openssl/crypto/asn1/bio_asn1.c

450 lines
11 KiB
C

/*
* Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* Experimental ASN1 BIO. When written through the data is converted to an
* ASN1 string type: default is OCTET STRING. Additional functions can be
* provided to add prefix and suffix data.
*/
#include <string.h>
#include "internal/bio.h"
#include <openssl/asn1.h>
#include "internal/cryptlib.h"
/* Must be large enough for biggest tag+length */
#define DEFAULT_ASN1_BUF_SIZE 20
typedef enum {
ASN1_STATE_START,
ASN1_STATE_PRE_COPY,
ASN1_STATE_HEADER,
ASN1_STATE_HEADER_COPY,
ASN1_STATE_DATA_COPY,
ASN1_STATE_POST_COPY,
ASN1_STATE_DONE
} asn1_bio_state_t;
typedef struct BIO_ASN1_EX_FUNCS_st {
asn1_ps_func *ex_func;
asn1_ps_func *ex_free_func;
} BIO_ASN1_EX_FUNCS;
typedef struct BIO_ASN1_BUF_CTX_t {
/* Internal state */
asn1_bio_state_t state;
/* Internal buffer */
unsigned char *buf;
/* Size of buffer */
int bufsize;
/* Current position in buffer */
int bufpos;
/* Current buffer length */
int buflen;
/* Amount of data to copy */
int copylen;
/* Class and tag to use */
int asn1_class, asn1_tag;
asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;
/* Extra buffer for prefix and suffix data */
unsigned char *ex_buf;
int ex_len;
int ex_pos;
void *ex_arg;
} BIO_ASN1_BUF_CTX;
static int asn1_bio_write(BIO *h, const char *buf, int num);
static int asn1_bio_read(BIO *h, char *buf, int size);
static int asn1_bio_puts(BIO *h, const char *str);
static int asn1_bio_gets(BIO *h, char *str, int size);
static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int asn1_bio_new(BIO *h);
static int asn1_bio_free(BIO *data);
static long asn1_bio_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);
static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
asn1_ps_func *cleanup, asn1_bio_state_t next);
static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
asn1_ps_func *setup,
asn1_bio_state_t ex_state,
asn1_bio_state_t other_state);
static const BIO_METHOD methods_asn1 = {
BIO_TYPE_ASN1,
"asn1",
/* TODO: Convert to new style write function */
bwrite_conv,
asn1_bio_write,
/* TODO: Convert to new style read function */
bread_conv,
asn1_bio_read,
asn1_bio_puts,
asn1_bio_gets,
asn1_bio_ctrl,
asn1_bio_new,
asn1_bio_free,
asn1_bio_callback_ctrl,
};
const BIO_METHOD *BIO_f_asn1(void)
{
return &methods_asn1;
}
static int asn1_bio_new(BIO *b)
{
BIO_ASN1_BUF_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
if (ctx == NULL)
return 0;
if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {
OPENSSL_free(ctx);
return 0;
}
BIO_set_data(b, ctx);
BIO_set_init(b, 1);
return 1;
}
static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)
{
if ((ctx->buf = OPENSSL_malloc(size)) == NULL) {
ASN1err(ASN1_F_ASN1_BIO_INIT, ERR_R_MALLOC_FAILURE);
return 0;
}
ctx->bufsize = size;
ctx->asn1_class = V_ASN1_UNIVERSAL;
ctx->asn1_tag = V_ASN1_OCTET_STRING;
ctx->state = ASN1_STATE_START;
return 1;
}
static int asn1_bio_free(BIO *b)
{
BIO_ASN1_BUF_CTX *ctx;
if (b == NULL)
return 0;
ctx = BIO_get_data(b);
if (ctx == NULL)
return 0;
if (ctx->prefix_free != NULL)
ctx->prefix_free(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
if (ctx->suffix_free != NULL)
ctx->suffix_free(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
OPENSSL_free(ctx->buf);
OPENSSL_free(ctx);
BIO_set_data(b, NULL);
BIO_set_init(b, 0);
return 1;
}
static int asn1_bio_write(BIO *b, const char *in, int inl)
{
BIO_ASN1_BUF_CTX *ctx;
int wrmax, wrlen, ret;
unsigned char *p;
BIO *next;
ctx = BIO_get_data(b);
next = BIO_next(b);
if (in == NULL || inl < 0 || ctx == NULL || next == NULL)
return 0;
wrlen = 0;
ret = -1;
for (;;) {
switch (ctx->state) {
/* Setup prefix data, call it */
case ASN1_STATE_START:
if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,
ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))
return -1;
break;
/* Copy any pre data first */
case ASN1_STATE_PRE_COPY:
ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,
ASN1_STATE_HEADER);
if (ret <= 0)
goto done;
break;
case ASN1_STATE_HEADER:
ctx->buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;
if (!ossl_assert(ctx->buflen <= ctx->bufsize))
return -1;
p = ctx->buf;
ASN1_put_object(&p, 0, inl, ctx->asn1_tag, ctx->asn1_class);
ctx->copylen = inl;
ctx->state = ASN1_STATE_HEADER_COPY;
break;
case ASN1_STATE_HEADER_COPY:
ret = BIO_write(next, ctx->buf + ctx->bufpos, ctx->buflen);
if (ret <= 0)
goto done;
ctx->buflen -= ret;
if (ctx->buflen)
ctx->bufpos += ret;
else {
ctx->bufpos = 0;
ctx->state = ASN1_STATE_DATA_COPY;
}
break;
case ASN1_STATE_DATA_COPY:
if (inl > ctx->copylen)
wrmax = ctx->copylen;
else
wrmax = inl;
ret = BIO_write(next, in, wrmax);
if (ret <= 0)
goto done;
wrlen += ret;
ctx->copylen -= ret;
in += ret;
inl -= ret;
if (ctx->copylen == 0)
ctx->state = ASN1_STATE_HEADER;
if (inl == 0)
goto done;
break;
case ASN1_STATE_POST_COPY:
case ASN1_STATE_DONE:
BIO_clear_retry_flags(b);
return 0;
}
}
done:
BIO_clear_retry_flags(b);
BIO_copy_next_retry(b);
return (wrlen > 0) ? wrlen : ret;
}
static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
asn1_ps_func *cleanup, asn1_bio_state_t next)
{
int ret;
if (ctx->ex_len <= 0)
return 1;
for (;;) {
ret = BIO_write(BIO_next(b), ctx->ex_buf + ctx->ex_pos, ctx->ex_len);
if (ret <= 0)
break;
ctx->ex_len -= ret;
if (ctx->ex_len > 0)
ctx->ex_pos += ret;
else {
if (cleanup)
cleanup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
ctx->state = next;
ctx->ex_pos = 0;
break;
}
}
return ret;
}
static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
asn1_ps_func *setup,
asn1_bio_state_t ex_state,
asn1_bio_state_t other_state)
{
if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {
BIO_clear_retry_flags(b);
return 0;
}
if (ctx->ex_len > 0)
ctx->state = ex_state;
else
ctx->state = other_state;
return 1;
}
static int asn1_bio_read(BIO *b, char *in, int inl)
{
BIO *next = BIO_next(b);
if (next == NULL)
return 0;
return BIO_read(next, in, inl);
}
static int asn1_bio_puts(BIO *b, const char *str)
{
return asn1_bio_write(b, str, strlen(str));
}
static int asn1_bio_gets(BIO *b, char *str, int size)
{
BIO *next = BIO_next(b);
if (next == NULL)
return 0;
return BIO_gets(next, str, size);
}
static long asn1_bio_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
{
BIO *next = BIO_next(b);
if (next == NULL)
return 0;
return BIO_callback_ctrl(next, cmd, fp);
}
static long asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)
{
BIO_ASN1_BUF_CTX *ctx;
BIO_ASN1_EX_FUNCS *ex_func;
long ret = 1;
BIO *next;
ctx = BIO_get_data(b);
if (ctx == NULL)
return 0;
next = BIO_next(b);
switch (cmd) {
case BIO_C_SET_PREFIX:
ex_func = arg2;
ctx->prefix = ex_func->ex_func;
ctx->prefix_free = ex_func->ex_free_func;
break;
case BIO_C_GET_PREFIX:
ex_func = arg2;
ex_func->ex_func = ctx->prefix;
ex_func->ex_free_func = ctx->prefix_free;
break;
case BIO_C_SET_SUFFIX:
ex_func = arg2;
ctx->suffix = ex_func->ex_func;
ctx->suffix_free = ex_func->ex_free_func;
break;
case BIO_C_GET_SUFFIX:
ex_func = arg2;
ex_func->ex_func = ctx->suffix;
ex_func->ex_free_func = ctx->suffix_free;
break;
case BIO_C_SET_EX_ARG:
ctx->ex_arg = arg2;
break;
case BIO_C_GET_EX_ARG:
*(void **)arg2 = ctx->ex_arg;
break;
case BIO_CTRL_FLUSH:
if (next == NULL)
return 0;
/* Call post function if possible */
if (ctx->state == ASN1_STATE_HEADER) {
if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,
ASN1_STATE_POST_COPY, ASN1_STATE_DONE))
return 0;
}
if (ctx->state == ASN1_STATE_POST_COPY) {
ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,
ASN1_STATE_DONE);
if (ret <= 0)
return ret;
}
if (ctx->state == ASN1_STATE_DONE)
return BIO_ctrl(next, cmd, arg1, arg2);
else {
BIO_clear_retry_flags(b);
return 0;
}
default:
if (next == NULL)
return 0;
return BIO_ctrl(next, cmd, arg1, arg2);
}
return ret;
}
static int asn1_bio_set_ex(BIO *b, int cmd,
asn1_ps_func *ex_func, asn1_ps_func *ex_free_func)
{
BIO_ASN1_EX_FUNCS extmp;
extmp.ex_func = ex_func;
extmp.ex_free_func = ex_free_func;
return BIO_ctrl(b, cmd, 0, &extmp);
}
static int asn1_bio_get_ex(BIO *b, int cmd,
asn1_ps_func **ex_func,
asn1_ps_func **ex_free_func)
{
BIO_ASN1_EX_FUNCS extmp;
int ret;
ret = BIO_ctrl(b, cmd, 0, &extmp);
if (ret > 0) {
*ex_func = extmp.ex_func;
*ex_free_func = extmp.ex_free_func;
}
return ret;
}
int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix,
asn1_ps_func *prefix_free)
{
return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);
}
int BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix,
asn1_ps_func **pprefix_free)
{
return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);
}
int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix,
asn1_ps_func *suffix_free)
{
return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);
}
int BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix,
asn1_ps_func **psuffix_free)
{
return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);
}