5 changed files with 31 additions and 264 deletions
@ -1,124 +0,0 @@
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From f07f6c2639b0a127475aad7ccbeb40e10dc565e5 Mon Sep 17 00:00:00 2001
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From: Damien Goutte-Gattat <dgouttegattat@incenp.org>
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Date: Wed, 10 Dec 2014 01:13:23 +0100
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Subject: [PATCH 1/2] Allow signing with other algorithms than MD5+SHA1
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To: gnupg-devel@gnupg.org
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* src/agent.c (scute_agent_sign): Determine the hash algorithm of the
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message digest by checking for known ASN.1 prefixes.
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* src/support.h (STR): New.
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--
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This is a streamlined version of a patch proposed by Werner Koch
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<http://lists.gnupg.org/pipermail/gnupg-devel/2014-September/028750.html>
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without unrelated, cosmetic changes.
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---
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src/agent.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
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src/support.h | 3 +++
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2 files changed, 57 insertions(+), 3 deletions(-)
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diff --git a/src/agent.c b/src/agent.c
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index 9265ca2..b1fdbf0 100644
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--- a/src/agent.c
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+++ b/src/agent.c
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@@ -989,6 +989,28 @@ pksign_cb (void *opaque, const void *buffer, size_t length)
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#define SIG_LEN 128
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#define SIG_LEN_2 256
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+
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+static unsigned char sha1_prefix[15] = /* (1.3.14.3.2.26) */
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+ { 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03,
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+ 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14 };
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+static unsigned char sha224_prefix[19] = /* (2.16.840.1.101.3.4.2.4) */
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+ { 0x30, 0x2D, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48,
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+ 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, 0x05, 0x00, 0x04,
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+ 0x1C };
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+static unsigned char sha256_prefix[19] = /* (2.16.840.1.101.3.4.2.1) */
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+ { 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
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+ 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05,
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+ 0x00, 0x04, 0x20 };
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+static unsigned char sha384_prefix[19] = /* (2.16.840.1.101.3.4.2.2) */
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+ { 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
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+ 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05,
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+ 0x00, 0x04, 0x30 };
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+static unsigned char sha512_prefix[19] = /* (2.16.840.1.101.3.4.2.3) */
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+ { 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
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+ 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05,
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+ 0x00, 0x04, 0x40 };
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+
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+
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/* Call the agent to learn about a smartcard. */
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gpg_error_t
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scute_agent_sign (char *grip, unsigned char *data, int len,
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@@ -996,10 +1018,12 @@ scute_agent_sign (char *grip, unsigned char *data, int len,
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{
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char cmd[150];
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gpg_error_t err;
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-#define MAX_DATA_LEN 36
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+#define MAX_DATA_LEN 64 /* For SHA-512 - see below. */
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unsigned char pretty_data[2 * MAX_DATA_LEN + 1];
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int i;
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struct signature sig;
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+ const char *algostr;
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+ int off;
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sig.len = 0;
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@@ -1025,11 +1049,38 @@ scute_agent_sign (char *grip, unsigned char *data, int len,
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if (err)
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return err;
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+ /* Find out the digest algorithm and strip off the prefix. */
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+#define X(a,b) \
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+ (len == sizeof a ## _prefix + (b) \
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+ && !memcmp (data, a ## _prefix, sizeof a ## _prefix)) \
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+ { \
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+ algostr = STR(a); \
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+ off = sizeof a ## _prefix; \
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+ len -= sizeof a ## _prefix; \
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+ }
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+
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+ if (len == 36)
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+ {
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+ algostr = "tls-md5sha1";
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+ off = 0;
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+ }
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+ else if X(sha1, 20)
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+ else if X(sha224, 28)
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+ else if X(sha256, 32)
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+ else if X(sha384, 48)
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+ else if X(sha512, 64) /* MAX_DATA_LEN must be at least this. */
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+ else
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+ {
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+ DEBUG (DBG_INFO, "sign input data format is unknown, size=%d\n", len);
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+ return gpg_error (GPG_ERR_DIGEST_ALGO);
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+ }
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+#undef X
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+
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for (i = 0; i < len; i++)
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- snprintf (&pretty_data[2 * i], 3, "%02X", data[i]);
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+ snprintf (&pretty_data[2 * i], 3, "%02X", data[off+i]);
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pretty_data[2 * len] = '\0';
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- snprintf (cmd, sizeof (cmd), "SETHASH --hash=tls-md5sha1 %s", pretty_data);
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+ snprintf (cmd, sizeof (cmd), "SETHASH --hash=%s %s", algostr, pretty_data);
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err = assuan_transact (agent_ctx, cmd, NULL, NULL, default_inq_cb,
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NULL, NULL, NULL);
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if (err)
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diff --git a/src/support.h b/src/support.h
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index 8f4d538..859d1de 100644
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--- a/src/support.h
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+++ b/src/support.h
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@@ -40,6 +40,9 @@
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#define xtoi_2(p) ((xtoi_1(p) * 16) + xtoi_1((p)+1))
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#define DIM(x) (sizeof (x) / sizeof (x[0]))
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+#ifndef STR
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+# define STR(v) #v
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+#endif
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/* Copy a string into its location, with blank character padding. */
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static inline void
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--
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1.8.4
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@ -1,126 +0,0 @@
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From 3e13d5493c74427655a7208a7bc4fcbcabda6774 Mon Sep 17 00:00:00 2001
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From: Damien Goutte-Gattat <dgouttegattat@incenp.org>
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Date: Wed, 28 Jan 2015 16:03:10 +0100
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Subject: [PATCH 2/2] Remove extra nul byte in signature data
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To: gnupg-devel@gnupg.org
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* src/agent.c (scute_agent_sign): Check for extra nul byte at the
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beginning of signature data.
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--
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GPG Agent 2.1 prepends a nul byte in the signature value if the first
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byte has its most significant bit set, to prevent it from being
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interpreted as a sign bit (see agent_pksign_do, in GnuPG's
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agent/pksign.c).
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But Scute expects the signature to be always of a fixed size (128 or
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256 bytes), and it will reject a signature containing this extra nul
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byte.
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This patch makes Scute read the effective size of the signature from
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the S-expression, and remove the prepended nul byte if present.
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Signed-off-by: Damien Goutte-Gattat <dgouttegattat@incenp.org>
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---
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src/agent.c | 57 ++++++++++++++++++++++++++++++++-------------------------
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1 file changed, 32 insertions(+), 25 deletions(-)
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diff --git a/src/agent.c b/src/agent.c
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index 9265ca2..547c587 100644
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--- a/src/agent.c
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+++ b/src/agent.c
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@@ -981,13 +981,12 @@ pksign_cb (void *opaque, const void *buffer, size_t length)
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}
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-#define SIG_PREFIX "(7:sig-val(3:rsa(1:s128:"
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-#define SIG_PREFIX_2 "(7:sig-val(3:rsa(1:s256:"
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+#define SIG_PREFIX "(7:sig-val(3:rsa(1:s"
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#define SIG_PREFIX_LEN (sizeof (SIG_PREFIX) - 1)
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#define SIG_POSTFIX ")))"
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#define SIG_POSTFIX_LEN (sizeof (SIG_POSTFIX) - 1)
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-#define SIG_LEN 128
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-#define SIG_LEN_2 256
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+#define SIG_MIN_LEN 128
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+#define SIG_MAX_LEN 256
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/* Call the agent to learn about a smartcard. */
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gpg_error_t
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@@ -1009,14 +1008,14 @@ scute_agent_sign (char *grip, unsigned char *data, int len,
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if (sig_result == NULL)
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{
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/* FIXME: We return the largest supported size - is that correct? */
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- *sig_len = SIG_LEN_2;
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+ *sig_len = SIG_MAX_LEN;
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return 0;
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}
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if (len > MAX_DATA_LEN)
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return gpg_error (GPG_ERR_INV_ARG);
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- if (grip == NULL || sig_result == NULL || *sig_len < SIG_LEN)
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+ if (grip == NULL || sig_result == NULL || *sig_len < SIG_MIN_LEN)
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return gpg_error (GPG_ERR_INV_ARG);
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snprintf (cmd, sizeof (cmd), "SIGKEY %s", grip);
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@@ -1041,30 +1040,38 @@ scute_agent_sign (char *grip, unsigned char *data, int len,
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return err;
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/* FIXME: we need a real parser to cope with all kind of S-expressions. */
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- if (sig.len == SIG_PREFIX_LEN + SIG_LEN_2 + SIG_POSTFIX_LEN)
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+ if (!memcmp (sig.data, SIG_PREFIX, SIG_PREFIX_LEN))
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{
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- if (memcmp (sig.data, SIG_PREFIX_2, SIG_PREFIX_LEN))
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- return gpg_error (GPG_ERR_BAD_SIGNATURE);
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- if (memcmp (sig.data + sig.len - SIG_POSTFIX_LEN,
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- SIG_POSTFIX, SIG_POSTFIX_LEN))
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- return gpg_error (GPG_ERR_BAD_SIGNATURE);
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- memcpy (sig_result, sig.data + SIG_PREFIX_LEN, SIG_LEN_2);
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- *sig_len = SIG_LEN_2;
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- }
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- else
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- {
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- if (sig.len != SIG_PREFIX_LEN + SIG_LEN + SIG_POSTFIX_LEN)
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+ unsigned char *sig_val;
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+ unsigned int sig_val_len;
|
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+
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+ sig_val_len = strtol (sig.data + SIG_PREFIX_LEN, (char **)&sig_val, 10);
|
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+
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+ if (*(sig_val++) != ':')
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return gpg_error (GPG_ERR_BAD_SIGNATURE);
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- if (memcmp (sig.data, SIG_PREFIX, SIG_PREFIX_LEN))
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+ if (sig.len != sig_val - sig.data + sig_val_len + SIG_POSTFIX_LEN)
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return gpg_error (GPG_ERR_BAD_SIGNATURE);
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- if (memcmp (sig.data + sig.len - SIG_POSTFIX_LEN,
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- SIG_POSTFIX, SIG_POSTFIX_LEN))
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+ if (memcmp (sig.data + sig.len - SIG_POSTFIX_LEN, SIG_POSTFIX,
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+ SIG_POSTFIX_LEN))
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return gpg_error (GPG_ERR_BAD_SIGNATURE);
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- memcpy (sig_result, sig.data + SIG_PREFIX_LEN, SIG_LEN);
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- *sig_len = SIG_LEN;
|
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+
|
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+ if ( *sig_val == 0 && *(sig_val+1) & 0x80 )
|
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+ {
|
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+ /* Remove the extra nul byte that was added to prevent
|
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+ * the signature from being interpreted as a negative value. */
|
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+ sig_val += 1;
|
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+ sig_val_len -= 1;
|
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+ }
|
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+
|
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+ if ( sig_val_len > *sig_len )
|
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+ return gpg_error (GPG_ERR_TOO_LARGE);
|
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+
|
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+ memcpy (sig_result, sig_val, sig_val_len);
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+ *sig_len = sig_val_len;
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}
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-
|
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-
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+ else
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+ return gpg_error( GPG_ERR_BAD_SIGNATURE ); /* Unexpected prefix. */
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+
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return 0;
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}
|
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|
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--
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1.8.4
|
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|
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@ -0,0 +1,13 @@
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diff --git a/src/Makefile.am b/src/Makefile.am
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index 43fa086..9ceef93 100644
|
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--- a/src/Makefile.am
|
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+++ b/src/Makefile.am
|
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@@ -58,7 +58,7 @@ sources = cryptoki.h pkcs11.h debug.c debug.h settings.h support.h \
|
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p11-signrecover.c p11-signrecoverinit.c p11-signupdate.c \
|
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p11-unwrapkey.c p11-verify.c p11-verifyfinal.c p11-verifyinit.c \
|
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p11-verifyrecover.c p11-verifyrecoverinit.c p11-verifyupdate.c \
|
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- p11-waitforslotevent.c p11-wrapkey.c
|
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+ p11-waitforslotevent.c p11-wrapkey.c sexp-parse.h
|
||||
|
||||
|
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if HAVE_LD_VERSION_SCRIPT
|
||||
@ -1 +0,0 @@
|
||||
e28141d2b03612c09512651795976c58ed3f8035 scute-1.4.0.tar.bz2 |
||||
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Reference in new issue