X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sshecc.c;h=e1166827f1143a3f9d692c17d6f8913879a4b05d;hb=a3d14d77f566a41fc61dfdc5c2e0e384c9e6ae8b;hp=6915eaf0fc401ed84781ca519b9eb713568169c4;hpb=8682246d33f21e369a3e5b38fa2fdec58b1e4425;p=PuTTY.git diff --git a/sshecc.c b/sshecc.c index 6915eaf0..e1166827 100644 --- a/sshecc.c +++ b/sshecc.c @@ -24,6 +24,10 @@ * Handbook of elliptic and hyperelliptic curve cryptography, Chapter 13 * http://cs.ucsb.edu/~koc/ccs130h/2013/EllipticHyperelliptic-CohenFrey.pdf * + * Curve25519 spec from libssh (with reference to other things in the + * libssh code): + * https://git.libssh.org/users/aris/libssh.git/tree/doc/curve25519-sha256@libssh.org.txt + * * Edwards DSA: * http://ed25519.cr.yp.to/ed25519-20110926.pdf */ @@ -37,10 +41,11 @@ * Elliptic curve definitions */ -static int initialise_wcurve(struct ec_curve *curve, int bits, unsigned char *p, - unsigned char *a, unsigned char *b, - unsigned char *n, unsigned char *Gx, - unsigned char *Gy) +static void initialise_wcurve(struct ec_curve *curve, int bits, + const unsigned char *p, + const unsigned char *a, const unsigned char *b, + const unsigned char *n, const unsigned char *Gx, + const unsigned char *Gy) { int length = bits / 8; if (bits % 8) ++length; @@ -49,37 +54,23 @@ static int initialise_wcurve(struct ec_curve *curve, int bits, unsigned char *p, curve->fieldBits = bits; curve->p = bignum_from_bytes(p, length); - if (!curve->p) goto error; /* Curve co-efficients */ curve->w.a = bignum_from_bytes(a, length); - if (!curve->w.a) goto error; curve->w.b = bignum_from_bytes(b, length); - if (!curve->w.b) goto error; /* Group order and generator */ curve->w.n = bignum_from_bytes(n, length); - if (!curve->w.n) goto error; curve->w.G.x = bignum_from_bytes(Gx, length); - if (!curve->w.G.x) goto error; curve->w.G.y = bignum_from_bytes(Gy, length); - if (!curve->w.G.y) goto error; curve->w.G.curve = curve; curve->w.G.infinity = 0; - - return 1; - error: - if (curve->p) freebn(curve->p); - if (curve->w.a) freebn(curve->w.a); - if (curve->w.b) freebn(curve->w.b); - if (curve->w.n) freebn(curve->w.n); - if (curve->w.G.x) freebn(curve->w.G.x); - return 0; } -static int initialise_mcurve(struct ec_curve *curve, int bits, unsigned char *p, - unsigned char *a, unsigned char *b, - unsigned char *Gx) +static void initialise_mcurve(struct ec_curve *curve, int bits, + const unsigned char *p, + const unsigned char *a, const unsigned char *b, + const unsigned char *Gx) { int length = bits / 8; if (bits % 8) ++length; @@ -88,33 +79,23 @@ static int initialise_mcurve(struct ec_curve *curve, int bits, unsigned char *p, curve->fieldBits = bits; curve->p = bignum_from_bytes(p, length); - if (!curve->p) goto error; /* Curve co-efficients */ curve->m.a = bignum_from_bytes(a, length); - if (!curve->m.a) goto error; curve->m.b = bignum_from_bytes(b, length); - if (!curve->m.b) goto error; /* Generator */ curve->m.G.x = bignum_from_bytes(Gx, length); - if (!curve->m.G.x) goto error; curve->m.G.y = NULL; curve->m.G.z = NULL; curve->m.G.curve = curve; curve->m.G.infinity = 0; - - return 1; - error: - if (curve->p) freebn(curve->p); - if (curve->m.a) freebn(curve->m.a); - if (curve->m.b) freebn(curve->m.b); - return 0; } -static int initialise_ecurve(struct ec_curve *curve, int bits, unsigned char *p, - unsigned char *l, unsigned char *d, - unsigned char *Bx, unsigned char *By) +static void initialise_ecurve(struct ec_curve *curve, int bits, + const unsigned char *p, + const unsigned char *l, const unsigned char *d, + const unsigned char *Bx, const unsigned char *By) { int length = bits / 8; if (bits % 8) ++length; @@ -123,87 +104,64 @@ static int initialise_ecurve(struct ec_curve *curve, int bits, unsigned char *p, curve->fieldBits = bits; curve->p = bignum_from_bytes(p, length); - if (!curve->p) goto error; /* Curve co-efficients */ curve->e.l = bignum_from_bytes(l, length); - if (!curve->e.l) goto error; curve->e.d = bignum_from_bytes(d, length); - if (!curve->e.d) goto error; /* Group order and generator */ curve->e.B.x = bignum_from_bytes(Bx, length); - if (!curve->e.B.x) goto error; curve->e.B.y = bignum_from_bytes(By, length); - if (!curve->e.B.y) goto error; curve->e.B.curve = curve; curve->e.B.infinity = 0; - - return 1; - error: - if (curve->p) freebn(curve->p); - if (curve->e.l) freebn(curve->e.l); - if (curve->e.d) freebn(curve->e.d); - if (curve->e.B.x) freebn(curve->e.B.x); - return 0; } -unsigned char nistp256_oid[] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07}; -int nistp256_oid_len = 8; -unsigned char nistp384_oid[] = {0x2b, 0x81, 0x04, 0x00, 0x22}; -int nistp384_oid_len = 5; -unsigned char nistp521_oid[] = {0x2b, 0x81, 0x04, 0x00, 0x23}; -int nistp521_oid_len = 5; -unsigned char curve25519_oid[] = {0x06, 0x0A, 0x2B, 0x06, 0x01, 0x04, 0x01, 0x97, 0x55, 0x01, 0x05, 0x01}; -int curve25519_oid_len = 12; - -struct ec_curve *ec_p256(void) +static struct ec_curve *ec_p256(void) { static struct ec_curve curve = { 0 }; static unsigned char initialised = 0; if (!initialised) { - unsigned char p[] = { + static const unsigned char p[] = { 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; - unsigned char a[] = { + static const unsigned char a[] = { 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfc }; - unsigned char b[] = { + static const unsigned char b[] = { 0x5a, 0xc6, 0x35, 0xd8, 0xaa, 0x3a, 0x93, 0xe7, 0xb3, 0xeb, 0xbd, 0x55, 0x76, 0x98, 0x86, 0xbc, 0x65, 0x1d, 0x06, 0xb0, 0xcc, 0x53, 0xb0, 0xf6, 0x3b, 0xce, 0x3c, 0x3e, 0x27, 0xd2, 0x60, 0x4b }; - unsigned char n[] = { + static const unsigned char n[] = { 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbc, 0xe6, 0xfa, 0xad, 0xa7, 0x17, 0x9e, 0x84, 0xf3, 0xb9, 0xca, 0xc2, 0xfc, 0x63, 0x25, 0x51 }; - unsigned char Gx[] = { + static const unsigned char Gx[] = { 0x6b, 0x17, 0xd1, 0xf2, 0xe1, 0x2c, 0x42, 0x47, 0xf8, 0xbc, 0xe6, 0xe5, 0x63, 0xa4, 0x40, 0xf2, 0x77, 0x03, 0x7d, 0x81, 0x2d, 0xeb, 0x33, 0xa0, 0xf4, 0xa1, 0x39, 0x45, 0xd8, 0x98, 0xc2, 0x96 }; - unsigned char Gy[] = { + static const unsigned char Gy[] = { 0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b, 0x8e, 0xe7, 0xeb, 0x4a, 0x7c, 0x0f, 0x9e, 0x16, 0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce, 0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5 }; - if (!initialise_wcurve(&curve, 256, p, a, b, n, Gx, Gy)) { - return NULL; - } + initialise_wcurve(&curve, 256, p, a, b, n, Gx, Gy); + curve.textname = curve.name = "nistp256"; /* Now initialised, no need to do it again */ initialised = 1; @@ -212,14 +170,14 @@ struct ec_curve *ec_p256(void) return &curve; } -struct ec_curve *ec_p384(void) +static struct ec_curve *ec_p384(void) { static struct ec_curve curve = { 0 }; static unsigned char initialised = 0; if (!initialised) { - unsigned char p[] = { + static const unsigned char p[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -227,7 +185,7 @@ struct ec_curve *ec_p384(void) 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff }; - unsigned char a[] = { + static const unsigned char a[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -235,7 +193,7 @@ struct ec_curve *ec_p384(void) 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xfc }; - unsigned char b[] = { + static const unsigned char b[] = { 0xb3, 0x31, 0x2f, 0xa7, 0xe2, 0x3e, 0xe7, 0xe4, 0x98, 0x8e, 0x05, 0x6b, 0xe3, 0xf8, 0x2d, 0x19, 0x18, 0x1d, 0x9c, 0x6e, 0xfe, 0x81, 0x41, 0x12, @@ -243,7 +201,7 @@ struct ec_curve *ec_p384(void) 0xc6, 0x56, 0x39, 0x8d, 0x8a, 0x2e, 0xd1, 0x9d, 0x2a, 0x85, 0xc8, 0xed, 0xd3, 0xec, 0x2a, 0xef }; - unsigned char n[] = { + static const unsigned char n[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -251,7 +209,7 @@ struct ec_curve *ec_p384(void) 0x58, 0x1a, 0x0d, 0xb2, 0x48, 0xb0, 0xa7, 0x7a, 0xec, 0xec, 0x19, 0x6a, 0xcc, 0xc5, 0x29, 0x73 }; - unsigned char Gx[] = { + static const unsigned char Gx[] = { 0xaa, 0x87, 0xca, 0x22, 0xbe, 0x8b, 0x05, 0x37, 0x8e, 0xb1, 0xc7, 0x1e, 0xf3, 0x20, 0xad, 0x74, 0x6e, 0x1d, 0x3b, 0x62, 0x8b, 0xa7, 0x9b, 0x98, @@ -259,7 +217,7 @@ struct ec_curve *ec_p384(void) 0x55, 0x02, 0xf2, 0x5d, 0xbf, 0x55, 0x29, 0x6c, 0x3a, 0x54, 0x5e, 0x38, 0x72, 0x76, 0x0a, 0xb7 }; - unsigned char Gy[] = { + static const unsigned char Gy[] = { 0x36, 0x17, 0xde, 0x4a, 0x96, 0x26, 0x2c, 0x6f, 0x5d, 0x9e, 0x98, 0xbf, 0x92, 0x92, 0xdc, 0x29, 0xf8, 0xf4, 0x1d, 0xbd, 0x28, 0x9a, 0x14, 0x7c, @@ -268,9 +226,8 @@ struct ec_curve *ec_p384(void) 0x7a, 0x43, 0x1d, 0x7c, 0x90, 0xea, 0x0e, 0x5f }; - if (!initialise_wcurve(&curve, 384, p, a, b, n, Gx, Gy)) { - return NULL; - } + initialise_wcurve(&curve, 384, p, a, b, n, Gx, Gy); + curve.textname = curve.name = "nistp384"; /* Now initialised, no need to do it again */ initialised = 1; @@ -279,14 +236,14 @@ struct ec_curve *ec_p384(void) return &curve; } -struct ec_curve *ec_p521(void) +static struct ec_curve *ec_p521(void) { static struct ec_curve curve = { 0 }; static unsigned char initialised = 0; if (!initialised) { - unsigned char p[] = { + static const unsigned char p[] = { 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -297,7 +254,7 @@ struct ec_curve *ec_p521(void) 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; - unsigned char a[] = { + static const unsigned char a[] = { 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -308,7 +265,7 @@ struct ec_curve *ec_p521(void) 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfc }; - unsigned char b[] = { + static const unsigned char b[] = { 0x00, 0x51, 0x95, 0x3e, 0xb9, 0x61, 0x8e, 0x1c, 0x9a, 0x1f, 0x92, 0x9a, 0x21, 0xa0, 0xb6, 0x85, 0x40, 0xee, 0xa2, 0xda, 0x72, 0x5b, 0x99, 0xb3, @@ -319,7 +276,7 @@ struct ec_curve *ec_p521(void) 0x34, 0xf1, 0xef, 0x45, 0x1f, 0xd4, 0x6b, 0x50, 0x3f, 0x00 }; - unsigned char n[] = { + static const unsigned char n[] = { 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -330,7 +287,7 @@ struct ec_curve *ec_p521(void) 0x47, 0xae, 0xbb, 0x6f, 0xb7, 0x1e, 0x91, 0x38, 0x64, 0x09 }; - unsigned char Gx[] = { + static const unsigned char Gx[] = { 0x00, 0xc6, 0x85, 0x8e, 0x06, 0xb7, 0x04, 0x04, 0xe9, 0xcd, 0x9e, 0x3e, 0xcb, 0x66, 0x23, 0x95, 0xb4, 0x42, 0x9c, 0x64, 0x81, 0x39, 0x05, 0x3f, @@ -341,7 +298,7 @@ struct ec_curve *ec_p521(void) 0x42, 0x9b, 0xf9, 0x7e, 0x7e, 0x31, 0xc2, 0xe5, 0xbd, 0x66 }; - unsigned char Gy[] = { + static const unsigned char Gy[] = { 0x01, 0x18, 0x39, 0x29, 0x6a, 0x78, 0x9a, 0x3b, 0xc0, 0x04, 0x5c, 0x8a, 0x5f, 0xb4, 0x2c, 0x7d, 0x1b, 0xd9, 0x98, 0xf5, 0x44, 0x49, 0x57, 0x9b, @@ -353,9 +310,8 @@ struct ec_curve *ec_p521(void) 0x66, 0x50 }; - if (!initialise_wcurve(&curve, 521, p, a, b, n, Gx, Gy)) { - return NULL; - } + initialise_wcurve(&curve, 521, p, a, b, n, Gx, Gy); + curve.textname = curve.name = "nistp521"; /* Now initialised, no need to do it again */ initialised = 1; @@ -364,41 +320,43 @@ struct ec_curve *ec_p521(void) return &curve; } -struct ec_curve *ec_curve25519(void) +static struct ec_curve *ec_curve25519(void) { static struct ec_curve curve = { 0 }; static unsigned char initialised = 0; if (!initialised) { - unsigned char p[] = { + static const unsigned char p[] = { 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xed }; - unsigned char a[] = { + static const unsigned char a[] = { 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, 0x07, 0x6d, 0x06 }; - unsigned char b[] = { + static const unsigned char b[] = { 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, 0x01 }; - unsigned char gx[32] = { + static const unsigned char gx[32] = { 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, 0x09 }; - if (!initialise_mcurve(&curve, 256, p, a, b, gx)) { - return NULL; - } + initialise_mcurve(&curve, 256, p, a, b, gx); + /* This curve doesn't need a name, because it's never used in + * any format that embeds the curve name */ + curve.name = NULL; + curve.textname = "Curve25519"; /* Now initialised, no need to do it again */ initialised = 1; @@ -406,48 +364,51 @@ struct ec_curve *ec_curve25519(void) return &curve; } -struct ec_curve *ec_ed25519(void) + +static struct ec_curve *ec_ed25519(void) { static struct ec_curve curve = { 0 }; static unsigned char initialised = 0; if (!initialised) { - unsigned char q[] = { + static const unsigned char q[] = { 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xed }; - unsigned char l[32] = { + static const unsigned char l[32] = { 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x14, 0xde, 0xf9, 0xde, 0xa2, 0xf7, 0x9c, 0xd6, 0x58, 0x12, 0x63, 0x1a, 0x5c, 0xf5, 0xd3, 0xed }; - unsigned char d[32] = { + static const unsigned char d[32] = { 0x52, 0x03, 0x6c, 0xee, 0x2b, 0x6f, 0xfe, 0x73, 0x8c, 0xc7, 0x40, 0x79, 0x77, 0x79, 0xe8, 0x98, 0x00, 0x70, 0x0a, 0x4d, 0x41, 0x41, 0xd8, 0xab, 0x75, 0xeb, 0x4d, 0xca, 0x13, 0x59, 0x78, 0xa3 }; - unsigned char Bx[32] = { + static const unsigned char Bx[32] = { 0x21, 0x69, 0x36, 0xd3, 0xcd, 0x6e, 0x53, 0xfe, 0xc0, 0xa4, 0xe2, 0x31, 0xfd, 0xd6, 0xdc, 0x5c, 0x69, 0x2c, 0xc7, 0x60, 0x95, 0x25, 0xa7, 0xb2, 0xc9, 0x56, 0x2d, 0x60, 0x8f, 0x25, 0xd5, 0x1a }; - unsigned char By[32] = { + static const unsigned char By[32] = { 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x58 }; + /* This curve doesn't need a name, because it's never used in + * any format that embeds the curve name */ + curve.name = NULL; - if (!initialise_ecurve(&curve, 256, q, l, d, Bx, By)) { - return NULL; - } + initialise_ecurve(&curve, 256, q, l, d, Bx, By); + curve.textname = "Ed25519"; /* Now initialised, no need to do it again */ initialised = 1; @@ -456,131 +417,6 @@ struct ec_curve *ec_ed25519(void) return &curve; } -static struct ec_curve *ec_name_to_curve(const char *name, int len) { - if (len > 11 && !memcmp(name, "ecdsa-sha2-", 11)) { - name += 11; - len -= 11; - } else if (len > 10 && !memcmp(name, "ecdh-sha2-", 10)) { - name += 10; - len -= 10; - } else if (len == 11 && !memcmp(name, "ssh-ed25519", 11)) { - return ec_ed25519(); - } - - if (len == 8 && !memcmp(name, "nistp", 5)) { - name += 5; - if (!memcmp(name, "256", 3)) { - return ec_p256(); - } else if (!memcmp(name, "384", 3)) { - return ec_p384(); - } else if (!memcmp(name, "521", 3)) { - return ec_p521(); - } - } - - if (len == 28 && !memcmp(name, "curve25519-sha256@libssh.org", 28)) { - return ec_curve25519(); - } - - return NULL; -} - -/* Type enumeration for specifying the curve name */ -enum ec_name_type { EC_TYPE_DSA, EC_TYPE_DH, EC_TYPE_CURVE }; - -static int ec_curve_to_name(enum ec_name_type type, const struct ec_curve *curve, - unsigned char *name, int len) { - if (curve->type == EC_WEIERSTRASS) { - int length, loc; - if (type == EC_TYPE_DSA) { - length = 19; - loc = 16; - } else if (type == EC_TYPE_DH) { - length = 18; - loc = 15; - } else { - length = 8; - loc = 5; - } - - /* Return length of string */ - if (name == NULL) return length; - - /* Not enough space for the name */ - if (len < length) return 0; - - /* Put the name in the buffer */ - switch (curve->fieldBits) { - case 256: - memcpy(name+loc, "256", 3); - break; - case 384: - memcpy(name+loc, "384", 3); - break; - case 521: - memcpy(name+loc, "521", 3); - break; - default: - return 0; - } - - if (type == EC_TYPE_DSA) { - memcpy(name, "ecdsa-sha2-nistp", 16); - } else if (type == EC_TYPE_DH) { - memcpy(name, "ecdh-sha2-nistp", 15); - } else { - memcpy(name, "nistp", 5); - } - - return length; - } else if (curve->type == EC_EDWARDS) { - /* No DH for ed25519 - use Montgomery instead */ - if (type == EC_TYPE_DH) return 0; - - if (type == EC_TYPE_CURVE) { - /* Return length of string */ - if (name == NULL) return 7; - - /* Not enough space for the name */ - if (len < 7) return 0; - - /* Unknown curve field */ - if (curve->fieldBits != 256) return 0; - - memcpy(name, "ed25519", 7); - return 7; - - } else { - /* Return length of string */ - if (name == NULL) return 11; - - /* Not enough space for the name */ - if (len < 11) return 0; - - /* Unknown curve field */ - if (curve->fieldBits != 256) return 0; - - memcpy(name, "ssh-ed25519", 11); - return 11; - } - } else { - /* No DSA for curve25519 */ - if (type == EC_TYPE_DSA || type == EC_TYPE_CURVE) return 0; - - /* Return length of string */ - if (name == NULL) return 28; - - /* Not enough space for the name */ - if (len < 28) return 0; - - /* Unknown curve field */ - if (curve->fieldBits != 256) return 0; - - memcpy(name, "curve25519-sha256@libssh.org", 28); - return 28; - } -} - /* Return 1 if a is -3 % p, otherwise return 0 * This is used because there are some maths optimisations */ static int ec_aminus3(const struct ec_curve *curve) @@ -593,7 +429,6 @@ static int ec_aminus3(const struct ec_curve *curve) } _p = bignum_add_long(curve->w.a, 3); - if (!_p) return 0; ret = !bignum_cmp(curve->p, _p); freebn(_p); @@ -610,18 +445,11 @@ static Bignum ecf_add(const Bignum a, const Bignum b, Bignum a1, b1, ab, ret; a1 = bigmod(a, curve->p); - if (!a1) return NULL; b1 = bigmod(b, curve->p); - if (!b1) - { - freebn(a1); - return NULL; - } ab = bigadd(a1, b1); freebn(a1); freebn(b1); - if (!ab) return NULL; ret = bigmod(ab, curve->p); freebn(ab); @@ -640,16 +468,16 @@ static Bignum ecf_treble(const Bignum a, const struct ec_curve *curve) /* Double */ tmp = bignum_lshift(a, 1); - if (!tmp) return NULL; /* Add itself (i.e. treble) */ ret = bigadd(tmp, a); freebn(tmp); /* Normalise */ - while (ret != NULL && bignum_cmp(ret, curve->p) >= 0) + while (bignum_cmp(ret, curve->p) >= 0) { tmp = bigsub(ret, curve->p); + assert(tmp); freebn(ret); ret = tmp; } @@ -660,10 +488,10 @@ static Bignum ecf_treble(const Bignum a, const struct ec_curve *curve) static Bignum ecf_double(const Bignum a, const struct ec_curve *curve) { Bignum ret = bignum_lshift(a, 1); - if (!ret) return NULL; if (bignum_cmp(ret, curve->p) >= 0) { Bignum tmp = bigsub(ret, curve->p); + assert(tmp); freebn(ret); return tmp; } @@ -721,40 +549,16 @@ static int ec_point_verify(const struct ec_point *a) int ret; y2 = ecf_square(a->y, a->curve); - if (!y2) { - return 0; - } x2 = ecf_square(a->x, a->curve); - if (!x2) { - freebn(y2); - return 0; - } tmp = modmul(a->curve->e.d, x2, a->curve->p); - if (!tmp) { - freebn(x2); - freebn(y2); - return 0; - } tmp2 = modmul(tmp, y2, a->curve->p); freebn(tmp); - if (!tmp2) { - freebn(x2); - freebn(y2); - return 0; - } tmp = modsub(y2, x2, a->curve->p); freebn(y2); freebn(x2); - if (!tmp) { - freebn(tmp2); - return 0; - } tmp3 = modsub(tmp, tmp2, a->curve->p); freebn(tmp); freebn(tmp2); - if (!tmp3) { - return 0; - } ret = !bignum_cmp(tmp3, One); freebn(tmp3); return ret; @@ -765,29 +569,21 @@ static int ec_point_verify(const struct ec_point *a) Bignum lhs = NULL, x3 = NULL, ax = NULL, x3ax = NULL, x3axm = NULL, x3axb = NULL, rhs = NULL; Bignum Three = bignum_from_long(3); - if (!Three) return 0; lhs = modmul(a->y, a->y, a->curve->p); - if (!lhs) goto error; /* This uses montgomery multiplication to optimise */ x3 = modpow(a->x, Three, a->curve->p); freebn(Three); - if (!x3) goto error; ax = modmul(a->curve->w.a, a->x, a->curve->p); - if (!ax) goto error; x3ax = bigadd(x3, ax); - if (!x3ax) goto error; freebn(x3); x3 = NULL; freebn(ax); ax = NULL; x3axm = bigmod(x3ax, a->curve->p); - if (!x3axm) goto error; freebn(x3ax); x3ax = NULL; x3axb = bigadd(x3axm, a->curve->w.b); - if (!x3axb) goto error; freebn(x3axm); x3axm = NULL; rhs = bigmod(x3axb, a->curve->p); - if (!rhs) goto error; freebn(x3axb); ret = bignum_cmp(lhs, rhs) ? 0 : 1; @@ -795,15 +591,6 @@ static int ec_point_verify(const struct ec_point *a) freebn(rhs); return ret; - - error: - if (x3) freebn(x3); - if (ax) freebn(ax); - if (x3ax) freebn(x3ax); - if (x3axm) freebn(x3axm); - if (x3axb) freebn(x3axb); - if (lhs) freebn(lhs); - return 0; } else { return 0; } @@ -841,9 +628,6 @@ static int ecp_normalise(struct ec_point *a) } Z2 = ecf_square(a->z, a->curve); - if (!Z2) { - return 0; - } Z2inv = modinv(Z2, a->curve->p); if (!Z2inv) { freebn(Z2); @@ -851,17 +635,9 @@ static int ecp_normalise(struct ec_point *a) } tx = modmul(a->x, Z2inv, a->curve->p); freebn(Z2inv); - if (!tx) { - freebn(Z2); - return 0; - } Z3 = modmul(Z2, a->z, a->curve->p); freebn(Z2); - if (!Z3) { - freebn(tx); - return 0; - } Z3inv = modinv(Z3, a->curve->p); freebn(Z3); if (!Z3inv) { @@ -870,10 +646,6 @@ static int ecp_normalise(struct ec_point *a) } ty = modmul(a->y, Z3inv, a->curve->p); freebn(Z3inv); - if (!ty) { - freebn(tx); - return 0; - } freebn(a->x); a->x = tx; @@ -901,9 +673,6 @@ static int ecp_normalise(struct ec_point *a) } tmp2 = modmul(a->x, tmp, a->curve->p); freebn(tmp); - if (!tmp2) { - return 0; - } freebn(a->z); a->z = NULL; @@ -933,25 +702,13 @@ static struct ec_point *ecp_doublew(const struct ec_point *a, const int aminus3) Bignum Y2, XY2, _2XY2; Y2 = ecf_square(a->y, a->curve); - if (!Y2) { - return NULL; - } XY2 = modmul(a->x, Y2, a->curve->p); freebn(Y2); - if (!XY2) { - return NULL; - } _2XY2 = ecf_double(XY2, a->curve); freebn(XY2); - if (!_2XY2) { - return NULL; - } S = ecf_double(_2XY2, a->curve); freebn(_2XY2); - if (!S) { - return NULL; - } } /* Faster calculation if a = -3 */ @@ -964,39 +721,17 @@ static struct ec_point *ecp_doublew(const struct ec_point *a, const int aminus3) } else { Z2 = ecf_square(a->z, a->curve); } - if (!Z2) { - freebn(S); - return NULL; - } XpZ2 = ecf_add(a->x, Z2, a->curve); - if (!XpZ2) { - freebn(S); - freebn(Z2); - return NULL; - } XmZ2 = modsub(a->x, Z2, a->curve->p); freebn(Z2); - if (!XmZ2) { - freebn(S); - freebn(XpZ2); - return NULL; - } second = modmul(XpZ2, XmZ2, a->curve->p); freebn(XpZ2); freebn(XmZ2); - if (!second) { - freebn(S); - return NULL; - } M = ecf_treble(second, a->curve); freebn(second); - if (!M) { - freebn(S); - return NULL; - } } else { /* M = 3*X^2 + a*Z^4 */ Bignum _3X2, X2, aZ4; @@ -1007,44 +742,18 @@ static struct ec_point *ecp_doublew(const struct ec_point *a, const int aminus3) Bignum Z2, Z4; Z2 = ecf_square(a->z, a->curve); - if (!Z2) { - freebn(S); - return NULL; - } Z4 = ecf_square(Z2, a->curve); freebn(Z2); - if (!Z4) { - freebn(S); - return NULL; - } aZ4 = modmul(a->curve->w.a, Z4, a->curve->p); freebn(Z4); } - if (!aZ4) { - freebn(S); - return NULL; - } X2 = modmul(a->x, a->x, a->curve->p); - if (!X2) { - freebn(S); - freebn(aZ4); - return NULL; - } _3X2 = ecf_treble(X2, a->curve); freebn(X2); - if (!_3X2) { - freebn(S); - freebn(aZ4); - return NULL; - } M = ecf_add(_3X2, aZ4, a->curve); freebn(_3X2); freebn(aZ4); - if (!M) { - freebn(S); - return NULL; - } } /* X' = M^2 - 2*S */ @@ -1052,28 +761,10 @@ static struct ec_point *ecp_doublew(const struct ec_point *a, const int aminus3) Bignum M2, _2S; M2 = ecf_square(M, a->curve); - if (!M2) { - freebn(S); - freebn(M); - return NULL; - } - _2S = ecf_double(S, a->curve); - if (!_2S) { - freebn(M2); - freebn(S); - freebn(M); - return NULL; - } - outx = modsub(M2, _2S, a->curve->p); freebn(M2); freebn(_2S); - if (!outx) { - freebn(S); - freebn(M); - return NULL; - } } /* Y' = M*(S - X') - 8*Y^4 */ @@ -1082,53 +773,19 @@ static struct ec_point *ecp_doublew(const struct ec_point *a, const int aminus3) SX = modsub(S, outx, a->curve->p); freebn(S); - if (!SX) { - freebn(M); - freebn(outx); - return NULL; - } MSX = modmul(M, SX, a->curve->p); freebn(SX); freebn(M); - if (!MSX) { - freebn(outx); - return NULL; - } Y2 = ecf_square(a->y, a->curve); - if (!Y2) { - freebn(outx); - freebn(MSX); - return NULL; - } Y4 = ecf_square(Y2, a->curve); freebn(Y2); - if (!Y4) { - freebn(outx); - freebn(MSX); - return NULL; - } Eight = bignum_from_long(8); - if (!Eight) { - freebn(outx); - freebn(MSX); - freebn(Y4); - return NULL; - } _8Y4 = modmul(Eight, Y4, a->curve->p); freebn(Eight); freebn(Y4); - if (!_8Y4) { - freebn(outx); - freebn(MSX); - return NULL; - } outy = modsub(MSX, _8Y4, a->curve->p); freebn(MSX); freebn(_8Y4); - if (!outy) { - freebn(outx); - return NULL; - } } /* Z' = 2*Y*Z */ @@ -1140,19 +797,9 @@ static struct ec_point *ecp_doublew(const struct ec_point *a, const int aminus3) } else { YZ = modmul(a->y, a->z, a->curve->p); } - if (!YZ) { - freebn(outx); - freebn(outy); - return NULL; - } outz = ecf_double(YZ, a->curve); freebn(YZ); - if (!outz) { - freebn(outx); - freebn(outy); - return NULL; - } } return ec_point_new(a->curve, outx, outy, outz, 0); @@ -1172,81 +819,31 @@ static struct ec_point *ecp_doublem(const struct ec_point *a) Bignum tmp; tmp = ecf_add(a->x, z, a->curve); - if (!tmp) { - return NULL; - } xpz = ecf_square(tmp, a->curve); freebn(tmp); - if (!xpz) { - return NULL; - } tmp = modsub(a->x, z, a->curve->p); - if (!tmp) { - freebn(xpz); - return NULL; - } xmz = ecf_square(tmp, a->curve); freebn(tmp); - if (!xmz) { - freebn(xpz); - return NULL; - } } /* outx = (x + z)^2 * (x - z)^2 */ outx = modmul(xpz, xmz, a->curve->p); - if (!outx) { - freebn(xpz); - freebn(xmz); - return NULL; - } /* outz = 4xz * ((x - z)^2 + ((A + 2) / 4)*4xz) */ { Bignum _4xz, tmp, tmp2, tmp3; tmp = bignum_from_long(2); - if (!tmp) { - freebn(xpz); - freebn(outx); - freebn(xmz); - return NULL; - } tmp2 = ecf_add(a->curve->m.a, tmp, a->curve); freebn(tmp); - if (!tmp2) { - freebn(xpz); - freebn(outx); - freebn(xmz); - return NULL; - } _4xz = modsub(xpz, xmz, a->curve->p); freebn(xpz); - if (!_4xz) { - freebn(tmp2); - freebn(outx); - freebn(xmz); - return NULL; - } tmp = modmul(tmp2, _4xz, a->curve->p); freebn(tmp2); - if (!tmp) { - freebn(_4xz); - freebn(outx); - freebn(xmz); - return NULL; - } tmp2 = bignum_from_long(4); - if (!tmp2) { - freebn(tmp); - freebn(_4xz); - freebn(outx); - freebn(xmz); - return NULL; - } tmp3 = modinv(tmp2, a->curve->p); freebn(tmp2); if (!tmp3) { @@ -1259,28 +856,13 @@ static struct ec_point *ecp_doublem(const struct ec_point *a) tmp2 = modmul(tmp, tmp3, a->curve->p); freebn(tmp); freebn(tmp3); - if (!tmp2) { - freebn(_4xz); - freebn(outx); - freebn(xmz); - return NULL; - } tmp = ecf_add(xmz, tmp2, a->curve); freebn(xmz); freebn(tmp2); - if (!tmp) { - freebn(_4xz); - freebn(outx); - return NULL; - } outz = modmul(_4xz, tmp, a->curve->p); freebn(_4xz); freebn(tmp); - if (!outz) { - freebn(outx); - return NULL; - } } return ec_point_new(a->curve, outx, NULL, outz, 0); @@ -1325,36 +907,14 @@ static struct ec_point *ecp_addw(const struct ec_point *a, Bignum Z2, Z3; Z2 = ecf_square(b->z, a->curve); - if (!Z2) { - return NULL; - } U1 = modmul(a->x, Z2, a->curve->p); - if (!U1) { - freebn(Z2); - return NULL; - } Z3 = modmul(Z2, b->z, a->curve->p); freebn(Z2); - if (!Z3) { - freebn(U1); - return NULL; - } S1 = modmul(a->y, Z3, a->curve->p); freebn(Z3); - if (!S1) { - freebn(U1); - return NULL; - } } else { U1 = copybn(a->x); - if (!U1) { - return NULL; - } S1 = copybn(a->y); - if (!S1) { - freebn(U1); - return NULL; - } } /* U2 = X2*Z1^2 */ @@ -1363,48 +923,14 @@ static struct ec_point *ecp_addw(const struct ec_point *a, Bignum Z2, Z3; Z2 = ecf_square(a->z, b->curve); - if (!Z2) { - freebn(U1); - freebn(S1); - return NULL; - } U2 = modmul(b->x, Z2, b->curve->p); - if (!U2) { - freebn(U1); - freebn(S1); - freebn(Z2); - return NULL; - } Z3 = modmul(Z2, a->z, b->curve->p); freebn(Z2); - if (!Z3) { - freebn(U1); - freebn(S1); - freebn(U2); - return NULL; - } S2 = modmul(b->y, Z3, b->curve->p); freebn(Z3); - if (!S2) { - freebn(U1); - freebn(S1); - freebn(U2); - return NULL; - } } else { U2 = copybn(b->x); - if (!U2) { - freebn(U1); - freebn(S1); - return NULL; - } S2 = copybn(b->y); - if (!S2) { - freebn(U1); - freebn(S1); - freebn(U2); - return NULL; - } } /* Check if multiplying by self */ @@ -1433,94 +959,27 @@ static struct ec_point *ecp_addw(const struct ec_point *a, /* H = U2 - U1 */ H = modsub(U2, U1, a->curve->p); freebn(U2); - if (!H) { - freebn(U1); - freebn(S1); - freebn(S2); - return NULL; - } /* R = S2 - S1 */ R = modsub(S2, S1, a->curve->p); freebn(S2); - if (!R) { - freebn(H); - freebn(S1); - freebn(U1); - return NULL; - } /* X3 = R^2 - H^3 - 2*U1*H^2 */ { Bignum R2, H2, _2UH2, first; H2 = ecf_square(H, a->curve); - if (!H2) { - freebn(U1); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } UH2 = modmul(U1, H2, a->curve->p); freebn(U1); - if (!UH2) { - freebn(H2); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } H3 = modmul(H2, H, a->curve->p); freebn(H2); - if (!H3) { - freebn(UH2); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } R2 = ecf_square(R, a->curve); - if (!R2) { - freebn(H3); - freebn(UH2); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } _2UH2 = ecf_double(UH2, a->curve); - if (!_2UH2) { - freebn(R2); - freebn(H3); - freebn(UH2); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } first = modsub(R2, H3, a->curve->p); freebn(R2); - if (!first) { - freebn(H3); - freebn(_2UH2); - freebn(UH2); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } outx = modsub(first, _2UH2, a->curve->p); freebn(first); freebn(_2UH2); - if (!outx) { - freebn(H3); - freebn(UH2); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } } /* Y3 = R*(U1*H^2 - X3) - S1*H^3 */ @@ -1529,42 +988,16 @@ static struct ec_point *ecp_addw(const struct ec_point *a, UH2mX = modsub(UH2, outx, a->curve->p); freebn(UH2); - if (!UH2mX) { - freebn(outx); - freebn(H3); - freebn(S1); - freebn(H); - freebn(R); - return NULL; - } RUH2mX = modmul(R, UH2mX, a->curve->p); freebn(UH2mX); freebn(R); - if (!RUH2mX) { - freebn(outx); - freebn(H3); - freebn(S1); - freebn(H); - return NULL; - } SH3 = modmul(S1, H3, a->curve->p); freebn(S1); freebn(H3); - if (!SH3) { - freebn(RUH2mX); - freebn(outx); - freebn(H); - return NULL; - } outy = modsub(RUH2mX, SH3, a->curve->p); freebn(RUH2mX); freebn(SH3); - if (!outy) { - freebn(outx); - freebn(H); - return NULL; - } } /* Z3 = H*Z1*Z2 */ @@ -1572,36 +1005,15 @@ static struct ec_point *ecp_addw(const struct ec_point *a, Bignum ZZ; ZZ = modmul(a->z, b->z, a->curve->p); - if (!ZZ) { - freebn(outx); - freebn(outy); - freebn(H); - return NULL; - } outz = modmul(H, ZZ, a->curve->p); freebn(H); freebn(ZZ); - if (!outz) { - freebn(outx); - freebn(outy); - return NULL; - } } else if (a->z) { outz = modmul(H, a->z, a->curve->p); freebn(H); - if (!outz) { - freebn(outx); - freebn(outy); - return NULL; - } } else if (b->z) { outz = modmul(H, b->z, a->curve->p); freebn(H); - if (!outz) { - freebn(outx); - freebn(outy); - return NULL; - } } else { outz = H; } @@ -1633,74 +1045,29 @@ static struct ec_point *ecp_addm(const struct ec_point *a, /* (Xa + Za) * (Xb - Zb) */ tmp = ecf_add(a->x, az, a->curve); - if (!tmp) { - return NULL; - } tmp2 = modsub(b->x, bz, a->curve->p); - if (!tmp2) { - freebn(tmp); - return NULL; - } tmp3 = modmul(tmp, tmp2, a->curve->p); freebn(tmp); freebn(tmp2); - if (!tmp3) { - return NULL; - } /* (Xa - Za) * (Xb + Zb) */ tmp = modsub(a->x, az, a->curve->p); - if (!tmp) { - freebn(tmp3); - return NULL; - } tmp2 = ecf_add(b->x, bz, a->curve); - if (!tmp2) { - freebn(tmp); - freebn(tmp3); - return NULL; - } tmp4 = modmul(tmp, tmp2, a->curve->p); freebn(tmp); freebn(tmp2); - if (!tmp4) { - freebn(tmp3); - return NULL; - } tmp = ecf_add(tmp3, tmp4, a->curve); - if (!tmp) { - freebn(tmp3); - freebn(tmp4); - return NULL; - } outx = ecf_square(tmp, a->curve); freebn(tmp); - if (!outx) { - freebn(tmp3); - freebn(tmp4); - return NULL; - } tmp = modsub(tmp3, tmp4, a->curve->p); - freebn(tmp3); - freebn(tmp4); - if (!tmp) { - freebn(outx); - return NULL; - } + freebn(tmp3); + freebn(tmp4); tmp2 = ecf_square(tmp, a->curve); freebn(tmp); - if (!tmp2) { - freebn(outx); - return NULL; - } outz = modmul(base->x, tmp2, a->curve->p); freebn(tmp2); - if (!outz) { - freebn(outx); - return NULL; - } } return ec_point_new(a->curve, outx, NULL, outz, 0); @@ -1717,46 +1084,16 @@ static struct ec_point *ecp_adde(const struct ec_point *a, Bignum tmp, tmp2, tmp3, tmp4; tmp = modmul(a->x, b->y, a->curve->p); - if (!tmp) - { - return NULL; - } tmp2 = modmul(b->x, a->y, a->curve->p); - if (!tmp2) - { - freebn(tmp); - return NULL; - } tmp3 = ecf_add(tmp, tmp2, a->curve); - if (!tmp3) - { - freebn(tmp); - freebn(tmp2); - return NULL; - } tmp4 = modmul(tmp, tmp2, a->curve->p); freebn(tmp); freebn(tmp2); - if (!tmp4) - { - freebn(tmp3); - return NULL; - } dmul = modmul(a->curve->e.d, tmp4, a->curve->p); freebn(tmp4); - if (!dmul) { - freebn(tmp3); - return NULL; - } tmp = ecf_add(One, dmul, a->curve); - if (!tmp) - { - freebn(tmp3); - freebn(dmul); - return NULL; - } tmp2 = modinv(tmp, a->curve->p); freebn(tmp); if (!tmp2) @@ -1769,11 +1106,6 @@ static struct ec_point *ecp_adde(const struct ec_point *a, outx = modmul(tmp3, tmp2, a->curve->p); freebn(tmp3); freebn(tmp2); - if (!outx) - { - freebn(dmul); - return NULL; - } } /* outy = (a->y * b->y + a->x * b->x) / @@ -1783,11 +1115,6 @@ static struct ec_point *ecp_adde(const struct ec_point *a, tmp = modsub(One, dmul, a->curve->p); freebn(dmul); - if (!tmp) - { - freebn(outx); - return NULL; - } tmp2 = modinv(tmp, a->curve->p); freebn(tmp); @@ -1798,38 +1125,14 @@ static struct ec_point *ecp_adde(const struct ec_point *a, } tmp = modmul(a->y, b->y, a->curve->p); - if (!tmp) - { - freebn(tmp2); - freebn(outx); - return NULL; - } tmp3 = modmul(a->x, b->x, a->curve->p); - if (!tmp3) - { - freebn(tmp); - freebn(tmp2); - freebn(outx); - return NULL; - } tmp4 = ecf_add(tmp, tmp3, a->curve); freebn(tmp); freebn(tmp3); - if (!tmp4) - { - freebn(tmp2); - freebn(outx); - return NULL; - } outy = modmul(tmp4, tmp2, a->curve->p); freebn(tmp4); freebn(tmp2); - if (!outy) - { - freebn(outx); - return NULL; - } } return ec_point_new(a->curve, outx, outy, NULL, 0); @@ -1869,7 +1172,7 @@ static struct ec_point *ecp_mul_(const struct ec_point *a, const Bignum b, int a ret = ec_point_new(a->curve, NULL, NULL, NULL, 1); bits = bignum_bitcount(b); - for (i = 0; ret != NULL && A != NULL && i < bits; ++i) + for (i = 0; i < bits; ++i) { if (bignum_bit(b, i)) { @@ -1885,13 +1188,7 @@ static struct ec_point *ecp_mul_(const struct ec_point *a, const Bignum b, int a } } - if (!A) { - ec_point_free(ret); - ret = NULL; - } else { - ec_point_free(A); - } - + ec_point_free(A); return ret; } @@ -1939,18 +1236,11 @@ static struct ec_point *ecp_mulm(const struct ec_point *p, const Bignum n) /* P1 <- P and P2 <- [2]P */ P2 = ecp_double(p, 0); - if (!P2) { - return NULL; - } P1 = ec_point_copy(p); - if (!P1) { - ec_point_free(P2); - return NULL; - } /* for i = bits − 2 down to 0 */ bits = bignum_bitcount(n); - for (i = bits - 2; P1 != NULL && P2 != NULL && i >= 0; --i) + for (i = bits - 2; i >= 0; --i) { if (!bignum_bit(n, i)) { @@ -1978,12 +1268,7 @@ static struct ec_point *ecp_mulm(const struct ec_point *p, const Bignum n) } } - if (!P2) { - if (P1) ec_point_free(P1); - P1 = NULL; - } else { - ec_point_free(P2); - } + ec_point_free(P2); if (!ecp_normalise(P1)) { ec_point_free(P1); @@ -2047,20 +1332,9 @@ static Bignum *ecp_edx(const struct ec_curve *curve, const Bignum y) Bignum tmp, tmp2, tmp3; tmp = ecf_square(y, curve); - if (!tmp) { - return NULL; - } tmp2 = modmul(curve->e.d, tmp, curve->p); - if (!tmp2) { - freebn(tmp); - return NULL; - } tmp3 = ecf_add(tmp2, One, curve); freebn(tmp2); - if (!tmp3) { - freebn(tmp); - return NULL; - } tmp2 = modinv(tmp3, curve->p); freebn(tmp3); if (!tmp2) { @@ -2070,16 +1344,9 @@ static Bignum *ecp_edx(const struct ec_curve *curve, const Bignum y) tmp3 = modsub(tmp, One, curve->p); freebn(tmp); - if (!tmp3) { - freebn(tmp2); - return NULL; - } xx = modmul(tmp3, tmp2, curve->p); freebn(tmp3); freebn(tmp2); - if (!xx) { - return NULL; - } } /* x = xx^((p + 3) / 8) */ @@ -2087,22 +1354,10 @@ static Bignum *ecp_edx(const struct ec_curve *curve, const Bignum y) Bignum tmp, tmp2; tmp = bignum_add_long(curve->p, 3); - if (!tmp) { - freebn(xx); - return NULL; - } tmp2 = bignum_rshift(tmp, 3); freebn(tmp); - if (!tmp2) { - freebn(xx); - return NULL; - } x = modpow(xx, tmp2, curve->p); freebn(tmp2); - if (!x) { - freebn(xx); - return NULL; - } } /* if x^2 - xx != 0 then x = x*(2^((p - 1) / 4)) */ @@ -2110,55 +1365,26 @@ static Bignum *ecp_edx(const struct ec_curve *curve, const Bignum y) Bignum tmp, tmp2; tmp = ecf_square(x, curve); - if (!tmp) { - freebn(x); - freebn(xx); - return NULL; - } tmp2 = modsub(tmp, xx, curve->p); freebn(tmp); freebn(xx); - if (!tmp2) { - freebn(x); - return NULL; - } if (bignum_cmp(tmp2, Zero)) { Bignum tmp3; freebn(tmp2); tmp = modsub(curve->p, One, curve->p); - if (!tmp) { - freebn(x); - return NULL; - } tmp2 = bignum_rshift(tmp, 2); freebn(tmp); - if (!tmp2) { - freebn(x); - return NULL; - } tmp = bignum_from_long(2); - if (!tmp) { - freebn(tmp2); - freebn(x); - return NULL; - } tmp3 = modpow(tmp, tmp2, curve->p); freebn(tmp); freebn(tmp2); - if (!tmp3) { - freebn(x); - return NULL; - } tmp = modmul(x, tmp3, curve->p); freebn(x); freebn(tmp3); x = tmp; - if (!tmp) { - return NULL; - } } else { freebn(tmp2); } @@ -2169,9 +1395,6 @@ static Bignum *ecp_edx(const struct ec_curve *curve, const Bignum y) Bignum tmp = modsub(curve->p, x, curve->p); freebn(x); x = tmp; - if (!tmp) { - return NULL; - } } return x; @@ -2212,9 +1435,6 @@ struct ec_point *ec_public(const Bignum privateKey, const struct ec_curve *curve hash[31] |= 0x40; /* Set 2^(b-2) */ /* Chop off the top part and convert to int */ a = bignum_from_bytes_le(hash, 32); - if (!a) { - return NULL; - } ret = ecp_mul(&curve->e.B, a); freebn(a); @@ -2249,7 +1469,6 @@ static int _ecdsa_verify(const struct ec_point *publicKey, /* z = left most bitlen(curve->n) of data */ z = bignum_from_bytes(data, dataLen); - if (!z) return 0; n_bits = bignum_bitcount(publicKey->curve->w.n); z_bits = bignum_bitcount(z); if (z_bits > n_bits) @@ -2257,7 +1476,6 @@ static int _ecdsa_verify(const struct ec_point *publicKey, Bignum tmp = bignum_rshift(z, z_bits - n_bits); freebn(z); z = tmp; - if (!z) return 0; } /* Ensure z in range of n */ @@ -2265,7 +1483,6 @@ static int _ecdsa_verify(const struct ec_point *publicKey, Bignum tmp = bigmod(z, publicKey->curve->w.n); freebn(z); z = tmp; - if (!z) return 0; } /* Calculate signature */ @@ -2279,18 +1496,8 @@ static int _ecdsa_verify(const struct ec_point *publicKey, return 0; } u1 = modmul(z, w, publicKey->curve->w.n); - if (!u1) { - freebn(z); - freebn(w); - return 0; - } u2 = modmul(r, w, publicKey->curve->w.n); freebn(w); - if (!u2) { - freebn(z); - freebn(u1); - return 0; - } tmp = ecp_summul(u1, u2, publicKey); freebn(u1); @@ -2302,10 +1509,6 @@ static int _ecdsa_verify(const struct ec_point *publicKey, x = bigmod(tmp->x, publicKey->curve->w.n); ec_point_free(tmp); - if (!x) { - freebn(z); - return 0; - } valid = (bignum_cmp(r, x) == 0) ? 1 : 0; freebn(x); @@ -2334,7 +1537,6 @@ static void _ecdsa_sign(const Bignum privateKey, const struct ec_curve *curve, /* z = left most bitlen(curve->n) of data */ z = bignum_from_bytes(data, dataLen); - if (!z) return; n_bits = bignum_bitcount(curve->w.n); z_bits = bignum_bitcount(z); if (z_bits > n_bits) @@ -2343,7 +1545,6 @@ static void _ecdsa_sign(const Bignum privateKey, const struct ec_curve *curve, tmp = bignum_rshift(z, z_bits - n_bits); freebn(z); z = tmp; - if (!z) return; } /* Generate k between 1 and curve->n, using the same deterministic @@ -2351,7 +1552,6 @@ static void _ecdsa_sign(const Bignum privateKey, const struct ec_curve *curve, SHA_Simple(data, dataLen, digest); k = dss_gen_k("ECDSA deterministic k generator", curve->w.n, privateKey, digest, sizeof(digest)); - if (!k) return; kG = ecp_mul(&curve->w.G, k); if (!kG) { @@ -2363,45 +1563,18 @@ static void _ecdsa_sign(const Bignum privateKey, const struct ec_curve *curve, /* r = kG.x mod n */ *r = bigmod(kG->x, curve->w.n); ec_point_free(kG); - if (!*r) { - freebn(z); - freebn(k); - return; - } /* s = (z + r * priv)/k mod n */ { Bignum rPriv, zMod, first, firstMod, kInv; rPriv = modmul(*r, privateKey, curve->w.n); - if (!rPriv) { - freebn(*r); - freebn(z); - freebn(k); - return; - } zMod = bigmod(z, curve->w.n); freebn(z); - if (!zMod) { - freebn(rPriv); - freebn(*r); - freebn(k); - return; - } first = bigadd(rPriv, zMod); freebn(rPriv); freebn(zMod); - if (!first) { - freebn(*r); - freebn(k); - return; - } firstMod = bigmod(first, curve->w.n); freebn(first); - if (!firstMod) { - freebn(*r); - freebn(k); - return; - } kInv = modinv(k, curve->w.n); freebn(k); if (!kInv) { @@ -2412,10 +1585,6 @@ static void _ecdsa_sign(const Bignum privateKey, const struct ec_curve *curve, *s = modmul(firstMod, kInv, curve->w.n); freebn(firstMod); freebn(kInv); - if (!*s) { - freebn(*r); - return; - } } } @@ -2471,9 +1640,6 @@ static int decodepoint_ed(const char *p, int length, struct ec_point *point) int negative; point->y = bignum_from_bytes_le((const unsigned char*)p, length); - if (!point->y) { - return 0; - } if ((unsigned)bignum_bitcount(point->y) > point->curve->fieldBits) { freebn(point->y); point->y = NULL; @@ -2482,6 +1648,7 @@ static int decodepoint_ed(const char *p, int length, struct ec_point *point) /* Read x bit and then reset it */ negative = bignum_bit(point->y, point->curve->fieldBits - 1); bignum_set_bit(point->y, point->curve->fieldBits - 1, 0); + bn_restore_invariant(point->y); /* Get the x from the y */ point->x = ecp_edx(point->curve, point->y); @@ -2494,11 +1661,6 @@ static int decodepoint_ed(const char *p, int length, struct ec_point *point) Bignum tmp = modsub(point->curve->p, point->x, point->curve->p); freebn(point->x); point->x = tmp; - if (!tmp) { - freebn(point->y); - point->y = NULL; - return 0; - } } /* Verify the point is on the curve */ @@ -2533,14 +1695,8 @@ static int decodepoint(const char *p, int length, struct ec_point *point) } length = length / 2; point->x = bignum_from_bytes((const unsigned char *)p, length); - if (!point->x) return 0; p += length; point->y = bignum_from_bytes((const unsigned char *)p, length); - if (!point->y) { - freebn(point->x); - point->x = NULL; - return 0; - } point->z = NULL; /* Verify the point is on the curve */ @@ -2569,6 +1725,15 @@ static int getmppoint(const char **data, int *datalen, struct ec_point *point) * Exposed ECDSA interface */ +struct ecsign_extra { + struct ec_curve *(*curve)(void); + const struct ssh_hash *hash; + + /* These fields are used by the OpenSSH PEM format importer/exporter */ + const unsigned char *oid; + int oidlen; +}; + static void ecdsa_freekey(void *key) { struct ec_key *ec = (struct ec_key *) key; @@ -2585,8 +1750,11 @@ static void ecdsa_freekey(void *key) sfree(ec); } -static void *ecdsa_newkey(const char *data, int len) +static void *ecdsa_newkey(const struct ssh_signkey *self, + const char *data, int len) { + const struct ecsign_extra *extra = + (const struct ecsign_extra *)self->extra; const char *p; int slen; struct ec_key *ec; @@ -2597,31 +1765,29 @@ static void *ecdsa_newkey(const char *data, int len) if (!p) { return NULL; } - curve = ec_name_to_curve(p, slen); - if (!curve) return NULL; - - if (curve->type != EC_WEIERSTRASS && curve->type != EC_EDWARDS) { - return NULL; - } + curve = extra->curve(); + assert(curve->type == EC_WEIERSTRASS || curve->type == EC_EDWARDS); /* Curve name is duplicated for Weierstrass form */ if (curve->type == EC_WEIERSTRASS) { getstring(&data, &len, &p, &slen); - if (curve != ec_name_to_curve(p, slen)) return NULL; + if (!p) return NULL; + if (!match_ssh_id(slen, p, curve->name)) return NULL; } ec = snew(struct ec_key); + ec->signalg = self; ec->publicKey.curve = curve; ec->publicKey.infinity = 0; ec->publicKey.x = NULL; ec->publicKey.y = NULL; ec->publicKey.z = NULL; + ec->privateKey = NULL; if (!getmppoint(&data, &len, &ec->publicKey)) { ecdsa_freekey(ec); return NULL; } - ec->privateKey = NULL; if (!ec->publicKey.x || !ec->publicKey.y || bignum_cmp(ec->publicKey.x, curve->p) >= 0 || @@ -2643,17 +1809,17 @@ static char *ecdsa_fmtkey(void *key) if (!ec->publicKey.x || !ec->publicKey.y || !ec->publicKey.curve) return NULL; - pos = ec_curve_to_name(EC_TYPE_CURVE, ec->publicKey.curve, NULL, 0); - if (pos == 0) return NULL; - len = 4 + 2 + 1; /* 2 x "0x", punctuation, \0 */ - len += pos; /* Curve name */ + if (ec->publicKey.curve->name) + len += strlen(ec->publicKey.curve->name); /* Curve name */ len += 4 * (bignum_bitcount(ec->publicKey.x) + 15) / 16; len += 4 * (bignum_bitcount(ec->publicKey.y) + 15) / 16; p = snewn(len, char); - pos = ec_curve_to_name(EC_TYPE_CURVE, ec->publicKey.curve, (unsigned char*)p, pos); - pos += sprintf(p + pos, ",0x"); + pos = 0; + if (ec->publicKey.curve->name) + pos += sprintf(p + pos, "%s,", ec->publicKey.curve->name); + pos += sprintf(p + pos, "0x"); nibbles = (3 + bignum_bitcount(ec->publicKey.x)) / 4; if (nibbles < 1) nibbles = 1; @@ -2680,10 +1846,10 @@ static unsigned char *ecdsa_public_blob(void *key, int *len) int i; unsigned char *blob, *p; + fullnamelen = strlen(ec->signalg->name); + if (ec->publicKey.curve->type == EC_EDWARDS) { /* Edwards compressed form "ssh-ed25519" point y[:-1] + x[0:1] */ - fullnamelen = ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, NULL, 0); - if (fullnamelen == 0) return NULL; pointlen = ec->publicKey.curve->fieldBits / 8; @@ -2692,12 +1858,12 @@ static unsigned char *ecdsa_public_blob(void *key, int *len) bloblen = 4 + fullnamelen + 4 + pointlen; blob = snewn(bloblen, unsigned char); - if (!blob) return NULL; p = blob; PUT_32BIT(p, fullnamelen); p += 4; - p += ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, p, fullnamelen); + memcpy(p, ec->signalg->name, fullnamelen); + p += fullnamelen; PUT_32BIT(p, pointlen); p += 4; @@ -2709,10 +1875,8 @@ static unsigned char *ecdsa_public_blob(void *key, int *len) *p = bignum_byte(ec->publicKey.y, i) & 0x7f; *p++ |= bignum_bit(ec->publicKey.x, 0) << 7; } else if (ec->publicKey.curve->type == EC_WEIERSTRASS) { - fullnamelen = ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, NULL, 0); - if (fullnamelen == 0) return NULL; - namelen = ec_curve_to_name(EC_TYPE_CURVE, ec->publicKey.curve, NULL, 0); - if (namelen == 0) return NULL; + assert(ec->publicKey.curve->name); + namelen = strlen(ec->publicKey.curve->name); pointlen = (bignum_bitcount(ec->publicKey.curve->p) + 7) / 8; @@ -2725,10 +1889,12 @@ static unsigned char *ecdsa_public_blob(void *key, int *len) p = blob; PUT_32BIT(p, fullnamelen); p += 4; - p += ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, p, fullnamelen); + memcpy(p, ec->signalg->name, fullnamelen); + p += fullnamelen; PUT_32BIT(p, namelen); p += 4; - p += ec_curve_to_name(EC_TYPE_CURVE, ec->publicKey.curve, p, namelen); + memcpy(p, ec->publicKey.curve->name, namelen); + p += namelen; PUT_32BIT(p, (2 * pointlen) + 1); p += 4; *p++ = 0x04; @@ -2788,14 +1954,15 @@ static unsigned char *ecdsa_private_blob(void *key, int *len) return blob; } -static void *ecdsa_createkey(const unsigned char *pub_blob, int pub_len, +static void *ecdsa_createkey(const struct ssh_signkey *self, + const unsigned char *pub_blob, int pub_len, const unsigned char *priv_blob, int priv_len) { struct ec_key *ec; struct ec_point *publicKey; const char *pb = (const char *) priv_blob; - ec = (struct ec_key*)ecdsa_newkey((const char *) pub_blob, pub_len); + ec = (struct ec_key*)ecdsa_newkey(self, (const char *) pub_blob, pub_len); if (!ec) { return NULL; } @@ -2831,7 +1998,8 @@ static void *ecdsa_createkey(const unsigned char *pub_blob, int pub_len, return ec; } -static void *ed25519_openssh_createkey(const unsigned char **blob, int *len) +static void *ed25519_openssh_createkey(const struct ssh_signkey *self, + const unsigned char **blob, int *len) { struct ec_key *ec; struct ec_point *publicKey; @@ -2845,11 +2013,8 @@ static void *ed25519_openssh_createkey(const unsigned char **blob, int *len) } ec = snew(struct ec_key); - if (!ec) - { - return NULL; - } + ec->signalg = self; ec->publicKey.curve = ec_ed25519(); ec->publicKey.infinity = 0; ec->privateKey = NULL; @@ -2864,17 +2029,13 @@ static void *ed25519_openssh_createkey(const unsigned char **blob, int *len) } getstring((const char**)blob, len, &q, &qlen); - if (!q) - return NULL; - if (qlen != 64) - return NULL; - - ec->privateKey = bignum_from_bytes_le((const unsigned char *)q, 32); - if (!ec->privateKey) { + if (!q || qlen != 64) { ecdsa_freekey(ec); return NULL; } + ec->privateKey = bignum_from_bytes_le((const unsigned char *)q, 32); + /* Check that private key generates public key */ publicKey = ec_public(ec->privateKey, ec->publicKey.curve); @@ -2950,8 +2111,11 @@ static int ed25519_openssh_fmtkey(void *key, unsigned char *blob, int len) return bloblen; } -static void *ecdsa_openssh_createkey(const unsigned char **blob, int *len) +static void *ecdsa_openssh_createkey(const struct ssh_signkey *self, + const unsigned char **blob, int *len) { + const struct ecsign_extra *extra = + (const struct ecsign_extra *)self->extra; const char **b = (const char **) blob; const char *p; int slen; @@ -2964,15 +2128,12 @@ static void *ecdsa_openssh_createkey(const unsigned char **blob, int *len) if (!p) { return NULL; } - curve = ec_name_to_curve(p, slen); - if (!curve) return NULL; - - if (curve->type != EC_WEIERSTRASS) { - return NULL; - } + curve = extra->curve(); + assert(curve->type == EC_WEIERSTRASS); ec = snew(struct ec_key); + ec->signalg = self; ec->publicKey.curve = curve; ec->publicKey.infinity = 0; ec->publicKey.x = NULL; @@ -3035,7 +2196,7 @@ static int ecdsa_openssh_fmtkey(void *key, unsigned char *blob, int len) } pointlen = (bignum_bitcount(ec->publicKey.curve->p) + 7) / 8; - namelen = ec_curve_to_name(EC_TYPE_CURVE, ec->publicKey.curve, NULL, 0); + namelen = strlen(ec->publicKey.curve->name); bloblen = 4 + namelen /* nistpXXX */ + 4 + 1 + (pointlen * 2) /* 0x04 pX pY */ @@ -3048,8 +2209,8 @@ static int ecdsa_openssh_fmtkey(void *key, unsigned char *blob, int len) PUT_32BIT(blob+bloblen, namelen); bloblen += 4; - - bloblen += ec_curve_to_name(EC_TYPE_CURVE, ec->publicKey.curve, blob+bloblen, namelen); + memcpy(blob+bloblen, ec->publicKey.curve->name, namelen); + bloblen += namelen; PUT_32BIT(blob+bloblen, 1 + (pointlen * 2)); bloblen += 4; @@ -3068,12 +2229,13 @@ static int ecdsa_openssh_fmtkey(void *key, unsigned char *blob, int len) return bloblen; } -static int ecdsa_pubkey_bits(const void *blob, int len) +static int ecdsa_pubkey_bits(const struct ssh_signkey *self, + const void *blob, int len) { struct ec_key *ec; int ret; - ec = (struct ec_key*)ecdsa_newkey((const char *) blob, len); + ec = (struct ec_key*)ecdsa_newkey(self, (const char *) blob, len); if (!ec) return -1; ret = ec->publicKey.curve->fieldBits; @@ -3086,6 +2248,8 @@ static int ecdsa_verifysig(void *key, const char *sig, int siglen, const char *data, int datalen) { struct ec_key *ec = (struct ec_key *) key; + const struct ecsign_extra *extra = + (const struct ecsign_extra *)ec->signalg->extra; const char *p; int slen; int digestLen; @@ -3094,16 +2258,17 @@ static int ecdsa_verifysig(void *key, const char *sig, int siglen, if (!ec->publicKey.x || !ec->publicKey.y || !ec->publicKey.curve) return 0; - /* Check the signature curve matches the key curve */ + /* Check the signature starts with the algorithm name */ getstring(&sig, &siglen, &p, &slen); if (!p) { return 0; } - if (ec->publicKey.curve != ec_name_to_curve(p, slen)) { + if (!match_ssh_id(slen, p, ec->signalg->name)) { return 0; } getstring(&sig, &siglen, &p, &slen); + if (!p) return 0; if (ec->publicKey.curve->type == EC_EDWARDS) { struct ec_point *r; Bignum s, h; @@ -3129,10 +2294,6 @@ static int ecdsa_verifysig(void *key, const char *sig, int siglen, } s = bignum_from_bytes_le((unsigned char*)p + (ec->publicKey.curve->fieldBits / 8), ec->publicKey.curve->fieldBits / 8); - if (!s) { - ec_point_free(r); - return 0; - } /* Get the hash of the encoded value of R + encoded value of pk + message */ { @@ -3164,11 +2325,6 @@ static int ecdsa_verifysig(void *key, const char *sig, int siglen, /* Convert to Bignum */ h = bignum_from_bytes_le(digest, sizeof(digest)); - if (!h) { - ec_point_free(r); - freebn(s); - return 0; - } } /* Verify sB == r + h*publicKey */ @@ -3214,6 +2370,7 @@ static int ecdsa_verifysig(void *key, const char *sig, int siglen, } else { Bignum r, s; unsigned char digest[512 / 8]; + void *hashctx; r = getmp(&p, &slen); if (!r) return 0; @@ -3223,17 +2380,11 @@ static int ecdsa_verifysig(void *key, const char *sig, int siglen, return 0; } - /* Perform correct hash function depending on curve size */ - if (ec->publicKey.curve->fieldBits <= 256) { - SHA256_Simple(data, datalen, digest); - digestLen = 256 / 8; - } else if (ec->publicKey.curve->fieldBits <= 384) { - SHA384_Simple(data, datalen, digest); - digestLen = 384 / 8; - } else { - SHA512_Simple(data, datalen, digest); - digestLen = 512 / 8; - } + digestLen = extra->hash->hlen; + assert(digestLen <= sizeof(digest)); + hashctx = extra->hash->init(); + extra->hash->bytes(hashctx, data, datalen); + extra->hash->final(hashctx, digest); /* Verify the signature */ ret = _ecdsa_verify(&ec->publicKey, digest, digestLen, r, s); @@ -3249,6 +2400,8 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, int *siglen) { struct ec_key *ec = (struct ec_key *) key; + const struct ecsign_extra *extra = + (const struct ecsign_extra *)ec->signalg->extra; unsigned char digest[512 / 8]; int digestLen; Bignum r = NULL, s = NULL; @@ -3292,9 +2445,6 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, hash[31] |= 0x40; /* Set 2^(b-2) */ /* Chop off the top part and convert to int */ a = bignum_from_bytes_le(hash, 32); - if (!a) { - return NULL; - } SHA512_Init(&hs); SHA512_Bytes(&hs, @@ -3305,10 +2455,6 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, SHA512_Final(&hs, hash); r = bignum_from_bytes_le(hash, 512/8); - if (!r) { - freebn(a); - return NULL; - } rp = ecp_mul(&ec->publicKey.curve->e.B, r); if (!rp) { freebn(r); @@ -3346,44 +2492,26 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, Bignum tmp, tmp2; tmp = bignum_from_bytes_le(hash, 512/8); - if (!tmp) { - ec_point_free(rp); - freebn(r); - freebn(a); - return NULL; - } tmp2 = modmul(tmp, a, ec->publicKey.curve->e.l); freebn(a); freebn(tmp); - if (!tmp2) { - ec_point_free(rp); - freebn(r); - return NULL; - } tmp = bigadd(r, tmp2); freebn(r); freebn(tmp2); - if (!tmp) { - ec_point_free(rp); - return NULL; - } s = bigmod(tmp, ec->publicKey.curve->e.l); freebn(tmp); - if (!s) { - ec_point_free(rp); - return NULL; - } } } /* Format the output */ - namelen = ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, NULL, 0); + namelen = strlen(ec->signalg->name); *siglen = 4+namelen+4+((ec->publicKey.curve->fieldBits / 8)*2); buf = snewn(*siglen, unsigned char); p = buf; PUT_32BIT(p, namelen); p += 4; - p += ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, p, namelen); + memcpy(p, ec->signalg->name, namelen); + p += namelen; PUT_32BIT(p, ((ec->publicKey.curve->fieldBits / 8)*2)); p += 4; @@ -3403,17 +2531,13 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, } freebn(s); } else { - /* Perform correct hash function depending on curve size */ - if (ec->publicKey.curve->fieldBits <= 256) { - SHA256_Simple(data, datalen, digest); - digestLen = 256 / 8; - } else if (ec->publicKey.curve->fieldBits <= 384) { - SHA384_Simple(data, datalen, digest); - digestLen = 384 / 8; - } else { - SHA512_Simple(data, datalen, digest); - digestLen = 512 / 8; - } + void *hashctx; + + digestLen = extra->hash->hlen; + assert(digestLen <= sizeof(digest)); + hashctx = extra->hash->init(); + extra->hash->bytes(hashctx, data, datalen); + extra->hash->final(hashctx, digest); /* Do the signature */ _ecdsa_sign(ec->privateKey, ec->publicKey.curve, digest, digestLen, &r, &s); @@ -3426,7 +2550,7 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, rlen = (bignum_bitcount(r) + 8) / 8; slen = (bignum_bitcount(s) + 8) / 8; - namelen = ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, NULL, 0); + namelen = strlen(ec->signalg->name); /* Format the output */ *siglen = 8+namelen+rlen+slen+8; @@ -3434,7 +2558,8 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, p = buf; PUT_32BIT(p, namelen); p += 4; - p += ec_curve_to_name(EC_TYPE_DSA, ec->publicKey.curve, p, namelen); + memcpy(p, ec->signalg->name, namelen); + p += namelen; PUT_32BIT(p, rlen + slen + 8); p += 4; PUT_32BIT(p, rlen); @@ -3453,6 +2578,10 @@ static unsigned char *ecdsa_sign(void *key, const char *data, int datalen, return buf; } +const struct ecsign_extra sign_extra_ed25519 = { + ec_ed25519, NULL, + NULL, 0, +}; const struct ssh_signkey ssh_ecdsa_ed25519 = { ecdsa_newkey, ecdsa_freekey, @@ -3468,8 +2597,17 @@ const struct ssh_signkey ssh_ecdsa_ed25519 = { ecdsa_sign, "ssh-ed25519", "ssh-ed25519", + &sign_extra_ed25519, }; +/* OID: 1.2.840.10045.3.1.7 (ansiX9p256r1) */ +static const unsigned char nistp256_oid[] = { + 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07 +}; +const struct ecsign_extra sign_extra_nistp256 = { + ec_p256, &ssh_sha256, + nistp256_oid, lenof(nistp256_oid), +}; const struct ssh_signkey ssh_ecdsa_nistp256 = { ecdsa_newkey, ecdsa_freekey, @@ -3485,8 +2623,17 @@ const struct ssh_signkey ssh_ecdsa_nistp256 = { ecdsa_sign, "ecdsa-sha2-nistp256", "ecdsa-sha2-nistp256", + &sign_extra_nistp256, }; +/* OID: 1.3.132.0.34 (secp384r1) */ +static const unsigned char nistp384_oid[] = { + 0x2b, 0x81, 0x04, 0x00, 0x22 +}; +const struct ecsign_extra sign_extra_nistp384 = { + ec_p384, &ssh_sha384, + nistp384_oid, lenof(nistp384_oid), +}; const struct ssh_signkey ssh_ecdsa_nistp384 = { ecdsa_newkey, ecdsa_freekey, @@ -3502,8 +2649,17 @@ const struct ssh_signkey ssh_ecdsa_nistp384 = { ecdsa_sign, "ecdsa-sha2-nistp384", "ecdsa-sha2-nistp384", + &sign_extra_nistp384, }; +/* OID: 1.3.132.0.35 (secp521r1) */ +static const unsigned char nistp521_oid[] = { + 0x2b, 0x81, 0x04, 0x00, 0x23 +}; +const struct ecsign_extra sign_extra_nistp521 = { + ec_p521, &ssh_sha512, + nistp521_oid, lenof(nistp521_oid), +}; const struct ssh_signkey ssh_ecdsa_nistp521 = { ecdsa_newkey, ecdsa_freekey, @@ -3519,12 +2675,17 @@ const struct ssh_signkey ssh_ecdsa_nistp521 = { ecdsa_sign, "ecdsa-sha2-nistp521", "ecdsa-sha2-nistp521", + &sign_extra_nistp521, }; /* ---------------------------------------------------------------------- * Exposed ECDH interface */ +struct eckex_extra { + struct ec_curve *(*curve)(void); +}; + static Bignum ecdh_calculate(const Bignum private, const struct ec_point *public) { @@ -3536,20 +2697,30 @@ static Bignum ecdh_calculate(const Bignum private, p->x = NULL; if (p->curve->type == EC_MONTGOMERY) { - /* Do conversion in network byte order */ + /* + * Endianness-swap. The Curve25519 algorithm definition + * assumes you were doing your computation in arrays of 32 + * little-endian bytes, and now specifies that you take your + * final one of those and convert it into a bignum in + * _network_ byte order, i.e. big-endian. + * + * In particular, the spec says, you convert the _whole_ 32 + * bytes into a bignum. That is, on the rare occasions that + * p->x has come out with the most significant 8 bits zero, we + * have to imagine that being represented by a 32-byte string + * with the last byte being zero, so that has to be converted + * into an SSH-2 bignum with the _low_ byte zero, i.e. a + * multiple of 256. + */ int i; - int bytes = (bignum_bitcount(ret)+7) / 8; + int bytes = (p->curve->fieldBits+7) / 8; unsigned char *byteorder = snewn(bytes, unsigned char); - if (!byteorder) { - ec_point_free(p); - freebn(ret); - return NULL; - } for (i = 0; i < bytes; ++i) { byteorder[i] = bignum_byte(ret, i); } freebn(ret); ret = bignum_from_bytes(byteorder, bytes); + smemclr(byteorder, bytes); sfree(byteorder); } @@ -3557,19 +2728,25 @@ static Bignum ecdh_calculate(const Bignum private, return ret; } -void *ssh_ecdhkex_newkey(const char *name) +const char *ssh_ecdhkex_curve_textname(const struct ssh_kex *kex) { + const struct eckex_extra *extra = (const struct eckex_extra *)kex->extra; + struct ec_curve *curve = extra->curve(); + return curve->textname; +} + +void *ssh_ecdhkex_newkey(const struct ssh_kex *kex) +{ + const struct eckex_extra *extra = (const struct eckex_extra *)kex->extra; struct ec_curve *curve; struct ec_key *key; struct ec_point *publicKey; - curve = ec_name_to_curve(name, strlen(name)); + curve = extra->curve(); key = snew(struct ec_key); - if (!key) { - return NULL; - } + key->signalg = NULL; key->publicKey.curve = curve; if (curve->type == EC_MONTGOMERY) { @@ -3583,11 +2760,8 @@ void *ssh_ecdhkex_newkey(const char *name) bytes[0] &= 248; bytes[31] &= 127; bytes[31] |= 64; - key->privateKey = bignum_from_bytes(bytes, sizeof(bytes)); - for (i = 0; i < sizeof(bytes); ++i) - { - ((volatile char*)bytes)[i] = 0; - } + key->privateKey = bignum_from_bytes_le(bytes, sizeof(bytes)); + smemclr(bytes, sizeof(bytes)); if (!key->privateKey) { sfree(key); return NULL; @@ -3637,9 +2811,6 @@ char *ssh_ecdhkex_getpublic(void *key, int *len) *len = pointlen; } point = (char*)snewn(*len, char); - if (!point) { - return NULL; - } p = point; if (ec->publicKey.curve->type == EC_WEIERSTRASS) { @@ -3695,30 +2866,102 @@ void ssh_ecdhkex_freekey(void *key) ecdsa_freekey(key); } +static const struct eckex_extra kex_extra_curve25519 = { ec_curve25519 }; static const struct ssh_kex ssh_ec_kex_curve25519 = { - "curve25519-sha256@libssh.org", NULL, KEXTYPE_ECDH, NULL, NULL, 0, 0, &ssh_sha256 + "curve25519-sha256@libssh.org", NULL, KEXTYPE_ECDH, + &ssh_sha256, &kex_extra_curve25519, }; +const struct eckex_extra kex_extra_nistp256 = { ec_p256 }; static const struct ssh_kex ssh_ec_kex_nistp256 = { - "ecdh-sha2-nistp256", NULL, KEXTYPE_ECDH, NULL, NULL, 0, 0, &ssh_sha256 + "ecdh-sha2-nistp256", NULL, KEXTYPE_ECDH, + &ssh_sha256, &kex_extra_nistp256, }; +const struct eckex_extra kex_extra_nistp384 = { ec_p384 }; static const struct ssh_kex ssh_ec_kex_nistp384 = { - "ecdh-sha2-nistp384", NULL, KEXTYPE_ECDH, NULL, NULL, 0, 0, &ssh_sha384 + "ecdh-sha2-nistp384", NULL, KEXTYPE_ECDH, + &ssh_sha384, &kex_extra_nistp384, }; +const struct eckex_extra kex_extra_nistp521 = { ec_p521 }; static const struct ssh_kex ssh_ec_kex_nistp521 = { - "ecdh-sha2-nistp521", NULL, KEXTYPE_ECDH, NULL, NULL, 0, 0, &ssh_sha512 + "ecdh-sha2-nistp521", NULL, KEXTYPE_ECDH, + &ssh_sha512, &kex_extra_nistp521, }; static const struct ssh_kex *const ec_kex_list[] = { &ssh_ec_kex_curve25519, &ssh_ec_kex_nistp256, &ssh_ec_kex_nistp384, - &ssh_ec_kex_nistp521 + &ssh_ec_kex_nistp521, }; const struct ssh_kexes ssh_ecdh_kex = { sizeof(ec_kex_list) / sizeof(*ec_kex_list), ec_kex_list }; + +/* ---------------------------------------------------------------------- + * Helper functions for finding key algorithms and returning auxiliary + * data. + */ + +const struct ssh_signkey *ec_alg_by_oid(int len, const void *oid, + const struct ec_curve **curve) +{ + static const struct ssh_signkey *algs_with_oid[] = { + &ssh_ecdsa_nistp256, + &ssh_ecdsa_nistp384, + &ssh_ecdsa_nistp521, + }; + int i; + + for (i = 0; i < lenof(algs_with_oid); i++) { + const struct ssh_signkey *alg = algs_with_oid[i]; + const struct ecsign_extra *extra = + (const struct ecsign_extra *)alg->extra; + if (len == extra->oidlen && !memcmp(oid, extra->oid, len)) { + *curve = extra->curve(); + return alg; + } + } + return NULL; +} + +const unsigned char *ec_alg_oid(const struct ssh_signkey *alg, + int *oidlen) +{ + const struct ecsign_extra *extra = (const struct ecsign_extra *)alg->extra; + *oidlen = extra->oidlen; + return extra->oid; +} + +const int ec_nist_curve_lengths[] = { 256, 384, 521 }; +const int n_ec_nist_curve_lengths = lenof(ec_nist_curve_lengths); + +int ec_nist_alg_and_curve_by_bits(int bits, + const struct ec_curve **curve, + const struct ssh_signkey **alg) +{ + switch (bits) { + case 256: *alg = &ssh_ecdsa_nistp256; break; + case 384: *alg = &ssh_ecdsa_nistp384; break; + case 521: *alg = &ssh_ecdsa_nistp521; break; + default: return FALSE; + } + *curve = ((struct ecsign_extra *)(*alg)->extra)->curve(); + return TRUE; +} + +int ec_ed_alg_and_curve_by_bits(int bits, + const struct ec_curve **curve, + const struct ssh_signkey **alg) +{ + switch (bits) { + case 256: *alg = &ssh_ecdsa_ed25519; break; + default: return FALSE; + } + *curve = ((struct ecsign_extra *)(*alg)->extra)->curve(); + return TRUE; +}