Add function to recover RSA CRT params.
Some RSA private keys are specified with only n, e and d. Although we
can use these keys directly, it's nice to have a uniform representation
that includes the precomputed CRT values. This change adds a function
that can recover the primes from a minimal private key of that form.
diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h
index 23fca81..40ae790 100644
--- a/crypto/bn/bn.h
+++ b/crypto/bn/bn.h
@@ -367,6 +367,12 @@
* remainder or (BN_ULONG)-1 on error. */
BN_ULONG BN_div_word(BIGNUM *numerator, BN_ULONG divisor);
+/* BN_sqrt sets |*out_sqrt| (which may be the same |BIGNUM| as |in|) to the
+ * square root of |in|, using |ctx|. It returns one on success or zero on
+ * error. Negative numbers and non-square numbers will result in an error with
+ * appropriate errors on the error queue. */
+int BN_sqrt(BIGNUM *out_sqrt, const BIGNUM *in, BN_CTX *ctx);
+
/* Comparison functions */
@@ -781,6 +787,7 @@
#define BN_F_BN_mod_inverse_no_branch 121
#define BN_F_BN_generate_dsa_nonce 122
#define BN_F_BN_generate_prime_ex 123
+#define BN_F_BN_sqrt 124
#define BN_R_NOT_A_SQUARE 100
#define BN_R_TOO_MANY_ITERATIONS 101
#define BN_R_INPUT_NOT_REDUCED 102
@@ -797,5 +804,6 @@
#define BN_R_BIGNUM_TOO_LONG 113
#define BN_R_PRIVATE_KEY_TOO_LARGE 114
#define BN_R_BITS_TOO_SMALL 115
+#define BN_R_NEGATIVE_NUMBER 116
#endif /* OPENSSL_HEADER_BN_H */
