API tools faq
paste
Advertisement
Guest User

Custom EC curve NID_secp256k1

a guest
Dec 9th, 2013
619
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
Diff 6.65 KB | None | 0 0
raw download clone embed print report
  1. From 475dcc4a0ad77e81333be32f7833cdc9a4bc6548 Mon Sep 17 00:00:00 2001
  2. From: [email protected]
  3. Date: Mon, 9 Dec 2013 20:59:10 +0000
  4. Subject: [PATCH] Custom EC curve NID_secp256k1
  5.  
  6. Patch for bitcoin git with openssl, which is supporting ECC,
  7. but missing NID_secp256k1.
  8.  
  9. Donate to 1MyBTCJepaaM6Bs4iJgew3tVZbuUWunBV7
  10. ---
  11. src/key.cpp | 164 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
  12.  1 file changed, 162 insertions(+), 2 deletions(-)
  13.  
  14. diff --git a/src/key.cpp b/src/key.cpp
  15. index b57b7c5..5a3684b 100644
  16. --- a/src/key.cpp
  17. +++ b/src/key.cpp
  18. @@ -8,10 +8,170 @@
  19.  #include <openssl/ecdsa.h>
  20.  #include <openssl/obj_mac.h>
  21.  #include <openssl/rand.h>
  22. +#include <openssl/err.h>
  23.  
  24.  // anonymous namespace with local implementation code (OpenSSL interaction)
  25.  namespace {
  26.  
  27. +typedef struct {
  28. +    int    field_type, /* either NID_X9_62_prime_field or
  29. +                         * NID_X9_62_characteristic_two_field */
  30. +        seed_len,
  31. +        param_len;
  32. +    unsigned int cofactor; /* promoted to BN_ULONG */
  33. +} EC_CURVE_DATA;
  34. +
  35. +static const struct { EC_CURVE_DATA h; unsigned char data[0+32*6]; }
  36. +    _EC_SECG_PRIME_256K1 = {
  37. +        { NID_X9_62_prime_field,0,32,1 },
  38. +        {                          /* no seed */
  39. +            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* p */
  40. +            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
  41. +            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,
  42. +            0xFC,0x2F,
  43. +            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* a */
  44. +            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
  45. +            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
  46. +            0x00,0x00,
  47. +            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* b */
  48. +            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
  49. +            0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
  50. +            0x00,0x07,
  51. +            0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0, /* x */
  52. +            0x62,0x95,0xCE,0x87,0x0B,0x07,0x02,0x9B,0xFC,0xDB,
  53. +            0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
  54. +            0x17,0x98,
  55. +            0x48,0x3a,0xda,0x77,0x26,0xa3,0xc4,0x65,0x5d,0xa4, /* y */
  56. +            0xfb,0xfc,0x0e,0x11,0x08,0xa8,0xfd,0x17,0xb4,0x48,
  57. +            0xa6,0x85,0x54,0x19,0x9c,0x47,0xd0,0x8f,0xfb,0x10,
  58. +            0xd4,0xb8,
  59. +            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* order */
  60. +            0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,
  61. +            0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,0x8C,0xD0,0x36,
  62. +            0x41,0x41 }
  63. +    };
  64. +
  65. +static EC_GROUP *ec_group_new_from_data(const EC_CURVE_DATA *data)
  66. +{
  67. +    EC_GROUP *group=NULL;
  68. +    EC_POINT *P=NULL;
  69. +    BN_CTX  *ctx=NULL;
  70. +    BIGNUM  *p=NULL, *a=NULL, *b=NULL, *x=NULL, *y=NULL, *order=NULL;
  71. +    int     ok=0;
  72. +    int     seed_len,param_len;
  73. +    const unsigned char *params;
  74. +
  75. +    if ((ctx = BN_CTX_new()) == NULL) {
  76. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_MALLOC_FAILURE);
  77. +        goto err;
  78. +    }
  79. +
  80. +    seed_len  = data->seed_len;
  81. +    param_len = data->param_len;
  82. +    params   = (const unsigned char *)(data+1);    /* skip header */
  83. +    params  += seed_len;               /* skip seed   */
  84. +
  85. +    if (!(p = BN_bin2bn(params+0*param_len, param_len, NULL))
  86. +        || !(a = BN_bin2bn(params+1*param_len, param_len, NULL))
  87. +        || !(b = BN_bin2bn(params+2*param_len, param_len, NULL))) {
  88. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_BN_LIB);
  89. +        goto err;
  90. +    }
  91. +
  92. +    if ((group = EC_GROUP_new_curve_GFp(p, a, b, ctx)) == NULL) {
  93. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);
  94. +        goto err;
  95. +    }
  96. +
  97. +    if ((P = EC_POINT_new(group)) == NULL) {
  98. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);
  99. +        goto err;
  100. +    }
  101. +
  102. +    if (!(x = BN_bin2bn(params+3*param_len, param_len, NULL))
  103. +        || !(y = BN_bin2bn(params+4*param_len, param_len, NULL))) {
  104. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_BN_LIB);
  105. +        goto err;
  106. +    }
  107. +    if (!EC_POINT_set_affine_coordinates_GFp(group, P, x, y, ctx)) {
  108. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);
  109. +        goto err;
  110. +    }
  111. +    if (!(order = BN_bin2bn(params+5*param_len, param_len, NULL))
  112. +        || !BN_set_word(x, (BN_ULONG)data->cofactor))
  113. +    {
  114. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_BN_LIB);
  115. +        goto err;
  116. +    }
  117. +    if (!EC_GROUP_set_generator(group, P, order, x)) {
  118. +        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);
  119. +        goto err;
  120. +    }
  121. +    if (seed_len) {
  122. +        if (!EC_GROUP_set_seed(group, params-seed_len, seed_len)) {
  123. +            ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);
  124. +            goto err;
  125. +        }
  126. +    }
  127. +    ok=1;
  128. +err:
  129. +    if (!ok) {
  130. +        EC_GROUP_free(group);
  131. +        group = NULL;
  132. +    }
  133. +    if (P)
  134. +        EC_POINT_free(P);
  135. +    if (ctx)
  136. +        BN_CTX_free(ctx);
  137. +    if (p)
  138. +        BN_free(p);
  139. +    if (a)
  140. +        BN_free(a);
  141. +    if (b)
  142. +        BN_free(b);
  143. +    if (order)
  144. +        BN_free(order);
  145. +    if (x)
  146. +        BN_free(x);
  147. +    if (y)
  148. +        BN_free(y);
  149. +    return group;
  150. +}
  151. +
  152. +EC_GROUP *EC_GROUP_new_by_curve_name_NID_secp256k1(void)
  153. +{
  154. +    static EC_GROUP *group = NULL;
  155. +
  156. +    if (group == NULL) {
  157. +#ifdef HAVE_NID_SECP256K1
  158. +        group = EC_GROUP_new_by_curve_name(NID_secp256k1);
  159. +#else
  160. +        group = ec_group_new_from_data(&_EC_SECG_PRIME_256K1.h);
  161. +#endif
  162. +    }
  163. +
  164. +    return group;
  165. +}
  166. +
  167. +EC_KEY *EC_KEY_new_by_curve_name_NID_secp256k1(void)
  168. +{
  169. +    EC_KEY *ret = NULL;
  170. +    EC_GROUP *group = EC_GROUP_new_by_curve_name_NID_secp256k1();
  171. +
  172. +    if (group == NULL)
  173. +        return NULL;
  174. +
  175. +    ret = EC_KEY_new();
  176. +
  177. +    if (ret == NULL)
  178. +        return NULL;
  179. +
  180. +    EC_KEY_set_group(ret, group);
  181. +
  182. +    return ret;
  183. +}
  184. +
  185. +
  186.  // Generate a private key from just the secret parameter
  187.  int EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key)
  188.  {
  189. @@ -130,7 +290,7 @@ private:
  190.  
  191.  public:
  192.      CECKey() {
  193. -        pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
  194. +        pkey = EC_KEY_new_by_curve_name_NID_secp256k1();
  195.          assert(pkey != NULL);
  196.      }
  197.  
  198. @@ -288,7 +448,7 @@ public:
  199.          BIGNUM *bnSecret = BN_CTX_get(ctx);
  200.          BIGNUM *bnTweak = BN_CTX_get(ctx);
  201.          BIGNUM *bnOrder = BN_CTX_get(ctx);
  202. -        EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp256k1);
  203. +        EC_GROUP *group = EC_GROUP_new_by_curve_name_NID_secp256k1();
  204.          EC_GROUP_get_order(group, bnOrder, ctx); // what a grossly inefficient way to get the (constant) group order...
  205.          BN_bin2bn(vchTweak, 32, bnTweak);
  206.          if (BN_cmp(bnTweak, bnOrder) >= 0)
  207. --
  208. 1.8.4.2
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement
Public Pastes
Advertisement
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!