Add ASN.1 ENUMERATED tag support

Add ASN.1 ENUMERATED [1] tag to supported tag list.

1. https://tools.ietf.org/html/rfc3641#page-8

Signed-off-by: Mykhailo Sopiha <mykhailo.sopiha@linaro.org>
This commit is contained in:
Mykhailo Sopiha 2019-10-29 15:58:10 +02:00
parent 0eaf49c9be
commit 20180ca919
4 changed files with 71 additions and 11 deletions

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@ -75,6 +75,7 @@
#define MBEDTLS_ASN1_OCTET_STRING 0x04
#define MBEDTLS_ASN1_NULL 0x05
#define MBEDTLS_ASN1_OID 0x06
#define MBEDTLS_ASN1_ENUMERATED 0x0A
#define MBEDTLS_ASN1_UTF8_STRING 0x0C
#define MBEDTLS_ASN1_SEQUENCE 0x10
#define MBEDTLS_ASN1_SET 0x11
@ -254,13 +255,32 @@ int mbedtls_asn1_get_bool( unsigned char **p,
* a valid ASN.1 INTEGER.
* \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does
* not fit in an \c int.
* \return An ASN.1 error code if the input does not start with
* a valid ASN.1 INTEGER.
*/
int mbedtls_asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val );
/**
* \brief Retrieve an enumerated ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p On entry, \c *p points to the start of the ASN.1 element.
* On successful completion, \c *p points to the first byte
* beyond the ASN.1 element.
* On error, the value of \c *p is undefined.
* \param end End of data.
* \param val On success, the parsed value.
*
* \return 0 if successful.
* \return An ASN.1 error code if the input does not start with
* a valid ASN.1 ENUMERATED.
* \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does
* not fit in an \c int.
*/
int mbedtls_asn1_get_enum( unsigned char **p,
const unsigned char *end,
int *val );
/**
* \brief Retrieve a bitstring ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
@ -367,8 +387,6 @@ int mbedtls_asn1_get_sequence_of( unsigned char **p,
* \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does
* not fit in an \c int.
* \return An MPI error code if the parsed value is too large.
* \return An ASN.1 error code if the input does not start with
* a valid ASN.1 INTEGER.
*/
int mbedtls_asn1_get_mpi( unsigned char **p,
const unsigned char *end,

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@ -192,6 +192,21 @@ int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start,
*/
int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val );
/**
* \brief Write an enum tag (#MBEDTLS_ASN1_ENUMERATED) and value
* in ASN.1 format.
*
* \note This function works backwards in data buffer.
*
* \param p The reference to the current position pointer.
* \param start The start of the buffer, for bounds-checking.
* \param val The integer value to write.
*
* \return The number of bytes written to \p p on success.
* \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure.
*/
int mbedtls_asn1_write_enum( unsigned char **p, unsigned char *start, int val );
/**
* \brief Write a string in ASN.1 format using a specific
* string encoding tag.

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@ -139,17 +139,20 @@ int mbedtls_asn1_get_bool( unsigned char **p,
return( 0 );
}
int mbedtls_asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val )
static int asn1_get_tagged_int( unsigned char **p,
const unsigned char *end,
int tag, int *val )
{
int ret;
size_t len;
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, tag ) ) != 0 )
return( ret );
/* len==0 is malformed (0 must be represented as 020100). */
/*
* len==0 is malformed (0 must be represented as 020100 for INTEGER,
* or 0A0100 for ENUMERATED tags
*/
if( len == 0 )
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
/* This is a cryptography library. Reject negative integers. */
@ -180,6 +183,20 @@ int mbedtls_asn1_get_int( unsigned char **p,
return( 0 );
}
int mbedtls_asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val )
{
return( asn1_get_tagged_int( p, end, MBEDTLS_ASN1_INTEGER, val) );
}
int mbedtls_asn1_get_enum( unsigned char **p,
const unsigned char *end,
int *val )
{
return( asn1_get_tagged_int( p, end, MBEDTLS_ASN1_ENUMERATED, val) );
}
#if defined(MBEDTLS_BIGNUM_C)
int mbedtls_asn1_get_mpi( unsigned char **p,
const unsigned char *end,

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@ -231,7 +231,7 @@ int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, int boolea
return( (int) len );
}
int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
static int asn1_write_tagged_int( unsigned char **p, unsigned char *start, int val, int tag )
{
int ret;
size_t len = 0;
@ -255,11 +255,21 @@ int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
}
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_INTEGER ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, tag ) );
return( (int) len );
}
int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
{
return( asn1_write_tagged_int( p, start, val, MBEDTLS_ASN1_INTEGER ) );
}
int mbedtls_asn1_write_enum( unsigned char **p, unsigned char *start, int val )
{
return( asn1_write_tagged_int( p, start, val, MBEDTLS_ASN1_ENUMERATED ) );
}
int mbedtls_asn1_write_tagged_string( unsigned char **p, unsigned char *start, int tag,
const char *text, size_t text_len )
{