/*
* Parse a public key
*/
int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
const unsigned char *key, size_t keylen )
{
int ret;
unsigned char *p;
#if defined(MBEDTLS_PEM_PARSE_C)
size_t len;
mbedtls_pem_context pem;
mbedtls_pem_init( &pem );
/* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
if( keylen == 0 || key[keylen - 1] != '\0' )
ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
else
ret = mbedtls_pem_read_buffer( &pem,
"-----BEGIN PUBLIC KEY-----",
"-----END PUBLIC KEY-----",
key, NULL, 0, &len );
if( ret == 0 )
{
/*
* Was PEM encoded
*/
key = pem.buf;
keylen = pem.buflen;
}
else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
{
mbedtls_pem_free( &pem );
return( ret );
}
#endif /* MBEDTLS_PEM_PARSE_C */
p = (unsigned char *) key;
ret = mbedtls_pk_parse_subpubkey( &p, p + keylen, ctx );
#if defined(MBEDTLS_PEM_PARSE_C)
mbedtls_pem_free( &pem );
#endif
return( ret );
}
/*
* Parse a CSR in DER format
*/
int mbedtls_x509_csr_parse_der( mbedtls_x509_csr *csr,
const unsigned char *buf, size_t buflen )
{
int ret;
size_t len;
unsigned char *p, *end;
mbedtls_x509_buf sig_params;
memset( &sig_params, 0, sizeof( mbedtls_x509_buf ) );
/*
* Check for valid input
*/
if( csr == NULL || buf == NULL )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
mbedtls_x509_csr_init( csr );
/*
* first copy the raw DER data
*/
p = mbedtls_calloc( 1, len = buflen );
if( p == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
memcpy( p, buf, buflen );
csr->raw.p = p;
csr->raw.len = len;
end = p + len;
/*
* CertificationRequest ::= SEQUENCE {
* certificationRequestInfo CertificationRequestInfo,
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT );
}
if( len != (size_t) ( end - p ) )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
/*
* CertificationRequestInfo ::= SEQUENCE {
*/
csr->cri.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
end = p + len;
csr->cri.len = end - csr->cri.p;
/*
* Version ::= INTEGER { v1(0) }
*/
if( ( ret = x509_csr_get_version( &p, end, &csr->version ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
csr->version++;
if( csr->version != 1 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
}
/*
* subject Name
*/
csr->subject_raw.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
if( ( ret = mbedtls_x509_get_name( &p, p + len, &csr->subject ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
csr->subject_raw.len = p - csr->subject_raw.p;
/*
* subjectPKInfo SubjectPublicKeyInfo
*/
if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &csr->pk ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
/*
* attributes [0] Attributes
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
// TODO Parse Attributes / extension requests
p += len;
end = csr->raw.p + csr->raw.len;
/*
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING
*/
if( ( ret = mbedtls_x509_get_alg( &p, end, &csr->sig_oid, &sig_params ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( ( ret = mbedtls_x509_get_sig_alg( &csr->sig_oid, &sig_params,
&csr->sig_md, &csr->sig_pk,
&csr->sig_opts ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG );
}
if( ( ret = mbedtls_x509_get_sig( &p, end, &csr->sig ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( p != end )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
return( 0 );
}
/*
* Parse a CSR in DER format
*/
int mbedtls_x509_csr_parse_der( mbedtls_x509_csr *csr,
const unsigned char *buf, size_t buflen )
{
int ret;
size_t len;
unsigned char *p, *end;
mbedtls_x509_buf sig_params;
memset( &sig_params, 0, sizeof( mbedtls_x509_buf ) );
/*
* Check for valid input
*/
if( csr == NULL || buf == NULL )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
mbedtls_x509_csr_init( csr );
/*
* first copy the raw DER data
*/
p = mbedtls_calloc( 1, len = buflen );
if( p == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
memcpy( p, buf, buflen );
csr->raw.p = p;
csr->raw.len = len;
end = p + len;
/*
* CertificationRequest ::= SEQUENCE {
* certificationRequestInfo CertificationRequestInfo,
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING
* }
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT );
}
if( len != (size_t) ( end - p ) )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
/*
* CertificationRequestInfo ::= SEQUENCE {
*/
csr->cri.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
end = p + len;
csr->cri.len = end - csr->cri.p;
/*
* Version ::= INTEGER { v1(0) }
*/
if( ( ret = x509_csr_get_version( &p, end, &csr->version ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
csr->version++;
if( csr->version != 1 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
}
/*
* subject Name
*/
csr->subject_raw.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
if( ( ret = mbedtls_x509_get_name( &p, p + len, &csr->subject ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
csr->subject_raw.len = p - csr->subject_raw.p;
/*
* subjectPKInfo SubjectPublicKeyInfo
*/
if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &csr->pk ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
/*
* attributes [0] Attributes
*
* The list of possible attributes is open-ended, though RFC 2985
* (PKCS#9) defines a few in section 5.4. We currently don't support any,
* so we just ignore them. This is a safe thing to do as the worst thing
* that could happen is that we issue a certificate that does not match
* the requester's expectations - this cannot cause a violation of our
* signature policies.
*/
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
p += len;
end = csr->raw.p + csr->raw.len;
/*
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING
*/
if( ( ret = mbedtls_x509_get_alg( &p, end, &csr->sig_oid, &sig_params ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( ( ret = mbedtls_x509_get_sig_alg( &csr->sig_oid, &sig_params,
&csr->sig_md, &csr->sig_pk,
&csr->sig_opts ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG );
}
if( ( ret = mbedtls_x509_get_sig( &p, end, &csr->sig ) ) != 0 )
{
mbedtls_x509_csr_free( csr );
return( ret );
}
if( p != end )
{
mbedtls_x509_csr_free( csr );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
return( 0 );
}
/*
* Verify a signature.
*
* Parameters are passed using the DER encoding format following the ASN.1
* structures detailed above.
*/
static int verify_signature(void *data_ptr, unsigned int data_len,
void *sig_ptr, unsigned int sig_len,
void *sig_alg, unsigned int sig_alg_len,
void *pk_ptr, unsigned int pk_len)
{
mbedtls_asn1_buf sig_oid, sig_params;
mbedtls_asn1_buf signature;
mbedtls_md_type_t md_alg;
mbedtls_pk_type_t pk_alg;
mbedtls_pk_context pk;
int rc;
void *sig_opts = NULL;
const mbedtls_md_info_t *md_info;
unsigned char *p, *end;
unsigned char hash[MBEDTLS_MD_MAX_SIZE];
/* Get pointers to signature OID and parameters */
p = (unsigned char *)sig_alg;
end = (unsigned char *)(p + sig_alg_len);
rc = mbedtls_asn1_get_alg(&p, end, &sig_oid, &sig_params);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
/* Get the actual signature algorithm (MD + PK) */
rc = mbedtls_oid_get_sig_alg(&sig_oid, &md_alg, &pk_alg);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
/* Parse the public key */
mbedtls_pk_init(&pk);
p = (unsigned char *)pk_ptr;
end = (unsigned char *)(p + pk_len);
rc = mbedtls_pk_parse_subpubkey(&p, end, &pk);
if (rc != 0) {
return CRYPTO_ERR_SIGNATURE;
}
/* Get the signature (bitstring) */
p = (unsigned char *)sig_ptr;
end = (unsigned char *)(p + sig_len);
signature.tag = *p;
rc = mbedtls_asn1_get_bitstring_null(&p, end, &signature.len);
if (rc != 0) {
rc = CRYPTO_ERR_SIGNATURE;
goto end;
}
signature.p = p;
/* Calculate the hash of the data */
md_info = mbedtls_md_info_from_type(md_alg);
if (md_info == NULL) {
rc = CRYPTO_ERR_SIGNATURE;
goto end;
}
p = (unsigned char *)data_ptr;
rc = mbedtls_md(md_info, p, data_len, hash);
if (rc != 0) {
rc = CRYPTO_ERR_SIGNATURE;
goto end;
}
/* Verify the signature */
rc = mbedtls_pk_verify_ext(pk_alg, sig_opts, &pk, md_alg, hash,
mbedtls_md_get_size(md_info),
signature.p, signature.len);
if (rc != 0) {
rc = CRYPTO_ERR_SIGNATURE;
goto end;
}
/* Signature verification success */
rc = CRYPTO_SUCCESS;
end:
mbedtls_pk_free(&pk);
return rc;
}