add ed448_keypair

7 files changed, 41 insertions, 16 deletions

diff --git a/.gitignore b/.gitignore
index 4349545..88b3a2b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,4 @@
 *.py
 .vscode/
 *.out
-t/
\ No newline at end of file
+t/
diff --git a/defs.h b/defs.h
index 40c0b13..40c6fae 100644
--- a/defs.h
+++ b/defs.h
@@ -11,4 +11,6 @@ typedef uint16_t crypto_uint16;
 typedef int32_t crypto_int32;
 typedef uint32_t crypto_uint32;
 
+int crypto_sign_ed448_keypair(unsigned char *pk, unsigned char *sk);
+
 #endif /* DEFS_H */
diff --git a/ed448.c b/ed448.c
new file mode 100644
index 0000000..63a0dd6
--- /dev/null
+++ b/ed448.c
@@ -0,0 +1,31 @@
+#include "defs.h"
+#include "sha3.h"
+#include "ge448.h"
+
+/* temporarily use getrandom() */
+#include <sys/random.h>
+
+/* sk and pk are both 57 bytes, sk is not followed by pk */
+int crypto_sign_ed448_keypair(
+    unsigned char *pk,
+    unsigned char *sk)
+{
+    sc448 scsk;
+    ge448 gepk;
+    unsigned char extsk[114];
+    sha3_ctx_t ctx;
+
+    (void)getrandom(sk, 57, 0);
+    shake256_init(&ctx);
+    shake_update(&ctx, sk, 57);
+    shake_xof(&ctx);
+    shake_out(&ctx, extsk, 114);
+    extsk[56] = 0;
+    extsk[55] |= 0x80;
+    extsk[0] &= 0xFC;
+
+    sc448_from57bytes(&scsk, extsk);
+    ge448_scalarmult_base(&gepk, &scsk);
+    ge448_pack(pk, &gepk);
+    return 0;
+}
diff --git a/ge448_gen.c b/ge448_gen.c
index 2c09974..445eaa2 100644
--- a/ge448_gen.c
+++ b/ge448_gen.c
@@ -2,19 +2,6 @@
 #include <stdio.h>
 #include <assert.h>
 
-/*const ge448 ge448_base = {{{0x5E, 0xC0, 0x0C, 0xC7, 0x2B, 0xA8, 0x26, 0x26, 0x8E, 0x93, 0x00, 0x8B, 0xE1, 0x80, 0x3B, 0x43,
-                            0x11, 0x65, 0xB6, 0x2A, 0xF7, 0x1A, 0xAE, 0x12, 0x64, 0xA4, 0xD3, 0xA3, 0x24, 0xE3, 0x6D, 0xEA,
-                            0x67, 0x17, 0x0F, 0x47, 0x70, 0x65, 0x14, 0x9E, 0xDA, 0x36, 0xBF, 0x22, 0xA6, 0x15, 0x1D, 0x22,
-                            0xED, 0x0D, 0xED, 0x6B, 0xC6, 0x70, 0x19, 0x4F, 0x00}},
-                          {{0x14, 0xFA, 0x30, 0xF2, 0x5B, 0x79, 0x08, 0x98, 0xAD, 0xC8, 0xD7, 0x4E, 0x2C, 0x13, 0xBD, 0xFD,
-                            0xC4, 0x39, 0x7C, 0xE6, 0x1C, 0xFF, 0xD3, 0x3A, 0xD7, 0xC2, 0xA0, 0x05, 0x1E, 0x9C, 0x78, 0x87,
-                            0x40, 0x98, 0xA3, 0x6C, 0x73, 0x73, 0xEA, 0x4B, 0x62, 0xC7, 0xC9, 0x56, 0x37, 0x20, 0x76, 0x88,
-                            0x24, 0xBC, 0xB6, 0x6E, 0x71, 0x46, 0x3F, 0x69, 0x00}},
-                          {{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-                            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-                            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-                            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}}};
- */
 #define ge448_p3 ge448 /* use projective coordinates only */
 
 static const fe448 ge448_ecd = {{0x56, 0x67, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
diff --git a/sc448.h b/sc448.h
index b9df529..16152a5 100644
--- a/sc448.h
+++ b/sc448.h
@@ -40,8 +40,10 @@ void sc448_sub_nored(sc448 *r, const sc448 *x, const sc448 *y);
 
 void sc448_mul(sc448 *r, const sc448 *x, const sc448 *y);
 
-/* Convert s into a representation of the form \sum_{i=0}^{84}r[i]2^3
+/* 
+ * Convert s into a representation of the form \sum_{i=0}^{150}r[i]2^3
  * with r[i] in {-4,...,3}
+ * need 150 bytes, because the r[148] may be 4 
  */
 void sc448_window3(signed char r[150], const sc448 *s);
 
diff --git a/sha3.c b/sha3.c
index 931ae02..2fdbf05 100644
--- a/sha3.c
+++ b/sha3.c
@@ -1,3 +1,5 @@
+/* Copied from https://github.com/mjosaarinen/tiny_sha3 */
+
 // sha3.c
 // 19-Nov-11  Markku-Juhani O. Saarinen <mjos@iki.fi>
 
diff --git a/sha3.h b/sha3.h
index 99e99fd..36d4046 100644
--- a/sha3.h
+++ b/sha3.h
@@ -1,3 +1,5 @@
+/* Copied from https://github.com/mjosaarinen/tiny_sha3 */
+
 // sha3.h
 // 19-Nov-11  Markku-Juhani O. Saarinen <mjos@iki.fi>
 
@@ -44,4 +46,3 @@ void shake_xof(sha3_ctx_t *c);
 void shake_out(sha3_ctx_t *c, void *out, size_t len);
 
 #endif
-