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Move token buffers off the stack (Issue #117)

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This commit is contained in:
Michael R Sweet
2025-04-04 21:20:23 -04:00
parent fe755eac3d
commit 0bd9edc845
4 changed files with 170 additions and 35 deletions
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128
pdfio-value.c
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@@ -125,8 +125,7 @@ _pdfioValueDecrypt(pdfio_file_t *pdf, // I - PDF file
_pdfio_crypto_ctx_t ctx; // Decryption context
_pdfio_crypto_cb_t cb; // Decryption callback
size_t ivlen; // Number of initialization vector bytes
uint8_t temp[PDFIO_MAX_STRING + 32];
// Temporary buffer for decryption
uint8_t *temp = NULL; // Temporary buffer for decryption
size_t templen; // Number of actual data bytes
time_t timeval; // Date/time value
@@ -153,11 +152,16 @@ _pdfioValueDecrypt(pdfio_file_t *pdf, // I - PDF file
case PDFIO_VALTYPE_BINARY :
// Decrypt the binary string...
if (v->value.binary.datalen > (sizeof(temp) - 32))
if (v->value.binary.datalen > PDFIO_MAX_STRING)
{
_pdfioFileError(pdf, "Unable to read encrypted binary string - too long.");
return (false);
}
else if ((temp = (uint8_t *)_pdfioStringAllocBuffer(pdf)) == NULL)
{
_pdfioFileError(pdf, "Unable to read encrypted binary string - out of memory.");
return (false);
}
ivlen = v->value.binary.datalen;
if ((cb = _pdfioCryptoMakeReader(pdf, obj, &ctx, v->value.binary.data, &ivlen)) == NULL)
@@ -172,6 +176,8 @@ _pdfioValueDecrypt(pdfio_file_t *pdf, // I - PDF file
v->value.binary.datalen = templen - temp[templen - 1];
else
v->value.binary.datalen = templen;
_pdfioStringFreeBuffer(pdf, (char *)temp);
break;
case PDFIO_VALTYPE_STRING :
@@ -301,7 +307,9 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
_pdfio_value_t *v, // I - Value
size_t depth) // I - Depth of value
{
char token[PDFIO_MAX_STRING];// Token buffer
_pdfio_value_t *ret = NULL; // Return value
char *token = _pdfioStringAllocBuffer(pdf);
// Token buffer
time_t timeval; // Date/time value
#ifdef DEBUG
static const char * const valtypes[] =
@@ -323,8 +331,11 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
PDFIO_DEBUG("_pdfioValueRead(pdf=%p, obj=%p, v=%p)\n", pdf, obj, v);
if (!_pdfioTokenGet(tb, token, sizeof(token)))
return (NULL);
if (!token)
goto done;
if (!_pdfioTokenGet(tb, token, PDFIO_MAX_STRING))
goto done;
if (!strcmp(token, "["))
{
@@ -332,12 +343,14 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
if (depth >= PDFIO_MAX_DEPTH)
{
_pdfioFileError(pdf, "Too many nested arrays.");
return (NULL);
goto done;
}
v->type = PDFIO_VALTYPE_ARRAY;
if ((v->value.array = _pdfioArrayRead(pdf, obj, tb, depth + 1)) == NULL)
return (NULL);
goto done;
ret = v;
}
else if (!strcmp(token, "<<"))
{
@@ -345,29 +358,34 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
if (depth >= PDFIO_MAX_DEPTH)
{
_pdfioFileError(pdf, "Too many nested dictionaries.");
return (NULL);
goto done;
}
v->type = PDFIO_VALTYPE_DICT;
if ((v->value.dict = _pdfioDictRead(pdf, obj, tb, depth + 1)) == NULL)
return (NULL);
goto done;
ret = v;
}
else if ((timeval = get_date_time(token + 1)) != 0)
{
v->type = PDFIO_VALTYPE_DATE;
v->value.date = timeval;
ret = v;
}
else if (token[0] == '(')
{
// String
v->type = PDFIO_VALTYPE_STRING;
v->value.string = pdfioStringCreate(pdf, token + 1);
ret = v;
}
else if (token[0] == '/')
{
// Name
v->type = PDFIO_VALTYPE_NAME;
v->value.name = pdfioStringCreate(pdf, token + 1);
ret = v;
}
else if (token[0] == '<')
{
@@ -380,7 +398,7 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
if ((v->value.binary.data = (unsigned char *)malloc(v->value.binary.datalen)) == NULL)
{
_pdfioFileError(pdf, "Out of memory for hex string.");
return (NULL);
goto done;
}
// Convert hex to binary...
@@ -407,6 +425,8 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
*dataptr++ = (unsigned char)d;
}
ret = v;
}
else if (strchr("0123456789-+.", token[0]) != NULL)
{
@@ -494,7 +514,8 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
PDFIO_DEBUG("_pdfioValueRead: Returning indirect value %lu %u R.\n", (unsigned long)v->value.indirect.number, v->value.indirect.generation);
return (v);
ret = v;
goto done;
}
}
}
@@ -502,27 +523,41 @@ _pdfioValueRead(pdfio_file_t *pdf, // I - PDF file
// If we get here, we have a number...
v->type = PDFIO_VALTYPE_NUMBER;
v->value.number = _pdfio_strtod(pdf, token);
ret = v;
}
else if (!strcmp(token, "true") || !strcmp(token, "false"))
{
// Boolean value
v->type = PDFIO_VALTYPE_BOOLEAN;
v->value.boolean = !strcmp(token, "true");
ret = v;
}
else if (!strcmp(token, "null"))
{
// null value
v->type = PDFIO_VALTYPE_NULL;
ret = v;
}
else
{
_pdfioFileError(pdf, "Unexpected '%s' token seen.", token);
return (NULL);
}
PDFIO_DEBUG("_pdfioValueRead: Returning %s value.\n", valtypes[v->type]);
done:
return (v);
if (token)
_pdfioStringFreeBuffer(pdf, token);
if (ret)
{
PDFIO_DEBUG("_pdfioValueRead: Returning %s value.\n", valtypes[ret->type]);
return (ret);
}
else
{
PDFIO_DEBUG("_pdfioValueRead: Returning NULL.\n");
return (NULL);
}
}
@@ -547,9 +582,10 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
case PDFIO_VALTYPE_BINARY :
{
size_t databytes; // Bytes to write
uint8_t temp[PDFIO_MAX_STRING + 32],
// Temporary buffer for encryption
uint8_t *temp = NULL, // Temporary buffer for encryption
*dataptr; // Pointer into data
bool ret = false; // Return value
if (obj && pdf->encryption)
{
@@ -558,11 +594,16 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
_pdfio_crypto_cb_t cb; // Encryption callback
size_t ivlen; // Number of initialization vector bytes
if (v->value.binary.datalen > (sizeof(temp) - 32))
if (v->value.binary.datalen > PDFIO_MAX_STRING)
{
_pdfioFileError(pdf, "Unable to write encrypted binary string - too long.");
return (false);
}
else if ((temp = (uint8_t *)_pdfioStringAllocBuffer(pdf)) == NULL)
{
_pdfioFileError(pdf, "Unable to write encrypted binary string - out of memory.");
return (false);
}
cb = _pdfioCryptoMakeWriter(pdf, obj, &ctx, temp, &ivlen);
databytes = (cb)(&ctx, temp + ivlen, v->value.binary.data, v->value.binary.datalen) + ivlen;
@@ -575,18 +616,25 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
}
if (!_pdfioFilePuts(pdf, "<"))
return (false);
goto bindone;
for (; databytes > 1; databytes -= 2, dataptr += 2)
{
if (!_pdfioFilePrintf(pdf, "%02X%02X", dataptr[0], dataptr[1]))
return (false);
goto bindone;
}
if (databytes > 0)
return (_pdfioFilePrintf(pdf, "%02X>", dataptr[0]));
else
return (_pdfioFilePuts(pdf, ">"));
if (databytes > 0 && !_pdfioFilePrintf(pdf, "%02X", dataptr[0]))
goto bindone;
ret = _pdfioFilePuts(pdf, ">");
bindone:
if (temp)
_pdfioStringFreeBuffer(pdf, (char *)temp);
return (ret);
}
case PDFIO_VALTYPE_BOOLEAN :
@@ -611,8 +659,7 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
if (obj && pdf->encryption)
{
// Write encrypted string...
uint8_t temp[PDFIO_MAX_STRING + 32],
// Encrypted bytes
uint8_t temp[64], // Encrypted bytes
*tempptr; // Pointer into encrypted bytes
_pdfio_crypto_ctx_t ctx; // Encryption context
_pdfio_crypto_cb_t cb; // Encryption callback
@@ -663,8 +710,7 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
if (obj && pdf->encryption)
{
// Write encrypted string...
uint8_t temp[PDFIO_MAX_STRING + 32],
// Encrypted bytes
uint8_t *temp = NULL, // Encrypted bytes
*tempptr; // Pointer into encrypted bytes
_pdfio_crypto_ctx_t ctx; // Encryption context
_pdfio_crypto_cb_t cb; // Encryption callback
@@ -672,29 +718,41 @@ _pdfioValueWrite(pdfio_file_t *pdf, // I - PDF file
// Length of value
ivlen, // Number of initialization vector bytes
tempbytes; // Number of output bytes
bool ret = false; // Return value
if (len > (sizeof(temp) - 32))
if (len > PDFIO_MAX_STRING)
{
_pdfioFileError(pdf, "Unable to write encrypted string - too long.");
return (false);
}
else if ((temp = (uint8_t *)_pdfioStringAllocBuffer(pdf)) == NULL)
{
_pdfioFileError(pdf, "Unable to write encrypted string - out of memory.");
return (false);
}
cb = _pdfioCryptoMakeWriter(pdf, obj, &ctx, temp, &ivlen);
tempbytes = (cb)(&ctx, temp + ivlen, (const uint8_t *)v->value.string, len) + ivlen;
if (!_pdfioFilePuts(pdf, "<"))
return (false);
goto strdone;
for (tempptr = temp; tempbytes > 1; tempbytes -= 2, tempptr += 2)
{
if (!_pdfioFilePrintf(pdf, "%02X%02X", tempptr[0], tempptr[1]))
return (false);
goto strdone;
}
if (tempbytes > 0)
return (_pdfioFilePrintf(pdf, "%02X>", *tempptr));
else
return (_pdfioFilePuts(pdf, ">"));
if (tempbytes > 0 && !_pdfioFilePrintf(pdf, "%02X", *tempptr))
goto strdone;
ret = _pdfioFilePuts(pdf, ">");
strdone :
_pdfioStringFreeBuffer(pdf, (char *)temp);
return (ret);
}
else
{