pem_read_buffer() already update use_len after header and footer are read

After header and footer are read, pem_read_buffer() is able to determine
the length of input data used. This allows calling functions to skip
this PEM bit if an error occurs during its parsing.
(cherry picked from commit 9255e8300e)
This commit is contained in:
Paul Bakker 2013-06-24 13:02:41 +02:00
parent b2a1140469
commit 00b2860e8d
5 changed files with 31 additions and 22 deletions

View file

@ -1,7 +1,7 @@
/*
* Privacy Enhanced Mail (PEM) decoding
*
* Copyright (C) 2006-2010, Brainspark B.V.
* Copyright (C) 2006-2013, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@ -183,7 +183,7 @@ int pem_read_buffer( pem_context *ctx, char *header, char *footer, const unsigne
int ret, enc;
size_t len;
unsigned char *buf;
unsigned char *s1, *s2;
const unsigned char *s1, *s2, *end;
#if defined(POLARSSL_MD5_C) && (defined(POLARSSL_DES_C) || defined(POLARSSL_AES_C))
unsigned char pem_iv[16];
cipher_type_t enc_alg = POLARSSL_CIPHER_NONE;
@ -193,22 +193,28 @@ int pem_read_buffer( pem_context *ctx, char *header, char *footer, const unsigne
#endif /* POLARSSL_MD5_C && (POLARSSL_AES_C || POLARSSL_DES_C) */
if( ctx == NULL )
return( POLARSSL_ERR_PEM_INVALID_DATA );
return( POLARSSL_ERR_PEM_BAD_INPUT_DATA );
s1 = (unsigned char *) strstr( (const char *) data, header );
if( s1 == NULL )
return( POLARSSL_ERR_PEM_NO_HEADER_PRESENT );
return( POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
s2 = (unsigned char *) strstr( (const char *) data, footer );
if( s2 == NULL || s2 <= s1 )
return( POLARSSL_ERR_PEM_INVALID_DATA );
return( POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
s1 += strlen( header );
if( *s1 == '\r' ) s1++;
if( *s1 == '\n' ) s1++;
else return( POLARSSL_ERR_PEM_INVALID_DATA );
else return( POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
end = s2;
end += strlen( footer );
if( *end == '\r' ) end++;
if( *end == '\n' ) end++;
*use_len = end - data;
enc = 0;
@ -330,10 +336,6 @@ int pem_read_buffer( pem_context *ctx, char *header, char *footer, const unsigne
ctx->buf = buf;
ctx->buflen = len;
s2 += strlen( footer );
if( *s2 == '\r' ) s2++;
if( *s2 == '\n' ) s2++;
*use_len = s2 - data;
return( 0 );
}