httpdigest.c File Reference

Hyper Text Transfer Protocol (HTTP) Digest authentication. More...

#include <stdio.h>
#include <errno.h>
#include <strings.h>
#include <ipxe/uri.h>
#include <ipxe/md5.h>
#include <ipxe/base16.h>
#include <ipxe/vsprintf.h>
#include <ipxe/http.h>

Go to the source code of this file.

Data Structures
struct	http_digest_field
	An HTTP Digest "WWW-Authenticate" response field. More...

Macros
#define	EACCES_USERNAME   __einfo_error ( EINFO_EACCES_USERNAME )
#define	EINFO_EACCES_USERNAME
#define	HTTP_DIGEST_FIELD(_name)
	Define an HTTP Digest "WWW-Authenticate" response field.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static void	http_digest_field (struct http_transaction *http, struct http_digest_field *field, char *value)
	Set HTTP Digest "WWW-Authenticate" response field value.
static int	http_parse_digest_auth (struct http_transaction *http, char *line)
	Parse HTTP "WWW-Authenticate" header for Digest authentication.
static void	http_digest_init (struct md5_context *ctx)
	Initialise HTTP Digest.
static void	http_digest_update (struct md5_context *ctx, const char *string)
	Update HTTP Digest with new data.
static void	http_digest_final (struct md5_context *ctx, char *out, size_t len)
	Finalise HTTP Digest.
static int	http_digest_authenticate (struct http_transaction *http)
	Perform HTTP Digest authentication.
static int	http_format_digest_auth (struct http_transaction *http, char *buf, size_t len)
	Construct HTTP "Authorization" header for Digest authentication.
	REQUIRING_SYMBOL (http_digest_auth)
	REQUIRE_OBJECT (httpauth)

Variables
static struct http_digest_field	http_digest_fields []
	HTTP Digest "WWW-Authenticate" fields.
struct http_authentication http_digest_auth	__http_authentication
	HTTP Digest authentication scheme.

Detailed Description

Hyper Text Transfer Protocol (HTTP) Digest authentication.

Definition in file httpdigest.c.

Macro Definition Documentation

EACCES_USERNAME

#define EACCES_USERNAME   __einfo_error ( EINFO_EACCES_USERNAME )

Definition at line 44 of file httpdigest.c.

EINFO_EACCES_USERNAME

#define EINFO_EACCES_USERNAME

Value:

        __einfo_uniqify ( EINFO_EACCES, 0x01,                                \
                          "No username available for Digest authentication" )

Definition at line 45 of file httpdigest.c.

#define EINFO_EACCES_USERNAME                                           \
        __einfo_uniqify ( EINFO_EACCES, 0x01,                           \
                          "No username available for Digest authentication" )

HTTP_DIGEST_FIELD

#define HTTP_DIGEST_FIELD

(

_name

)

Value:

                {                                       \
                .name = #_name,                                         \
                .offset = offsetof ( struct http_transaction,           \
                                     response.auth.digest._name ),      \
        }

Define an HTTP Digest "WWW-Authenticate" response field.

Definition at line 58 of file httpdigest.c.

#define HTTP_DIGEST_FIELD( _name ) {                                    \
                .name = #_name,                                         \
                .offset = offsetof ( struct http_transaction,           \
                                     response.auth.digest._name ),      \
        }

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

http_digest_field()

void http_digest_field ( struct http_transaction * http, struct http_digest_field * field, char * value )

inlinestatic

Set HTTP Digest "WWW-Authenticate" response field value.

Parameters

http	HTTP transaction
field	Response field
value	Field value

Definition at line 72 of file httpdigest.c.

                                                                   {
        char **ptr;
 
        ptr = ( ( ( void * ) http ) + field->offset );
        *ptr = value;
}

References http_digest_field::offset, and value.

Referenced by http_parse_digest_auth().

http_parse_digest_auth()

int http_parse_digest_auth ( struct http_transaction * http, char * line )

static

Parse HTTP "WWW-Authenticate" header for Digest authentication.

Parameters

http	HTTP transaction
line	Remaining header line

Return values

rc	Return status code

Definition at line 96 of file httpdigest.c.

                                                 {
        struct http_digest_field *field;
        char *key;
        char *value;
        unsigned int i;
 
        /* Process fields */
        while ( ( key = http_token ( &line, &value ) ) ) {
                for ( i = 0 ; i < ( sizeof ( http_digest_fields ) /
                                    sizeof ( http_digest_fields[0] ) ) ; i++){
                        field = &http_digest_fields[i];
                        if ( strcasecmp ( key, field->name ) == 0 )
                                http_digest_field ( http, field, value );
                }
        }
 
        /* Allow HTTP request to be retried if the request had not
         * already tried authentication.
         */
        if ( ! http->request.auth.auth )
                http->response.flags |= HTTP_RESPONSE_RETRY;
 
        return 0;
}

References http_request::auth, http_request_auth::auth, http_response::flags, http_digest_field(), http_digest_fields, HTTP_RESPONSE_RETRY, http_token(), key, http_digest_field::name, http_transaction::request, http_transaction::response, strcasecmp(), and value.

http_digest_init()

void http_digest_init ( struct md5_context * ctx )

static

Initialise HTTP Digest.

Parameters

ctx	Digest context
string	Initial string

Definition at line 128 of file httpdigest.c.

                                                         {
 
        /* Initialise MD5 digest */
        digest_init ( &md5_algorithm, ctx );
}

References ctx, digest_init(), and md5_algorithm.

Referenced by http_digest_authenticate().

http_digest_update()

void http_digest_update ( struct md5_context * ctx, const char * string )

static

Update HTTP Digest with new data.

Parameters

ctx	Digest context
string	String to append

Definition at line 140 of file httpdigest.c.

                                                                               {
        static const char colon = ':';
 
        /* Add (possibly colon-separated) field to MD5 digest */
        if ( ctx->len )
                digest_update ( &md5_algorithm, ctx, &colon, sizeof ( colon ) );
        digest_update ( &md5_algorithm, ctx, string, strlen ( string ) );
}

References ctx, digest_update(), md5_algorithm, and strlen().

Referenced by http_digest_authenticate().

http_digest_final()

void http_digest_final ( struct md5_context * ctx, char * out, size_t len )

static

Finalise HTTP Digest.

Parameters

ctx	Digest context
out	Buffer for digest output
len	Buffer length

Definition at line 156 of file httpdigest.c.

                                             {
        uint8_t digest[MD5_DIGEST_SIZE];
 
        /* Finalise and base16-encode MD5 digest */
        digest_final ( &md5_algorithm, ctx, digest );
        base16_encode ( digest, sizeof ( digest ), out, len );
}

References ctx, digest_final(), len, md5_algorithm, MD5_DIGEST_SIZE, and out.

Referenced by http_digest_authenticate().

http_digest_authenticate()

int http_digest_authenticate ( struct http_transaction * http )

static

Perform HTTP Digest authentication.

Parameters

http	HTTP transaction

Return values

rc	Return status code

Definition at line 171 of file httpdigest.c.

                                                                      {
        struct http_request_auth_digest *req = &http->request.auth.digest;
        struct http_response_auth_digest *rsp = &http->response.auth.digest;
        char ha1[ base16_encoded_len ( MD5_DIGEST_SIZE ) + 1 /* NUL */ ];
        char ha2[ base16_encoded_len ( MD5_DIGEST_SIZE ) + 1 /* NUL */ ];
        static const char md5sess[] = "MD5-sess";
        static const char md5[] = "MD5";
        struct md5_context ctx;
        const char *password;
 
        /* Check for required response parameters */
        if ( ! rsp->realm ) {
                DBGC ( http, "HTTP %p has no realm for Digest authentication\n",
                       http );
                return -EINVAL;
        }
        if ( ! rsp->nonce ) {
                DBGC ( http, "HTTP %p has no nonce for Digest authentication\n",
                       http );
                return -EINVAL;
        }
 
        /* Record username and password */
        if ( ! http->uri->user ) {
                DBGC ( http, "HTTP %p has no username for Digest "
                       "authentication\n", http );
                return -EACCES_USERNAME;
        }
        req->username = http->uri->user;
        password = ( http->uri->password ? http->uri->password : "" );
 
        /* Handle quality of protection */
        if ( rsp->qop ) {
 
                /* Use "auth" in subsequent request */
                req->qop = "auth";
 
                /* Generate a client nonce */
                snprintf ( req->cnonce, sizeof ( req->cnonce ),
                           "%08lx", random() );
 
                /* Determine algorithm */
                req->algorithm = md5;
                if ( rsp->algorithm &&
                     ( strcasecmp ( rsp->algorithm, md5sess ) == 0 ) ) {
                        req->algorithm = md5sess;
                }
        }
 
        /* Generate HA1 */
        http_digest_init ( &ctx );
        http_digest_update ( &ctx, req->username );
        http_digest_update ( &ctx, rsp->realm );
        http_digest_update ( &ctx, password );
        http_digest_final ( &ctx, ha1, sizeof ( ha1 ) );
        if ( req->algorithm == md5sess ) {
                http_digest_init ( &ctx );
                http_digest_update ( &ctx, ha1 );
                http_digest_update ( &ctx, rsp->nonce );
                http_digest_update ( &ctx, req->cnonce );
                http_digest_final ( &ctx, ha1, sizeof ( ha1 ) );
        }
 
        /* Generate HA2 */
        http_digest_init ( &ctx );
        http_digest_update ( &ctx, http->request.method->name );
        http_digest_update ( &ctx, http->request.uri );
        http_digest_final ( &ctx, ha2, sizeof ( ha2 ) );
 
        /* Generate response */
        http_digest_init ( &ctx );
        http_digest_update ( &ctx, ha1 );
        http_digest_update ( &ctx, rsp->nonce );
        if ( req->qop ) {
                http_digest_update ( &ctx, HTTP_DIGEST_NC );
                http_digest_update ( &ctx, req->cnonce );
                http_digest_update ( &ctx, req->qop );
        }
        http_digest_update ( &ctx, ha2 );
        http_digest_final ( &ctx, req->response, sizeof ( req->response ) );
 
        return 0;
}

References http_request_auth_digest::algorithm, http_request::auth, http_response::auth, base16_encoded_len(), http_request_auth_digest::cnonce, ctx, DBGC, http_request_auth::digest, http_response_auth::digest, EACCES_USERNAME, EINVAL, http_digest_final(), http_digest_init(), HTTP_DIGEST_NC, http_digest_update(), MD5_DIGEST_SIZE, http_request::method, http_method::name, password, uri::password, http_request_auth_digest::qop, random(), http_transaction::request, http_request_auth_digest::response, http_transaction::response, rsp, snprintf(), strcasecmp(), http_request::uri, http_transaction::uri, uri::user, and http_request_auth_digest::username.

http_format_digest_auth()

int http_format_digest_auth ( struct http_transaction * http, char * buf, size_t len )

static

Construct HTTP "Authorization" header for Digest authentication.

Parameters

http	HTTP transaction
buf	Buffer
len	Length of buffer

Return values

len	Length of header value, or negative error

Definition at line 263 of file httpdigest.c.

                                                             {
        struct http_request_auth_digest *req = &http->request.auth.digest;
        struct http_response_auth_digest *rsp = &http->response.auth.digest;
        size_t used = 0;
 
        /* Sanity checks */
        assert ( rsp->realm != NULL );
        assert ( rsp->nonce != NULL );
        assert ( req->username != NULL );
        if ( req->qop ) {
                assert ( req->algorithm != NULL );
                assert ( req->cnonce[0] != '\0' );
        }
        assert ( req->response[0] != '\0' );
 
        /* Construct response */
        used += ssnprintf ( ( buf + used ), ( len - used ),
                            "realm=\"%s\", nonce=\"%s\", uri=\"%s\", "
                            "username=\"%s\"", rsp->realm, rsp->nonce,
                            http->request.uri, req->username );
        if ( rsp->opaque ) {
                used += ssnprintf ( ( buf + used ), ( len - used ),
                                    ", opaque=\"%s\"", rsp->opaque );
        }
        if ( req->qop ) {
                used += ssnprintf ( ( buf + used ), ( len - used ),
                                    ", qop=%s, algorithm=%s, cnonce=\"%s\", "
                                    "nc=" HTTP_DIGEST_NC, req->qop,
                                    req->algorithm, req->cnonce );
        }
        used += ssnprintf ( ( buf + used ), ( len - used ),
                            ", response=\"%s\"", req->response );
 
        return used;
}

References http_request_auth_digest::algorithm, assert, http_request::auth, http_response::auth, http_request_auth_digest::cnonce, http_request_auth::digest, http_response_auth::digest, HTTP_DIGEST_NC, len, NULL, http_request_auth_digest::qop, http_transaction::request, http_request_auth_digest::response, http_transaction::response, rsp, ssnprintf(), http_request::uri, and http_request_auth_digest::username.

REQUIRING_SYMBOL()

REQUIRING_SYMBOL

(

http_digest_auth

)

REQUIRE_OBJECT()

REQUIRE_OBJECT

(

httpauth

)

Variable Documentation

http_digest_fields

struct http_digest_field http_digest_fields[]

static

Initial value:

= {
        HTTP_DIGEST_FIELD ( realm ),
        HTTP_DIGEST_FIELD ( qop ),
        HTTP_DIGEST_FIELD ( algorithm ),
        HTTP_DIGEST_FIELD ( nonce ),
        HTTP_DIGEST_FIELD ( opaque ),
}

HTTP Digest "WWW-Authenticate" fields.

Definition at line 81 of file httpdigest.c.

                                                       {
        HTTP_DIGEST_FIELD ( realm ),
        HTTP_DIGEST_FIELD ( qop ),
        HTTP_DIGEST_FIELD ( algorithm ),
        HTTP_DIGEST_FIELD ( nonce ),
        HTTP_DIGEST_FIELD ( opaque ),
};

Referenced by http_parse_digest_auth().

__http_authentication

struct http_authentication http_digest_auth __http_authentication

Initial value:

= {
        .name = "Digest",
        .parse = http_parse_digest_auth,
        .authenticate = http_digest_authenticate,
        .format = http_format_digest_auth,
}

HTTP Digest authentication scheme.

Definition at line 301 of file httpdigest.c.

                                                                    {
        .name = "Digest",
        .parse = http_parse_digest_auth,
        .authenticate = http_digest_authenticate,
        .format = http_format_digest_auth,
};