do not compress private keys - changed terminologiy from verify/sign to public/private

readme.md

@@ -31,15 +31,15 @@ include `ed25519.h` in any file you want to use the API. If you prefer to use
 a shared library, only copy `ed25519.h` and define `ED25519_DLL` before
 importing. A windows DLL is pre-built.
 
-There are no defined types for seeds, signing keys, verifying keys or
+There are no defined types for seeds, private keys, public keys or
 signatures. Instead simple `unsigned char` buffers are used with the following
 sizes:
 
 ```c
 unsigned char seed[32];
 unsigned char signature[64];
-unsigned char verify_key[32];
+unsigned char public_key[32];
-unsigned char signing_key[64];
+unsigned char private_key[64];
 ```
 
 API
@@ -52,38 +52,37 @@ Creates a 32 byte random seed in `seed` for key generation. `seed` must be a
 writable 32 byte buffer. Returns 0 on success, and nonzero on failure.
 
 ```c
-void ed25519_create_keypair(unsigned char *verify_key, unsigned char *sign_key, const unsigned char *seed);
+void ed25519_create_keypair(unsigned char *public_key, unsigned char *private_key, const unsigned char *seed);
 ```
 
-Creates a new key pair from the given seed. `verify_key` must be a writable 32
+Creates a new key pair from the given seed. `public_key` must be a writable 32
-byte buffer, `sign_key` must be a writable 64 byte buffer and `seed` must be a 32 byte buffer.
+byte buffer, `private_key` must be a writable 64 byte buffer and `seed` must be a 32 byte buffer.
 
 ```c
 void ed25519_sign(unsigned char *signature,
                  const unsigned char *message, size_t message_len,
-                 const unsigned char *sign_key);
+                 const unsigned char *public_key, const unsigned char *private_key);
 ```
 
-Creates a signature of the given message with `sign_key`. `signature` must be
+Creates a signature of the given message with the keypair `(public_key, private_key)`. `signature` must be
 a writable 64 byte buffer. `message` must have at least `message_len` bytes to
-be read. `sign_key` must be a 64 byte signing key generated by
+be read. The given keypair must be a keypair generated by `ed25519_create_keypair`.
-`ed25519_create_keypair`.
 
 ```c
 int ed25519_verify(const unsigned char *signature,
                    const unsigned char *message, size_t message_len,
-                   const unsigned char *verify_key);
+                   const unsigned char *public_key);
 ```
 
-Verifies the signature on the given message using verify_key. `signature` must be
+Verifies the signature on the given message using `public_key`. `signature` must be
 a readable 64 byte buffer. `message` must have at least `message_len` bytes to
-be read. `sign_key` must be a 32 byte verifying key generated by
+be read. `public_key` must be a 32 byte public key generated by
-`ed25519_create_keypair`. Returns 0 if the signature matches, 1 otherwise.
+`ed25519_create_keypair`. Returns 1 if the signature matches, 0 otherwise.
 
 Example
 -------
 ```c
-unsigned char seed[32], sign_key[64], verify_key[32], signature[64];
+unsigned char seed[32], public_key[32], private_key[64], signature[64];
 const unsigned char message[] = "TEST MESSAGE";
 
 /* create a random seed, and a keypair out of that seed */
@@ -92,15 +91,15 @@ if (ed25519_create_seed(seed)) {
     exit(1);
 }
 
-ed25519_create_keypair(verify_key, sign_key, seed);
+ed25519_create_keypair(public_key, private_key, seed);
 
-/* create signature on the message with the sign key */
+/* create signature on the message with the keypair */
-ed25519_sign(signature, message, strlen(message), sign_key);
+ed25519_sign(signature, message, strlen(message), public_key, private_key);
 
 /* verify the signature */
-if (ed25519_verify(signature, message, strlen(message), verify_key)) {
+if (ed25519_verify(signature, message, strlen(message), public_key)) {
-    printf("invalid signature\n");
-} else {
     printf("valid signature\n");
+} else {
+    printf("invalid signature\n");
 }
-```
+```

src/ed25519.h

@@ -24,13 +24,13 @@ extern "C" {
 int ED25519_DECLSPEC ed25519_create_seed(unsigned char *seed);
 #endif
 
-void ED25519_DECLSPEC ed25519_create_keypair(unsigned char *verify_key, unsigned char *sign_key, const unsigned char *seed);
+void ED25519_DECLSPEC ed25519_create_keypair(unsigned char *public_key, unsigned char *private_key, const unsigned char *seed);
-void ED25519_DECLSPEC ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *sign_key);
+void ED25519_DECLSPEC ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *public_key, const unsigned char *private_key);
-int ED25519_DECLSPEC ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *verify_key);
+int ED25519_DECLSPEC ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *private_key);
 
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif
+#endif

src/keypair.c

@@ -3,24 +3,14 @@
 #include "ge.h"
 
 
-void ed25519_create_keypair(unsigned char *verify_key, unsigned char *sign_key, const unsigned char *seed) {
+void ed25519_create_keypair(unsigned char *public_key, unsigned char *private_key, const unsigned char *seed) {
-    unsigned char h[64];
     ge_p3 A;
-    int i;
 
-    sha512(seed, 32, h);
+    sha512(seed, 32, private_key);
-    h[0] &= 248;
+    private_key[0] &= 248;
-    h[31] &= 63;
+    private_key[31] &= 63;
-    h[31] |= 64;
+    private_key[31] |= 64;
 
-    ge_scalarmult_base(&A, h);
+    ge_scalarmult_base(&A, private_key);
-    ge_p3_tobytes(verify_key, &A);
+    ge_p3_tobytes(public_key, &A);
-
-    for (i = 0; i < 32; ++i) {
-        sign_key[i] = seed[i];
-    }
-
-    for (i = 0; i < 32; ++i) {
-        sign_key[32 + i] = verify_key[i];
-    }
 }

src/sign.c

@@ -4,20 +4,15 @@
 #include "sc.h"
 
 
-void ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *sign_key) {
+void ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *public_key, const unsigned char *private_key) {
-    unsigned char az[64];
-    unsigned char r[64];
-    unsigned char hram[64];
-    ge_p3 R;
     sha512_context hash;
+    unsigned char hram[64];
+    unsigned char r[64];
+    ge_p3 R;
 
-    sha512(sign_key, 32, az);
-    az[0] &= 248;
-    az[31] &= 63;
-    az[31] |= 64;
 
     sha512_init(&hash);
-    sha512_update(&hash, az + 32, 32);
+    sha512_update(&hash, private_key + 32, 32);
     sha512_update(&hash, message, message_len);
     sha512_final(&hash, r);
 
@@ -27,10 +22,10 @@ void ed25519_sign(unsigned char *signature, const unsigned char *message, size_t
 
     sha512_init(&hash);
     sha512_update(&hash, signature, 32);
-    sha512_update(&hash, sign_key + 32, 32);
+    sha512_update(&hash, public_key, 32);
     sha512_update(&hash, message, message_len);
     sha512_final(&hash, hram);
 
     sc_reduce(hram);
-    sc_muladd(signature + 32, hram, az, r);
+    sc_muladd(signature + 32, hram, private_key, r);
 }

src/verify.c

@@ -44,7 +44,7 @@ static int consttime_equal(const unsigned char *x, const unsigned char *y) {
     return !r;
 }
 
-int ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *verify_key) {
+int ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *public_key) {
     unsigned char h[64];
     unsigned char checker[32];
     sha512_context hash;
@@ -52,16 +52,16 @@ int ed25519_verify(const unsigned char *signature, const unsigned char *message,
     ge_p2 R;
 
     if (signature[63] & 224) {
-        return -1;
+        return 0;
     }
 
-    if (ge_frombytes_negate_vartime(&A, verify_key) != 0) {
+    if (ge_frombytes_negate_vartime(&A, public_key) != 0) {
-        return -1;
+        return 0;
     }
 
     sha512_init(&hash);
     sha512_update(&hash, signature, 32);
-    sha512_update(&hash, verify_key, 32);
+    sha512_update(&hash, public_key, 32);
     sha512_update(&hash, message, message_len);
     sha512_final(&hash, h);
     
@@ -70,8 +70,8 @@ int ed25519_verify(const unsigned char *signature, const unsigned char *message,
     ge_tobytes(checker, &R);
 
     if (!consttime_equal(checker, signature)) {
-        return -1;
+        return 0;
     }
 
-    return 0;
+    return 1;
 }

test.c

@@ -9,40 +9,42 @@
 const char message[] = "Hello, world!";
 
 int main(int argc, char *argv[]) {
-    unsigned char sign_key[64], verify_key[32], seed[32];
+    unsigned char public_key[32], private_key[64], seed[32];
     unsigned char signature[64];
 
 	clock_t start;
 	clock_t end;
 	int i;
 
+    FILE *f;
+
     /* create a random seed, and a keypair out of that seed */
     ed25519_create_seed(seed);
-    ed25519_create_keypair(verify_key, sign_key, seed);
+    ed25519_create_keypair(public_key, private_key, seed);
 
-    /* create signature on the message with the sign key */
+    /* create signature on the message with the keypair */
-    ed25519_sign(signature, message, strlen(message), sign_key);
+    ed25519_sign(signature, message, strlen(message), public_key, private_key);
 
     /* verify the signature */
-    if (ed25519_verify(signature, message, strlen(message), verify_key)) {
+    if (ed25519_verify(signature, message, strlen(message), public_key)) {
-        printf("invalid signature\n");
-    } else {
         printf("valid signature\n");
+    } else {
+        printf("invalid signature\n");
     }
 
     /* make a slight adjustment and verify again */
     signature[44] ^= 0x10;
-    if (ed25519_verify(signature, message, strlen(message), verify_key)) {
+    if (ed25519_verify(signature, message, strlen(message), public_key)) {
-        printf("correctly detected signature change\n");
+        printf("did not detect signature change\n");
     } else {
-        printf("incorrectly accepted signature change\n");
+        printf("correctly detected signature change\n");
     }
 
     /* test performance */
     printf("testing sign performance: ");
     start = clock();
     for (i = 0; i < 10000; ++i) {
-        ed25519_sign(signature, message, strlen(message), sign_key);
+        ed25519_sign(signature, message, strlen(message), public_key, private_key);
     }
     end = clock();
 
@@ -51,11 +53,11 @@ int main(int argc, char *argv[]) {
     printf("testing verify performance: ");
     start = clock();
     for (i = 0; i < 10000; ++i) {
-        ed25519_verify(signature, message, strlen(message), verify_key);
+        ed25519_verify(signature, message, strlen(message), public_key);
     }
     end = clock();
 
     printf("%fus per signature\n", ((double) ((end - start) * 1000)) / CLOCKS_PER_SEC / i * 1000);
 
     return 0;
-}
+}