;
const unsigned char *s1, *s2, *end;
#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
unsigned char pem_iv[16];
mbedtls_cipher_type_t enc_alg = MBEDTLS_CIPHER_NONE;
#else
((void) pwd);
((void) pwdlen);
#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
if( !ctx )
return( MBEDTLS_ERR_PEM_BAD_INPUT_DATA );
s1 = (unsigned char *) strstr( (const char *) data, header );
if( !s1 )
return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
s2 = (unsigned char *) strstr( (const char *) data, footer );
if( !s2 || s2 <= s1 )
return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
s1 += strlen( header );
if( *s1 == ' ' ) s1++;
if( *s1 == '\r' ) s1++;
if( *s1 == '\n' ) s1++;
else return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
end = s2;
end += strlen( footer );
if( *end == ' ' ) end++;
if( *end == '\r' ) end++;
if( *end == '\n' ) end++;
*use_len = end - data;
enc = 0;
if( s2 - s1 >= 22 && timingsafe_bcmp( s1, "Proc-Type: 4,ENCRYPTED", 22 ) == 0 )
{
#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
enc++;
s1 += 22;
if( *s1 == '\r' ) s1++;
if( *s1 == '\n' ) s1++;
else return( MBEDTLS_ERR_PEM_INVALID_DATA );
#if defined(MBEDTLS_DES_C)
if( s2 - s1 >= 23 && timingsafe_bcmp( s1, "DEK-Info: DES-EDE3-CBC,", 23 ) == 0 )
{
enc_alg = MBEDTLS_CIPHER_DES_EDE3_CBC;
s1 += 23;
if( s2 - s1 < 16 || pem_get_iv( s1, pem_iv, 8 ) != 0 )
return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
s1 += 16;
}
else if( s2 - s1 >= 18 && timingsafe_bcmp( s1, "DEK-Info: DES-CBC,", 18 ) == 0 )
{
enc_alg = MBEDTLS_CIPHER_DES_CBC;
s1 += 18;
if( s2 - s1 < 16 || pem_get_iv( s1, pem_iv, 8) != 0 )
return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
s1 += 16;
}
#endif /* MBEDTLS_DES_C */
#if defined(MBEDTLS_AES_C)
if( s2 - s1 >= 14 && timingsafe_bcmp( s1, "DEK-Info: AES-", 14 ) == 0 )
{
if( s2 - s1 < 22 )
return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
else if( timingsafe_bcmp( s1, "DEK-Info: AES-128-CBC,", 22 ) == 0 )
enc_alg = MBEDTLS_CIPHER_AES_128_CBC;
else if( timingsafe_bcmp( s1, "DEK-Info: AES-192-CBC,", 22 ) == 0 )
enc_alg = MBEDTLS_CIPHER_AES_192_CBC;
else if( timingsafe_bcmp( s1, "DEK-Info: AES-256-CBC,", 22 ) == 0 )
enc_alg = MBEDTLS_CIPHER_AES_256_CBC;
else
return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
s1 += 22;
if( s2 - s1 < 32 || pem_get_iv( s1, pem_iv, 16 ) != 0 )
return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
s1 += 32;
}
#endif /* MBEDTLS_AES_C */
if( enc_alg == MBEDTLS_CIPHER_NONE )
return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
if( *s1 == '\r' ) s1++;
if( *s1 == '\n' ) s1++;
else return( MBEDTLS_ERR_PEM_INVALID_DATA );
#else
return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
}
if( s1 >= s2 )
return( MBEDTLS_ERR_PEM_INVALID_DATA );
ret = mbedtls_base64_decode( NULL, 0, &len, s1, s2 - s1 );
if( ret == MBEDTLS_ERR_BASE64_INVALID_CHARACTER )
return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
if( ( buf = mbedtls_calloc( 1, len ) ) == NULL )
return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
if( ( ret = mbedtls_base64_decode( buf, len, &len, s1, s2 - s1 ) ) != 0 )
{
mbedtls_platform_zeroize( buf, len );
mbedtls_free( buf );
return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
}
if( enc != 0 )
{
#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
if( pwd == NULL )
{
mbedtls_platform_zeroize( buf, len );
mbedtls_free( buf );
return( MBEDTLS_ERR_PEM_PASSWORD_REQUIRED );
}
ret = 0;
#if defined(MBEDTLS_DES_C)
if( enc_alg == MBEDTLS_CIPHER_DES_EDE3_CBC )
ret = pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen );
else if( enc_alg == MBEDTLS_CIPHER_DES_CBC )
ret = pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen );
#endif /* MBEDTLS_DES_C */
#if defined(MBEDTLS_AES_C)
if( enc_alg == MBEDTLS_CIPHER_AES_128_CBC )
ret = pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen );
else if( enc_alg == MBEDTLS_CIPHER_AES_192_CBC )
ret = pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen );
else if( enc_alg == MBEDTLS_CIPHER_AES_256_CBC )
ret = pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen );
#endif /* MBEDTLS_AES_C */
if( ret != 0 )
{
mbedtls_free( buf );
return( ret );
}
/*
* The result will be ASN.1 starting with a SEQUENCE tag, with 1 to 3
* length bytes (allow 4 to be sure) in all known use cases.
*
* Use that as a heuristic to try to detect password mismatches.
*/
if( len <= 2 || buf[0] != 0x30 || buf[1] > 0x83 )
{
mbedtls_platform_zeroize( buf, len );
mbedtls_free( buf );
return( MBEDTLS_ERR_PEM_PASSWORD_MISMATCH );
}
#else
mbedtls_platform_zeroize( buf, len );
mbedtls_free( buf );
return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
}
ctx->buf = buf;
ctx->buflen = len;
return( 0 );
}
void mbedtls_pem_free( mbedtls_pem_context *ctx )
{
if ( ctx->buf )
{
mbedtls_platform_zeroize( ctx->buf, ctx->buflen );
mbedtls_free( ctx->buf );
}
mbedtls_free( ctx->info );
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pem_context ) );
}
#endif /* MBEDTLS_PEM_PARSE_C */
#if defined(MBEDTLS_PEM_WRITE_C)
int mbedtls_pem_write_buffer( const char *header, const char *footer,
const unsigned char *der_data, size_t der_len,
unsigned char *buf, size_t buf_len, size_t *olen )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
unsigned char *encode_buf = NULL, *c, *p = buf;
size_t len = 0, use_len, add_len = 0;
mbedtls_base64_encode( NULL, 0, &use_len, der_data, der_len );
add_len = strlen( header ) + strlen( footer ) + ( use_len / 64 ) + 1;
if( use_len + add_len > buf_len )
{
*olen = use_len + add_len;
return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
}
if( use_len != 0 &&
( ( encode_buf = mbedtls_calloc( 1, use_len ) ) == NULL ) )
return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
if( ( ret = mbedtls_base64_encode( encode_buf, use_len, &use_len, der_data,
der_len ) ) != 0 )
{
mbedtls_free( encode_buf );
return( ret );
}
memcpy( p, header, strlen( header ) );
p += strlen( header );
c = encode_buf;
while( use_len )
{
len = ( use_len > 64 ) ? 64 : use_len;
memcpy( p, c, len );
use_len -= len;
p += len;
c += len;
*p++ = '\n';
}
memcpy( p, footer, strlen( footer ) );
p += strlen( footer );
*p++ = '\0';
*olen = p - buf;
/* Clean any remaining data previously written to the buffer */
mbedtls_platform_zeroize( buf + *olen, buf_len - *olen );
mbedtls_free( encode_buf );
return( 0 );
}
#endif /* MBEDTLS_PEM_WRITE_C */
#endif /* MBEDTLS_PEM_PARSE_C || MBEDTLS_PEM_WRITE_C */