/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int pk_get_rsapubkey( unsigned char **p,
const unsigned char *end,
mbedtls_rsa_context *rsa )
{
int ret;
size_t len;
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY + ret );
if( *p + len != end )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
if( ( ret = mbedtls_asn1_get_mpi( p, end, &rsa->N ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( p, end, &rsa->E ) ) != 0 )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY + ret );
if( *p != end )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
if( ( ret = mbedtls_rsa_check_pubkey( rsa ) ) != 0 )
return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
rsa->len = mbedtls_mpi_size( &rsa->N );
return( 0 );
}
/*
* Restartable read and check signature
*/
int mbedtls_ecdsa_read_signature_restartable( mbedtls_ecdsa_context *ctx,
const unsigned char *hash, size_t hlen,
const unsigned char *sig, size_t slen,
mbedtls_ecdsa_restart_ctx *rs_ctx )
{
int ret;
unsigned char *p = (unsigned char *) sig;
const unsigned char *end = sig + slen;
size_t len;
mbedtls_mpi r, s;
mbedtls_mpi_init( &r );
mbedtls_mpi_init( &s );
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
if( p + len != end )
{
ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
goto cleanup;
}
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
#if defined(MBEDTLS_ECDSA_VERIFY_ALT)
if( ( ret = mbedtls_ecdsa_verify( &ctx->grp, hash, hlen,
&ctx->Q, &r, &s ) ) != 0 )
goto cleanup;
#else
if( ( ret = ecdsa_verify_restartable( &ctx->grp, hash, hlen,
&ctx->Q, &r, &s, rs_ctx ) ) != 0 )
goto cleanup;
#endif /* MBEDTLS_ECDSA_VERIFY_ALT */
/* At this point we know that the buffer starts with a valid signature.
* Return 0 if the buffer just contains the signature, and a specific
* error code if the valid signature is followed by more data. */
if( p != end )
ret = MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH;
cleanup:
mbedtls_mpi_free( &r );
mbedtls_mpi_free( &s );
return( ret );
}
/*
* Read and check signature
*/
int mbedtls_ecdsa_read_signature( mbedtls_ecdsa_context *ctx,
const unsigned char *hash, size_t hlen,
const unsigned char *sig, size_t slen )
{
int ret;
unsigned char *p = (unsigned char *) sig;
const unsigned char *end = sig + slen;
size_t len;
mbedtls_mpi r, s;
mbedtls_mpi_init( &r );
mbedtls_mpi_init( &s );
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
if( p + len != end )
{
ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
goto cleanup;
}
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &r ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &s ) ) != 0 )
{
ret += MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
goto cleanup;
}
if( ( ret = mbedtls_ecdsa_verify( &ctx->grp, hash, hlen,
&ctx->Q, &r, &s ) ) != 0 )
goto cleanup;
if( p != end )
ret = MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH;
cleanup:
mbedtls_mpi_free( &r );
mbedtls_mpi_free( &s );
return( ret );
}
/*
* Parse a PKCS#1 encoded private RSA key
*/
static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
const unsigned char *key,
size_t keylen )
{
int ret;
size_t len;
unsigned char *p, *end;
p = (unsigned char *) key;
end = p + keylen;
/*
* This function parses the RSAPrivateKey (PKCS#1)
*
* RSAPrivateKey ::= SEQUENCE {
* version Version,
* modulus INTEGER, -- n
* publicExponent INTEGER, -- e
* privateExponent INTEGER, -- d
* prime1 INTEGER, -- p
* prime2 INTEGER, -- q
* exponent1 INTEGER, -- d mod (p-1)
* exponent2 INTEGER, -- d mod (q-1)
* coefficient INTEGER, -- (inverse of q) mod p
* otherPrimeInfos OtherPrimeInfos OPTIONAL
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
end = p + len;
if( ( ret = mbedtls_asn1_get_int( &p, end, &rsa->ver ) ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
if( rsa->ver != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
}
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->N ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->E ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->D ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->P ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->Q ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->DP ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->DQ ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->QP ) ) != 0 )
{
mbedtls_rsa_free( rsa );
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
rsa->len = mbedtls_mpi_size( &rsa->N );
if( p != end )
{
mbedtls_rsa_free( rsa );
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
if( ( ret = mbedtls_rsa_check_privkey( rsa ) ) != 0 )
{
mbedtls_rsa_free( rsa );
return( ret );
}
return( 0 );
}
/*
* Parse a SpecifiedECDomain (SEC 1 C.2) and (mostly) fill the group with it.
* WARNING: the resulting group should only be used with
* pk_group_id_from_specified(), since its base point may not be set correctly
* if it was encoded compressed.
*
* SpecifiedECDomain ::= SEQUENCE {
* version SpecifiedECDomainVersion(ecdpVer1 | ecdpVer2 | ecdpVer3, ...),
* fieldID FieldID {{FieldTypes}},
* curve Curve,
* base ECPoint,
* order INTEGER,
* cofactor INTEGER OPTIONAL,
* hash HashAlgorithm OPTIONAL,
* ...
* }
*
* We only support prime-field as field type, and ignore hash and cofactor.
*/
static int pk_group_from_specified( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
{
int ret;
unsigned char *p = params->p;
const unsigned char * const end = params->p + params->len;
const unsigned char *end_field, *end_curve;
size_t len;
int ver;
/* SpecifiedECDomainVersion ::= INTEGER { 1, 2, 3 } */
if( ( ret = mbedtls_asn1_get_int( &p, end, &ver ) ) != 0 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ver < 1 || ver > 3 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
/*
* FieldID { FIELD-ID:IOSet } ::= SEQUENCE { -- Finite field
* fieldType FIELD-ID.&id({IOSet}),
* parameters FIELD-ID.&Type({IOSet}{@fieldType})
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_field = p + len;
/*
* FIELD-ID ::= TYPE-IDENTIFIER
* FieldTypes FIELD-ID ::= {
* { Prime-p IDENTIFIED BY prime-field } |
* { Characteristic-two IDENTIFIED BY characteristic-two-field }
* }
* prime-field OBJECT IDENTIFIER ::= { id-fieldType 1 }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end_field, &len, MBEDTLS_ASN1_OID ) ) != 0 )
return( ret );
if( len != MBEDTLS_OID_SIZE( MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD ) ||
memcmp( p, MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
{
return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
}
p += len;
/* Prime-p ::= INTEGER -- Field of size p. */
if( ( ret = mbedtls_asn1_get_mpi( &p, end_field, &grp->P ) ) != 0 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
grp->pbits = mbedtls_mpi_bitlen( &grp->P );
if( p != end_field )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
/*
* Curve ::= SEQUENCE {
* a FieldElement,
* b FieldElement,
* seed BIT STRING OPTIONAL
* -- Shall be present if used in SpecifiedECDomain
* -- with version equal to ecdpVer2 or ecdpVer3
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( ret );
end_curve = p + len;
/*
* FieldElement ::= OCTET STRING
* containing an integer in the case of a prime field
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
( ret = mbedtls_mpi_read_binary( &grp->A, p, len ) ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
( ret = mbedtls_mpi_read_binary( &grp->B, p, len ) ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
}
p += len;
/* Ignore seed BIT STRING OPTIONAL */
if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_BIT_STRING ) ) == 0 )
p += len;
if( p != end_curve )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
/*
* ECPoint ::= OCTET STRING
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
if( ( ret = mbedtls_ecp_point_read_binary( grp, &grp->G,
( const unsigned char *) p, len ) ) != 0 )
{
/*
* If we can't read the point because it's compressed, cheat by
* reading only the X coordinate and the parity bit of Y.
*/
if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE ||
( p[0] != 0x02 && p[0] != 0x03 ) ||
len != mbedtls_mpi_size( &grp->P ) + 1 ||
mbedtls_mpi_read_binary( &grp->G.X, p + 1, len - 1 ) != 0 ||
mbedtls_mpi_lset( &grp->G.Y, p[0] - 2 ) != 0 ||
mbedtls_mpi_lset( &grp->G.Z, 1 ) != 0 )
{
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
}
}
p += len;
/*
* order INTEGER
*/
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &grp->N ) ) != 0 )
return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
grp->nbits = mbedtls_mpi_bitlen( &grp->N );
/*
* Allow optional elements by purposefully not enforcing p == end here.
*/
return( 0 );
}
/*
* Parse DHM parameters
*/
int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
size_t dhminlen )
{
int ret;
size_t len;
unsigned char *p, *end;
#if defined(MBEDTLS_PEM_PARSE_C)
mbedtls_pem_context pem;
mbedtls_pem_init( &pem );
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if( dhminlen == 0 || dhmin[dhminlen - 1] != '\0' )
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
else
ret = mbedtls_pem_read_buffer( &pem,
"-----BEGIN DH PARAMETERS-----",
"-----END DH PARAMETERS-----",
dhmin, NULL, 0, &dhminlen );
if( ret == 0 )
{
/*
* Was PEM encoded
*/
dhminlen = pem.buflen;
}
else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
goto exit;
p = ( ret == 0 ) ? pem.buf : (unsigned char *) dhmin;
#else
p = (unsigned char *) dhmin;
#endif /* MBEDTLS_PEM_PARSE_C */
end = p + dhminlen;
/*
* DHParams ::= SEQUENCE {
* prime INTEGER, -- P
* generator INTEGER, -- g
* privateValueLength INTEGER OPTIONAL
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
goto exit;
}
end = p + len;
if( ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->P ) ) != 0 ||
( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->G ) ) != 0 )
{
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
goto exit;
}
if( p != end )
{
/* This might be the optional privateValueLength.
* If so, we can cleanly discard it */
mbedtls_mpi rec;
mbedtls_mpi_init( &rec );
ret = mbedtls_asn1_get_mpi( &p, end, &rec );
mbedtls_mpi_free( &rec );
if ( ret != 0 )
{
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
goto exit;
}
if ( p != end )
{
ret = MBEDTLS_ERR_DHM_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
goto exit;
}
}
ret = 0;
dhm->len = mbedtls_mpi_size( &dhm->P );
exit:
#if defined(MBEDTLS_PEM_PARSE_C)
mbedtls_pem_free( &pem );
#endif
if( ret != 0 )
mbedtls_dhm_free( dhm );
return( ret );
}
