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authorChristian Grothoff <christian@grothoff.org>2015-03-17 11:37:21 +0100
committerChristian Grothoff <christian@grothoff.org>2015-03-17 11:37:21 +0100
commit4eeaff13557c507061872e2346bfb53af6d51f1e (patch)
tree6a6ede869db8d1eeacd356a525d7f2e211bb760c
parent0119f629b3603e9635932b691fc31967ff085f7e (diff)
downloadexchange-4eeaff13557c507061872e2346bfb53af6d51f1e.tar.gz
exchange-4eeaff13557c507061872e2346bfb53af6d51f1e.tar.bz2
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documentation, comments
-rw-r--r--src/mint/taler-mint-keyup.c251
-rw-r--r--src/util/amount.c46
2 files changed, 166 insertions, 131 deletions
diff --git a/src/mint/taler-mint-keyup.c b/src/mint/taler-mint-keyup.c
index 8a645b589..ac5f7b1d6 100644
--- a/src/mint/taler-mint-keyup.c
+++ b/src/mint/taler-mint-keyup.c
@@ -1,6 +1,6 @@
/*
This file is part of TALER
- Copyright (C) 2014 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
@@ -19,6 +19,7 @@
* using the mint's offline master key.
* @author Florian Dold
* @author Benedikt Mueller
+ * @author Christian Grothoff
*/
#include <platform.h>
#include <gnunet/gnunet_util_lib.h>
@@ -26,17 +27,20 @@
#include "key_io.h"
/**
- * FIXME: allow user to specify (within reason).
- */
-#define RSA_KEYSIZE 2048
-
-/**
- *
+ * When generating filenames from a cryptographic hash, we do not use
+ * all 512 bits but cut off after this number of characters (in
+ * base32-encoding). Base32 is 5 bit per character, and given that we
+ * have very few coin types we hash, at 100 bits the chance of
+ * collision (by accident over tiny set -- birthday paradox does not
+ * apply here!) is negligible.
*/
#define HASH_CUTOFF 20
/**
* Macro to round microseconds to seconds in GNUNET_TIME_* structs.
+ *
+ * @param name value to round
+ * @param field rel_value_us or abs_value_us
*/
#define ROUND_TO_SECS(name,us_field) name.us_field -= name.us_field % (1000 * 1000);
@@ -78,55 +82,71 @@ struct CoinTypeNBO
* What is the fee charged for melting?
*/
struct TALER_AmountNBO fee_refresh;
+
+ /**
+ * Key size in NBO.
+ */
+ uint32_t rsa_keysize;
};
GNUNET_NETWORK_STRUCT_END
/**
- *
+ * Set of all of the parameters that chracterize a coin.
*/
struct CoinTypeParams
{
/**
- *
+ * How long can the coin be spend? Should be significantly
+ * larger than @e duration_withdraw (i.e. years).
*/
struct GNUNET_TIME_Relative duration_spend;
/**
- *
+ * How long can the coin be withdrawn (generated)? Should be small
+ * enough to limit how many coins will be signed into existence with
+ * the same key, but large enough to still provide a reasonable
+ * anonymity set.
*/
struct GNUNET_TIME_Relative duration_withdraw;
/**
- *
+ * How much should coin creation (@e duration_withdraw) duration
+ * overlap with the next coin? Basically, the starting time of two
+ * coins is always @e duration_withdraw - @e duration_overlap apart.
*/
struct GNUNET_TIME_Relative duration_overlap;
/**
- *
+ * What is the value of the coin?
*/
struct TALER_Amount value;
/**
- *
+ * What is the fee charged for withdrawl?
*/
struct TALER_Amount fee_withdraw;
/**
- *
+ * What is the fee charged for deposits?
*/
struct TALER_Amount fee_deposit;
/**
- *
+ * What is the fee charged for melting?
*/
struct TALER_Amount fee_refresh;
/**
- *
+ * Time at which this coin is supposed to become valid.
*/
struct GNUNET_TIME_Absolute anchor;
+
+ /**
+ * Length of the RSA key in bits.
+ */
+ uint32_t rsa_keysize;
};
@@ -172,7 +192,6 @@ static struct GNUNET_CRYPTO_EddsaPublicKey *master_pub;
static struct GNUNET_TIME_Absolute lookahead_sign_stamp;
-
/**
* Obtain the name of the directory we use to store signing
* keys created at time @a start.
@@ -212,14 +231,13 @@ hash_coin_type (const struct CoinTypeParams *p,
memset (&p_nbo,
0,
sizeof (struct CoinTypeNBO));
-
p_nbo.duration_spend = GNUNET_TIME_relative_hton (p->duration_spend);
p_nbo.duration_withdraw = GNUNET_TIME_relative_hton (p->duration_withdraw);
p_nbo.value = TALER_amount_hton (p->value);
p_nbo.fee_withdraw = TALER_amount_hton (p->fee_withdraw);
p_nbo.fee_deposit = TALER_amount_hton (p->fee_deposit);
p_nbo.fee_refresh = TALER_amount_hton (p->fee_refresh);
-
+ p_nbo.rsa_keysize = htonl (p->rsa_keysize);
GNUNET_CRYPTO_hash (&p_nbo,
sizeof (struct CoinTypeNBO),
hash);
@@ -246,18 +264,19 @@ get_cointype_dir (const struct CoinTypeParams *p)
struct GNUNET_HashCode hash;
char *hash_str;
char *val_str;
- unsigned int i;
+ size_t i;
hash_coin_type (p, &hash);
hash_str = GNUNET_STRINGS_data_to_string_alloc (&hash,
sizeof (struct GNUNET_HashCode));
- GNUNET_assert (HASH_CUTOFF <= strlen (hash_str) + 1);
GNUNET_assert (NULL != hash_str);
+ GNUNET_assert (HASH_CUTOFF <= strlen (hash_str) + 1);
hash_str[HASH_CUTOFF] = 0;
val_str = TALER_amount_to_string (p->value);
for (i = 0; i < strlen (val_str); i++)
- if (':' == val_str[i] || '.' == val_str[i])
+ if ( (':' == val_str[i]) ||
+ ('.' == val_str[i]) )
val_str[i] = '_';
GNUNET_snprintf (dir,
@@ -267,23 +286,27 @@ get_cointype_dir (const struct CoinTypeParams *p)
val_str,
hash_str);
GNUNET_free (hash_str);
+ GNUNET_free (val_str);
return dir;
}
/**
+ * Obtain the name of the file we would use to store the key
+ * information for a coin of the given type @a p and validity
+ * start time @a start
*
- *
- * @param p
- * @param start
- * @return
+ * @param p parameters for the coin
+ * @param start when would the coin begin to be issued
+ * @return name of the file to use for this coin
+ * (valid until next call to this function)
*/
static const char *
-get_cointype_file (struct CoinTypeParams *p,
+get_cointype_file (const struct CoinTypeParams *p,
struct GNUNET_TIME_Absolute start)
{
- const char *dir;
static char filename[4096];
+ const char *dir;
dir = get_cointype_dir (p);
GNUNET_snprintf (filename,
@@ -296,13 +319,15 @@ get_cointype_file (struct CoinTypeParams *p,
/**
- * Get the latest key file from the past.
+ * Get the latest key file from a past run of the key generation
+ * tool. Used to calculate the starting time for the keys we
+ * generate during this invocation.
*
- * @param cls closure
+ * @param cls closure, a `struct GNUNET_TIME_Absolute *`, updated
+ * to contain the highest timestamp (below #now)
+ * that was found
* @param filename complete filename (absolute path)
- * @return #GNUNET_OK to continue to iterate,
- * #GNUNET_NO to stop iteration with no error,
- * #GNUNET_SYSERR to abort iteration with error!
+ * @return #GNUNET_OK (to continue to iterate)
*/
static int
get_anchor_iter (void *cls,
@@ -317,31 +342,28 @@ get_anchor_iter (void *cls,
stamp.abs_value_us = strtol (base,
&end,
10);
-
if ((NULL == end) || (0 != *end))
{
fprintf(stderr,
- "Ignoring unexpected file '%s'.\n",
+ "Ignoring unexpected file `%s'.\n",
filename);
return GNUNET_OK;
}
-
- // TODO: check if it's actually a valid key file
-
- if ( (stamp.abs_value_us <= now.abs_value_us) &&
- ( stamp.abs_value_us > anchor->abs_value_us) )
- *anchor = stamp;
-
+ // TODO: check if it's actually a valid key file?
+ if (stamp.abs_value_us <= now.abs_value_us)
+ *anchor = GNUNET_TIME_absolute_max (stamp,
+ *anchor);
return GNUNET_OK;
}
/**
* Get the timestamp where the first new key should be generated.
- * Relies on correctly named key files.
+ * Relies on correctly named key files (as we do not parse them,
+ * but just look at the filenames to "guess" at their contents).
*
- * @param dir directory with the signed stuff
- * @param duration how long is one key valid?
+ * @param dir directory that should contain the existing keys
+ * @param duration how long is one key valid (for signing)?
* @param overlap what's the overlap between the keys validity period?
* @param[out] anchor the timestamp where the first new key should be generated
*/
@@ -354,15 +376,14 @@ get_anchor (const char *dir,
GNUNET_assert (0 == duration.rel_value_us % 1000000);
GNUNET_assert (0 == overlap.rel_value_us % 1000000);
if (GNUNET_YES !=
- GNUNET_DISK_directory_test (dir, GNUNET_YES))
+ GNUNET_DISK_directory_test (dir,
+ GNUNET_YES))
{
*anchor = now;
- fprintf (stderr,
- "Cannot look for anchor (%s)\n",
- dir);
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "No existing keys found, starting with fresh key set.\n");
return;
}
-
*anchor = GNUNET_TIME_UNIT_ZERO_ABS;
if (-1 ==
GNUNET_DISK_directory_scan (dir,
@@ -370,23 +391,30 @@ get_anchor (const char *dir,
anchor))
{
*anchor = now;
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "No existing keys found, starting with fresh key set.\n");
return;
}
+ /* FIXME: this check is a bit dubious, as 'now'
+ may be way into the future if we want to generate
+ many keys... */
if ((GNUNET_TIME_absolute_add (*anchor,
duration)).abs_value_us < now.abs_value_us)
{
- // there's no good anchor, start from now
- // (existing keys are too old)
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Existing keys are way too old, starting with fresh key set.\n");
*anchor = now;
}
- else if (anchor->abs_value_us != now.abs_value_us)
+ else if (anchor->abs_value_us != now.abs_value_us) // Also odd...
{
- // we have a good anchor
- *anchor = GNUNET_TIME_absolute_add (*anchor, duration);
- *anchor = GNUNET_TIME_absolute_subtract (*anchor, overlap);
+ /* Real starting time is the last start time + duration - overlap */
+ *anchor = GNUNET_TIME_absolute_add (*anchor,
+ duration);
+ *anchor = GNUNET_TIME_absolute_subtract (*anchor,
+ overlap);
}
- // anchor is now the stamp where we need to create a new key
+ /* anchor is now the stamp where we need to create a new key */
}
@@ -395,7 +423,7 @@ get_anchor (const char *dir,
*
* @param start
* @param duration
- * @param pi
+ * @param pi[OUT]
*/
static void
create_signkey_issue_priv (struct GNUNET_TIME_Absolute start,
@@ -431,21 +459,7 @@ create_signkey_issue_priv (struct GNUNET_TIME_Absolute start,
/**
*
*
- * @param signkey_filename
- * @return
- */
-static int
-check_signkey_valid (const char *signkey_filename)
-{
- // FIXME: do real checks
- return GNUNET_OK;
-}
-
-
-/**
- *
- *
- * @return
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
static int
mint_keys_update_signkeys ()
@@ -513,28 +527,27 @@ mint_keys_update_signkeys ()
return GNUNET_SYSERR;
}
}
- else if (GNUNET_OK != check_signkey_valid (skf))
- {
- return GNUNET_SYSERR;
- }
- anchor = GNUNET_TIME_absolute_add (anchor, signkey_duration);
+ anchor = GNUNET_TIME_absolute_add (anchor,
+ signkey_duration);
}
return GNUNET_OK;
}
/**
+ * Parse configuration for coin type parameters. Also determines
+ * our anchor by looking at the existing coins of the same type.
*
- *
- * @param ct
- * @param params
- * @return
+ * @param ct section in the configuration file giving the coin type parameters
+ * @param params[OUT] set to the coin parameters from the configuration
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the configuration is invalid
*/
static int
get_cointype_params (const char *ct,
struct CoinTypeParams *params)
{
const char *dir;
+ unsigned long long rsa_keysize;
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_time (kcfg,
@@ -560,7 +573,8 @@ get_cointype_params (const char *ct,
ct);
return GNUNET_SYSERR;
}
- ROUND_TO_SECS (params->duration_spend, rel_value_us);
+ ROUND_TO_SECS (params->duration_spend,
+ rel_value_us);
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_time (kcfg,
"mint_denom_duration_overlap",
@@ -574,7 +588,26 @@ get_cointype_params (const char *ct,
}
ROUND_TO_SECS (params->duration_overlap,
rel_value_us);
-
+ if (GNUNET_OK !=
+ GNUNET_CONFIGURATION_get_value_number (kcfg,
+ "mint_denom_rsa_keysize",
+ ct,
+ &rsa_keysize))
+ {
+ fprintf (stderr,
+ "RSA keysize not given for coin type '%s'\n",
+ ct);
+ return GNUNET_SYSERR;
+ }
+ if ( (rsa_keysize > 4 * 2048) ||
+ (rsa_keysize < 1024) )
+ {
+ fprintf (stderr,
+ "Given RSA keysize %llu outside of permitted range\n",
+ rsa_keysize);
+ return GNUNET_SYSERR;
+ }
+ params->rsa_keysize = (unsigned int) rsa_keysize;
if (GNUNET_OK !=
TALER_config_get_denom (kcfg,
"mint_denom_value",
@@ -586,7 +619,6 @@ get_cointype_params (const char *ct,
ct);
return GNUNET_SYSERR;
}
-
if (GNUNET_OK !=
TALER_config_get_denom (kcfg,
"mint_denom_fee_withdraw",
@@ -598,7 +630,6 @@ get_cointype_params (const char *ct,
ct);
return GNUNET_SYSERR;
}
-
if (GNUNET_OK !=
TALER_config_get_denom (kcfg,
"mint_denom_fee_deposit",
@@ -610,7 +641,6 @@ get_cointype_params (const char *ct,
ct);
return GNUNET_SYSERR;
}
-
if (GNUNET_OK !=
TALER_config_get_denom (kcfg,
"mint_denom_fee_refresh",
@@ -624,22 +654,29 @@ get_cointype_params (const char *ct,
}
dir = get_cointype_dir (params);
- get_anchor (dir, params->duration_spend, params->duration_overlap, &params->anchor);
+ get_anchor (dir,
+ params->duration_spend,
+ params->duration_overlap,
+ &params->anchor);
return GNUNET_OK;
}
/**
+ * Initialize the private and public key information structure for
+ * signing coins into existence. Generates the private signing key
+ * and signes it together with the coin's meta data using the master
+ * signing key.
*
- *
- * @param params
- * @param dki
+ * @param params parameters used to initialize the @a dki
+ * @param dki[OUT] initialized according to @a params
*/
static void
-create_denomkey_issue (struct CoinTypeParams *params,
+create_denomkey_issue (const struct CoinTypeParams *params,
struct TALER_MINT_DenomKeyIssuePriv *dki)
{
- GNUNET_assert (NULL != (dki->denom_priv = GNUNET_CRYPTO_rsa_private_key_create (RSA_KEYSIZE)));
+ GNUNET_assert (NULL !=
+ (dki->denom_priv = GNUNET_CRYPTO_rsa_private_key_create (params->rsa_keysize)));
dki->denom_pub = GNUNET_CRYPTO_rsa_private_key_get_public (dki->denom_priv);
GNUNET_CRYPTO_rsa_public_key_hash (dki->denom_pub,
&dki->issue.denom_hash);
@@ -660,7 +697,6 @@ create_denomkey_issue (struct CoinTypeParams *params,
dki->issue.purpose.size = htonl (sizeof (struct TALER_MINT_DenomKeyIssuePriv) -
offsetof (struct TALER_MINT_DenomKeyIssuePriv,
issue.purpose));
-
GNUNET_assert (GNUNET_OK ==
GNUNET_CRYPTO_eddsa_sign (master_priv,
&dki->issue.purpose,
@@ -669,26 +705,11 @@ create_denomkey_issue (struct CoinTypeParams *params,
/**
+ * Generate new coin signing keys for the coin type of the given @a
+ * coin_alias.
*
- *
- * @param filename
- * @param params
- * @return
- */
-static int
-check_cointype_valid (const char *filename,
- struct CoinTypeParams *params)
-{
- // FIXME: add real checks
- return GNUNET_OK;
-}
-
-
-/**
- *
- *
- * @param coin_alias
- * @return
+ * @param coin_alias name of the coin's section in the configuration
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
*/
static int
mint_keys_update_cointype (const char *coin_alias)
@@ -732,10 +753,6 @@ mint_keys_update_cointype (const char *coin_alias)
return GNUNET_SYSERR;
}
}
- else if (GNUNET_OK != check_cointype_valid (dkf, &p))
- {
- return GNUNET_SYSERR;
- }
p.anchor = GNUNET_TIME_absolute_add (p.anchor, p.duration_spend);
p.anchor = GNUNET_TIME_absolute_subtract (p.anchor, p.duration_overlap);
}
diff --git a/src/util/amount.c b/src/util/amount.c
index 0b77de82b..b3e3b4217 100644
--- a/src/util/amount.c
+++ b/src/util/amount.c
@@ -30,8 +30,14 @@
#include "taler_util.h"
#include <gcrypt.h>
+/**
+ *
+ */
#define AMOUNT_FRAC_BASE 1000000
+/**
+ *
+ */
#define AMOUNT_FRAC_LEN 6
@@ -47,34 +53,39 @@ int
TALER_string_to_amount (const char *str,
struct TALER_Amount *denom)
{
- unsigned int i; // pos in str
+ size_t i; // pos in str
int n; // number tmp
- unsigned int c; // currency pos
+ size_t c; // currency pos
uint32_t b; // base for suffix
- memset (denom, 0, sizeof (struct TALER_Amount));
-
- i = n = c = 0;
+ memset (denom,
+ 0,
+ sizeof (struct TALER_Amount));
+ i = 0;
while (isspace(str[i]))
i++;
if (0 == str[i])
{
- printf("null before currency\n");
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "null before currency\n");
return GNUNET_SYSERR;
}
+ c = 0;
while (str[i] != ':')
{
if (0 == str[i])
{
- printf("null before colon");
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "null before colon");
return GNUNET_SYSERR;
}
if (c > 3)
{
- printf("currency too long\n");
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "currency too long\n");
return GNUNET_SYSERR;
}
denom->currency[c] = str[i];
@@ -87,7 +98,8 @@ TALER_string_to_amount (const char *str,
if (0 == str[i])
{
- printf("null before value\n");
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "null before value\n");
return GNUNET_SYSERR;
}
@@ -100,7 +112,10 @@ TALER_string_to_amount (const char *str,
n = str[i] - '0';
if (n < 0 || n > 9)
{
- printf("invalid character '%c' before comma at %u\n", (char) n, i);
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "invalid character '%c' before comma at %u\n",
+ (char) n,
+ i);
return GNUNET_SYSERR;
}
denom->value = (denom->value * 10) + n;
@@ -112,7 +127,8 @@ TALER_string_to_amount (const char *str,
if (0 == str[i])
{
- printf("null after dot");
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "null after dot");
return GNUNET_SYSERR;
}
@@ -121,9 +137,10 @@ TALER_string_to_amount (const char *str,
while (0 != str[i])
{
n = str[i] - '0';
- if (b == 0 || n < 0 || n > 9)
+ if ( (0 == b) || (n < 0) || (n > 9) )
{
- printf("error after comma");
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "error after comma");
return GNUNET_SYSERR;
}
denom->fraction += n * b;
@@ -293,7 +310,8 @@ TALER_amount_add (struct TALER_Amount a1,
struct TALER_Amount
TALER_amount_normalize (struct TALER_Amount amount)
{
- while (amount.value != UINT32_MAX && amount.fraction >= AMOUNT_FRAC_BASE)
+ while ( (amount.value != UINT32_MAX) &&
+ (amount.fraction >= AMOUNT_FRAC_BASE) )
{
amount.fraction -= AMOUNT_FRAC_BASE;
amount.value += 1;