helper library for handling URI-based HELLOs More...

#include "gnunet_time_lib.h"
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_signatures.h"
#include "gnunet_hello_uri_lib.h"
#include "gnunet_protocols.h"

Include dependency graph for hello-uri.c:

Data Structures
struct	PilsHelloSignaturePurpose
	Message signed as part of a HELLO block/URL. More...

struct	HelloUriMessage
	Message used when gossiping HELLOs between peers. More...

struct	BlockHeader
	Start of a 'block'. More...

struct	DhtHelloMessage
	Message used when a DHT provides its HELLO to direct neighbours. More...

struct	Address
	Address of a peer. More...

struct	GNUNET_HELLO_Builder
	Context for building (or parsing) HELLO URIs. More...

struct	AddressUriMergeResult
	Struct to wrap data to do the merge of to hello uris. More...

struct	GNUNET_HELLO_Parser
	Context for parsing HELLOs. More...

Functions
static void	hash_addresses (const struct Address addr_start, struct GNUNET_HashCode hash)

static enum GNUNET_GenericReturnValue	verify_hello (const struct GNUNET_HELLO_Parser parser, struct GNUNET_TIME_Absolute et, const struct GNUNET_CRYPTO_EddsaSignature sig)
	Verify HELLO signature.

static struct GNUNET_HELLO_Parser *	parser_new (const struct GNUNET_PeerIdentity *pid)

struct GNUNET_HELLO_Builder *	GNUNET_HELLO_builder_new ()
	Allocate builder.

const struct GNUNET_PeerIdentity *	GNUNET_HELLO_parser_get_id (const struct GNUNET_HELLO_Parser *parser)
	Get the PeerIdentity for this builder.

struct GNUNET_HELLO_Builder *	GNUNET_HELLO_builder_from_parser (const struct GNUNET_HELLO_Parser p, struct GNUNET_PeerIdentity pid)
	Allocate builder from parser.

void	GNUNET_HELLO_parser_free (struct GNUNET_HELLO_Parser *parser)
	Release resources of a builder.

void	GNUNET_HELLO_builder_free (struct GNUNET_HELLO_Builder *builder)
	Release resources of a builder.

struct GNUNET_HELLO_Parser *	GNUNET_HELLO_parser_from_msg (const struct GNUNET_MessageHeader msg, const struct GNUNET_PeerIdentity pid)
	Parse msg.

struct GNUNET_HELLO_Parser *	GNUNET_HELLO_parser_from_msg_ (const struct GNUNET_MessageHeader msg, const struct GNUNET_PeerIdentity pid, int noverify)
	Parse msg.

static enum GNUNET_GenericReturnValue	check_address (const char *address)

static int	cmp_address (void cls, struct Address a, struct Address *b)
	Alphanumeric sorting for addresses.

static enum GNUNET_GenericReturnValue	parser_add_address (struct GNUNET_HELLO_Parser parser, const char address)

struct GNUNET_HELLO_Parser *	GNUNET_HELLO_parser_from_block (const void *block, size_t block_size)
	Parse block.

struct GNUNET_HELLO_Parser *	GNUNET_HELLO_parser_from_block_ (const void *block, size_t block_size, int noverify)
	Parse block.

struct GNUNET_TIME_Absolute	GNUNET_HELLO_get_expiration_time_from_msg (const struct GNUNET_MessageHeader *msg)
	Get the expiration time for this HELLO.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_builder_add_address (struct GNUNET_HELLO_Builder builder, const char address)
	Add individual address to the builder.

struct GNUNET_HELLO_Parser *	GNUNET_HELLO_parser_from_url (const char *url)
	Parse GNUnet HELLO url.

char *	GNUNET_HELLO_parser_to_url (const struct GNUNET_HELLO_Parser *parser)
	Generate GNUnet HELLO URI from a parser.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_parser_to_block (const struct GNUNET_HELLO_Parser parser, void block, size_t *block_size)
	Generate DHT block from a parser.

struct GNUNET_MQ_Envelope *	GNUNET_HELLO_parser_to_env (const struct GNUNET_HELLO_Parser *parser)
	Generate envelope with GNUnet HELLO message (including peer ID) from a parser.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_builder_del_address (struct GNUNET_HELLO_Builder builder, const char address)
	Remove individual address from the builder.

void	GNUNET_HELLO_builder_iterate (const struct GNUNET_HELLO_Builder builder, GNUNET_HELLO_UriCallback uc, void uc_cls)
	Iterate over URIs in a builder.

const struct GNUNET_PeerIdentity *	GNUNET_HELLO_parser_iterate (const struct GNUNET_HELLO_Parser parser, GNUNET_HELLO_UriCallback uc, void uc_cls)
	Iterate over URIs in a parser.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_dht_msg_to_block (const struct GNUNET_MessageHeader hello, const struct GNUNET_PeerIdentity pid, void *block, size_t block_size, struct GNUNET_TIME_Absolute *block_expiration)
	Convert a DHT hello message to a HELLO block.

char *	GNUNET_HELLO_address_to_prefix (const char *address)
	Given an address as a string, extract the prefix that identifies the communicator offering transmissions to that address.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_build_url (const struct GNUNET_HELLO_Builder builder, const struct GNUNET_PeerIdentity pid, const struct GNUNET_CRYPTO_EddsaSignature sig, struct GNUNET_TIME_Absolute expiration, char *result)

void	GNUNET_HELLO_builder_hash_addresses (const struct GNUNET_HELLO_Builder builder, struct GNUNET_HashCode hash)
	Compute hash over addresses in builder.

struct GNUNET_MQ_Envelope *	GNUNET_HELLO_builder_to_env (const struct GNUNET_HELLO_Builder builder, const struct GNUNET_PeerIdentity pid, const struct GNUNET_CRYPTO_EddsaSignature *hello_sig, struct GNUNET_TIME_Absolute expiration_time)
	Generate envelope with GNUnet HELLO message (including peer ID) from a builder.

struct GNUNET_MessageHeader *	GNUNET_HELLO_parser_to_dht_hello_msg (const struct GNUNET_HELLO_Parser *parser)
	Generate DHT HELLO message from a parser.

struct GNUNET_MessageHeader *	GNUNET_HELLO_builder_to_dht_hello_msg (const struct GNUNET_HELLO_Builder builder, const struct GNUNET_PeerIdentity pid, const struct GNUNET_CRYPTO_EddsaSignature *hello_sig, struct GNUNET_TIME_Absolute expiration_time)
	Generate DHT HELLO message (without peer ID) from a builder.

void	GNUNET_HELLO_builder_to_block (const struct GNUNET_HELLO_Builder builder, const struct GNUNET_PeerIdentity pid, const struct GNUNET_CRYPTO_EddsaSignature sig, struct GNUNET_TIME_Absolute expiration_time, char block)
	Generate DHT block from a builder.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_builder_to_url2 (const struct GNUNET_HELLO_Builder builder, const struct GNUNET_PeerIdentity pid, const struct GNUNET_CRYPTO_EddsaSignature sig, struct GNUNET_TIME_Absolute validity, char *result)
	Generate GNUnet HELLO URI from a builder.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_builder_to_url (const struct GNUNET_HELLO_Builder builder, const struct GNUNET_PeerIdentity pid, const struct GNUNET_CRYPTO_EddsaSignature sig, char *result)
	Generate GNUnet HELLO URI from a builder.

size_t	GNUNET_HELLO_get_builder_to_block_size (const struct GNUNET_HELLO_Builder *builder)
	Get projected block size for builder.

enum GNUNET_GenericReturnValue	GNUNET_HELLO_builder_address_list_cmp (const struct GNUNET_HELLO_Builder abuilder, const struct GNUNET_HELLO_Builder bbuilder)
	Compare address lists of two builders.

Detailed Description

helper library for handling URI-based HELLOs

Author: Christian Grothoff

Note:

Current API does not support deserializing HELLO of another peer and then serializing it into another format (we always require the private key). Not sure if we need this, but if we do, we need to extend the builder and the API.
Current API does not allow overriding the default HELLO expiration time. We may want to add a function that does this to create bootstrap HELLOs shipped with the TGZ.

Definition in file hello-uri.c.

Function Documentation

◆ hash_addresses()

static void hash_addresses	(	const struct Address *	addr_start,
		struct GNUNET_HashCode *	hash
	)

static

Definition at line 267 of file hello-uri.c.

{
  struct GNUNET_HashContext *hc;
 
  hc = GNUNET_CRYPTO_hash_context_start ();
 
#if HELLO_DETERMINISTIC_PID_DERIVATION
  for (const struct Address *a = addr_start;
       NULL != a;
       a = a->next)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Hashing over %.*s\n",
                (int) a->uri_len,
                a->uri);
    GNUNET_CRYPTO_hash_context_read (hc,
                                     a->uri,
                                     a->uri_len);
  }
#endif
  GNUNET_CRYPTO_hash_context_finish (hc,
                                     hash);
 
}

References GNUNET_CRYPTO_hash_context_finish(), GNUNET_CRYPTO_hash_context_read(), GNUNET_CRYPTO_hash_context_start(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, and Address::next.

Referenced by GNUNET_HELLO_builder_hash_addresses(), and verify_hello().

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◆ verify_hello()

static enum GNUNET_GenericReturnValue verify_hello	(	const struct GNUNET_HELLO_Parser *	parser,
		struct GNUNET_TIME_Absolute	et,
		const struct GNUNET_CRYPTO_EddsaSignature *	sig
	)

static

Verify HELLO signature.

Parameters

builder	the builder to use
et	expiration time to verify
sig	signature to verify

Returns: GNUNET_OK if everything is ok, GNUNET_NO if the HELLO expired, GNUNET_SYSERR if the signature is wrong

Definition at line 304 of file hello-uri.c.

{
  struct PilsHelloSignaturePurpose hsp = {
    .purpose.size = htonl (sizeof (hsp)),
    .purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_HELLO),
    .expiration_time = GNUNET_TIME_absolute_hton (et)
  };
 
  hash_addresses (parser->a_head,
                  &hsp.h_addrs);
  if (GNUNET_OK !=
      GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_HELLO,
                                  &hsp,
                                  sig,
                                  &parser->pid.public_key))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "HELLO signature invalid, rejecting.\n");
    return GNUNET_SYSERR;
  }
  if (GNUNET_TIME_absolute_is_past (et))
    return GNUNET_NO;
  return GNUNET_OK;
}

References GNUNET_CRYPTO_eddsa_verify, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_NO, GNUNET_OK, GNUNET_SIGNATURE_PURPOSE_HELLO, GNUNET_SYSERR, GNUNET_TIME_absolute_hton(), GNUNET_TIME_absolute_is_past(), PilsHelloSignaturePurpose::h_addrs, hash_addresses(), PilsHelloSignaturePurpose::purpose, and GNUNET_CRYPTO_SignaturePurpose::size.

Referenced by GNUNET_HELLO_dht_msg_to_block(), GNUNET_HELLO_parser_from_block_(), and GNUNET_HELLO_parser_from_url().

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◆ parser_new()

static struct GNUNET_HELLO_Parser * parser_new ( const struct GNUNET_PeerIdentity * pid )

static

Definition at line 333 of file hello-uri.c.

{
  struct GNUNET_HELLO_Parser *p;
 
  p = GNUNET_new (struct GNUNET_HELLO_Parser);
  p->pid = *pid;
  return p;
}

References GNUNET_new, p, GNUNET_HELLO_Parser::pid, and GNUNET_Process::pid.

Referenced by GNUNET_HELLO_parser_from_block_(), and GNUNET_HELLO_parser_from_url().

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◆ check_address()

static enum GNUNET_GenericReturnValue check_address ( const char * address )

static

Definition at line 497 of file hello-uri.c.

{
  const char *e;
 
  if (NULL == (e = strstr (address,
                           "://")))
  {
    GNUNET_break_op (0);
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Invalid address `%s'\n",
                address);
    return GNUNET_SYSERR;
  }
  if (e == address)
  {
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  }
  for (const char *p = address; p != e; p++)
    if ( (! isalpha ((unsigned char) *p)) &&
         ('+' != *p) )
    {
      GNUNET_break_op (0);
      return GNUNET_SYSERR;
    }
  return GNUNET_OK;
}

References address, GNUNET_break_op, GNUNET_ERROR_TYPE_ERROR, GNUNET_log, GNUNET_OK, GNUNET_SYSERR, and p.

Referenced by GNUNET_HELLO_builder_add_address(), and parser_add_address().

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◆ cmp_address()

static int cmp_address	(	void *	cls,
		struct Address *	a,
		struct Address *	b
	)

static

Alphanumeric sorting for addresses.

Parameters

cls	NULL
a	first address
b	address to compare first address with

Returns: result of strcmp on the URI of the addresses

Definition at line 536 of file hello-uri.c.

{
  return strcmp (a->uri, b->uri);
}

References Address::uri.

Referenced by GNUNET_HELLO_builder_add_address(), and parser_add_address().

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◆ parser_add_address()

static enum GNUNET_GenericReturnValue parser_add_address	(	struct GNUNET_HELLO_Parser *	parser,
		const char *	address
	)

static

Definition at line 543 of file hello-uri.c.

{
  struct Address *a;
  enum GNUNET_GenericReturnValue ret;
  size_t alen = strlen (address) + 1;
 
  ret = check_address (address);
  if (GNUNET_OK != ret)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Failed to add address to builder\n");
    return ret;
  }
  /* check for duplicates */
  for (a = parser->a_head;
       NULL != a;
       a = a->next)
    if (0 == strcmp (address,
                     a->uri))
      return GNUNET_NO;
  a = GNUNET_malloc (sizeof (struct Address) + alen);
  a->uri_len = alen;
  memcpy (&a[1],
          address,
          alen);
  a->uri = (const char *) &a[1];
  GNUNET_CONTAINER_DLL_insert_sorted (struct Address,
                                      cmp_address,
                                      NULL,
                                      parser->a_head,
                                      parser->a_tail,
                                      a);
  parser->a_length++;
  return GNUNET_OK;
}

References address, check_address(), cmp_address(), GNUNET_CONTAINER_DLL_insert_sorted, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_malloc, GNUNET_NO, GNUNET_OK, Address::next, ret, Address::uri, and Address::uri_len.

Referenced by GNUNET_HELLO_parser_from_block_(), and GNUNET_HELLO_parser_from_url().

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Data Structures

Functions

Detailed Description

Function Documentation

◆ hash_addresses()

◆ verify_hello()

◆ parser_new()

◆ check_address()

◆ cmp_address()

◆ parser_add_address()