crypto/bio/bss_mem.c - third_party/openssl - Git at Google

 /*
  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (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
  */

 #include <stdio.h>
 #include <errno.h>
 #include "bio_local.h"
 #include "internal/cryptlib.h"

 static int mem_write(BIO *h, const char *buf, int num);
 static int mem_read(BIO *h, char *buf, int size);
 static int mem_puts(BIO *h, const char *str);
 static int mem_gets(BIO *h, char *str, int size);
 static long mem_ctrl(BIO *h, int cmd, long arg1, void *arg2);
 static int mem_new(BIO *h);
 static int secmem_new(BIO *h);
 static int mem_free(BIO *data);
 static int mem_buf_free(BIO *data);
 static int mem_buf_sync(BIO *h);

 static const BIO_METHOD mem_method = {
     BIO_TYPE_MEM,
     "memory buffer",
     bwrite_conv,
     mem_write,
     bread_conv,
     mem_read,
     mem_puts,
     mem_gets,
     mem_ctrl,
     mem_new,
     mem_free,
     NULL,                      /* mem_callback_ctrl */
 };

 static const BIO_METHOD secmem_method = {
     BIO_TYPE_MEM,
     "secure memory buffer",
     bwrite_conv,
     mem_write,
     bread_conv,
     mem_read,
     mem_puts,
     mem_gets,
     mem_ctrl,
     secmem_new,
     mem_free,
     NULL,                      /* mem_callback_ctrl */
 };

 /*
  * BIO memory stores buffer and read pointer
  * however the roles are different for read only BIOs.
  * In that case the readp just stores the original state
  * to be used for reset.
  */
 typedef struct bio_buf_mem_st {
     struct buf_mem_st *buf;   /* allocated buffer */
     struct buf_mem_st *readp; /* read pointer */
 } BIO_BUF_MEM;

 /*
  * bio->num is used to hold the value to return on 'empty', if it is 0,
  * should_retry is not set
  */

 const BIO_METHOD *BIO_s_mem(void)
 {
     return &mem_method;
 }

 const BIO_METHOD *BIO_s_secmem(void)
 {
     return(&secmem_method);
 }

 BIO *BIO_new_mem_buf(const void *buf, int len)
 {
     BIO *ret;
     BUF_MEM *b;
     BIO_BUF_MEM *bb;
     size_t sz;

     if (buf == NULL) {
         ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
         return NULL;
     }
     sz = (len < 0) ? strlen(buf) : (size_t)len;
     if ((ret = BIO_new(BIO_s_mem())) == NULL)
         return NULL;
     bb = (BIO_BUF_MEM *)ret->ptr;
     b = bb->buf;
     /* Cast away const and trust in the MEM_RDONLY flag. */
     b->data = (void *)buf;
     b->length = sz;
     b->max = sz;
     *bb->readp = *bb->buf;
     ret->flags |= BIO_FLAGS_MEM_RDONLY;
     /* Since this is static data retrying won't help */
     ret->num = 0;
     return ret;
 }

 static int mem_init(BIO *bi, unsigned long flags)
 {
     BIO_BUF_MEM *bb = OPENSSL_zalloc(sizeof(*bb));

     if (bb == NULL)
         return 0;
     if ((bb->buf = BUF_MEM_new_ex(flags)) == NULL) {
         OPENSSL_free(bb);
         return 0;
     }
     if ((bb->readp = OPENSSL_zalloc(sizeof(*bb->readp))) == NULL) {
         BUF_MEM_free(bb->buf);
         OPENSSL_free(bb);
         return 0;
     }
     *bb->readp = *bb->buf;
     bi->shutdown = 1;
     bi->init = 1;
     bi->num = -1;
     bi->ptr = (char *)bb;
     return 1;
 }

 static int mem_new(BIO *bi)
 {
     return mem_init(bi, 0L);
 }

 static int secmem_new(BIO *bi)
 {
     return mem_init(bi, BUF_MEM_FLAG_SECURE);
 }

 static int mem_free(BIO *a)
 {
     BIO_BUF_MEM *bb;

     if (a == NULL)
         return 0;

     bb = (BIO_BUF_MEM *)a->ptr;
     if (!mem_buf_free(a))
         return 0;
     OPENSSL_free(bb->readp);
     OPENSSL_free(bb);
     return 1;
 }

 static int mem_buf_free(BIO *a)
 {
     if (a == NULL)
         return 0;

     if (a->shutdown && a->init && a->ptr != NULL) {
         BIO_BUF_MEM *bb = (BIO_BUF_MEM *)a->ptr;
         BUF_MEM *b = bb->buf;

         if (a->flags & BIO_FLAGS_MEM_RDONLY)
             b->data = NULL;
         BUF_MEM_free(b);
     }
     return 1;
 }

 /*
  * Reallocate memory buffer if read pointer differs
  * NOT FOR RDONLY
  */
 static int mem_buf_sync(BIO *b)
 {
     if (b != NULL && b->init != 0 && b->ptr != NULL) {
         BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;

         if (bbm->readp->data != bbm->buf->data) {
             memmove(bbm->buf->data, bbm->readp->data, bbm->readp->length);
             bbm->buf->length = bbm->readp->length;
             bbm->readp->data = bbm->buf->data;
         }
     }
     return 0;
 }

 static int mem_read(BIO *b, char *out, int outl)
 {
     int ret = -1;
     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
     BUF_MEM *bm = bbm->readp;

     if (b->flags & BIO_FLAGS_MEM_RDONLY)
         bm = bbm->buf;
     BIO_clear_retry_flags(b);
     ret = (outl >= 0 && (size_t)outl > bm->length) ? (int)bm->length : outl;
     if ((out != NULL) && (ret > 0)) {
         memcpy(out, bm->data, ret);
         bm->length -= ret;
         bm->max -= ret;
         bm->data += ret;
     } else if (bm->length == 0) {
         ret = b->num;
         if (ret != 0)
             BIO_set_retry_read(b);
     }
     return ret;
 }

 static int mem_write(BIO *b, const char *in, int inl)
 {
     int ret = -1;
     int blen;
     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;

     if (b->flags & BIO_FLAGS_MEM_RDONLY) {
         ERR_raise(ERR_LIB_BIO, BIO_R_WRITE_TO_READ_ONLY_BIO);
         goto end;
     }
     BIO_clear_retry_flags(b);
     if (inl == 0)
         return 0;
     if (in == NULL) {
         ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
         goto end;
     }
     blen = bbm->readp->length;
     mem_buf_sync(b);
     if (BUF_MEM_grow_clean(bbm->buf, blen + inl) == 0)
         goto end;
     memcpy(bbm->buf->data + blen, in, inl);
     *bbm->readp = *bbm->buf;
     ret = inl;
  end:
     return ret;
 }

 static long mem_ctrl(BIO *b, int cmd, long num, void *ptr)
 {
     long ret = 1;
     char **pptr;
     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
     BUF_MEM *bm, *bo;            /* bio_mem, bio_other */
     long off, remain;

     if (b->flags & BIO_FLAGS_MEM_RDONLY) {
         bm = bbm->buf;
         bo = bbm->readp;
     } else {
         bm = bbm->readp;
         bo = bbm->buf;
     }
     off = (bm->data == bo->data) ? 0 : bm->data - bo->data;
     remain = bm->length;

     switch (cmd) {
     case BIO_CTRL_RESET:
         bm = bbm->buf;
         if (bm->data != NULL) {
             if (!(b->flags & BIO_FLAGS_MEM_RDONLY)) {
                 if (!(b->flags & BIO_FLAGS_NONCLEAR_RST)) {
                     memset(bm->data, 0, bm->max);
                     bm->length = 0;
                 }
                 *bbm->readp = *bbm->buf;
             } else {
                 /* For read only case just reset to the start again */
                 *bbm->buf = *bbm->readp;
             }
         }
         break;
     case BIO_C_FILE_SEEK:
         if (num < 0 || num > off + remain)
             return -1;   /* Can't see outside of the current buffer */

         bm->data = (num != 0) ? bo->data + num : bo->data;
         bm->length = bo->length - num;
         bm->max = bo->max - num;
         off = num;
         /* FALLTHRU */
     case BIO_C_FILE_TELL:
         ret = off;
         break;
     case BIO_CTRL_EOF:
         ret = (long)(bm->length == 0);
         break;
     case BIO_C_SET_BUF_MEM_EOF_RETURN:
         b->num = (int)num;
         break;
     case BIO_CTRL_INFO:
         ret = (long)bm->length;
         if (ptr != NULL) {
             pptr = (char **)ptr;
             *pptr = (char *)(bm->data);
         }
         break;
     case BIO_C_SET_BUF_MEM:
         mem_buf_free(b);
         b->shutdown = (int)num;
         bbm->buf = ptr;
         *bbm->readp = *bbm->buf;
         break;
     case BIO_C_GET_BUF_MEM_PTR:
         if (ptr != NULL) {
             if (!(b->flags & BIO_FLAGS_MEM_RDONLY))
                 mem_buf_sync(b);
             bm = bbm->buf;
             pptr = (char **)ptr;
             *pptr = (char *)bm;
         }
         break;
     case BIO_CTRL_GET_CLOSE:
         ret = (long)b->shutdown;
         break;
     case BIO_CTRL_SET_CLOSE:
         b->shutdown = (int)num;
         break;
     case BIO_CTRL_WPENDING:
         ret = 0L;
         break;
     case BIO_CTRL_PENDING:
         ret = (long)bm->length;
         break;
     case BIO_CTRL_DUP:
     case BIO_CTRL_FLUSH:
         ret = 1;
         break;
     case BIO_CTRL_PUSH:
     case BIO_CTRL_POP:
     default:
         ret = 0;
         break;
     }
     return ret;
 }

 static int mem_gets(BIO *bp, char *buf, int size)
 {
     int i, j;
     int ret = -1;
     char *p;
     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)bp->ptr;
     BUF_MEM *bm = bbm->readp;

     if (bp->flags & BIO_FLAGS_MEM_RDONLY)
         bm = bbm->buf;
     BIO_clear_retry_flags(bp);
     j = bm->length;
     if ((size - 1) < j)
         j = size - 1;
     if (j <= 0) {
         *buf = '\0';
         return 0;
     }
     p = bm->data;
     for (i = 0; i < j; i++) {
         if (p[i] == '\n') {
             i++;
             break;
         }
     }

     /*
      * i is now the max num of bytes to copy, either j or up to
      * and including the first newline
      */

     i = mem_read(bp, buf, i);
     if (i > 0)
         buf[i] = '\0';
     ret = i;
     return ret;
 }

 static int mem_puts(BIO *bp, const char *str)
 {
     int n, ret;

     n = strlen(str);
     ret = mem_write(bp, str, n);
     /* memory semantics is that it will always work */
     return ret;
 }
	/*
	* Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (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
	*/

	#include <stdio.h>
	#include <errno.h>
	#include "bio_local.h"
	#include "internal/cryptlib.h"

	static int mem_write(BIO h, const char buf, int num);
	static int mem_read(BIO h, char buf, int size);
	static int mem_puts(BIO h, const char str);
	static int mem_gets(BIO h, char str, int size);
	static long mem_ctrl(BIO h, int cmd, long arg1, void arg2);
	static int mem_new(BIO *h);
	static int secmem_new(BIO *h);
	static int mem_free(BIO *data);
	static int mem_buf_free(BIO *data);
	static int mem_buf_sync(BIO *h);

	static const BIO_METHOD mem_method = {
	BIO_TYPE_MEM,
	"memory buffer",
	bwrite_conv,
	mem_write,
	bread_conv,
	mem_read,
	mem_puts,
	mem_gets,
	mem_ctrl,
	mem_new,
	mem_free,
	NULL, /* mem_callback_ctrl */
	};

	static const BIO_METHOD secmem_method = {
	BIO_TYPE_MEM,
	"secure memory buffer",
	bwrite_conv,
	mem_write,
	bread_conv,
	mem_read,
	mem_puts,
	mem_gets,
	mem_ctrl,
	secmem_new,
	mem_free,
	NULL, /* mem_callback_ctrl */
	};

	/*
	* BIO memory stores buffer and read pointer
	* however the roles are different for read only BIOs.
	* In that case the readp just stores the original state
	* to be used for reset.
	*/
	typedef struct bio_buf_mem_st {
	struct buf_mem_st buf; / allocated buffer */
	struct buf_mem_st readp; / read pointer */
	} BIO_BUF_MEM;

	/*
	* bio->num is used to hold the value to return on 'empty', if it is 0,
	* should_retry is not set
	*/

	const BIO_METHOD *BIO_s_mem(void)
	{
	return &mem_method;
	}

	const BIO_METHOD *BIO_s_secmem(void)
	{
	return(&secmem_method);
	}

	BIO BIO_new_mem_buf(const void buf, int len)
	{
	BIO *ret;
	BUF_MEM *b;
	BIO_BUF_MEM *bb;
	size_t sz;

	if (buf == NULL) {
	ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
	return NULL;
	}
	sz = (len < 0) ? strlen(buf) : (size_t)len;
	if ((ret = BIO_new(BIO_s_mem())) == NULL)
	return NULL;
	bb = (BIO_BUF_MEM *)ret->ptr;
	b = bb->buf;
	/* Cast away const and trust in the MEM_RDONLY flag. */
	b->data = (void *)buf;
	b->length = sz;
	b->max = sz;
	bb->readp = bb->buf;
	ret->flags \|= BIO_FLAGS_MEM_RDONLY;
	/* Since this is static data retrying won't help */
	ret->num = 0;
	return ret;
	}

	static int mem_init(BIO *bi, unsigned long flags)
	{
	BIO_BUF_MEM bb = OPENSSL_zalloc(sizeof(bb));

	if (bb == NULL)
	return 0;
	if ((bb->buf = BUF_MEM_new_ex(flags)) == NULL) {
	OPENSSL_free(bb);
	return 0;
	}
	if ((bb->readp = OPENSSL_zalloc(sizeof(*bb->readp))) == NULL) {
	BUF_MEM_free(bb->buf);
	OPENSSL_free(bb);
	return 0;
	}
	bb->readp = bb->buf;
	bi->shutdown = 1;
	bi->init = 1;
	bi->num = -1;
	bi->ptr = (char *)bb;
	return 1;
	}

	static int mem_new(BIO *bi)
	{
	return mem_init(bi, 0L);
	}

	static int secmem_new(BIO *bi)
	{
	return mem_init(bi, BUF_MEM_FLAG_SECURE);
	}

	static int mem_free(BIO *a)
	{
	BIO_BUF_MEM *bb;

	if (a == NULL)
	return 0;

	bb = (BIO_BUF_MEM *)a->ptr;
	if (!mem_buf_free(a))
	return 0;
	OPENSSL_free(bb->readp);
	OPENSSL_free(bb);
	return 1;
	}

	static int mem_buf_free(BIO *a)
	{
	if (a == NULL)
	return 0;

	if (a->shutdown && a->init && a->ptr != NULL) {
	BIO_BUF_MEM bb = (BIO_BUF_MEM )a->ptr;
	BUF_MEM *b = bb->buf;

	if (a->flags & BIO_FLAGS_MEM_RDONLY)
	b->data = NULL;
	BUF_MEM_free(b);
	}
	return 1;
	}

	/*
	* Reallocate memory buffer if read pointer differs
	* NOT FOR RDONLY
	*/
	static int mem_buf_sync(BIO *b)
	{
	if (b != NULL && b->init != 0 && b->ptr != NULL) {
	BIO_BUF_MEM bbm = (BIO_BUF_MEM )b->ptr;

	if (bbm->readp->data != bbm->buf->data) {
	memmove(bbm->buf->data, bbm->readp->data, bbm->readp->length);
	bbm->buf->length = bbm->readp->length;
	bbm->readp->data = bbm->buf->data;
	}
	}
	return 0;
	}

	static int mem_read(BIO b, char out, int outl)
	{
	int ret = -1;
	BIO_BUF_MEM bbm = (BIO_BUF_MEM )b->ptr;
	BUF_MEM *bm = bbm->readp;

	if (b->flags & BIO_FLAGS_MEM_RDONLY)
	bm = bbm->buf;
	BIO_clear_retry_flags(b);
	ret = (outl >= 0 && (size_t)outl > bm->length) ? (int)bm->length : outl;
	if ((out != NULL) && (ret > 0)) {
	memcpy(out, bm->data, ret);
	bm->length -= ret;
	bm->max -= ret;
	bm->data += ret;
	} else if (bm->length == 0) {
	ret = b->num;
	if (ret != 0)
	BIO_set_retry_read(b);
	}
	return ret;
	}

	static int mem_write(BIO b, const char in, int inl)
	{
	int ret = -1;
	int blen;
	BIO_BUF_MEM bbm = (BIO_BUF_MEM )b->ptr;

	if (b->flags & BIO_FLAGS_MEM_RDONLY) {
	ERR_raise(ERR_LIB_BIO, BIO_R_WRITE_TO_READ_ONLY_BIO);
	goto end;
	}
	BIO_clear_retry_flags(b);
	if (inl == 0)
	return 0;
	if (in == NULL) {
	ERR_raise(ERR_LIB_BIO, ERR_R_PASSED_NULL_PARAMETER);
	goto end;
	}
	blen = bbm->readp->length;
	mem_buf_sync(b);
	if (BUF_MEM_grow_clean(bbm->buf, blen + inl) == 0)
	goto end;
	memcpy(bbm->buf->data + blen, in, inl);
	bbm->readp = bbm->buf;
	ret = inl;
	end:
	return ret;
	}

	static long mem_ctrl(BIO b, int cmd, long num, void ptr)
	{
	long ret = 1;
	char **pptr;
	BIO_BUF_MEM bbm = (BIO_BUF_MEM )b->ptr;
	BUF_MEM bm, bo; /* bio_mem, bio_other */
	long off, remain;

	if (b->flags & BIO_FLAGS_MEM_RDONLY) {
	bm = bbm->buf;
	bo = bbm->readp;
	} else {
	bm = bbm->readp;
	bo = bbm->buf;
	}
	off = (bm->data == bo->data) ? 0 : bm->data - bo->data;
	remain = bm->length;

	switch (cmd) {
	case BIO_CTRL_RESET:
	bm = bbm->buf;
	if (bm->data != NULL) {
	if (!(b->flags & BIO_FLAGS_MEM_RDONLY)) {
	if (!(b->flags & BIO_FLAGS_NONCLEAR_RST)) {
	memset(bm->data, 0, bm->max);
	bm->length = 0;
	}
	bbm->readp = bbm->buf;
	} else {
	/* For read only case just reset to the start again */
	bbm->buf = bbm->readp;
	}
	}
	break;
	case BIO_C_FILE_SEEK:
	if (num < 0 \|\| num > off + remain)
	return -1; /* Can't see outside of the current buffer */

	bm->data = (num != 0) ? bo->data + num : bo->data;
	bm->length = bo->length - num;
	bm->max = bo->max - num;
	off = num;
	/* FALLTHRU */
	case BIO_C_FILE_TELL:
	ret = off;
	break;
	case BIO_CTRL_EOF:
	ret = (long)(bm->length == 0);
	break;
	case BIO_C_SET_BUF_MEM_EOF_RETURN:
	b->num = (int)num;
	break;
	case BIO_CTRL_INFO:
	ret = (long)bm->length;
	if (ptr != NULL) {
	pptr = (char **)ptr;
	pptr = (char )(bm->data);
	}
	break;
	case BIO_C_SET_BUF_MEM:
	mem_buf_free(b);
	b->shutdown = (int)num;
	bbm->buf = ptr;
	bbm->readp = bbm->buf;
	break;
	case BIO_C_GET_BUF_MEM_PTR:
	if (ptr != NULL) {
	if (!(b->flags & BIO_FLAGS_MEM_RDONLY))
	mem_buf_sync(b);
	bm = bbm->buf;
	pptr = (char **)ptr;
	pptr = (char )bm;
	}
	break;
	case BIO_CTRL_GET_CLOSE:
	ret = (long)b->shutdown;
	break;
	case BIO_CTRL_SET_CLOSE:
	b->shutdown = (int)num;
	break;
	case BIO_CTRL_WPENDING:
	ret = 0L;
	break;
	case BIO_CTRL_PENDING:
	ret = (long)bm->length;
	break;
	case BIO_CTRL_DUP:
	case BIO_CTRL_FLUSH:
	ret = 1;
	break;
	case BIO_CTRL_PUSH:
	case BIO_CTRL_POP:
	default:
	ret = 0;
	break;
	}
	return ret;
	}

	static int mem_gets(BIO bp, char buf, int size)
	{
	int i, j;
	int ret = -1;
	char *p;
	BIO_BUF_MEM bbm = (BIO_BUF_MEM )bp->ptr;
	BUF_MEM *bm = bbm->readp;

	if (bp->flags & BIO_FLAGS_MEM_RDONLY)
	bm = bbm->buf;
	BIO_clear_retry_flags(bp);
	j = bm->length;
	if ((size - 1) < j)
	j = size - 1;
	if (j <= 0) {
	*buf = '\0';
	return 0;
	}
	p = bm->data;
	for (i = 0; i < j; i++) {
	if (p[i] == '\n') {
	i++;
	break;
	}
	}

	/*
	* i is now the max num of bytes to copy, either j or up to
	* and including the first newline
	*/

	i = mem_read(bp, buf, i);
	if (i > 0)
	buf[i] = '\0';
	ret = i;
	return ret;
	}

	static int mem_puts(BIO bp, const char str)
	{
	int n, ret;

	n = strlen(str);
	ret = mem_write(bp, str, n);
	/* memory semantics is that it will always work */
	return ret;
	}